6"x3/16"X1/16" Motor Stick

17 December 2024

It appears that a 6"x3/16"x1/16" motor stick is sufficiently sturdy for a single loop of 160mm x 1/16" rubber band. This motor stick could also serve as a spine for a small model plane's fuselage. Here's the steps involved:

1. Make the motor stick, install the nose bearing, tail hook, propeller shaft, propeller and rubber band.
2. Cut from polystyrene 2 pieces of the profile of the fuselage.
3. Lay the profile flat on the table and mark where the motor stick and rubber channel will be inside the profile.
4. Hot wire cut the channel in both profiles and bring them together, sandwiching the motor stick.
5. Cut and sand the polystyrene to the cross sections.
6. Cover with tissue, paint and the fuselage is done.  

For short nosed planes, for example the rotary engined biplanes in WW1, the nose moment is too short and requires much nose weight, which makes it difficult to fly as a free flight rubber powered model airplane. Let the motor stick protrude out of the stub-nosed model. Yes, it is un-scale like, but it is a trade off to lessen the nose weight. 

Further simplification can often make model planes easier and be great for their flying ability, example, making it a NoCal or making it Slab-Sided. Either set out the motor stick in the case of a NoCal, or set in the motor stick in the case of Slab-Sided. NoCal design is often used to maximise flying, but it is more work than SlabSided which also has the advantage of being aesthetically slightly better.

1. As before, make the motor stick etc, the rubber power unit.
2. Draw on a 1cm thick polystyrene sheet, the profile of the fuselage.
3. Strengthen those areas where necessary. You can make anchor points for undercarriage, hard points for wings/tails, dihedral braces etc.
4. Round off the polystyrene profile, on the starboard side, slit the thrustline, insert and glue the motor stick of the rubber power unit, only the rubber band and bearings are exposed to the starboard side.
5. Cover with tissue, paint and the fuselage is done.   

Experimentation is the way to discover them. I wonder, if it is possible to power a 6" plastic rubber powered propeller with a single loop of 1/16" rubber band. the main advantage is that it is ready made and the propeller's airfoil should be great. It is also more durable.