Paul Walkers B17 going electric?? Are the rumors true?

[Paul Walker]

Unfortunately there are no Spin 22's any more. I will start with 2 Pro 22's on motors 1 and 4. Then Spin 44's for motors 2 and 3. Packaging pro 22's are way easier than the 44's.

Yes  I am using 4S batteries. I will use at 4S 4500 to start with. I heard that there are new batteries that will take that to 5400 mah capacity for the same weight. Time will tell if I need those.

But weight is critical. The 44's weigh around another ounce than the 22's. I am spending considerable time perfecting the fuselage mould so the fuse shells can be 1/16" iso 3/32.  It has a long tail so this becomes more critical. I have to keep the weight down if this is going to be more than an interesting thing because of its shape. I want it to fly well!

Motor testing to date indicates they are sufficient along with a 4S configuration. First tests were on the number 1 B-17 with 4 independant power systems. It was to verify the motor size. It flew just like the IC version  but the 4 individual batteries could only give me 2 1/2 minutes on a charge. The 2nd big B-17 has a central 4S 4200 battery feeding 4 ESC's etc. With the motors in it ( Park 480's) the KV was too low to produce any meaningful boost. The third test shop was a 725 in^2 Impact. 4 profile nacelles were added. It flew originally with the smallest BA motors available. It could fly at 5.1 sec laps but had no room for boost. Could not maneuver at all. Switched to a higher KV motor and tried again. This  time it flew at 5.9 sec laps and could do many of the maneuvers. A 4S4200 LiPo was powering it. It was not a great test article as it weighed 85 ounces. Weather closed in up here before more testing of battery capacity could be done. But using info from those flights indicate that it had enough capacity and then some for a complete pattern.

Based on these tests I will be starting with BA 2310-1220 motors. I can jump to 2310-1660 motors if needed with no significant weight penalty.
Time will tell, but am anxious to fly it. The 85 ounce Impact version had plenty of power  even at 5.9 to do a pattern. Now, back to the shop!

[Ken Culbertson]

Thanks for confirming what concerned me on my twin.   I was really concerned that a single 2800mah 5s would leave me short.  Your explanation has really helped.  I wish I could have read this 18 months ago when I decided to make Endgame 4 a twin.  So many things I could have done better! 

Ken

[Doug Moon]

I see a Mustang tail in the background. Is that plane still flyable?

[M Spencer]

file:///C:/Users/OPAC/Downloads/B17_clrTmplt.pdf

fudge : https://stunthanger.com/smf/sina-goudarzi-3-views/w/

or under W there . https://stunthanger.com/smf/sina-goudarzi-3-views/

a 3 view of Mr Walkers Aeroplane . or Airplane . Think of the time saved not having to clean oil from four engine bays .

[Paul Walker]

I see a Mustang tail in the background. Is that plane still flyable?

Yes it could.

[Dave_Trible]

Paul all those nacelles had to be a pain to make and identical.   Had you given any thought to making a mold and making them from carbon?

Dave

[Steve Helmick]

It happens that I know who made the CF cowls for the #2 airframe (Howard), and also the guy that machined the aluminum pattern that the CF cowls were made from (me). I would not be surprised if Paul could easily adapt CF cowls, but my recaller says they were 10g apiece, which sounds light until you multiply by 4. I recall one time where one blew away while performing an engine swap or other fiddling. It was found 30' or so away, over against the grass.  Steve

[Paul Walker]

Correct. That was quite the surprise to find it so far away. And no scratches to boot.

The new ones are balsa laminate. It turned them on my lathe (aka a drill press) and when done weighed 2.5 grams each. With the electric power, and the way the motors are mounted, there is not as much overhang as with the carbon ones.

Working now on the fuselage shell mould, and then the assembly fixture. Fun times...
Well, not really. Just tedious....

[Crist Rigotti]

Paul,
Check your PM.

[Doug Moon]

Yes it could.

If it needs a new home I will pay the shipping! 

[Howard Rush]

It happens that I know who made the CF cowls for the #2 airframe (Howard), and also the guy that machined the aluminum pattern that the CF cowls were made from (me). I would not be surprised if Paul could easily adapt CF cowls, but my recaller says they were 10g apiece, which sounds light until you multiply by 4.

Just another way I set the B-17 project back. I should have had you make that pattern in halves so I could make a hard mold in halves.  I made a silicone mold so I could get the parts out. The vacuum bag pressed the cloth weave into the mold, leaving a bumpy part, to the dismay of the finishers. If I’d done it right, that cowl would have been lighter and blown farther.

[Steve Helmick]

Just another way I set the B-17 project back. I should have had you make that pattern in halves so I could make a hard mold in halves.  I made a silicone mold so I could get the parts out. The vacuum bag pressed the cloth weave into the mold, leaving a bumpy part, to the dismay of the finishers. If I’d done it right, that cowl would have been lighter and blown farther.

I recall asking if you wanted a slight draft angle on the cowl diameter, but that idea was declined. I envisioned that you'd make a fiberglass splash off the aluminum plug and then mold all 4 (+) cowls in that.

The first time I worked at Boeing ('65!), I worked in the fiberglass shop in Mockup, Renton plant. All the resin we used was epoxy. The most horrible thing we had to make was FG "P.I.E." award plaques. "Pride In Excellence"...or at least, that was what we were told!  The funnest project was the cowl LE ring for the C-5A mockup. Molded that (about 9' diameter through the bore) with a lap-joint, and removed the ring from the mold about like an orange peel. Sometimes, when parts just didn't want to come out, a small hole was drilled and an air nozzle held against it did the trick. Steve

[Dave_Trible]

Back (way, way back) in the days I was a BIA boat designer getting 19-24 foot boat hulls out of the molds was done by doing just that-  we'd jam an air nozzle into the mold flange and pump air until the hull broke loose.  Sometimes that took a while,  maybe 20-30 minutes to get enough air worked between the surfaces.

Dave

[Steve Helmick]

Back (way, way back) in the days I was a BIA boat designer getting 19-24 foot boat hulls out of the molds was done by doing just that-  we'd jam an air nozzle into the mold flange and pump air until the hull broke loose.  Sometimes that took a while,  maybe 20-30 minutes to get enough air worked between the surfaces.

Dave

Where possible, a Schraeder (sp?) valve (aka tire valve stem) or pipe fitting (or 6) could be epoxied into the mold, so you could hook up air hose(s) to the mold and really get some umph between the part and mold. We sometimes did that, and plugged the divot(s) with wax. Bee's wax, IIRC.    Steve

[Paul Walker]

Moving along...slowly.
Aft fuse shells on. WFA installed, and removable HT mounting in place. VT there for the photo op.

Now to build the remainder of the aft fuse which is the lower aft hatch and Vt install along with the tail gunners greenhouse.

Then on the the forward fuselage. It is removable to access the electronics bay and battery mounting.

[Doug Moon]

The cool factor is off the charts! You are only adding to your already enormous amount of lore.  Well done!!!

[wwwarbird]

 Looking great, an awesome project. It may have already been mentioned, but what's the wingspan/area?

[Paul Walker]

Looking great, an awesome project. It may have already been mentioned, but what's the wingspan/area?

65" span
700 in^2 area

[wwwarbird]

65" span
700 in^2 area

 Wow, interesting, nearly identical to my 64"/704 square PBY. Enjoying watching this build, the original IC one is one of the coolest C/L models of all time. 

[Paul Walker]

Wow, interesting, nearly identical to my 64"/704 square PBY. Enjoying watching this build, the original IC one is one of the coolest C/L models of all time. 

Thanks.
I liked it except for the speed it had to fly at. This new one shouldvresolve that issue!

[Brett Buck]

Thanks.
I liked it except for the speed it had to fly at. This new one shouldvresolve that issue!

   Didn't the first one fly a lot slower than the W/C airplane?

      Brett

[Dan McEntee]

Thanks.
I liked it except for the speed it had to fly at. This new one shouldvresolve that issue!

    Can I asked what lap times were and line length, just out of curiosity? I always imagined that you were right out there as far as you could go at 70 feet on a model that big.
  Type at you later,
    Dan McEntee

[Paul Walker]

    Can I asked what lap times were and line length, just out of curiosity? I always imagined that you were right out there as far as you could go at 70 feet on a model that big.
  Type at you later,
    Dan McEntee

Yes, I am on 70's, and it is big
Lsp times were 4.8 to 4.9  many times. At over 100 ounces  that becomes oppressive.

[Paul Walker]

   Didn't the first one fly a lot slower than the W/C airplane?

      Brett

A lot...no...some...yes.
It had engines on tanks  and could power up a little in maneuvers, thus allowing somewhat slower lap times. Plus that was the lighter of the two, at least when new.
 The sound might have helped as well.

[Dan McEntee]

Yes, I am on 70's, and it is big
Lsp times were 4.8 to 4.9  many times. At over 100 ounces  that becomes oppressive.

     You don't say!! I only got to see you fly one of them at a NATS, ( not sure of the year, Sean was flying Senior then) and I could tell that it was pretty intense!! I have flown some of my own at 70 ounces and that's manageable. I had Walt Brownell's Typhoon that while the airframe only weighed in the upper 50 ounce range, by the time I added in the OS .70 four stroke, prop and such it got to about 82 ounces. The airplane turned quite well for that weight, but it had to be flying at exactly 5.2 seconds on 70 foot lines for it to be some kind of comfortable to fly a pattern. I had a heck of a time trying to find the right prop and I'm not sure I did. That plane is hanging in someone's hanger now. I still want to do a twin and have a Sheek's Mosquito in mind, but I'll leave the four engine stuff to you more adventurous guys!!  Thanks!
   Type at you later,
     Dan McEntee

[Ken Culbertson]

The sound might have helped as well.

There is always this:  3.5grams (that does not include the grain of salt) 

https://www.aliexpress.us/item/3256805556941544.html?gatewayAdapt=glo2usa4itemAdapt

I am curious, in the last picture it appears the inboard nacelles are mounted but the outboard are not.  If they are mounted how will the covering attach?  Never mind - I was using a low resolution for the pix.  Expanded I see the place for the covering.

Ken

[Paul Walker]

There is always this:  3.5grams (that does not include the grain of salt) 

https://www.aliexpress.us/item/3256805556941544.html?gatewayAdapt=glo2usa4itemAdapt

I am curious, in the last picture it appears the inboard nacelles are mounted but the outboard are not.  If they are mounted how will the covering attach?  Never mind - I was using a low resolution for the pix.  Expanded I see the place for the covering.

Ken

They are all there. I can see them in that picture.

What is missing is the forward fuselage. One last mould in work for that.

[Doug Moon]

     You don't say!! I only got to see you fly one of them at a NATS, <<<
     Dan McEntee

We were there that year too. Me and Bob G were sitting off the edge of circle 4 in the grass and PW is getting ready for a practice flight. Bob says "I cant wait to see this..." Grinning ear to ear. I'm saying the same thing as this would be my first time to see it fly.  Flight starts like clockwork and looking solid at 4'. Over the top for the RWO and out at 4'! As it comes by Bob says in a very surprised voice "I thought for sure that rudder was coming off at 4'!" He was chucking like a little kid, me too.  We both intently watched the whole flight as were many others. After it was over he shook his head and smiled real big. We watched alot of other flights that day from that spot but that was the flight that got the most reactions and comments out of him. He really liked watching that plane fly, I did too. That is one of my favorite nats memories and there are many but that one stands out pretty good. Thanks.

[wwwarbird]

Lap times were 4.8 to 4.9  many times.

 It's a C/L "Combat" plane though, the ones I've seen are way faster than that! 

[wwwarbird]

At over 100 ounces  that becomes oppressive.

 100 ounces at that speed is COOKING! 

 I can sort of relate, my PBY is 82 ounces and ended up real happy on 68 foot lines. That gave lap times around 5.2-5.4. It was a really fun airplane but definitely demanded your attention. I didn't consider it oppressive, a VERY firm pull, but with the four-strokes it was consistent and quite manageable. Mainly, before giving the signal, I just had to be doubly conscious of establishing a good solid grip on the handle. Not a "panic" grip, just firmly and comfortably situated. From there it rolled out like it was on rails and gave a helluva ride!

[Paul Walker]

It's a C/L "Combat" plane though, the ones I've seen are way faster than that! 

Yes, but they don't weigh over 100 ounces!

[wwwarbird]

Yes, but they don't weigh over 100 ounces!

 You got me on that one! 

[Ken Culbertson]

How is the project coming?

Ken

[Brett Buck]

Update.
All 4 nacelles made. Next step is to make the fuselage.

Just that simple......

    I just looked at the wing carefully - that's some airfoil you got there!  That makes my wing look perfectly normal and reasonable. Scale is a NACA 0018, that looks like a NACA 0028.

      Brett

[Paul Walker]

Status update.
All ink lines done. Awaiting weathering. Then clear.
Hope to make it it GSSC in Oct.

Brett, the chord is rather long where the wing looks so thick. Not at all  28%.

[wwwarbird]

 Awesome. What's the nose art?

[Ken Culbertson]

This is by far the most impressive stunt ship I have ever seen.  I hope it flies as well as it looks. 

Ken

[wwwarbird]

This is by far the most impressive stunt ship I have ever seen. 

Ken

 You've never seen the world famous IC version? Coolest Stunt model of all time IMO. 

[Paul Walker]

Awesome. What's the nose art?

It is modeled after the "Knockout Dropper. Flew 75 missions. One of only two to have survived from the first deployment of B-17's in England.
So the name is there with a "Dropper" dispensing bombs.

[Paul Walker]

Here is nose art.
This is prior to all ink work being finished on nose section.

[wwwarbird]

 Nice, commemorating actual history. 

[Ken Culbertson]

You've never seen the world famous IC version? Coolest Stunt model of all time IMO. 

I have seen the pix and several videos.  This one is still #1.

Ken

[Claudio Chacon]

Another stunning, awesome plane, Paul!
Which is the projected weight?

Thanks,
Claudio.

[Dan McEntee]

Here is nose art.
This is prior to all ink work being finished on nose section.

     If you were to look at the old magazine from the WW-II period, they always had several plans for several kinds of models. There was always a plan for a solid scale model, and the plan showed that window and opening details were just dark patches like this, as for a solid wood model there was no way to make 3 dimensional lazed windows at that time. I have always found that kind of old school neat looking, the way the were presented in the magazines. Looks like it might have just jumped out of the pages of Air Trails magazine! 75 missions was quite a record, and I wonder how many original crew members made it that far? I think it was 25 missions before being rotated home for crew members in the early days of the war,  but that requirement increased as the war drug on.
    Type at you later,
  Dan McEntee

[Ken Culbertson]

I think it was 25 missions before being rotated home for crew members in the early days of the war,  but that requirement increased as the war drug on.
    Type at you later,
  Dan McEntee

My uncle flew some B-17s and mostly B-24s out of Italy and Libia in WWII and B-26s in Korea. He was a navigator/bombardier.  He kept a fuse safety pin from each mission in WWII.  I counted 46 but he was still deployed when the war ended so I think you are right.  I think he flew somewhere around 50 in Korea.  He never got over the low-level strafing and napalm missions in the B-26.  My father was on a destroyer at Normandy and his other brother was a tank commander with Patten.  All three came home without a scratch.

Ken

[Paul Walker]

Another stunning, awesome plane, Paul!
Which is the projected weight?

Thanks,
Claudio.

Around 70 ounces.

[M Spencer]

Cant complain at that .     

[Doug Moon]

I'm curious how you paint it. I have been using a paint stand for my models forever. But this one has no center motor mount??

[Paul Walker]

I'm curious how you paint it. I have been using a paint stand for my models forever. But this one has no center motor mount??

Good observation. The main fuse/wing assembly has to be done one side at a time.  It sits on a "table" with foam over it covered by a picnic plastic sheet all held down by clamps. 
The nacelles are not strong enough to cantilever it like a normal plane. I knew this problem was coming, but put off the solution until I couldn't procrastinate any longer...

[Paul Taylor]

I found the nose art!!!!

Norm Faith worked on the restoration years ago when she was still in Memphis.