Last winter before COVID-19 (seems like so long ago...) I cranked up a thread looking for suggestions on an intermediate stunt trainer for .29-.35 engines because I wanted to start flying stunt more seriously. There was a fair bit of discussion, and lots of ideas, but after taking three or four plans to my monthly club meeting, the resident stunt expert advised me to build the Veco Tomahawk, and even better, told me he'd help me learn to fly it and even donated an engine to the cause, a Fuji .15 that will run on modern fuel.

The Tomahawk plan is available for download from the Outer Zone here, and I traced all the parts into CAD to allow cutting a short kit on my CNC router. I made a few mods compared to the plan, including changing the wing leading edge configuration to a 1/2" thick rectangular section notched for ribs, and making a laminated fuselage from two 3/16" sides with a 1/16" cross-grained centre layer because I didn't have any 7/16" balsa as called for by the plans.

I launched with wing construction, and one of the advantages of cutting ribs with a CNC is they're all identical, making slipping them onto the three wing spars easy, with no worries about alignment. Spar fit was snug, but I was able to shimmy each of the ribs into position according to the plan before locking everything in place with the slotted LE and TE. Bellcrank mount was next, and then I had a very zen session with my razor plane and sanding block shaping the LE, using the time-honoured method of masking tape along the tops of the ribs to protect them while knowing when to stop sanding. The TE was shaped next, using a piece of 3/32" music wire as a sanding stop to ensure I didn't go too far. Wing tips, bellcrank and leadouts are next, but I'd be grateful for advice on leadout wires; I have some braided steel wire covered in plastic that's usually used for beading; will this be strong enough, or should I be thinking about something else?

Steve

If you know the core wire's diameter, then we can make a useful comment on its suitability for use as leadouts.


Kiwi

Originally Posted by The Kiwi

If you know the core wire's diameter, then we can make a useful comment on its suitability for use as leadouts.


Kiwi

It's seven-strand steel beading wire, nominally 0.015" diameter, but I don't know if that includes the nylon covering. I'll get my calipers out and see.

Steve

Your work looks fantastic. Very neat and clean. Looking forward to more pictures as you move on.....Gene

Leadouts are intended to be permanently installed and last a long time. They are usually not even visible for periodic inspection at the wear points. For something so critical I wouldn't use an unknown product. Brodak leadout wires are inexpensive. Go a little oversize and never have to worry.

Paul

p.s. Great Hobbies has some Brodak leadouts in stock.

Thanks, Gene, that's nice of you to say. Paul, you're right, I need some other control line supplies so I might as well get leadouts while I'm at it.

As mentioned earlier, I changed the fuselage construction by replacing the 7/16" balsa called for in the plan with a laminated fuselage made of two 3/16" balsa outer sides with a cross-grained 1/16" balsa ply between the two. The fuselage sandwich was clamped between two 1/8" steel plates to ensure it didn't warp, and was left to cure overnight. I tackled the wing tips while the fuse cured.

Steve

Work has continued on the Tomahawk, albeit at a slightly slower pace. Once the fuselage sides were dry, I cut some maple motor mounts and epoxied them into place before sealing them in under 1/16" ply doublers. I'd like to ensure the whole forward fuselage is completely sealed and fuel proof, and I have some Z-Poxy finishing resin on hand; will it be suitable for coating the fuselage doublers and motor mount area for fuel proofing?

Tail surfaces are 1/8" sheet balsa, and I'll be giving them a couple coats of lacquer before applying some silkspan to smooth and toughen them.

Steve

Clean build! I'm enjoying the show.

Thanks, Jim. It's kind of a stroll down memory lane for me, building a profile CL model. One thing's for sure, my fifteen year-old self would admire the workmanship too!

Steve

Super neat build . You are a fine craftsman . I hope you found some heavier lead out wire , .015 is way to light for that size of plane .

Mike1484

Thanks Mike. Yeah, I yielded to the voice of experience and ordered some .027 lead out wire. Who says old dogs can't learn new tricks?

Steve

Hi Steve ,

.027 is what I use for anything bigger than 1/2 A . .021 is what I use for 1/2 A . I think this is what Sig sells . Love those old Veco control line and free flight designs .

Mike1484

Any more progress steve? I been following along with your build....Gene

Hey Gene,

Time for the Tomahawk has been limited, but I've managed to hinge and prep the tail surfaces for paint. They all got a couple of coats of lacquer before I applied silkspan, and then another 4 coats of lacquer on top of that. Some 400 grit to remove the bumps, and they're ready for paint. My leadout wire finally arrived, so bellcrank installation will be next.

I think I'm going to cover the wing in clear orange iron-on covering (I forget what brand...) and the fuselage and tail surfaces will be sprayed glossy white.

Steve

Sounds like a plan Steve. I always liked the Tomahawk and enjoy watching your build.....Gene