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Start Date March 30 2013
Back in the 1970's I was always reading Flying Model magazine. It seemed that every month Jack Sheeks had a new airplane in it. He quickly made a impression on me. I finally got to meet him in person in 1990. I didn't put 2 +2 together until now.
In this forum somewhere I built a 11 day Ares and it took many concourse trophy's for classic. Built in 11 Days. It was all because of the I beam construction. This is why I mentioned Jack. 99% of his planes were beamer's.
So last night I was looking at my shop trying to figure out how I could make a mess in the clean area. So I thought a derivative of a Crossfire is in order. I started cutting a kit for it. I almost cut the end of my finger off stripping wood but I still press on. So far I have the Stab and elevators,Beam all the ribs cut and No I am progressing to the fuse. I will post pictures in the electric section and the building section. I figure with the speed of this it should be all framed by next Sunday.
I am using the Bob Hunt hard nose mounting system in this.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30968.0;attach=124241;image)
Stab and ele weighs 2.5 OZ. My target weight finished and ready to fly is 55 OZ.
Here is the jig I made to cut this project. I should have everything finished cutting today and start assembly tomorrow.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124243;image)
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Explain the rib jig a little more. I remember Jack and his "beamer of the month" and have met him several times. Got to sit at the same table with Jack, Bill Netziband, Allen Brickhaus and Gary Hajek at VSC banquet one year. Got a few of his plans also.
When you get the chance, demo the jig a little bit.
Was that you out at Buder a couple of afternoons this week? Saw someone down on the square pad but could not tell for sure.
HAPPY EASTER!
Dan McEntee
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I was not me. I am still waiting for the weather to break. Here is a shot of my fuse doublers in its mold. Also shown is the finished beam. Weight is 2.5 OZ
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124245;image)
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here is one way to cut beamer ribs. First you make a template and the thickness of that template dictates the thickness of the ribs. shown here.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124249;image)
Cut wood to legnth and rest on the fence. Cut first from the bottom and move the wood down. You then cut the next line.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124251;image)
I cut 50 ribs in about 45 min.
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Very cool Sparky, you're starting to crank them out again.
James
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I will build at least 3 this year
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Mine looks like this
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I was told that I-beam wings are very hard to sand out because of the risk of cutting through the covering as you sand around the ribs.
That doesn't compute with an 11-day build.
What's the story?
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the trick to I beam wings is how little sanding you can do. Make everything perfect so you don't need to sand much. Best advice is buy the I beam wings tape from Bob Hunt. I built many before watching this tape but it helps to watch a master at it "Billy Werwage".
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Before building my Cobra, I watched the video of Bill Weredge<sp?> building an I-Beam. I had no problem sanding through on the wings, the only place I sanded through was on the rudder. I guess after breaking EVERY rib in the wing at least once building the plane I became just gun shy enough to not sand through!
Pat
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In the first day (although a long one) I have all the parts ready to assemble. Getting some sleep now so I can start on it in the morning. I should have the wing in the fuse tomorrow.
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Did you see he also did the top and bottom blocks/moldings of the fuselage before starting the wing peices into the fuse. If you want a challenge, do his Staggerwing. Two wings one fuselage.
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First pic of second day of work. Should have a complete airframe today.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30968.0;attach=124277;image)
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Today was a little slower than expected. I only got one wing done. I had a heck of a time jigging this plane as my equipment was not set up for it and my glass table is too small for this large of beam wing. But at Easter dinner I figured out how to handle it. So here is a picture of the progress. Tomorrow I should be on tract. Still not too bad for 3 days work.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124313;image)
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Lookin' good! y1 This will be neat to see, the I-beam mod will really give the Crossfire a Classic look when it's finished.
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Well I changed the numbers some so we shall see how it goes. Bad or good it keeps me busy.
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Looks great Robert.
Marcus
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Robert,
TE is swept forward. You'll use two control horns, correct?
Looks good!
Charles
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Robert,
TE is swept forward. You'll use two control horns, correct?
Looks good!
Charles
No and no lucky box either.
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No and no lucky box either.
Charles, I can't be sure what Robert is planning. However, if you read posts here on the subject and if you think about it (and maybe even experiment), you'll find that if the sweep is mild enough you can firmly affix the flap horn to both surfaces and count on the springiness in the system to absorb the angular mismatch. Things that would never work if you were using infinitely rigid materials become possible when you use spring steel.
It will have a slight tendency to spring to the center, or possibly to a pair of preferred spots on either side of center, but if the sweep is mild enough that spring will be lost in the noise of the other control system forces.
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Here is the beamer at 4 days. It weighs 12.5 oz total as seen.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124323;image)
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Robert, when you get to the point of putting in the root ribs, and again when you cover that area, could you make sure to takes some detail shots of that area?
Thanks in advance. Curious eyes want to see.
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Robert, when you get to the point of putting in the root ribs, and again when you cover that area, could you make sure to takes some detail shots of that area?
Thanks in advance. Curious eyes want to see.
I'd like to see that too. y1
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Robert,
Looking good!
I apologize for the off topic question.
I'll be purchasing the NAPA gray primer you recommended.
What grade paper do you scratch the surface up with before you spray it?
Charles
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Robert, I've been considering doing an I beamer for my next ship, but I ran away when I was trying to figure out the geometry of the ribs.
Considering that you're cutting the trailing edge off the rib for the taper, does that mean that if you start with a leading edge butt joint in the vertical plane, does that then lean back as you trim the trailing edge off the rib? Do you resand the LE back to square or not worry about it?
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Robert,
Looking good!
I apologize for the off topic question.
I'll be purchasing the NAPA gray primer you recommended.
What grade paper do you scratch the surface up with before you spray it?
Charles
Any paint job is in the sanding so I sand up to 400 before prime and sand primer with 600
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Hi Tim, I have to disagree with you on the spring back bit. I did one wrong and it did spring back, but during the over heads and in the four leaf and gave me fits until I realized what I did wrong. The TE inside the fuselage, as stated else where, is in fact a straight line TE so there is no spring back, just free controls. H^^ D>K
I know that you and Robert have both said this, but if there are two distinct hinge lines then there is going to be a need for flex that will have to be absorbed someplace. Maybe with a rigid assembly the flex and the springback is slight enough to not be noticeable, but unless all the hinges are on the exact same line, there is going to be geometry-induced flex, and hence geometry-induced spring. Sanding a flat in the TE where the horn affixes won't obviate the need for flex, but it will certainly make the controls smoother.
Perhaps the terminology problem is that you're speaking English and I'm speaking Engineer, where anyone who's been in the biz for any length of time knows that there is no "perfect". There is only "good enough" and "not good enough", and often "detectable" and "undetectable", but perfection is just a dangerous illusion that makes you spend money on unproven technology that bites you after you've spent a bunch of money and now need to ship a product with deep built-in problems. Moreover, most engineers have been in situations where someone is insisting "no! it is perfect!" about a part that ends up being a source of very expensive problems.
So engineers don't use the words "perfect" or "none" without qualification unless they are quite aware that they are speaking hypothetically, engaging in hyperbole, or are outright dreaming.
I'm perfectly willing to believe that you have built wings with swept trailing edges and no detectable spring-back, that had an effect on the airplane performance that was not apparent given the magnitude of all the other forces involved. But you can't sweep a TE, rigidly affix a horn to your two flaps, and not have some springback, however thoroughly you might fail to notice it, or however thoroughly it may fail to affect the flight of your plane.
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Hi Tim, I have to disagree with you on the spring back bit. I did one wrong and it did spring back, but during the over heads and in the four leaf and gave me fits until I realized what I did wrong. The TE inside the fuselage, as stated else where, is in fact a straight line TE so there is no spring back, just free controls. H^^ D>K
That's not sufficient, just because it is straight where the horn is doesn't mean you get no spring from it. It might be negligible, but you still need the tails of the horn to most relative to the flaps to get *no* spring.
Brett
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I use a square to make the tang on the horn 90 degrees to the trailing edge. Its close enough to be undetectable. So if you don't feel it its not there so it must be perfect. This has always been a problem with engineers. That's one reason Burt Rutan was able to go into space from a junk yard. He didn't need a over engineered $5000.00 door handle he just used car parts to do the same job, that were close enough.
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I have also built several ships with a swept forward TE and used a single horn with absolutely no ill effects. I also know that two World Champions and another gentleman with a second in the World Championships who do the same. Billy Werwage (Ares, Juno), Bob Hunt ('80 Genesis and Crossfire) and Al Rabe (Bearcats and Mustangs). All use a single horn with apparently no ill effects. It is so insignificant that there is completely free controls.
I am presently working on Pat Johnson's P-47 (the big one) and it has dihedral with only one horn. Doesn't seem like it should work but it does.
BIG Bear
RNMM/AMM
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The center section is three 1/2 in ribs glued together then fit to the fuse. Easy, I usually only use one 1/2 rib but this is a larger model and I don't need any accidents in the covering while handling so I used 1 bay thickness. 1.25 width.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124375;image)
Leave them out until top blocks or molded shells are sanded to shape so you don't beat them up.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124377;image)
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I have also built several ships with a swept forward TE and used a single horn with absolutely no ill effects. I also know that two World Champions and another gentleman with a second in the World Championships who do the same. Billy Werwage (Ares, Juno), Bob Hunt ('80 Genesis and Crossfire) and Al Rabe (Bearcats and Mustangs). All use a single horn with apparently no ill effects. It is so insignificant that there is completely free controls.
I am presently working on Pat Johnson's P-47 (the big one) and it has dihedral with only one horn. Doesn't seem like it should work but it does.
BIG Bear
RNMM/AMM
Bill,
My last Stiletto can also be added to your list. Randy Smith has the plane now but "shrinkage" has the controls pretty well stuck, however, they worked good enough "back in the day".
Oh, and it's great to watch Sparky build a beamer, these things just have a certain look and appeal. You can build wings stronger and more accurately in other formats but for pure sex appeal------
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Oh, and it's great to watch Sparky build a beamer, these things just have a certain look and appeal. You can build wings stronger and more accurately in other formats but for pure sex appeal------
Many are intimidated by this type construction but in my opinion they are by far the easyest to build and get straight. I am working on the hardest part today. The sanding of the LE and TE. Very slow going. I will post a picture later.
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Bill,
My last Stiletto can also be added to your list. Randy Smith has the plane now but "shrinkage" has the controls pretty well stuck, however, they worked good enough "back in the day".
Oh, and it's great to watch Sparky build a beamer, these things just have a certain look and appeal. You can build wings stronger and more accurately in other formats but for pure sex appeal------
Thanks for the information, Les! So I can add another World Champion to the list. I was not aware that your last Stiletto had a swept forward TE.
Thanks, again!
Bill
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I love this kind of construction (not that I am anybody that matters! Lol!) And it has been great hanging out with Bill Little and getting his input and help on my Colossus! Took my daughter to Bills today, and now she REALLY has the bug! She wants to build a copy of Bills Vulcan. No petty little trainers for her! Thanks a ton for everything Bill!
Pat Maset
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Thanks for the information, Les! So I can add another World Champion to the list. I was not aware that your last Stiletto had a swept forward TE.
Thanks, again!
Bill
HMmmmmmm I did, i knew that...umm imagine that :-O ;D ;D ;D ;D ;D ;D ;D
Randy
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Well no pics today sorry. It went kind of slow today. I just finished sanding the LE took most of the day. I am also working on barnyard engineering a landing gear mounting system. SO maybe tomorrow some pics. Stay tuned
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Well no pics today sorry. It went kind of slow today. I just finished sanding the LE took most of the day. I am also working on barnyard engineering a landing gear mounting system. SO maybe tomorrow some pics. Stay tuned
Really looking forward to seeing how you shape the LE and TE and want to see your tools and tricks. The input of others with some experience in this would br good too. This is a mystery to me and seems like you would want to taper the TE before assembly. This stuff was not covered in the Werwage video. Anyway keep posting. Might be nice to have an I beam forum.
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Bill,
My last Stiletto can also be added to your list. Randy Smith has the plane now but "shrinkage" has the controls pretty well stuck, however, they worked good enough "back in the day".
Oh, and it's great to watch Sparky build a beamer, these things just have a certain look and appeal. You can build wings stronger and more accurately in other formats but for pure sex appeal------
Les
How did it fly? Would you build another this way?
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Les
How did it fly? Would you build another this way?
Les won a World Championship with the plane...so it flew pretty well 8)
Randy
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Les won a World Championship with the plane...so it flew pretty well 8)
Randy
My bad. I thought less won all of the WC with the 660 that was published in MA. So I guess it did fly pretty good or Les flew it pretty good. I ask cause people seem to get worked up about the benefits of the tapered TE.
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My bad. I thought less won all of the WC with the 660 that was published in MA. So I guess it did fly pretty good or Les flew it pretty good. I ask cause people seem to get worked up about the benefits of the tapered TE.
"Benefits" of the swept forward TE? I have heard Paul Walker say "Never again!", but then he did it again, with the 2nd B-17 Stunter. I asked why; he said they were harder to trim. That's good enough for me, but y'all do as you please, because that's what this hobby is all about. Just make sure you can do the same thing twice and have the same results, please! H^^ Steve
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Something I learned a long time ago when building a I/Beam is to sand the trailing edge before installing it. It only takes 30 minutes if done in advance but doing it in the plane can take a long time and breaking ribs is a problem. I now use a built up trailing edge that looks like a 1/2x1/2" but is much stronger and straight.
Ed
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I do not pre-sand anything. I use no fixtures or special tools. I use a light and sanding block. First I rough carve it and then finish sand to shape. This takes time. So that's why the pictures are slow coming in. I had to barnyard engineer the landing gear mounts and shape the LE. Tomorrow I will shape the TE. and start the tips. I am still thinking on how I want to attack that. Should they be a solid block or more like a conventional I beam wing tip.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124509;image)
I was going to make this a quick build but its not in my nature to have a shabby looking plane. I have decided to make it a front line airplane. Notice I didn't say front row. I have made my mind up to do this plane all old school. Silkspan and dope. No Urethane. So that leaves off 2 oz and the airframe by a guess will be 8-10 oz lighter than my foam one. This is all a guess so don't bash me yet on weights. Ill keep you posted. But as of now the plane with no top or bottom shells is 12 OZ including stab. So almost a whole plane weighs as much as just a wing. So I figure 2 oz more for flaps and 1.5 OZ in pushrods. 3 oz top and bottom shells and .5 in a rudder we are looking at a 19 oz airframe. add 4oz. to be safe and that's a 23 oz airframe. We shall see but I think it will be close to that ready to cover. I hope its lighter but who knows. 23 +6 OZ finish and 20 OZ in electric hardware and I am looking at 49 oz plane. The finish will stop at 55. so I do have 6 oz of leeway.
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That looks great, Robert. I love the sexy look of an I-beamer. Probably why I keep building them. This plane should be a real beauty.
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The reason I like them is you can get them super straight and they are not lumber wagons. The build fast although a pain in the ass to sand well worth the trouble. For those who have never built on its the easyest to construct.
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Know that the VSC has an award for "Best I-Beamer" each year. Next: March 2014. Judge: Warren Tiahrt.
Time to get building and planning to attend.
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Well the hard part is done and I can move onto easyer things now. The weight is 473 grams or 16.5 with controls installed.
So lets project the finished weight.
16.5 airframe
2 oz flaps
3 oz shells
2oz gear
8 oz finish
20 oz hardware
51 OZ we know that is never works out exactly as planned so 4 oz leway for a 55 oz model. But I am shooting for the low side.
7 Days old
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124635;image)
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Robert
Would you post a top view pic of your flap horn installation??
I'll be building a swept forward TE (Rogue), and would like to see how you did it.
So far your barnyard engineering seems to be working great!!
When I'm done with all the builds I have here, I'll do one beamer, it looks fun to build one.
Thanks in advance.
Marcus
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Its not a big deal and don't let anyone tell you it is.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124639;image)
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124641;image)
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Thanks Robert.
I can see it clearly now...
Marcus
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Its all together and its 18 oz so far. Plus 4 on shells I am looking at 22 OZ ready to cover. However I am going to cover it tomorrow then put top and bottom on. I want to lock the wing up. I think its good progress for 8 days.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124759;image)
Flight report. Very troubling day today. I loaded my Crossfire into the car ,drove to the park. I set everything up and had Ted hold the plane. beep-beep and walked to the handle. Waited 30 seconds and the motor started slowly. I waved for Ted to launch. It did not move. Ted grabbed the airplane and I walked back to it. The motor was spinning maybe 1000 RPM. Long story short. The ESC had a corrupt file. This was found out after a call to Will D and working through the issue. Try again this week.
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Robert,
That is amazing! It takes me 8 days just to find all the tools I'm going to use. Truly a work of art!
Paul
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I see you bypassed the rear spar with the verticle peices. Your ESC problem is like me getting to the field and finding out the battery did not charge up on my pit box. Even the headlocks were down for some some reason.
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The rear spar offers little support and slightly more weight. I will be sewing in that area with Kevlar thread, It gets X out top to bottom in those braces. Weighs nothing.
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Really cool building.
can't wait to see the finished plane!!
Marcus
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Very nice and very fast, Robert. Wow.
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I will be concluding this build up to the finish in all Amped up section.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124867;image)
This is 11 days progress and I hope to have it in the air first part of next month.
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Some have followed in the building section my beam-er. Today I am mounting the motor and getting the nose section done. This build is 11 days ol and hope to see it in the air first part of next month. Finish takes the longest so we shall see.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124869;image)
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WHOAH!!! LOOK HOW CLEAN SPARKY'S SHOP IS!!! :o :o :o ;D :##
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WHOAH!!! LOOK HOW CLEAN SPARKY'S SHOP IS!!! :o :o :o ;D :##
Thats so I can get something done.
Today I put in the hardnose and sanded the canopy into shape.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124911;image)
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This morning I made mold bucks. Heres a few shots
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=124949;image)
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Hmm, must not be done building Crossfires. ;D
Just don't forget where you put the P-47 bucks! S?P
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Hmm, must not be done building Crossfires. ;D
Just don't forget where you put the P-47 bucks! S?P
It will be a long time before I build another one of the 47s Too draggy
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It will be a long time before I build another one of the 47s Too draggy
Maybe a variant...?
http://img.wp.scn.ru/camms/ar/350/pics/3_202_b1.jpg
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Okay, Wayne ...
more input, please! What was the nomenclature and back story on this critter?
Thanks in advance,
Dean
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Looks like the XP-47H. I prefer the XP-72
http://img684.imageshack.us/img684/8888/republicxp72.jpg
Looks "a little" more like a Thunderbolt to my eyes.
Nice ventilation around the edge of the spinner as well.
TTFN
John.
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I see your point, John.
Dean
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Its on its wheels took less than 2 weeks. Tonight I will add the last piece the bottom shell.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=125021;image)
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Lookin' good! y1
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Here it is all framed out and ready to start finishing. I will be doing a step by step finish how to in the finishing section. As it sits now complete with wheels its 23.5 oz.
(http://stunthanger.com/smf/index.php?action=dlattach;topic=30972.0;attach=125037;image)
Recap on the dates it took 14 days total to this point.
http://stunthanger.com/smf/index.php?topic=31150.new#new
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I'll be following intently...
Marcus
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Me too, will be watching. #^
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Great thread!
I've been away from the forum for about a week off and just noticed the earlier discussion of binding in swept forward trailing-edge flaps. Despite my own original scepticism, two comments:
1) Friends have bowed (like Al Rabe) connectors or bent their flap connector wires in a couple places, rather than a "V" in the center when not using "Lucky" boxes. They havent done Sparky's straight version. Their flaps have negligable centering forces on Sterling Yak-9's compared to mine with the stock part. One has barrel type hinges, and the flaps are quite free. My flaps with original "V" connector do bind and twist the flaps on deflection.
2) I examined Bill Werwage's '62 Areas at VSC 14, and his flaps were so free that they dropped of their own weight, and I could not feel the mechanical binding at all. The friction was truly negligible.
SK
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Were's the cooling? HB~> HB~> HB~> Z@@ZZZ Z@@ZZZ LL~ LL~ LL~ LL~ LL~ LL~
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As this project closes in the finishing section in less than 30 days I think back as to what was the hardest pert to do. I think I spent the most time on the leading edge. It took a full day to shape. Now after covering and finishing I think it was well worth the time. I only wish I would have paid more attention to the trailing edge. While its acceptable its just not perfect. So in retrospect I would take a day on mating the TE as well next time.