Thorp Air Command - T18.net

Hi all
I am a new and novice builder.
I am based in Coffs Harbour, Australia and am just starting out on a standard T18 project. I have a set of plans and have an old damaged T18 for some parts. , The main challenge is to build a new fuselage, I think I can salvage most of the rest of the old A/C .

Being new to this business I need to get a few tools together, I guess I will need most of an RV Builders tool kit! While that happens I thought I would start making the firewall.

I was planning start by cutting out the plywood form blocks for the firewall as per plan #604 and wanted to check with those more knowledgeable than myself if I should cut the form block with the edges at the set angle of the flanges or just at 90 degrees and then set the angle on the flanges somehow later.
I confess I am yet to read all the old newsletters to see if this information is already out there but I didn't see it so far in my reading and was hoping someone may be willing to offer a hint.

Thanks
Stuart

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Stug

Stuart,
Would suggest you make the form block edges angled back for the flanges. Really only important on the top curved edges. I made my firewall out of 025 stainless and it needed flutes around the top edges for the "extra" metal. You have to think about where the rivets are going to be before fluting so mark the form block ahead of time.

Also a note not in the plans or newsletters......make the bulkhead on the back of the baggage compartment with the flanges facing aft....backwards compared to the plans. This simple change would make baggage compartment construction much easier. Dont think that reversing this would screw anything elso up but.......

SS

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Scott Stine
Vincennes, IN
812-881-7923
Arrow 545WA

You can do it either way. I made mine off a straight cut form block then bent the edges later. The more important part is what Scott mentioned above, ie planning your flutes.

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Cubes
831GR
Las Vegas

Accuracy is the key. The closer to the plans built numbers (measurements), the better the fit and look. [:D] A 1/32-1/64 of an inch added up over several parts during the assembly will really show up when you try to fit part A to part Z (with parts B thru Y between). It may not seem like much, but the numbers don't lie ! [:0] "If it doesn't fit, you must...redo !" Or words to that effect. "Trust me", this would not be your first part to end up in the re-cycle bin.

RB

Thanks for the responses
I notice on the old bent firewall I am using as a rough guide that there are about 4 flutes on the top edge either side of the centreline and where the flange goes around the steep part of the curve the flange actually has notches, 7 of them, cut between rivet holes!
So the previous builder just removed the extra metal, does that sound right?

Stuart

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Stug

Stuart

I am building a T18C folding wing at Camden. There are also T18 builders at
Deniliquin, and Wyong.

If you have any questions please contact me by email or 0408164946.

Happy building

Mike Nolan

*** admin posted for Mike ***

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Forum Administrator