Scratch Designing/Building 88.75" 50CC P-47 Thunderbolt

[bobsuruncle]

Hi Ladies/Gents,

First post here. I am not new to online flying sites having been a longtime member of "another one" under the "SydDythers" moniker. I like the Giant's site due to its focus so decided to move my posts over here.

Anyhow, if any of you are interested in following along, I am in the final stages of tweaking a P-47 outline in solidworks before designing the construction (see attached pic) for laser cutting. I'll post some screens as I go along and am certainly open to design suggestions! I want to stay away from the usual two piece fuse construction method

This a P-47 D-25 bubble canopy. I am hoping to get it in under 19lbs but am really shooting for 18lbs with retracts. It will have a WS of 88.75", Length 77" (1:5.5 scale) and will be designed for the DA/DL 50. The design will be tricked out with the usual compliments of retracts flaps, etc... I am using a NACA 23012 airfoil for the wings.

This will be my first warbird design after having successfully creating/building a 50CCYak 54, Electric Yak 54 and a 50CC Edge 540. I have also designed but not yet built an Extra 260 and Pitts M14.

Cheers,

John

[50%plane]

	Quote: Originally Posted by bobsuruncle
	Hi Ladies/Gents, First post here. I am not new to online flying sites having been a longtime member of "another one" under the "SydDythers" moniker. I like the Giant's site due to its focus so decided to move my posts over here. Anyhow, if any of you are interested in following along, I am in the final stages of tweaking a P-47 outline in solidworks before designing the construction (see attached pic) for laser cutting. I'll post some screens as I go along and am certainly open to design suggestions! I want to stay away from the usual two piece fuse construction method This a P-47 D-25 bubble canopy. I am hoping to get it in under 19lbs but am really shooting for 18lbs with retracts. It will have a WS of 88.75", Length 77" (1:5.5 scale) and will be designed for the DA/DL 50. The design will be tricked out with the usual compliments of retracts flaps, etc... I am using a NACA 23012 airfoil for the wings. This will be my first warbird design after having successfully creating/building a 50CCYak 54, Electric Yak 54 and a 50CC Edge 540. I have also designed but not yet built an Extra 260 and Pitts M14. Cheers, John

Sweet! Back when I was on RCU all the time, I looked foward to your threads! Your Yak looked like an awesome plane. I can't wait to see this build as well! Subscribed!

50%

[bobsuruncle]

Thx 50%, glad to see you over here.

Anyhow, my first design choice is whether to use a one piece wing or implement a wing tube for easy portability. A 1" diameter, 36" length tube can be accommodated by the wing as seen in the picture attached. I should have no problem designing the spars for this as there really isn't any change needed. The sheer webbing for the D-tube would just be cut on an angle. I would have a hatch to access the inside of the fuse for wing bolts, similar to what we have on our aerobats.

Any thoughts?

John

[bobsuruncle]

Oh crud, I don't think having a tube will accommodate retracts

[Vic3D]

You could always do a front and back tube.

[selleri]

What about 3 part wing, split on flaps/ailerons? I'll go down that road on my 92" Ziroli Jug.

[bobsuruncle]

Good suggestions!

I was thinking of a three part wing with the middle piece fixed in place as part of the fuse. I attached a pic showing two 0.5" tubes. I am worried about wing strength if the wingtube isn't centered between the spars. Plus, the tubes are aft of the thickest part of the rib so building the D-tube would be a bit of a pain.

Another thought is to borrow a "Paffy" innovation and extend the spars out from the root rib and rig up a way to secure them to the fuse but be removable. I'll see how that looks tomorrow.

Cheers,

John

[bobsuruncle]

I have set the wing tube question aside for now and just started a bit of the fuse work. Balsa rings have been designed to be sanded to shape just aft of the cowl. I've started some rudimentary work on the formers and box structure. I fixed a DA-50 I mocked up a while ago to the F1 former and it almost fits 100%.

Thats it for this weekend...superbowl time!

[bobsuruncle]

Box structure is taking shape. I'll start hogging out some lightening features once I have all the formers set. I have determined the optimal wingtube position/length and size (30" x .75"). I need to put some thought into designing a hatch somewhere to provide access to tighten the wingbolts.

[3D Joy]

How about putting a wing tube in front of the gear and one in the rear of the gear??

Just relocate the wing spars at wing tube locations. You would avoid making monster heavy duty ribs...

You are doing some outstanding job!!

[Delrin]

That software, Solidworks, is sick.....

I imagine it's expensive? It's pretty sweet.....

[bobsuruncle]

I have been picking away at the design here and there when I can get a spare moment in front of the PC which isn't very often these days unfortunately. Progress is slow but steady anyhow. Latest work shown below...

I will start on adding stringers when the aft formers are complete. On the forward section exists a large gap between formers. This will be transformed into a hatch for access to the internals and wing bolts.

Delrin,

If you can get a student copy then it is much cheaper. Great tool to design with but fairly steep learning curve. I am still learning new tricks two years after first playing around with it.

3D Joy,

Sent you a reply PM to your question on the DA-50. As for the wing tube(s), I still haven't decided on what I will do but for now I am going with a single tube. When I start the wing decide, this could change.

John

[bobsuruncle]

More progress. Hatch is designed. I will figure out the best way to secure it later on in the design process but will likely use screw tabs.

[bobsuruncle]

A bit more progress on the aft portion of the fuse. I am trying to figure out weather I want the horizontal stabs to be fixed or removable. I am leaning toward fixed at the moment...

[gideon.edge540]

Hi John
I wonder if you got plans of a Yak that you can help me with for starting a scratch built project on one of those.

Thanks Giddie