Yellow P-47 Build!!
 

Hi all,

I haven't seen any recent or popular Yellow P-47 builds on this forum yet, so I figured I'd start my own! My only other warbird experience is a rather short :( trist with a 1/7th Top Flite P-51, and I had such a good time putting that together that I thought I'd go back for more. I plan to use a DA-50 in this plane, and this will be my first giant-scale/gas build. I'm really excited about it!

The quality of this kit is amazing. The fiberglass work is just about perfect, with plenty of scale detail molded in. I love the way you can see through the polyester to the fixtures inside, this really helps when aligning and gluing items inside the fuse. The wing sheeting appears flawless. I think it would be hard to wind up with a poor flying model with just a bit of attention to the build process. Glass builds like this one sure reduce the variables vs a stick built plane, thats for certain.

Here's some shots of the early steps of this build. The cowl mounting and servo tray are attached with Hysol (Aeropoxy), as it sticks like crazy on the polyester fiberglass. Also, here's a quick video of the retract test.

http://www.youtube.com/watch?v=SgFm8rQ1mM8

More to come soon.

Regards,
George

RE: Yellow P-47 Build!!
 

looks nice george cant wait to see some more pic's on the build

RE: Yellow P-47 Build!!
 

Hi George, I just put a DL 50 in one of these and everything but the exaust tip fit insde the cowl. These are great flyers, you'll love it.
Aaron D.

RE: Yellow P-47 Build!!
 

One problem I had right off the bat was assembling the Yellow Aircraft wheels. They are a two peice aluminum hub that screw together to sandwitch a tire of foam. I finally figured out the following procedure to get the job done. Posted for reference if anyone has this trouble.

[ul][*] unscrew the two halves of the wheel hub from each other [*] test fit each side of the rim in the tire, this stretches the foam a bit and will ease final assembly [*] grease the threads of the two halves. [*] grease the surface of the *spokes* side of the hub on the inner surfaces where it would come in contact with the foam. dont' do this to the other, solid surfaced rim half [*] cut two wood dowels of about 1/4 inch diameter to a length of about 1.5 inches each. these dowels need to fit in the spokes of the hub [*] place the two dowels vertically in a vice, sticking up from the suface of the vice about 1/2 inch, and as far apart as possible while still being able to fit the spoke half of the hub onto your new "spanner" [*] insert the solid half into the tire, then the spoked half, then work them together until you can get the threads started. Be careful and dont cross thread them [*] place the assembled wheel spoke side down onto your vice/dowel fixture [*] grip the tire and solid hub half with both hands and begin to tighten clockwise
[/u]

RE: Yellow P-47 Build!!
 

One of these days I'm going to build one of these...I've seen them fly and they fly great - I'm subscribing to this thread :)

RE: Yellow P-47 Build!!
 

A bit of progress while waiting for my DA-50 to show up from Arizona (apparently by way of the Panama Canal). I've skipped ahead a bit and begun work on the tail. Got the stab leading and trailing edges shaped, along with the stab tips and hinge gap covers. Also finished hinging one half of the elevators with hinge points.

Regards,
George

RE: Yellow P-47 Build!!
 

Hi all,

Got the DA mounted today, and the various fixtures and firewall passthroughs completed and mounted. I had to switch from an inverted wrap-around style pitts muffler to a bisson inverted muffler, which is essentially a side box with downdraft tubes. There's just not enough room behind the motor for the pitts without removing a very large area of firewall. Anyways, it should completely fit inside the cowl without anything showing but the two exit tubes at the very bottom.. a nice scale look.

Also have the stab joined and ready for glassing. This bird is going together nice!

Regards,
George

RE: Yellow P-47 Build!!
 

Lookin good G

Aaron D.

RE: Yellow P-47 Build!!
 

George can you please give some more details about this airplane - things like wing span, length, advertised weight, price, where to buy?
the wings are foam sheeted with balsa, are you gonna fiberglass them?
It sure looks appealing not an arf but also not giant scale two year build.

regards
Alex

RE: Yellow P-47 Build!!
 

Yellow Aircraft are ARFs....which means Almost Ready to Finish :):):)

RE: Yellow P-47 Build!!
 

This should tell you pretty much everything you need to know.

http://yellowaircraft.com/props/p47.htm

It is a foam sheeted wing/stab (already sheeted). Yes, the foam parts need to be glassed and painted. I'd say this build is going very nicely so far, but thats just the kiss of death lol :)

Regards,
George

RE: Yellow P-47 Build!!
 

Hi again!

Progress is good. I've got the servo trays installed for the tail and the throttle. I've relocated the fuel tank to the throttle servo platform so it is close to the CG, and I'll utilize the stock fuel tank location for the ignition components. I plan to use an A123 2300 pack for ignition, along with an opti-kill switch. That plus the DA ignition module will take up most of that space.

I've also got the stab joiner provided for and the dowls glued in. And lastly one side of the stab center section glass.

Regards,
George

RE: Yellow P-47 Build!!
 

Lots of progress in tonight's update. I finished glassing the stab using .75 oz cloth and Z Poxy. This was my first experience glassing an airframe and it came out surprisingly good. I attribute this to a couple *excellent* tips I got off other threads on this topic. The first of which is the clothespins. These have just the right amount of mass to pull gently down on the cloth and help it to smooth out around the edges (along with some strategic slicing of the overhanging cloth). Second is the use of a roll of toilet paper (!!) to use as a combination roller and sponge. Just keep rolling it over the surface once your glass and resin are down and smooth. The TP soaks up the excess resin and helps make a bubble free contact between cloth and wood. It's genius, and I never would have been smart enough to come up with that on my own.

Next, I mounted the retract air can on the side of the fuse by creating a couple of cradles made of 1/8 light ply and 1/4" balsa square stock. Hysol'd to the fuse and lined with clear silicone for the tank.

After that, I got the stab inserted in the fuselage, aligned and glued down. I used hysol on this, injected under the fillets using a very small tip, and worked into the back of the fillets from the tail gear door well, using a really long tip. It should be strong as heck. Two tips for those working on this step:

1) The stab is really hard to insert into the cutout, as it tapers from tip to root. Hard that is, until you realize that the cutout can be "flexed" quite a bit by grabbing the vstab and bottom of the fuse, and gently spreading them. You can generate just enough extra clearance to get the thing to slide in without effort. This technique should be in the manual!

2) The stab is too deep (chord wise), such that the back of the rudder post doesn't quite line up flush with the trailing edge of the stab. I had to hollow out a small radius in the back of the stab to allow the rudder to have one straight hinge line from the top of the rudder post, through the stab, and on to the bottom part of the rudder post. See the last pic for a sample.

Enjoy!
George

RE: Yellow P-47 Build!!
 

I have one of these in the box waiting for an appropriate time to start it, you are finally giving me the incentive I need. Nice work, keep documenting your build, it will be useful. I plan on using the same engine, muffler combination as well.
Tommy

RE: Yellow P-47 Build!!
 

Tommy you stinker.......one NIB - holy cow!!!!!! You never told me (sniff sniff)...NOW is the time to start - or, if you want to wait, SEND IT TO ME and I'll 'start' on it for you :):):)

Jerry

RE: Yellow P-47 Build!!
 

Got a great deal on it a year or so ago from a guy who bought it and changed his mind. It was too good to pass up.

RE: Yellow P-47 Build!!
 

Well the fuselage is pretty much complete, so I've moved on to the wings. It is here that I hit my first snag. It seems that the foam cores for the left and right half are not the same width of chord at the tip. They are the same at the root, however, as evidenced in the first two pics. This became obvious when I was test fitting the wingtips, as the first tip was a perfect fit, and the second had about a 1/8th inch overhang on the leading edge when the trailing edge was lined up perfectly. To resolve this, I've added a 1/8th wide strip of balsa to the leading edge of that wing, for about the outer 2/3rds of the span. I'll have a fun time trying to make that one perfect taper from root to tip, im sure :(

Additionally I've noticed that there are some other subtle assymetrical features of the two halves, like where the various embedded spars and holes are at the root. So in short, the foam work on this kit does not live up to the quality of the glass work. Oh well, not a huge issue... i hope...

RE: Yellow P-47 Build!!
 

Aileron hinging has begun, and this is a rather complicated setup on the Yellow P-47. First off, due to the anti-flutter provisions built into the kit (notably the lead weights in the aileron leading edge) the instructions call for a very specific hinge pin location. The aileron should pivot at a point about 1/2 inch back from the aileron leading edge, which is quite a bit farther back than most applications require. This leads to deep wells for the hinge to swing the proper degrees of deflection, and a deep relief that needs to be cut out of the aileron leading edge. Also, there's a need to sleeve the wing side of the aileron hinge with a 2 inch piece of 7/32nds brass tube. I assume this makes the hinge strong and rigid enough to cope with this installation.

Note that the plans do not appear accurate and were probably drawn prior to the change in design to this hinge method. They don't seem to me to show nearly enough depth to the hinge pivot point.

The final two pics show the results of my wing leading edge "adjustment". I was worried about this one, but it turned out just fine.

Regards,
George

RE: Yellow P-47 Build!!
 

Few more items done... I've gotten the flaps hinged, although this was a pain. The fact that the flaps are bottom hinged, and that it seems sensible to angle the holes into the wing and flap into the core of the surface, made it hard to line up the holes vertically and get a nice edge. I wound up with enlarged holes in several places, which will require quite a bit of epoxy at hinge time to sort out. It will work out fine in the end, but I'm not happy with the technique.

Also started on the flap and aileron servo bay work. Doors are made and installed. I'll make up a mix of epoxy and milled fiber to form a fillet under each of the sqare hatch mount blocks to beef them up a bit.

Regards,
George

RE: Yellow P-47 Build!!
 

Looking good.....keep up the good work..which retracts are you going to use?

RE: Yellow P-47 Build!!
 

I've got the Yellow retracts. They look and work really nicely.

RE: Yellow P-47 Build!!
 

We'll I've made my first real mistake so far on this build. Note the image below. The double-thick rib moulded into the flap is that wide so that it can accomodate both the hinge and the flap horn. The intention is to drill the flap hinge off to one side, leaving room for the horn along side it. Trouble is, I chose which side to favor the hinge using the plans... which are showing the bottom surface... a fact that I missed. As a result, you can see that the horn would like to be directly behind the flap servo arm, but mine is offset 3/8th or so. No huge deal, but if you are building one, pay extra attention to which side you drill the hinge on. Use the cutout for the servo pocket to guide you to the correct side!

-G

RE: Yellow P-47 Build!!
 

Mistake behind me now, I've made some nice progress. I got the Bisson muffler installed and the cutout made for the exhaust tubes. They are unobtrusive on the very bottom of the cowl. I might cut them off some to keep them even less noticible... not sure.

Also, I've lined the wheel wells with plywood. The instructions call for 1/32nd, but I had 1/64th handy and went with that instead.

Finally, you can see the 1/4" dowel installed in the control surfaces with a 4-40 threaded hole in the middle of it. I found this very difficult to acheive without a drill press! Next stop: wing joining!!!

Regards,
G

P.S. In the second to last pic, if you look closely at the servo pocket, you can see the four square ply mounting blocks with 4-40 holes it them. These secure the servo hatch to the wing, and those hatches have the servo's mounted in them. I wanted to make sure the blocks don't loosen, so look close and you'll see that I've made a fillet of epoxy and milled fiberglass under each of them. Should hold.

RE: Yellow P-47 Build!!
 

Nice job on the wheel wells....what filler did you use along the joints?

RE: Yellow P-47 Build!!
 

Tks! It's good ol' epoxy + microbaloons. I had some small gaps that I wanted to glue as well as fill. For any further filling I'll probably just use balsalite.