Squirrel Motors

Darcy,

I forgot to bring the Squirrel to the Gym on Sunday. I had sixteen boxes of stuff for the class and forgot my own planes! No kids showed up, although three adults flew and needed help.

This morning there was a slight wind and overcast, but I decided to take a chance. I looped two 7″ x 1/16″ square office rubber bands together, lubed them and wound up to 1,600 turns, close to breaking turns. The plane wanted to fly right, so I let it fly right. It would rise barely above my head, launched from the shoulder, then come down with most of the turns remaining. This is not enough power.  it is also too many turns for finger winding.  I put on a second set, making four strands of 1/16″ square, 14″ long, and with 800 turns got a decent flight, but not high or long.  More turns could be used, but 800 is already pretty tedious.  I would not recommend using these for your 1,000 Squirrels flight. You could try 10″ x 1/8″ rubber bands, but I think that Tan Super Sport would be better.

I like to use a motor twice the hook distance, and my formula says 19 1/2″ of 0.076″ wide strip, but that requires a winder and a stripper. You will want a motor only slightly longer than the 9 3/4″ distance, or about a 10″ loop for finger winding. 3/32″ will work well for this. The slightly thicker than necessary cross section means you will see a steeper climb to higher altitude with fewer turns on the motor, better for hand winding.

10″ loop of 3/32″
119.9 turns per inch

% Break,  Turns
100           1199
95              1139
90             1079
85              1019
80                959
75                899
70                839
65                779
60                719

That is still a lot of turns to hand wind.

10″ loop of 1/8″
103.8 turns per inch

% Break, Turns
100          1038
95               986
90              935
85              883
80              831
75             779
70             727
65             675
60             623

That may be still too many for many people.

You know best what motors the Squirrel needs.

Gary

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