Isllewis-RCU on te ailerons you are suppose to cut off enough foam to accomadate the leding edge balsa. Sheet shape and put the hinges in. After you do that they should fit like a glove in the aileron openings. Of course you have to trim the ends also so they will fit in the cut outs. Also before you sheet the ailerons make a small pocket where you plan on haveing the control horn and epoxy a piece of lite-ply one inch square for the controle horn. Then sheet the aileron and shape.

Thanks nchrome,

I have moved along some the ailerons and flaps are done, I need to install the hardwood block for the control horn, but I have waited to get the servos in the wing so that the alignment is correct. The starboard wing panel is shown in the picture, the port side has the servos installed (dry fit).

Just about to glue the aileron hinges in the wing and remembered the CA glue eats foam. Oops. The hinges are designed to be glued with CA. New hinges?

Nope, searching RCUniverse I found they make "Foam Friendly CA glue" On my way to pick up Maria and in a hurry I stop at the LHS. The guy that runs the place knows everything and has the glue faster than the eye can see. Cute gal rings up the cost; 20 grams $9.00!!!!!!!!!!!!!!!!!!!!!!!

I focused on the wing panel, cut the hinge slots in the wing, aileron and flap. If I had realized Tower has the GP Slot Machine for 20 bucks I would have done a lot better job. It is now on my "Wish List." The Du_Bro slot thing is not adequate. I embedded the hardwood for the control horns, pinned the hinges in the wing. Pinning the hinges in the control surface did not work out, there is not enough material.

As the photo will show, I covered the edges, flaps and ailerons. Cut away some of the Monokote to be sure I got CA in the slots. Question: Are you ever sure?

This minor step in the construction of the 7th Chadwick took the better part of the day. I was in and out of the house twice, Maria's car was in for routine maintenance. Why does "routine" maintenance cost $300? It was an overcast and dull day here in Southwest Florida, yet very comfortable outside and it beats the H... out of Snow.

Question 1. - The front of the nacelle hangs on the wing and the rear is held by the TE. The majority is glued to the balsa sheeting on the underside of the wing. It seems to me that this design is working in shear to pull off the sheeting and delaminate the wing. It seems to me that the nacelle load should be transferred to the top of the wing and put it in compression.

I think a 1/8 inch wood dowel going through the wing, attaching to the topside sheeting, or maybe a secondary rectangle of balsa (to spread the load) would be a good modification. The top side of the wing above the nacelle is hidden by a plastic covering.

Quesstion 2. - For installation of retracts the nacelle bulkhead moves forward 1 inch. Yet the retracts do not clear the aft bulkhead by 1/4 inch. Why not move the bulkhead forward 1.25 inches? Drawing attached

Your advise and experience will be appreciated.

I thought I was the only one addicted enough to start building that early in the am. 6:43 am? On the weekends I do try to be in the shop at 6:30, The noiseless enviroment is great. Nothing like a smoke, a cup of coffee and a pile of balsa to get you going!

I am not an experianced builder so take this comment just as an observation. I you moved the bulkhead forward 1/4 of an inch further so the LG would clear the aft bulkhead, wouldn't that affect the CG, Both for ground handleing and flying? I t seems to me it would shift weight towards the tail on the ground but then as soon as you lift off the increase would shift forward. Both with gear down and up.

Would this make it more difficult to balance?

Sorry to answer a question with a question. I guess I just assume that the designers (engineers?) take all of this in account during the design phase.

Forfun42us,
Thanks for your observation. First, I generally do not like to change a design. I spent a bunch of years designing electronic equipment and I have a rule not to second guess the designer. It can be dangerous. As a consequence I am asking everyone that might know.

I believe you are correct it will move the CG forward but this model tends to be tail heavy so I do not think that will be an issue.

If you move the gear mount forward, the location of the extended gear will move closer to the CG, and will reduce the amout of actual weight on the nose gear at rest. It also make the plane hard to handle on the ground, as the nose wheel steering does not work as well. Nose wheel tends to loose contact with the ground, before enough speed is achieved to make the rudders effective. I found this out the hard way on my wing P-38.

Thank you Terry. Discretion is the better part of valor. We shall install the bulkhead as designed.

Terry your rite except that if you flly a war bird you should always use the rudder. Besides if you attatch the nose gear to the rudder like your suppose to then they work in tandum. If your having that much trouble then put a little down in the elevator while you taxi or will you are building up speed. Should solve the problem. On most warbirds you shouldn't yank them off any way. You let them fly before you put in any elevator cause airspeed is your friend horse power doesn't always save you. Especially on a P-38 and a Corsair. Another thing like Twinman said RELIABILITY IS MANDATORY.

Read the post.

The information for building the hatches for the nacelles is minimal. There are two bulkheads (H1 & H2) for the ends of the hatch and cross sections one at H1 the other at H2. They are so close to identical they are of little help. Your left on your own to figure out how to build them. Thanks to the inventor of Hobby Lite Filler they look better than they are. The hatches are on the bottom of the nacelle so they will not be too visible, but there should be a better way to build them. The real question is "What are they for?" The only access they provide is to the fuel tank, not something you normally need, but nice. For this electrical version there will be access to the wiring.

The plans call for planking the remainder of the nacelle, this is the area where the LG is located. Seems to me if you need access to anything it is the LG mounting and in the case of retracts the retracts themselves. So we are trying to bash the aft covering into a hatch. In our case we want to have access to allow us to change out the fixed gear and install the retracts. Or visa versa. If you have read all of this thread you will know we are worried about the 10 oz. the retracts add to the wing loading. As this will be electric weight is extremely important. As an inexperienced warbird pilot we would like to keep the wing loading down so we might be able to fly her.

The picture shows the forward hatches on the nacelles and the rough beginning of the aft hatch.

Larry:

Make the hatches as light as you can. They don't support anything but themselves, any extra weight does no good at all.

Pictured hatches are 1/16" thick, made of two layers of 1/32" balsa dampened and curved around a cylinder as they dried. The two layers are cross grained, their only reinforcement is another two plies of 1/32" at the edges. The heaviest thing about the hatches is the two screws that hold them on.

And yes, they are for tank and gear access.

Bill.

Wow!

Sure wish I had asked you how too first! Your hatches are beautiful. Your construction technique is brilliant. I hate the idea of rebuilding the hatches but...

I really did not want to trash all the work building the hatches for the nacelles. What I built following the plans was inadequate and today I gave up, I will re-do them. Monday I will go to our LHS and get the balsa I need to build a decent hatch. Designed following the procedures described by Bill. One for the forward equipment the second for the aft section.

I have to come up to a 1/4' wide side wall. So I will laminate two 1/16 sheets then add another 1/8 reinforcement along the edge. They will not be as light as Bill's but lots better that the originals. I weighed the four hatches and found they were pushing 2.4 oz and like Bill says they are not doing anything.

Meanwhile I started working on the nose cones. Found the center and cut clearance for the gear box. I should back up. I have already laminated a 3/8 inch plywood circle to the inside of the cowling. The electric motors will be mounted to the cowl, the front of the cowling that would normally be cut out was reinforced with plywood and fiberglass. The cowling will be held to the nacelles with substantial hardware. We saw this technique first with our electric Bonnie. It works very well and there was no trouble.

Enough for tonight!

Larry:

NO!!!! NO! NO! Do not use 1/16" wood. You do not have to make the hatch edges as thick as the side walls. And you are going to make them twice as heavy if you do.

Go ahead and use the 1/32" or if your LHS stocks it, 1/64" is even better. The 1/64" when cross grained is a lot stronger than you might think, and is still far stronger than needed.

Give me a day or two, I'll post some pictures and more explanation on how to make them.

Actually, I posted it all here about a year ago, but I wouldn't hope to find it now.

Bill.

OK! OK! OK!!! I consider myself severely chastised. So I bought 1/32 balsa per your instructions at the LHS. I have taken a couple pics of the nacelle to give you an idea of what is required. The hatch on the front covers the nacelle from the firewall N-1 to N-2 the LG mounting bulkhead. The remainder back to N-3 is to be planked. I want it removable for access to the LG and potentially the installation of retracts. The outside surface of the hatch must match the outside surface of the nacelle.

So how do I do this Bill? I am ready to cut balsa.

Two pics, one gives the overall nacelle, the other gives the detail dim.

Meanwhile I have made templates of the cowling mounting hole pattern. I am trying to get each assembly identical so cowlings, engines and nacelles can be interchanged. I have modified the original design to accommodate my electric motors. More on the motors in my next update. I added a 3/16 circular plywood re-enforcement to the front of the cowling, This is the area you would normally cut out for a glow engine. I fiberglassed the inside and have bonded the cowl to the exhaust flaps. The assembly mounts to the nacelle with 4-40 machine screws. The screws go through the spacers into blind nuts. I need to get some cooling air into the cowling so that modification remains to be designed.

Any ideas? Suggestions appreciated. The picture shows the inside of the cowl.

Larry:

Let's get you started.

We want the hatch skin to be two p[lies, with the grain of the two plies running 90 degrees one to the other.

The ply with the grain running the long dimensin is no problem, butthe cross grain one willo have to be made from edge glued sheets.

Dimensions: You didn'tnote the width of the nacelles, so all I can do there is guess. Lay a steel tape across the arc of the bigger former, add at least 1" to this measurement. We are going to make the skin blank a lot bigger than needed. much easier to cut to fit than add to one that's too small. If you measured, say 3 1/2" around the former. we'll make the raw skin 4 1/2" x 8" since two sheets of 4" width glued edge to edge will give the 8" length. And the 4" width will let us make the lengthwise grain ply from one piece. If you got 3" width (Sorry I forgot to mention the 4" width) make the raw skin 6" by 9" leaving the seam in the outer ply in the middle of the hatch.

PLEASE NOTE: DIMENSIONS HERE ASSUME 4" WILL BE WIDE ENOUGH!! If you find you need a wider blank, increase the size accordingly.

Using your 3" width, cut three pieces 4" long, and two pieces 8" long. Edge glue the three 4" pieces into one piece 4" by 9" with the grain running crosswise, parallel to the shorter sides. The 8" pieces are to be edge glued into one piece 6" by 8" with the grain running parallel to the 8" dimension.

Gluing these use a PVA glue, the "Old" Elmer's that is not waterproof. At this point don't use the waterproof aliphatics - when we form the plywood a waterproof seam will make the wood curve unevenly. Use aliphatic when we actually lay the plies up. You will want the assembly to be waterproof.

Looking ahead, you are going to need a waterproof cylinder with about the same radius as your finished hatches. If you should happen to find one long enough, you can make a long section of raw hatch skin and cut off lengths for each of the four you need. But it's easier to handle the smaller individual sections. The cylinder can be a butane cylinder, a spray paint can, even a glass bottle if it's the right diameter and has a long enough cylindric section. If all else fails, a heavy walled mailing tube can be used if you waterproof it.

I'll be back.

Bill.

PS: Drawing shows what you should have at this stage. wr.

I have the cross grain cut and edge glued I had to use 3" balsa as our LHS selection of balsa is all messed up. Wrong sizes everywhere. The outside ply with the grain running the long was is of 4" wide balsa and I think it will be ok. The nacelles width is 3" inches. And I have a form, almost gave up on that until I saw an empty quart bottle of Wildcat it is almost a perfect fit.

What's next?

Larry:

Next comes the hardest part of the whole job; getting the cross grained sheet to accept the curve.

Wet both plies, then form the cross grained ply to the cylinder you've chosen for a mold. This is the hard part, you might ruin one or two before you get it right. And for wetting the plies I generally use rubbing alcohol, some say an ammonia mix is best. The rubbing alcohol doesn't offend my nose so that's what I use.

Let's look ahead for a moment. You are going to lay the plies up on your cylinder, and let the glue dry while they are fastened to it, so you'll need to cover the cylinder with "Glue-proofer." Monocote liner, a plastic grocery bag, waxed paper, almost anything waterproof is fine. Cover your cylinder with whatever you've decided to use. I've used a grocery bag in the pictures.

Now back to the bother. Your cross grained sheet should have been soaking for a bit now, see if you can put it on the cylinder, with the long dimension in line with the center, and form the cross grain to the curve. Using the 1/32" wood it shouldn't be too hard, just take it slowly. It can help if you put it on a hard surface and help it by rolling a steel bar on it, push down hard. You'll compress the wood a bit, and help it curve to match the mold. See first picture - the grain doesn't show but it's at a right angle to the bar.

When you have the inner ply where it will curve to match the mold, do the same with the outer. It will conform more easily, but if you are careless you can still split it so be careful.

Now you have both plies roughly curved, and the mold, suitably glueproofed. Now, with both plies dampened, spread a thin layer of glue on the outer surface of the inner ply, and the inner surface of the outer ply. Use the aliphatic, waterproof, white glue this time. Put them together on your mold, and tie them down. I like to use nylon cord, and square sticks at the edges. The sticks keep from having a lifted spot between the strands of cord. You can also tape them down, or use rubber bands, anything to hold them together tightly. After you have them clamped, inspect the edges carefully, you can find the two plies aren't in full contact near the edges. Correct as necessary, and then let it sit for a day. See second picture.

Notes: The wood needs to be wet when glued, the water in the glue can cause distortion if just the glued sides are wet. Also, it helps the resulting plywood keep the curve.

Now you can prepare the wood for hatches two, three, and four, if you have enough room on your mold (or more molds) you can go head and make the other three skins.

Bill.

Cracked my frst try.

Larry:

Told you that was the hardest part. I broke one also doing my "Build-along."

Here's mine off the mold.

Bill.

[&o] Number two is history. Got to stop no more today other obligations.

I was able to bend one panel of the 1/32 balsa cross grain but did not secure it properly so it came out wrinkled!

[:@] That is a minor problem. In double checking the dimensions for the aft nacelle hatch (my addition not on the plans) something did not seem correct. At last the light came on, the balsa tail pieces were upside down! The nacelles are built upside down and I lost track of top and bottom. The nacelles are big and if they do not look good the whole plane will suffer. I have pulled them off and will rebuild them, what a darn set-back!