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Building Tips and technical articles. => Building techniques => Topic started by: wwwarbird on December 22, 2016, 12:27:14 AM

Title: Hutch's P-38 Lightning
Post by: wwwarbird on December 22, 2016, 12:27:14 AM
 This is the Lockheed P-38 "Lightning", designed by Don Hutchinson. It's built-up profile construction, 60" in wingspan, and designed for two .25's. This particular build was originally started quite some time ago by the late Albert Kraus. I remember first seeing photos of it at roughly this stage in Albert's shop over on the Stuka Stunt forum.
 
 Sometime after Albert's passing Dennis Saydak acquired the partially built model, up in Canada. Being very interested in all of Don's Warbird designs I had followed this P-38's trail from the start and occasionally pestered Dennis about his progress with it. I'd always hoped to see how this one turned out. It's kind of a long story, but the short version is that as a result of a very generous "handoff" from Dennis I have now taken over the project. As I received it, this could essentially be considered a custom built ARC kit.
 
 As seen in this first group of photos all of the major components are built and are just set together for trial fitting. Up to this point the build is very clean and well done. I only see a couple things I'm planning to tidy up or re-do, basically just a few cosmetic outline details and shaping.
 
 So far, all I have done is to work on finalizing the control system, making up all carbon pushrods with titanium ends and ball links throughout. The "Hutch" designed aluminum bellcranks, internal linkage, and leadouts were already done and installed in the wing. I have also built and added a tip weight box in the bottom of the wing. I'm pretty close to being ready to close up the wing sheeting and then having the wing ready to cover. If all goes as planned, this one will be ready to go come spring.  H^^
Title: Re: Hutch's P-38 Lightning
Post by: Jim Oliver on December 22, 2016, 08:16:31 AM
Which engines are you planning to use? 

And don't tell us "E power"! VD~
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on December 22, 2016, 10:11:48 AM
Looks like I had better get on the stick.
Title: Re: Hutch's P-38 Lightning
Post by: jim gevay on December 22, 2016, 11:22:37 AM
Way to go Wayne!
That should be a real looker when you're done.
Title: Re: Hutch's P-38 Lightning
Post by: Astropuppy on December 22, 2016, 06:46:54 PM
That is going to be a great model. Thanks for sharing.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 22, 2016, 09:34:20 PM
Which engines are you planning to use? 

And don't tell us "E power"! VD~

 Heh-heh Jim, you'll never catch me with a ceiling fan motor in my airplane. This one will be getting a brand new pair of FP.35's. VD~
Title: Re: Hutch's P-38 Lightning
Post by: Jim Oliver on December 22, 2016, 11:22:01 PM
 ;D
Title: Re: Hutch's P-38 Lightning
Post by: Mark Scarborough on December 23, 2016, 10:50:25 AM
Heh-heh Jim, you'll never catch me with a ceiling fan motor in my airplane. This one will be getting a brand new pair of FP.35's. VD~

planning on a bit of racing or something? thats a lot of engines!
with electric you can dial them baCK ASY  S?P D>K y1
Title: Re: Hutch's P-38 Lightning
Post by: Glenn (Gravitywell) Reach on December 23, 2016, 12:30:14 PM
Hahahahahahaha......ceiling fan motors!  That made me laugh out loud, had the wife wondering what I was up to! LL~ H^^
Title: Re: Hutch's P-38 Lightning
Post by: Steve Helmick on December 23, 2016, 02:56:34 PM
Heh-heh Jim, you'll never catch me with a ceiling fan motor in my airplane. This one will be getting a brand new pair of FP.35's. VD~


The FP.35's might be a bit much. A pair of FP .20-.25's would be sweet. I'm hoping you made a typo...  y1 Steve
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 23, 2016, 11:49:46 PM

The FP.35's might be a bit much. A pair of FP .20-.25's would be sweet. I'm hoping you made a typo...  y1 Steve

 Nope, no typo guys, it's getting the .35's. y1

 Built as a featherweight I'm sure the .25's would be ok. I just don't feel like there would be much, if any, reserve power under certain conditions. I'd also like to be clear that I'm not second guessing Don's specs here either, I'm just looking at what's in front of me and following my own preferences.
 
 Seeing it in the flesh this P-38 is a pretty good sized airplane. Also, while it's built nicely, in this particular case some of the wood selection is harder (thus heavier) than I would have used. It won't by any means be a total brick, but I'm not counting every gram as I go either, it is what it is. Within reason, I typically build in plenty of strength everywhere too, and my typical finishes are probably just slightly on the heavy side.
 
 Playing with my 700 square inch PBY (and searching for power with it) for a few years taught me some things. The final version of the Catalina is an honest 84 ounces ready to fly. I battled that plane for two full seasons with a pair of Saito .30's, trying every prop, fuel, and RPM combo you can imagine and it just never had enough oomph to be comfortable doing anything but a giant lazy loop. It would never even stay solid over the top of a wingover. I was very close to just chalking it up and hanging it on the wall for good. Finally though, I bit the bullet and swapped the .30's out for a pair of Saito .40's running Master Airscrew 10x7 three bladers and it instantly turned into a full blown stunt machine. I tried a few other props on it after the swap too but ended up going back to and staying with the original 10x7's. I have never done anything other than set the needle valves since. I think many here would be amazed at how good the airplane actually is in capable hands.
 
 So, this P-38 has about 140 or so less squares than the PBY but it's still nearly identical in overall size and frontal area. Flap, stab, and elevator areas are very close too. My theory here is that the finished flying weight difference between running a pair of .35's instead of .25's will only be about four ounces on what will probably end up being about a 70ish (or more) ounce model RTF. Yeah, it's gonna honk with the .35's, but that's also why they put that screwy thing in the end of the spray bar. Anymore I'm of the philosophy that it's a lot easier to slow these things down than it is to "squeeze the turnip" looking for every ounce of power whenever you're at the field. Operating on that fine line can leave you with a finicky model and take a lot of the fun out of things in my opinion. I'm confident that once the P-38 is all dialed in with the right prop, RPM, and line length combo it will do quite well, plus, it'll sound ten times cooler than a ceiling fan. ;D
Title: Re: Hutch's P-38 Lightning
Post by: Brett Buck on December 24, 2016, 12:53:58 PM
Nope, no typo guys, it's getting the .35's. y1

 Built as a featherweight I'm sure the .25's would be ok. I just don't feel like there would be much, if any, reserve power under certain conditions. I'd also like to be clear that I'm not second guessing Don's specs here either, I'm just looking at what's in front of me and following my own preferences.
 
 Seeing it in the flesh this P-38 is a pretty good sized airplane. Also, while it's built nicely, in this particular case some of the wood selection is harder (thus heavier) than I would have used. It won't by any means be a total brick, but I'm not counting every gram as I go either, it is what it is. Within reason, I typically build in plenty of strength everywhere too, and my typical finishes are probably just slightly on the heavy side.
 

   How big is this thing?  There were local plans to build a regular stunt plane (65 oz 650 square inch) with two 20's and we never considered that would not be enough. Given that people have flown 35-size airplanes with 15FPs, I would guess 2 25s would be good into the 700 square inch/80 ounce area - *as long as you run them at full power*. If they have been "improved" then all bets are off.

     Brett
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 24, 2016, 08:54:07 PM
  How big is this thing?
    

 The Hutchinson P-38 is 60" span, 563 square inches, with a relatively high aspect ratio. I'll be amazed if this particular one comes in any less than 70oz, I'll be happy if it's under 80.

 FWIW I do actually agree that built nice and light this design could work with a good pair of .25's. We're not looking to make the World Team with this one though, just a "Sunday Funday" stunter. Per my own preference and since I know it will be slightly heavy, I'm going with the .35's. I'm pretty sure Don thinks I'm crazy too.  ;D
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 24, 2016, 09:16:18 PM
   I would guess 2 25s would be good into the 700 square inch/80 ounce area - *as long as you run them at full power*.

 I've heard this kind of thing on occasion, and not to argue, but I don't know where some of these brutish .15's and .25's come from. I did once see a combat flyer in our club experiment with flying a foam wing 48" combat plane with a bone stock LA.15 and some small APC prop. The wing was fairly thick too, I think it was a "Gotcha". I would have never guessed it but the thing was fast and really ripped it up, I was amazed. Even after seeing that though, and also being a great fan of them, I still don't feel like two LA or FP.25's would've ever done the job on my PBY.

 I'm still waiting in the wings to hear how Doc's B-25 ends up performing too. He's sticking with the prescribed smaller engines on that one, it will be interesting to hear how it works out.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 25, 2016, 11:34:57 AM

 Other than Doc's B-25, is there anyone else out there currently working on a Hutchinson Warbird?
Title: Re: Hutch's P-38 Lightning
Post by: Paul Smith on December 25, 2016, 12:07:54 PM
I figured that if I built something like that I would use two bellcranks, one in each fuselage.  Then I could do a pull-pull on the flipper and deal with the bent flap line.
Title: Re: Hutch's P-38 Lightning
Post by: Don Hutchinson AMA5402 on December 25, 2016, 03:57:55 PM
Exactly as designed. A custom bellcrank in each fuselage so all pushrods are on underside of the wings, elevator rods on inside of booms to make them less visible yet control elevator from both ends, flap rods under the wings for same visibility reason. Pull tests pulled from inside fuselage. I never expected this one to be a Nat's winner, just a decent flying model. You want a great flying warbird, build a T-6 or SBD.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 25, 2016, 05:13:14 PM
Exactly as designed. ...so all pushrods are on underside of the wings...

 Ooh, thanks for the reminder Don, just in time. When I received this project the initial rough cutouts for the elevator pushrod exits were already there, in the top of the wing sheeting. Without even thinking about it I've finished up those cutouts and am now about ready to close the wing sheeting up. Even though it would work just fine that way I might take another look and consider moving those exits to the bottom. It would give the top view a cleaner look when finished. The flap exits are finished and ready to go, in the bottom of the wing. One step forward, two steps back...
Title: Re: Hutch's P-38 Lightning
Post by: Brett Buck on December 25, 2016, 05:26:03 PM
I've heard this kind of thing on occasion, and not to argue, but I don't know where some of these brutish .15's and .25's come from. I did once see a combat flyer in our club experiment with flying a foam wing 48" combat plane with a bone stock LA.15 and some small APC prop. The wing was fairly thick too, I think it was a "Gotcha". I would have never guessed it but the thing was fast and really ripped it up, I was amazed. Even after seeing that though, and also being a great fan of them, I still don't feel like two LA or FP.25's would've ever done the job on my PBY.

 I'm still waiting in the wings to hear how Doc's B-25 ends up performing too. He's sticking with the prescribed smaller engines on that one, it will be interesting to hear how it works out.

     Do as you like, of course, but if it's 563 square inches and 80 ounces, you aren't going to like it no matter what engine you put on it. And, depending on which 35 you plan on using, it might actually have less effective power. Just looking at it, I would guess it could easily be built in the mid 50-ounce range, which would concern me for using even 25s - never get it slowed down using any commonly available prop. I've seen several people fly airplanes that size and up to about 50 ounces with a single 25FP. That's probably not optimum, but it can be done.

      Again, I don't care if you do something else, but to me it looks like an airplane designed for 15FPs, and 20's if you are willing to depitch props. Think of it this way - it's about half of a B17, all things considered, and the B17 had *plenty* of power with 4 15FPs. 2 35FPs would be insanely too much, 2 Foxes would be about right but you won't be able to get them to run reliably and it *will* shake the airplane to pieces unless they are ABC with Randy's cranks, and 2 20FPs would be about the same weight as a Fox model and fly better.

     Brett
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 25, 2016, 08:50:40 PM
 Just for the sake of reference, including all built and rough sanded airframe parts, control surfaces and control system, we're at 30.7 ounces right now...

 
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 25, 2016, 08:54:09 PM
 Further comparison, FP.25 = 6.2oz vs FP.35 = 8.3oz.

 With the .35's we're already at 47.3 ounces total, with the .25's we'd be at 43.1. Still need to add Polyspan to the wing, silkspan over the rest of the entire model, glue up the airframe and add fillets, and the complete finish all the way to final clear. Then add tongue mufflers, fuel tanks, L/G and wheels, hinges, control horns, tip weight and all the other necessary small hardware bits. Estimating at this point it should come in closer to the 70 side than 80. That would be a good thing. Less than 70 would be great, we'll see. D>K
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on December 26, 2016, 10:29:51 AM
Myself I would say the 25's would be more than enough power.   They would be turning 10-4 or 10-5 props times two.   On my Ringmaster twin I'm going down to 9-5 props as the 9-6's is too much.   Take off rpm is just below 10 thousand.   of course the altitude you fly at has a lot to do with it.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 26, 2016, 06:23:46 PM

 Thanks Doc,

 What are some of the specs on your Ringmaster twin?

 Wingspan and area?

 All up RTF weight?
Title: Re: Hutch's P-38 Lightning
Post by: Brett Buck on December 26, 2016, 06:56:40 PM
Myself I would say the 25's would be more than enough power.   They would be turning 10-4 or 10-5 props times two.   On my Ringmaster twin I'm going down to 9-5 props as the 9-6's is too much.   Take off rpm is just below 10 thousand.   of course the altitude you fly at has a lot to do with it.

10,000 is about 2000-2500 RPM too slow. Try 9-4 APCs, peak the engine out lean, then back off until you get a distinct change in note, about 5-6 clicks in the front needle. You are getting something like 1/2 power running it that slow.

    Brett
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 26, 2016, 07:36:05 PM
10,000 is about 2000-2500 RPM too slow. Try 9-4 APCs, peak the engine out lean, then back off until you get a distinct change in note, about 5-6 clicks in the front needle. You are getting something like 1/2 power running it that slow.

    Brett

 ...5-6 clicks in the front needle? Huh?
Title: Re: Hutch's P-38 Lightning
Post by: Brett Buck on December 26, 2016, 07:45:17 PM
...5-6 clicks in the front needle? Huh?

   The needle has click stops. Peak, then back off 5-6 clicks until you get a distinct change. That's for the front-needle version. For the rear-needle version, it might be 2-3 clicks.

     Brett
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 26, 2016, 08:15:41 PM
 Gotcha Brett, I just didn't know what you meant by "front" needle.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 04, 2017, 08:26:00 PM
 
 Well, finally thru with the holidays and now getting back to the important stuff.  ;D

 I got controls all finished up the other day (thanks Tom!) and finished closing up the wing sheeting just last night. Tonight was just a little sanding in those areas and now we're ready for covering. Reaching that point where you sit back and proclaim a wing ready to cover is always one of my favorite parts of any build...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 06, 2017, 10:09:31 PM
 Planning ahead...

 Sometimes it's really hard to judge how something will work out (or not) when it comes to certain finishing details that will be coming down the road. I kept looking at the fuselage pod and just couldn't gain enough confidence that my planned canopy detail was going to fit and work out proportionally. To check, and make sure, I covered the area with yellow Frogtape and then "test" drew in the canopy detail. Once I was happy with the size and detail I added a layer of clear packing tape over the drawing, lifted the whole works off, and then stuck it on my glass bench top for later reference.  
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 06, 2017, 10:26:42 PM
 Plugging along... ;D

 Literally. Since the holes were already drilled for .25's and I'll be using .35's I plugged them all using sections of hardwood dowel and 30 minute epoxy. I also plugged the fuel tank openings, since I prefer to mount the tank right against the side on a profile fuselage. For these plugs I used 3/4" balsa and 30 minute epoxy. I centered the 3/4" plugs in the nacelles to leave a bit of excess sticking out of each side, once fully cured this will allow for easy flush sanding later on.
Title: Re: Hutch's P-38 Lightning
Post by: Don Hutchinson AMA5402 on January 07, 2017, 04:39:49 PM
Looking good! When you are ready to assemble and glue the wings, tail and booms together, the genius designer made the tops of the booms flat and parallel to the thrust lines so you can assemble the stab, wings and booms upside down on a flat surface, just don't put the pilots pod in til after the above is complete.
Don
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 07, 2017, 11:31:39 PM
 Thanks Don, I hope you're not too offended that a few things going on here aren't "per the plan".

 Since the fuse pod was already fully assembled I'll be gluing it onto the wing before the booms etc. Actually, one of the first things I did after receiving and taking over this project was to cut it off of the wing. I took that slight step backwards to make finishing the wing work easier. Once I get the wing done in Polyspan I will also be silkspanning all of the other major components before the final assembly. The entire model will be covered. No worries though with any of these deviations from Don's great design, it's just the way I roll, it's all gonna be just fine.  y1

Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 17, 2017, 08:55:16 PM

 What $98.30 looks like...
Title: Re: Hutch's P-38 Lightning
Post by: Don Hutchinson AMA5402 on January 18, 2017, 10:48:16 AM
It's all OK, I just wanted to throw the word genius in there!
Title: Re: Hutch's P-38 Lightning
Post by: Dennis Saydak on January 21, 2017, 06:23:56 PM
It's all OK, I just wanted to throw the word genius in there!

Sorry Don but I already beat you to that. Just ask Wayne.  ;D
Only a genius could design the control system for the P-38.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 11, 2017, 10:13:32 PM
 Haven't checked in here for a bit, but I have actually been making a little progress.

 I've finally got all of the engine (re)mount work done. As designed there is no plywood in the engine nacelles, it's all balsa construction except for the maple engine bearers. So, I decided to do what I could to beef up the overall assembly for running the bigger .35's. This operation may not have been necessary but I just don't want to find out the hard way, possibly ending up with a big-time buzz bomb in the end.
 
 First, I routed away a rectangle in the existing 1/8" balsa sheeting, just down to and flush with the maple mounts on each side of each engine crutch. I then added a 3/32" plywood section in those areas using 30 minute epoxy. That entire procedure was deemed necessary so that the triplers to be added later would have a uniformly flat surface to be attached to. Next was recessing in some 4/40 blind nuts into the inboard plywood sections for engine mounting. I then added 1/8" aluminum engine mount pads to the opposite side, drilling and tapping them all the way through into the maple beams and then on into the blind nuts. Threads now run all the way through the entire assembly. I also marked all the engine pads and beams with corresponding numbers so that everything fits down the road. Once all that was done I added a 1/4" balsa tripler on the inboard and a 1/4" "quadrupler?" on the outboard of each engine nacelle. I left an opening in each outboard "quadrupler" so that the engine mounts and fuel tanks can still end up resting on the plywood doublers as per normal profile construction. All of this additional construction is not necessary per Don's plans, I've only added it all with the idea of helping contain the "fury" of running the .35's.  ;D
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 11, 2017, 10:15:20 PM

 Triplers and quadruplers...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 11, 2017, 10:23:23 PM
 Backing up just a bit here...

  Before I dug into the engine mount work described above I cut away the forward portions of the engine nacelles and cleaned up the area up to the engine bearers. Then I replaced those sections with large enough balsa pieces to allow my updating the profile outline later on. This step was done strictly as preparation for a cosmetic change because I wasn't satisfied with the (pre)existing profile outline. I'll also be using 1/4" larger spinners than what it had been set up for. Once I get a bit further along here we'll be looking at a more scale-like outline...
Title: Re: Hutch's P-38 Lightning
Post by: Mark Scarborough on February 12, 2017, 11:54:43 AM
boy howdy, this build is just ripping right along,

kind of like the airplane will once you mount those two 35s on there,,

we want video of you getting drug around,, ,, I mean flying this beast LOL
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 12, 2017, 11:58:36 AM
 This thing'll gobble up an ME-109 in short order Mark!  VD~
Title: Re: Hutch's P-38 Lightning
Post by: Mark Scarborough on February 12, 2017, 01:39:00 PM
This thing'll gobble up an ME-109 in short order Mark!  VD~
pffttt P-38s I dont recall ever had the oppurtunity,, but hey come on up you are more than willing to try,  S?P
assuming it ever gets built
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on February 12, 2017, 02:54:33 PM
Mark, you telling us the ME-109nia still hiding under the bench??? LL~ LL~ LL~
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 12, 2017, 09:02:55 PM
pffttt P-38s I dont recall ever had the oppurtunity,,

 Yeah, I don't think the P-38's saw too much action over Germany, and "YIPPEE" probably spent most of it's time posing over Burbank.
Title: Re: Hutch's P-38 Lightning
Post by: Mark Scarborough on February 12, 2017, 09:18:23 PM
Mark, you telling us the ME-109nia still hiding under the bench??? LL~ LL~ LL~
Noper it  was finished and flown,, and subsequently retired for structural reasons, I actually talked to Paul W this weekend about it, and should I decide to, I have a plan to repair it
Title: Re: Hutch's P-38 Lightning
Post by: Air Ministry . on February 13, 2017, 10:03:21 PM
I think the .25s on 9x5 or 10x4s might be acceptable .

After some type put a ' Whats the Lightest 35 ' post here , we fitted the two Max 35 Ses to the Mosquito , in liu of the Veco 19 BBs .
And 10 x6 nylon topflights .
On a heat stroke day test flight , on run up , the inner got reset at launch to match the outer . about two turns out .
We call this DIRtTin the line .
On the Launch the obstruction cleared and the inner went two turns rich & the outer went from a wet 4 to a ' on note ' Howl , . . .
Therefore the Mosquito did the ' Go for the Pilots Teeth ' trick .

Oh Dear .

Amazing how much inertia the big nylon top flights have . the mayve actually been 11 inch .Seems 6 pitch on anything
will give you a tourque swing on a hand launch on a twin . Theyve Always gotta be launched Banked Out ,
So they ' come flat ' as the wires tighten . Hopefully .

Therefore if you do try the 35s , look out for some nice light props , and dont overprop it . the tourque reaction'll get Ya .
Title: Re: Hutch's P-38 Lightning
Post by: proparc on February 14, 2017, 01:50:18 PM
Heh-heh Jim, you'll never catch me with a ceiling fan motor in my airplane. This one will be getting a brand new pair of FP.35's. VD~

 LL~ LL~ LL~
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 14, 2017, 06:31:56 PM
I think the .25s on 9x5 or 10x4s might be acceptable .

After some type put a ' Whats the Lightest 35 ' post here , we fitted the two Max 35 Ses to the Mosquito , in liu of the Veco 19 BBs .
And 10 x6 nylon topflights .
On a heat stroke day test flight , on run up , the inner got reset at launch to match the outer . about two turns out .
We call this DIRtTin the line .
On the Launch the obstruction cleared and the inner went two turns rich & the outer went from a wet 4 to a ' on note ' Howl , . . .
Therefore the Mosquito did the ' Go for the Pilots Teeth ' trick .

Oh Dear .

Amazing how much inertia the big nylon top flights have . the mayve actually been 11 inch .Seems 6 pitch on anything
will give you a tourque swing on a hand launch on a twin . Theyve Always gotta be launched Banked Out ,
So they ' come flat ' as the wires tighten . Hopefully .

Therefore if you do try the 35s , look out for some nice light props , and dont overprop it . the tourque reaction'll get Ya .

 Matt,

 Thanks for offering some information but I often wonder, have you ever tried reading one of your posts? I don't know where "Elsewhere" is but English must not be the primary language. 
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on February 15, 2017, 09:59:41 AM
Now don't pick on Matt.  I've first heard of him on the Barton site when his Folkerts wash the lead picture.   Have all the stuff to replicate it including some extra stuff from him.  But, what I've read on different forums he must be quite a character and I would like to meet him where ever he located at the time.  D>K
Title: Re: Hutch's P-38 Lightning
Post by: Jim Dincau on February 15, 2017, 05:02:31 PM
Yeah, I don't think the P-38's saw too much action over Germany, and "YIPPEE" probably spent most of it's time posing over Burbank.
Actually it was re painted OD and went to the South Pacific.

http://iloveww2warbirds.com/yippee-p-38-lightning/
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 15, 2017, 05:49:19 PM
Now don't pick on Matt.  I've first heard of him on the Barton site when his Folkerts wash the lead picture.   Have all the stuff to replicate it including some extra stuff from him.  But, what I've read on different forums he must be quite a character and I would like to meet him where ever he located at the time.  D>K

 Doc,

 I just mean that I often try to read his stuff, and with genuine interest, but it's pretty tricky to decipher.  D>K
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 15, 2017, 05:53:09 PM
Actually it was re painted OD and went to the South Pacific.

 Thanks for that info Jim, interesting stuff!  y1
Title: Re: Hutch's P-38 Lightning
Post by: Brett Buck on February 15, 2017, 09:16:02 PM
Yeah, I don't think the P-38's saw too much action over Germany, and "YIPPEE" probably spent most of it's time posing over Burbank.

   They were extensively used in Europe, as escorts with much longer range than the P-47 or other available airplanes. They were supplanted by P-51 which was a generally better airplane, of course. A lot of the issues they found on the P-38 were because it was in a different performance range that the other existing fighters at the time. In particular it was the first airplane that could easily get into the transonic speed range, and then its pretty thick airfoil was a serious issue that was impractical to completely solve, once they realized the issue.

    Brett
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 15, 2017, 10:19:53 PM
  In particular it was the first airplane that could easily get into the transonic speed range, and then its pretty thick airfoil was a serious issue that was impractical to completely solve, once they realized the issue.

    Brett

 Yeah, now that you mention that Brett I think I recall that the P-38 had some sort of issue with compression of airflow or something at extreme speeds in a dive, rendering the plane uncontrollable and/or unrecoverable.
Title: Re: Hutch's P-38 Lightning
Post by: Brett Buck on February 15, 2017, 11:56:54 PM
Yeah, now that you mention that Brett I think I recall that the P-38 had some sort of issue with compression of airflow or something at extreme speeds in a dive, rendering the plane uncontrollable and/or unrecoverable.

   There were two problems, both related to transonic flow. The first- the controls "locking" in a dive at high altitude - was transonic flow over the wing. The airplane would dive at high altitude, where the speed of sound was slower because it was cold, the flow would choke over the top of the wing and the dive just got steeper. At lower altitudes this went away, but by then you are going like a bat out of hell, nearly vertically, and have to try to pull out. Sometimes they got out of it, and other times they didn't. They eventually diagnosed it, and came up with a deployable spoiler for the bottom of the wing, which altered it enough to retain control. The other was a severe buffeting in the stabilizer, which caused by transonic flow over the wing root. they spent a long time trying to solve it as a flutter issue, but the real solution was a large fillet around the pilot's pod.

      What it really needed was a much thinner wing. Then, as now, they wanted a thick airfoil to both improve the turn, provide space for internal parts, and for strength. But the thicker the wing, the more the air is accelerated as it moves around it, so at some speed, it deviates from the assumption of an incompressible fluid, hence a a compressibility problem. By the time they realized that, it was in production and trying to use a thinner airfoil would result in a complete redesign of the airplane.

     There were also substantial difficulties with the Allison engines. The P-38 was one of the few/only airplanes that had all the turbosupercharging intended for the maximum performance version of the engine, and it took a long time to work it all out. The airplane was designed as it was to house all the parts, the two scoops on the booms, for instance, were the turbosupercharger air intakes.

     Brett
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 16, 2017, 06:39:14 PM

 More interesting stuff, thanks Brett.  y1
Title: Re: Hutch's P-38 Lightning
Post by: Brett Buck on February 16, 2017, 11:13:17 PM
More interesting stuff, thanks Brett.  y1

  You are welcome. Most of what I know about this was detailed very nicely in the late, lamented Lockheed Horizons quarterly magazine/house organ. It included an interview with The Man himself, Kelly Johnson, founder of the Skunk Works, designer of the Lightning, P-80 Shooting Star and it's brothers, the C-130,  F-104, U2, A-12/SR-71, D-21 and D-21B drones, the CL-1200 Lancer (which, had it been built, might have been a tough opponent for an F-15) and many others. ]

     Brett
Title: Re: Hutch's P-38 Lightning
Post by: Trostle on February 17, 2017, 01:05:23 AM
Yeah, I don't think the P-38's saw too much action over Germany, and "YIPPEE" probably spent most of it's time posing over Burbank.
 

I am not sure if I really understand some of the comments regarding P-38 operations in Europe.  Anyway, just to set the record straight --

In August, 1942, the pilots of a P-38 and a P-40 share credit for the first German aircraft destroyed, a Fw 200 Condor, in the European Theater of Operations by the USAAF off the Icelandic coast,  In North Africa, P-38's saw action against German aircraft and then moved on to other locations in the Mediterranean, including Italy, where they were used against the Italian and German aircraft.  In the Italian theater, P-38 pilots are credited with 608 enemy aircraft destroyed in the air.  In the European theater, P-38's were used for bomber escort starting in November 1943 with significant numbers of victories, were later replaced in this role by P-51's and were then used through D-Day for bombing and strafing missions.  The German pilots called it der gabelschwanz Teufel (the fork-tail devil).

Keith
Title: Re: Hutch's P-38 Lightning
Post by: Mark Scarborough on February 17, 2017, 08:15:57 AM
 

I am not sure if I really understand some of the comments regarding P-38 operations in Europe.  Anyway, just to set the record straight --

In August, 1942, the pilots of a P-38 and a P-40 share credit for the first German aircraft destroyed, a Fw 200 Condor, in the European Theater of Operations by the USAAF off the Icelandic coast,  In North Africa, P-38's saw action against German aircraft and then moved on to other locations in the Mediterranean, including Italy, where they were used against the Italian and German aircraft.  In the Italian theater, P-38 pilots are credited with 608 enemy aircraft destroyed in the air.  In the European theater, P-38's were used for bomber escort starting in November 1943 with significant numbers of victories, were later replaced in this role by P-51's and were then used through D-Day for bombing and strafing missions.  The German pilots called it der gabelschwanz Teufel (the fork-tail devil).

Keith
I cant beleive I forgot/missed this info, I read the book " the Fork tailed devil" about the development of the P-38 and for some reason I simply dont recall it being that active in the european theater,, thanks for bringing this to light Mr. Trostle and Brett
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 17, 2017, 11:04:53 PM

 I guess what I really meant back there was that I knew the P-38's were used some in Europe, but I've just always associated them more with Pacific operations. Once the P-51 came along things changed pretty quickly though, especially in Europe.

 Thinking about all of this I just tracked down a photo that I recalled from long ago showing a large formation of P-38's decked out with invasion stripes, probably from D-Day or very shortly after. Also, the first P-38 I ever saw in person was in Oshkosh about 1980, all polished aluminum with big red "Der Gabelschwanz Teuful" nose art. Not sure where that one is these days.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 31, 2017, 09:01:27 PM

 Well, I haven't touched the '38 for three weeks or better, pretty disappointing and way behind schedule for spring. Picked up a nagging cough that just won't go away and hanging out in a cloud of balsa dust just hasn't sounded fun. Still fighting it, waah, waah, waah...
 
 Before that though I did get the engines mounted, spinners fit, and the engine nacelles about 98% sanded to shape. Keeping the shapes the same during the process was a bit of a trick, sand on one for a bit, then the other, back to the other, back and forth back and forth. Anyway, getting very close to busting out the silkspan at this point...

Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 31, 2017, 09:11:53 PM

 Comparing the profile outline I started with to my redone version...
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on April 01, 2017, 09:51:44 AM
Making matching engine cowls/nacelles/fuselages is a lot of fun isn't it.   If the doctor doesn't clear me and the weather clear up you will be air borne before me.   You construction is looking great.
Title: Re: Hutch's P-38 Lightning
Post by: Michael Boucher on April 05, 2017, 04:20:47 AM
HI Wayne, I Hope you still don't have the cough. If you do or for the next time, try drinking pineapple juice. It contains four times the stuff in cough medicine to get you to stop coughing. The P-38 is outstanding! All the best, Michael Boucher
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on April 05, 2017, 06:45:42 PM
HI Wayne, I Hope you still don't have the cough. If you do or for the next time, try drinking pineapple juice. It contains four times the stuff in cough medicine to get you to stop coughing.

 Thanks for the tip Michael, I'll keep it in mind. Does it help if you put a little vodka in with it?
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on October 12, 2017, 08:54:05 PM

 "Building Season" is fast approaching, back on the '38 soon...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on November 03, 2017, 08:56:26 PM

 ...spent a couple hours sanding and shaping the '38 booms tonight, it's on for the season.  ;D
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on November 09, 2017, 09:59:31 PM

 No photo worthy developments but I've officially stepped into Building Season, cleaned up the shop, and have been working on the '38 the past three nights now. Silkspan covering of major components has begun. First up was the twin booms and they are now covered. Next will be getting out the polyspan and covering the wing...  ;D
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on November 10, 2017, 01:49:08 PM
Well don't feel lone some.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on November 22, 2017, 11:01:06 PM

 Finished covering the wing tonight, Polyspan from tip to tip. Gotta let it dry overnight then out comes the heat gun.
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on November 23, 2017, 09:41:13 AM
Watch that heat gun.  But, it is easy to repair a hole if it pops up or appears. 
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on November 23, 2017, 08:46:42 PM

 Came out good Doc, got'er pulled down nice and tight with a couple thin spots but no real issues. I still say Polyspan is the only way to go but it definitely takes some finesse with the heat gun.

 Right after that came two good heavy coats of 50/50 Brodak clear...
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on November 24, 2017, 10:17:46 AM
Looking good. H^^
Title: Re: Hutch's P-38 Lightning
Post by: Gary Mondry on November 30, 2017, 08:45:13 PM
You dope with a foam brush???  Doesn't it come apart and leave foam bits on everything?  (apparently not)  Does it take one brush per coat?
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on November 30, 2017, 09:51:36 PM
You dope with a foam brush???  Doesn't it come apart and leave foam bits on everything?  (apparently not)  Does it take one brush per coat?

 I only use the foam brush for adding the clear coats after the covering has been applied. I do everything up to that point with a regular brush. I've found that the clear coats lay out much better and dry smoother and more evenly using a foam brush. The foam brush holds a lot of material too, which allows you to control the flow once you get a feel for it. A two inch brush works very well, as that's pretty close to an average wing bay width.
 At this stage I'm using roughly a 70/30 mixture, 70 thinner, 30 clear. Starting at one wingtip and brushing T/E to L/E you can work your way across a wing pretty quickly. It only took about ten minutes to go across this 60" wing. On open bays I usually only do one coat per session, preferring to allow for a 24 hour drying time between coats.
 As an example, tonight I did what will be the last coat on the wing. I did the bottom side first and then let it dry just enough to be able to flip over, about 20 or 30 minutes. During that waiting period I did another heavy coat on both sides of the fuselage pod. Then I went back and did the top of the wing, all with the same brush, no deterioration. The brush does swell just a little but I haven't had any trouble with them coming apart. You do of course only get one session out of a brush, because you can't clean it. Determined by my local Home Depot, this routine works out to 77 cents per session.
Title: Re: Hutch's P-38 Lightning
Post by: Gary Mondry on December 01, 2017, 11:29:36 AM
No kidding.  I would never have tried that, convinced that the thinner in the dope would melt the foam before I got done.  Now, maybe...

Thanks, Wayne.
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on December 01, 2017, 11:58:00 AM
I have tried the foam brushes and they do work, but if you get interrupted they don't.  Like wife saying it's time to eat or grand kids need a ride.   Also when I dope a wing I don't do one panel like top side and then the bottom side as such.   Usually start at either tip or center and do a couple of rib bays, flip over and do same rib bays with a couple of extra and flip over.   When done I go to other half of wing.  It was a chore with the B-25 as that is huge plane and I didn't fabricate a paint stand for it.   In fact I brushed the dope out side of the shop to have room to maneuver.  Any way I anxious to see this P-38 of yours in the air. H^^
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 01, 2017, 08:03:43 PM
I have tried the foam brushes and they do work, but if you get interrupted they don't.  Like wife saying it's time to eat or grand kids need a ride.

  LL~ LL~ LL~
Title: Re: Hutch's P-38 Lightning
Post by: Brett Buck on December 01, 2017, 08:28:14 PM
No kidding.  I would never have tried that, convinced that the thinner in the dope would melt the foam before I got done.  Now, maybe...

   This may have been discovered by, and it was almost certainly first described in a nationally-distributed magazine, by none other than the inestimable Dirty Dan Rutherford back in Model Builder magazine.

     Brett
 
Title: Re: Hutch's P-38 Lightning
Post by: Gary Mondry on December 01, 2017, 09:34:42 PM
I'm not surprised.
I miss Dan's creative writing style...
Title: Re: Hutch's P-38 Lightning
Post by: Brett Buck on December 03, 2017, 06:11:33 PM
I'm not surprised.
I miss Dan's creative writing style...

   It's just my opinion, and no offense to anyone else, but Dan may be the best model airplane magazine writer I have ever read.  Always entertaining even when he really has nothing to say, verbose but so well-constructed that you don't get the "wall of text" effect, proper grammar, etc.

     Brett
Title: Re: Hutch's P-38 Lightning
Post by: Dan McEntee on December 03, 2017, 08:51:45 PM
   It's just my opinion, and no offense to anyone else, but Dan may be the best model airplane magazine writer I have ever read.  Always entertaining even when he really has nothing to say, verbose but so well-constructed that you don't get the "wall of text" effect, proper grammar, etc.

     Brett

     As a collector and reader of model magazines, I have read a few in the last 50 years and would whole heartedly agree with this statement. As a good second place but with a completely different writing style is Dave Thornburg of "Do You Speak Model Airplane" fame. Ted Fancher is right up there also.
   Type at you later,
    Dan McEntee
Title: Re: Hutch's P-38 Lightning
Post by: Dennis Saydak on December 04, 2017, 09:21:03 AM
Hi Wayne; It's great to see the P-38 project coming along so nicely.  I have to sincerely thank you for taking it on for me while I was unable to because of medical reasons. I'm currently recovering from total hip replacement surgery and looking forward to finally getting active in the hobby again. I plan to be back in the shop in another week and look forward to finally finishing a few stalled projects. I may even get in the shop today to work on a small project.............I need to make me a back scratcher.  y1 y1
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 04, 2017, 10:11:03 PM

 I was wondering where you'd been Dennis, good luck with your recovery and looking forward to some build posts from you.

 BTW, I'd been thinking all along that this thing was 60" span, not sure though if I'd ever even measured it. Getting near ready to attach the fuse pod and booms I had the tape measure out tonight to find wing center and create some reference points, it's actually 65" wingspan.  :o
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on December 05, 2017, 08:31:55 AM
Yeah Don likes them big for a twin.   Guess I should measure the B-25.  I know the thing had some work done out side the shop and does span the back seat of my Suburban.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 11, 2017, 07:39:08 PM
 ...sanding, filling, priming, sanding, filling, priming, fitting, sanding some more, filling some more, a little primer, sanding, sanding, measuring and checking fits, sanding, filling, sanding, sanding...
Title: Re: Hutch's P-38 Lightning
Post by: Dennis Saydak on December 12, 2017, 11:04:14 AM
...sanding, filling, priming, sanding, filling, priming, fitting, sanding some more, filling some more, a little primer, sanding, sanding, measuring and checking fits, sanding, filling, sanding, sanding...

Sounds like there might be nothing left after you get through with it.   ;D
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on December 12, 2017, 12:09:12 PM
Now you know why this old man does not have 20 point finishes.  In fact I ask the judges to move back about 20 feet before giving appearance points.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 13, 2017, 07:50:32 PM

 Slow progress. The fuse pod is glued to the wing now, but I'm finding the need for a LOT of filling and sanding before the booms will be ready to mount. The fuse pod and twin booms are built up and sheeted in construction and the sheeting on the booms has a lot of high/low spots that showed up after the silkspanning process. The problem boils down to a wood selection issue with the sheeting. I don't know the proper term, but it's like when you get a real soft, almost mushy, piece of wood that even though it's sanded perfectly smooth beforehand it gets all grainy and uneven once the dope and silkspan cures. Once I get them finished up to a satisfactory compromise I'll re-add the new cooling scoops I made and then finally get them mounted to the wing...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 22, 2017, 08:36:57 PM
 A little bit getting done here and there. Did the fillet on the outboard side of the fuse pod tonight. Letting it cure overnight and then tomorrow the inboard should get done. The new scoops are also on the booms now and along with their fillets are all sanded, primed, and ready to go. Once the other fillet on the fuse pod is done and cured it'll be time to attach the booms to the wing...then four more fillets...then... 
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 25, 2017, 04:18:52 PM

 the new air scoops...

 
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 25, 2017, 04:22:21 PM

 "...two booms-a-curin'..."  ;D
Title: Re: Hutch's P-38 Lightning
Post by: Jim Oliver on December 26, 2017, 09:26:20 AM
How would two Brodak .25s work for this project?

Jim
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 26, 2017, 12:32:54 PM
How would two Brodak .25s work for this project?

Jim

 Not very well at all IMO. The Hutchinson P-38 design is actually intended for two .25's, like LA's or FP's, but even using those I feel it would have to be built as an absolute featherweight to be a good stunt performer. I've never run a Brodak .25, but I do have experience with the Brodak .15 where I was not at all impressed with the power, I feel the LA and FP .15's are much better engines, at least they have always proven so for me. Judging by the comparison with the .15's I'd assume the same with the Brodak .25's.
 
 As always, there are a lot of different opinions on all of this, I'm just explaining my own. There is some additional discussion pertaining to power options for this model back toward the beginning of this thread. My version here will be set up with two FP.35's, power will not be a problem.  ;D
Title: Re: Hutch's P-38 Lightning
Post by: George Albo on December 29, 2017, 08:13:55 AM
A little bit getting done here and there. Did the fillet on the outboard side of the fuse pod tonight. Letting it cure overnight and then tomorrow the inboard should get done. The new scoops are also on the booms now and along with their fillets are all sanded, primed, and ready to go. Once the other fillet on the fuse pod is done and cured it'll be time to attach the booms to the wing...then four more fillets...then...

Nice fillets. What are you using?

George Albo
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 29, 2017, 07:17:58 PM
 
 The fillets are done with SuperFil from Aircraft Spruce, it's great stuff.

 http://www.aircraftspruce.com/catalog/cmpages/superfil.php?gclid=EAIaIQobChMInOCv4NSw2AIVARcBCh27aQA0EAEYASABEgK8ZfD_BwE
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on January 04, 2018, 09:51:06 PM
Wayne,
Yeah, nice job on the fillets.  Send my best to all.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 04, 2018, 10:25:14 PM
Wayne,
Yeah, nice job on the fillets.  Send my best to all.

 Thanks Crist, and will do.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 04, 2018, 10:26:33 PM

 Hey Crist, what do you think of this paint scheme?

 
Title: Re: Hutch's P-38 Lightning
Post by: George Albo on January 05, 2018, 10:32:06 AM

 The fillets are done with SuperFil from Aircraft Spruce, it's great stuff.

 http://www.aircraftspruce.com/catalog/cmpages/superfil.php?gclid=EAIaIQobChMInOCv4NSw2AIVARcBCh27aQA0EAEYASABEgK8ZfD_BwE

Great! Thanks.

Happy New Year

George
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 05, 2018, 09:28:56 PM

 Finally working on all the tail feathers now, getting the silkspan on at this point. They'll be all primed and sanded and basically ready for color before they get attached...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 05, 2018, 10:10:02 PM
 I almost always use nylon control horns on my stuff. When using them it's a good idea to reinforce that mounting area to add strength, and also make the control surface more resistant to crushing when tightening the horns on final installation. Before the control surfaces get their silkspan I've got a routine for this reinforcement using 1/64" plywood and drywall spackling. These photos show reinforcing the elevator for the P-38, it uses two horns, one on each end.
 
 First, I add a 1/64" plywood reinforcement piece to the horn mounting area using CA, doing both the top and bottom of the control surface. Next I'll put a sanding reference around the control surface using some low-tack blue tape. Then goop on the spackling, making sure it's thick enough to fill what will end up being the transition area from the plywood surface back down to the original control surface. It doesn't have to be pretty, just make sure you add enough of it to do the job.
 Let the spackling dry overnight to make sure it's set up well all the way through. Then take a FLAT sanding tool of choice and slowly and carefully sand the spackling down to where it's level and even with the plywood, and the plywood is showing again completely. A sanding bar with 320 works best for this process. Then, start to angle your sanding bar down from the plywood to the original control surface, aiming at the blue tape reference line. Keep sanding at this angle until you've sanded all the way through the spackling right at the tape line. You want your sanding "goal" with all of this to be a straight and level surface from the edge of the plywood over and down to the tape reference line.
 Once you have everything sanded to this point then CAREFULLY remove the blue tape, pulling it off by keeping it flat against the control surface and at an angle away from the spackling. After that the area should just need a minor touch up with some 600 or 800 to completely smooth the transition and have it all ready for silkspan.
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on January 05, 2018, 11:13:34 PM
Hey Crist, what do you think of this paint scheme?

I like it!  I like it a lot!
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on January 05, 2018, 11:18:16 PM
Sweet on the spackle thing.
Title: Re: Hutch's P-38 Lightning
Post by: Allan Perret on January 06, 2018, 11:20:10 AM
What I do in a case like this is to feather the edges of the ply doublers before gluing, eliminating the need for the spackling.
Title: Re: Hutch's P-38 Lightning
Post by: Glenn (Gravitywell) Reach on January 06, 2018, 02:35:48 PM
I do the same as Allan.  I just make the ply piece an eighth of an inch bigger all the way round and feather it out.  Saves all the spackling work.  Love watching this build.....I have got to get back on my F6F.  I turned the fuselage into a banana and it put me in a funk about her.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 06, 2018, 09:28:16 PM
 Allan and Glenn's way certainly works well too, and is actually what I used to do. I'm just showing the way I've done it for quite a while now. I've found that done carefully as shown, and after the silkspan and final finish, this spackle routine allows you to "spread out" the transition distance more, leaving a virtually unnoticeable reinforcement. 
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 06, 2018, 09:32:33 PM
I like it!  I like it a lot!

 I thought you might!  ;D
Title: Re: Hutch's P-38 Lightning
Post by: Glenn (Gravitywell) Reach on January 07, 2018, 04:36:43 PM
Hi wwwarbird, I can certainly see how your feathered edge would be far less conspicuous than mine.  I don't do "real" scale....I'm more of a  stand-way-the-heck-off scale kind of guy.  The way I do it, it looks good from twenty feet away....lol  And I'm real sorry, I didn't mean any disrespect to your way of doing things.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 07, 2018, 05:53:06 PM
  And I'm real sorry, I didn't mean any disrespect to your way of doing things.

 None taken at all Glenn, just showing my current method for those who might want to give it a try.
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on January 08, 2018, 10:41:10 AM
Yes, there are many ways of doing things.   And as one person told me many years ago if you don't try some thing new it might help you.  If it doesn't stash it away in the memory banks as it may help in the future. D>K
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 12, 2018, 08:00:18 PM
 The past week has been spent getting all the tail surfaces silkspanned, sanded, primed, sanded again etc. and ready for final attachment. I prep each piece to the point of being 99% ready for color before assembly. Prepping each piece separately like this makes getting the completed airframe ready for final painting much easier when that time arrives, not having to work around everything throughout the prep process. Doing it this way leaves you with pretty much just the fillet work and some very minor sanding prior to painting.

 I had been scratching my head for awhile trying to come up with a slick way to keep the fin/rudder assemblies aligned while curing. I use 30 minute epoxy for that process and didn't care to have to hold them in place all that time. Even more importantly, once they would be set in place I felt the need to be able to step back and eyeball everything, double and triple checking alignments, before the epoxy started to set up.
 
 What I came up with was making a simple alignment jig that slips over the top of the fin/rudder assembly. It incorporates a vertical slot the same width as the thickness of the fin/rudder with a horizontal base that simply rests on the stab, exactly square to the vertical. An angled relief cut was added at the jig base too, to keep it safely away from the glue joint and avoid making the jig part of the airplane. It all worked out perfectly, holding the fin/rudder in place and allowing me to let go of it all and be able to walk around and do my required eyeballing...

 
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on January 13, 2018, 10:24:23 AM
Why didn't you tell me this stuff before I glued the B-25 together.   Lost count how many times I knocked rudders loose while doing what little finish I did.  Any way the P-38 is looking great. D>K

And the saying still goes, "Learn some thing new every day".  Thanks. H^^
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 19, 2018, 11:12:49 PM
 This past week has been spent working on the final fitting and function of all the control surfaces. There's only five moveable surfaces, 28 hinge slots, 14 of those to recess, two bellcranks, two flap pushrods, two elevator pushrods with couplers, eight ball joints and four control horns to deal with. Tonight I just finished gluing 10 hinges into the wing T/E, it only took four separate batches of 30 minute epoxy.  n~
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on January 20, 2018, 09:22:15 PM
What's on the bench?
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 20, 2018, 11:43:50 PM
What's on the bench?

 Uh, thaaat bench??? It's one of two work benches in my small shop, one that's at "sit down" height and topped with a piece of ceiling tile that holds pins. The other bench is "stand up" height with a 3/8" glass top. The "sit down" one is where I usually frame up wings and other built-up assemblies. Since I haven't had to frame up a wing in quite a while it's gradually turned into a catch all with some rolled up plans and stuff covering up another couple levels of about everything you can think of. It just needs a good cleaning once the '38 gets finished before the next build.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 29, 2018, 08:59:45 PM

 Still working on shaping and fitting the flaps, all FOUR of them. Part of this equation is that they don't go all the way out to the wingtips, there's about a 3" long fixed flap section at each wingtip. To make sure these little wingtip widgets end up aligned properly I made a lite-ply jig of the rib/airfoil outline that includes the flap. The jig then slides onto the wing and holds the flap exactly at neutral. Then I roughed out a piece of T/E stock to create the widget, gluing it on with 15 minute epoxy while aligning it with the flap...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on January 29, 2018, 09:07:08 PM

 Shaping the wingtip widgets here. Once the top-view outline was matched up with the flap, and the T/E rounded, it then gets blended into the wing using the same spackle/fill routine as described earlier for the control horn reinforcements. Once filled and sanded to satisfaction they will get covered with silkspan and finally smoothed into the wing...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 01, 2018, 08:31:17 PM

 The past few evenings have been spent adding the 1/64" ply control horn reinforcements (x8) to the four flap sections. Then spackle filled and sanded the transitions, final overall sanding/shaping, and now silkspanning. Tedium.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 19, 2018, 08:17:53 PM
 
 All four flaps are finished with silkspan, primed, sanded and attached. Next I'll go around and drill/pin them with round toothpicks (x28) per my usual routine. Seems I'm at that stage where you work and work and work and nothing looks any different.  D>K
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on February 20, 2018, 06:14:12 PM

 All four flaps are finished with silkspan, primed, sanded and attached. Next I'll go around and drill/pin them with round toothpicks (x28) per my usual routine. Seems I'm at that stage where you work and work and work and nothing looks any different.  D>K

Yeah, a lot of work especially between all the times you have to go out and shovel the snow!  :D
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 20, 2018, 07:21:45 PM
Yeah, a lot of work especially between all the times you have to go out and shovel the snow!  :D

 Thankfully we haven't had to do too much of that this winter, yet.
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on February 21, 2018, 05:26:03 PM
You do nice work Wayne.  Stay warm.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on February 21, 2018, 06:25:19 PM

 Thanks Crist, I'm not worth a crap at doing Monokote though.  VD~
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on February 23, 2018, 01:54:12 PM
Thanks Crist, I'm not worth a crap at doing Monokote though.  VD~

White Monokote is the easiest to do!
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 01, 2018, 09:11:46 PM
 Haven't had a chance to spend much time in the shop lately. I have gotten the pushrod exit covers made up this week though and then attached tonight, all four of them. First two pics are of one of the elevator covers, they're on top of the wing and inboard of the booms. The last pic is one of the flap covers, which are under the wing outboard of the booms...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 01, 2018, 09:21:04 PM
 Oh yeah, last week I (final) attached all four of the flap sections, joiner wires with bearings, and hinges. I think next on the list will be drilling and pinning the hinges.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 10, 2018, 10:16:19 PM

 Finally got around to pinning the hinges on the wing and flaps tonight. I've offered a separate "how-to" here...

 https://stunthanger.com/smf/building-techniques/'failure-proof'-hinge-pinning/

 
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 10, 2018, 10:17:34 PM

 Did the fillet work all around the tail surfaces tonight too...

 
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on March 11, 2018, 11:56:13 AM
Nice.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 12, 2018, 08:05:44 PM
Nice.

 Thanks Crist. I've resigned myself to "passable" at this point, just trying to get this thing done.
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on March 13, 2018, 12:18:00 PM
Well don't rush it.  It is looking great to this point.  I'm guilty of rushing the finish on planes as I want to get them flying. D>K
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 23, 2018, 08:31:20 PM
 Well, I've actually been chipping away again, one fillet per evening for about the last week or so. This thing had a lot of them, just got the last one finished tonight. I let out a silent cheer in my mind afterward. All of the hinges are now pinned, filled and finish sanded too.

 Next will be to finish bending up the landing gear and getting it glued in. After that this thing might actually be ready for paint.  :)

Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on March 27, 2018, 09:40:44 PM
Sweeeet fillets!
Title: Re: Hutch's P-38 Lightning
Post by: Dennis Saydak on March 28, 2018, 03:45:51 PM
I have to ask - why is this project taking so long?  S?P S?P S?P y1 y1 y1
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 28, 2018, 06:12:08 PM
I have to ask - why is this project taking so long?  S?P S?P S?P y1 y1 y1

 Howdy Dennis,

 Well, if I didn't have a job I could have built six of these by now.  ;D

 Even with the great head start on the '38 there was still a LOT of work to do, this one is a little more complicated than a Ringmaster. I've ended up changing and/or fixing a fair number of things along the way too. Another thing is that I pretty much only spend time in the shop through the winter months, just can't get myself to hide out in the basement when it's nice outside. FWIW, other than a bit of a start on building a little Tee Dee .09 powered profile Jap Zero I've been only working on the P-38 since I got ahold of it. We're really close to being ready for paint at this point and I've got the graphics sitting here ready to go. Kind of seeing the light at the end now, finally.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 28, 2018, 08:48:15 PM

 The past couple evenings have been getting the L/G figured out, bent up, and attached. I'm installing the mains first so I'll be able to set it on the wheels and then measure and determine the desired "angle of attack" stance when I'm ready to bend up the nose gear. I fiddled around quite awhile last night and realized I'd never get the mains aligned to match and glued in without a few more hands. In an effort to end up with both wheels pointed in the same general direction I came up with a jig idea to hold everything in place while I poured the epoxy into the L/G slots...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 28, 2018, 08:51:38 PM

 ...(semi) confident with everything being properly in place it was time to fill the mounting slots with 30 minute epoxy. A few micro balloons were added in the mix too...
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 28, 2018, 08:53:38 PM
 ...all cleaned up and curing, time to cross the fingers and WALK AWAY.  ;D
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on March 29, 2018, 08:28:44 AM
Nice idea on using the jig.
Title: Re: Hutch's P-38 Lightning
Post by: Glenn (Gravitywell) Reach on March 29, 2018, 02:21:49 PM
Stellar jig idea, and it can be used on any airplane.  One jig and drill extra LG clamp holes as needed.  Another great idea I've got off this build thread. H^^
Title: Re: Hutch's P-38 Lightning
Post by: Dennis Saydak on March 29, 2018, 05:19:22 PM
Hey Wayne, no need to explain you're tardiness, ha ha. I was only yanking your chain. You've done a great job and I believe the P-38 will fly really well and be very impressive in the air. Unfinished projects and medical problems prevented me from completing it. I really appreciate the job you are doing and my buddy in heaven would be proud of your work.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 29, 2018, 06:19:30 PM
Hey Wayne, no need to explain you're tardiness, ha ha.

 That's what I thought Dennis, I just figured I'd 'splain the story. I'll be really glad to get this one done though, feeling good to finally be this close.  ;D
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 29, 2018, 06:22:17 PM
  One jig and drill extra LG clamp holes as needed. H^^

 Didn't even think of that Glenn. Heck, if a guy built enough different planes you could end up having a free cribbage board out of the deal.  ;D

Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 29, 2018, 09:22:54 PM

 Got the nose gear bent up, tweaked to near perfection, and glued in tonight. The chunk of L/E stock taped to the fuse is for a visual alignment reference when looking from head on. The main gear jig worked out perfectly, both wheels ended up pointing the same direction.  ;D
Title: Re: Hutch's P-38 Lightning
Post by: Glenn (Gravitywell) Reach on March 30, 2018, 10:57:35 AM
Didn't even think of that Glenn. Heck, if a guy built enough different planes you could end up having a free cribbage board out of the deal.  ;D
That's even better.....a landing gear jig and cribbage board!  Can it get any better?  Maybe cup holders?  %^@ H^^
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 30, 2018, 09:26:36 PM

 On the wheels, at last...

Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on March 30, 2018, 09:47:16 PM
Wayne,
Looks nice. 
But it looks like it has too much "nose up" sitting on the ground.  I always set my tri gear models with just a slight nose up.  Or in other words "just a little positive incidence on the wing".  This prevents a "zooming" take off.

Also I would put just a degree or so of "toe-in" on the mains.

Just what I did on my models. Not a criticism, just food for thought.
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on March 30, 2018, 10:08:43 PM
 Good points, and all were considered as I went Crist, but I opted for a more scale appearing stance over what might be considered an optimum "stunt stance".

 I put it on the scale tonight too, first time since way back in this thread. My original RTF estimates are going to be very close. For now I'll just say that other than from the sheer power it will have I don't anticipate it springing off the ground. If you want to bring your lead boots to Polk City I'll let you take it for a spin.
Title: Re: Hutch's P-38 Lightning
Post by: Crist Rigotti on April 01, 2018, 07:39:30 PM
Good points, and all were considered as I went Crist, but I opted for a more scale appearing stance over what might be considered an optimum "stunt stance".

 I put it on the scale tonight too, first time since way back in this thread. My original RTF estimates are going to be very close. For now I'll just say that other than from the sheer power it will have I don't anticipate it springing off the ground. If you want to bring your lead boots to Polk City I'll let you take it for a spin.

Duly noted on the stunt stance!
If I get up there I'll take ya up on that!
Say hi to the gang for me.
Title: Re: Hutch's P-38 Lightning
Post by: Dan McEntee on April 01, 2018, 08:58:36 PM
 Looking good Wayne! Wayne is correct, in that when at rest and engines not running, the P-38 sits tail low. When engines are running and making hydraulic pressure, the main gear struts extend a bit and it sits more level. Tough choice when cutting landing gear lengths. A little bit of down control on the take off roll will help it track and stay down until ready to rotate.
  Type at you later,
   Dan McEntee
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on April 02, 2018, 09:47:43 AM
That is looking great and I am waiting for the finish to be done.  If it flies like my B-25all you basically have to do is hold neutral and tight lines for take off.  Now I have all the moving surfaces lined up I hope to get more flight on the B-25.  Just need to learn how to operate this camera I purchased of the bay.  In fact I have different cameras.  One is a Snap Cam  tap n' snap and the other is a Go Pro Hero.  May have to take grand son or wife to run the cameras. H^^
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on April 05, 2018, 08:35:18 PM

 The past few evenings have been spent doing more final touch-up filling, sanding, priming, sanding, priming, filling, sanding, priming, sanding, DENTING, filling, sanding, priming, sanding...not necessarily in that order.  n~ 
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 26, 2018, 09:40:17 PM
 
 Ordered paint and more thinner tonight from Aircraft Spruce, gotta get back on this thing.  ;D
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on December 27, 2018, 10:05:33 AM
And I thought I was slow.   LL~ LL~  I await flight reports. D>K
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on December 27, 2018, 08:19:11 PM
And I thought I was slow.   LL~ LL~  I await flight reports. D>K

 You're far from slow Doc, watching the forum here you've cranked out quite a few new models in the past couple years. I'd almost bet more than anyone else here.  y1
Title: Re: Hutch's P-38 Lightning
Post by: john e. holliday on December 28, 2018, 10:52:51 AM
I now have 4 more almost ready for test flights.   Also after seeing a video some where I'm redesigning my combat stooge.  That is if launch angle made steeper doesn't help. D>K
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on April 07, 2019, 09:32:26 PM
 Well, after another long hiatus I finally got around to shooting some color on the P-38 the past couple evenings. I'd originally planned on getting into it hot-n-heavy last fall, finishing it, and then starting in on the next build. As last summer and fall wound down I was really looking forward to a more productive building season since I hadn't accomplished much over the past couple. As it turned out I've been fighting a nasty plantar fasciitis problem that popped up in early October, both feet, and I've been half-stepping and hobbling around like a 100 year old since then. Extreme pain practically 24/7, standing, sitting, doesn't matter, and it's been all I can do to continue making it to work. Wah-wah-wah, but it does REALLY suck. Anyway, this has resulted in me spending zero time in the shop all winter but I'm now sucking it up and basically forcing myself to try and get this thing done. Pretty soon I'll get some fresh pics going here in the Painting & Finishing section.
Title: Re: Hutch's P-38 Lightning
Post by: Clint Ormosen on April 08, 2019, 10:10:59 AM
Wow! I missed this entire build thread while I was away. I just spent the last hour reading all of it. Quite a project! Looking forward to more pictures, though.

Wayne, I think you’re me just in MN. We always seem to have the same issues. Allergies, foot problems..ect.  LL~
Title: Re: Hutch's P-38 Lightning
Post by: wwwarbird on April 09, 2019, 10:03:53 PM

 It's red...very, very red...


 https://stunthanger.com/smf/paint-and-finishing/painting-hutch's-p-38/new/#new
Title: Re: Hutch's P-38 Lightning
Post by: Clint Ormosen on April 09, 2019, 10:56:38 PM
It's red...very, very red


It certainly is. Hope you've got a good pair of sunglasses.