Well, it finally got time (after 1 year) to start my first "scale" Stearman. 96" wings, fuse longer than my building table, LOTS of - DOWELS.

This is my first experience building with dowels instead of square balsa sticks. I started by figuring out how to cut saddle joints into the dowels. The kind that you see on pipe joints (and on the full-scale Stearman). One of the reasons I chose this model is the review in High Flight magazine from 1981. The plan review praised the design highly and I wanted to do a showpiece that I could scale out with an interior.

I used 5/16" poplar (the only kind locally available)instead of spruce - a judgement call. They're both from the Spruce/Poplar/Larch family. A little heavy but a nice tight grain. I used a chainsaw file to notch, then dressed the saddle with 100 grit wrapped around a 1/4" dowel.

Gap-filling CA was tried and found sufficient to make strong joints, though they broke with lateral stress. I gusseted each joint after the fuse was framed with 1/16" poplar ply. For this I used slow epoxy.

Results - the frame is probably 10% heavier than using hard balsa, but with the gussets it takes much more of a load - won't bend at all with hand pressure.

Stab and rudder - no real surprises here except that the stab is a flat-bottomed airfoil AND had 3% positive incidence built into the stab seat. This is probably due to a combination of the weight projected for the full-castering, self-centering, shock-absorbing tail wheel, the average weight of the stab and the slightly heavier than I'd like elevator. It uses a 3/8" dowel for a front spar and has a nice 1/16" wrap around leading edge.

Of note is that the elevator uses an internal "horn". I'm probably going to go with aerodynamic boost tabs to help out the servo even though I'm going to use giant-scale servos for the flying surfaces.

Next phase - crossmembers and bracing. I'll probably gusset these too, and then paint the frame with "zinc chromate" to simulate the true finish.

How about some construction pics? I'd love to see how you work with the dowels, gussets and all. I've never done any of this type work, and it sounds like it would work well for scale versions of tubular steel/fabric aircraft.

That's exactly the reason I'm giving it a shot - scale inner structure. I thought of aluminum tubing, but the cost and having to learn mini-IG welding (as well as the equipment cost) or using lexan tubing (still a possiblity someday) were considered as well.

I'll take some pics as I go along.

I have been looking for a set of Barron plans for the Stearman, but have not been able to find any. Is there a source for them or would anyone have a set they would part with? Dean

Progress - fuse framed up. I'll shoot pics when I get it cleaned up. Looks pretty neat and is still less than 2 lbs. I'm going to start another thread about scale accuracy.

Minor fitting problems because dowels are NEVER straight in this diameter. Another good reason to frame with CA and epoxy - some heat and a palm smack and they usually cab be worked loose.

Probably had to cut 6 braces (per the plan) to keep the frame straight and square.

The plans show 4 dowels notched into the firewall to hold it to the frame. Right now I'm assuming I'll be notching the rest of the stringers in too. This will be weak if not done (as far as I can tell now).

Next step is the shock absorbing landing gear - 1/4 in music wire (I bought the mighty bender from K&S. Last time I tried this I used a 5 lb sledge and a bench vise - you NEED to use a glove doing it this way!

Yes, I made a banana

Well, after getting all the crossmembers and firewall in place, I stood back and discovered a real banana fuse. A little (liveable) twist by the tail, but at the cockpit about 1/2 in out.

Back to the drawing board - marked all the crossmembers at the centerline, pulled a piece of dental floss from the centerline of the firewall across all the crossmembers and back to the tail. NOT a pretty picture.

Took a cut off wheel and the Dremel and cut off all the crossmembers and braces.

THIS time I'm going to mark a centerline on the plans, put them on my worktable and screw some blocks to the outline of the fuse at the crossmember location. That will get the bottom lined up. For the top I can turn it over since the fuse is symetrical. Some weights to hold the fuse to the table ( I was also thinking of using those clamps you put on 1/4" tubing when you do swamp cooler lines) would probably work to hold it real firmly in place.

I guess the basic problem is that I'm used to working with balsa and using hardwood dowels (with their built-in warps) instead requires a much firmer jig than pins and eyeballs. Well, nothing wasted but about a day of time and a dollar in dowels.

NOTE: One interesting thing about the dowels is that they don't suck up much glue because of their tight grain structure. It was relatively easy to break apart the frame without destroying it. Anywhere where the dowel wasn't sanded the epoxy (30 min) didn't really stick all that well. Must be some sort of wax coating on it. BUT to be honest, I did heat it up while using the abrasive wheel and the joints that did separate easily really didn't have that much surface are except for the gussets I put on the sides of the joints. The cross member dowels usually broke cleanly away from the epoxy in both the joint and from the gusset. I'll have to make sure there's a clean surface this time.

Back to the workbench - learning all the time!!!