Here are the pictures I promised.
The first one is a shot of all three types. A 1/2A Proto, a Class 1 Mouse, and a Class 2 Mouse.
The second one is a closeup of the Class 1 Mouse. 24" wing span. It uses a Cox derived engine. Simply mix and match Cox part until it feels right. The glo plug is a Norvel Freedom plug and clamp ring. The engine mount is a piece of aluminum "T" stock I cut on a band saw and rounded the corners on a belt sander. For a kit targeting kids and beginning adults, 1/8" or 3/16" plywood staked on with some 1/8" wooden dowels would work just fine. Yep the elevator hinges are broken.
The third one is a Class 2 Mouse. Also 24" span. It uses a Cyclon engine. Basically it is the same airframe as the Class 1 Mouse. While the fuselage is round, it is simply the flat core with the balsa fairing run to the tail and rounded. Notice the flat horizontal tail rather than the butterfly tail of the Class 1 Mouse. The engine mount on this one is more complex. It was machined from a piece of 1/4" aluminum "T" stock on a Taig lathe. But that was because of the engine I use on it. Plus it was a nice exercise for me to learn how to do interrupted cuts on a lathe.
The fourth one is the 1/2A Proto. I think this design would also make a nice Mouse Racer. It has an 18" span. The wing area on all three models is about 46 sq in. If I was going to make this as a Mouse racer, I'd drop the sub-rudder for a tail skid and go to the single wheel landing gear like the other two models have.
I build the long wing Class 1 models 6 at a time. Basically I cut six kits on my table saw using a taper jig to get the angles correct. My son and I build all six of them up over a weekend. I used to carve the airfoil with a block plane and a sanding block. Now I use a Porter Cable random orbit sander with 60 grit , then go to 150 grit, then hand block sand with 220 grit to finish. The finish on the Class 1 Mouse is Glass Kote. It has not yellowed in 2 years. Still nice and clear. The finish on the Class 2 Mouse is simply finishing resin. It yellowed the first summer to a nice warm amber patina. It is about 4 years old. The 1/2 Proto is finished with K&B Super Poxy (it is 9 years old).
Why do we build so many Class 1 models at a time? One, the event is sometimes a demolition derby, it helps to have spares. Two, we have models to lend. And three, we give them away to any kid at the contest that looks interested and doesn't have one. Unfortunately, even though the kids that get the models have parents that are modelers, for all those we have given away we have only seen one in the air at a later time. We have never had one show up at a later race. Since we are on our third or fourth batch in 10 years we are probably up to 10 or 12 given away.
This design is nice and stable. I even converted one to monoline to learn how to fly that way and it flew well. 1/2A reed valve monoline speed anyone?
Hope this is useful.
BTW, I picked up an American Boy kit last summer. I had one as a kid, lots of good times with that plane. I'm thinking of building it for Mouse with a single wheel gear just to see how it would do.
later,
Dave