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- This topic has 4 replies, 4 voices, and was last updated 13 years, 3 months ago by Norm Furutani.
12/19/2009 at 11:24 pm #41278AnonymousInactive
I’ve been making my coupe motors 12×1/16 on my motor insert stick and I’m struggling to not end up with one really loose or tight loop at the end of things. Any tricks, tecniques or jigs that might make this easier? My concern is mostly that a tight loop will increase the chances of breaking. Is this a non-issue?
-Andrew12/19/2009 at 11:51 pm #48327Norm FurutaniParticipant
Making motors on your insertion stick would be a pain!
I have a special board for making up motors. It has a fixed dowel on one end and a row of holes for a movable dowel on the other end. About 1/2″ apart. If the loops come out uneven, I adjust the length to fit. Usually, the rest of that box of rubber won’t need adjustment.
Before I wind, I stretch the motor, relax, stretch again and wind. This helps to take out minor uneveness.
– Norm12/20/2009 at 7:56 pm #48328AnonymousInactive
I weigh out 10g rubber exactly.I wind the 6 loops as described above and then tie the knot.This leaves 2 small tails to trim off.The motor now weighs 9.8 g. I then lubricate it and reweigh it.If it is just under 10g I use it in competition.If it is way under or just over then I use it for trimming flights.Then I attach it to the stuffing stick,but I hold it at one end with a rubber band to release the tension.
Preparing the motor by stretching is another matter,and I am not an expert.
I always have 5 motors on stuffing sticks ready for a flying session,and I put a paper note on each about the type of rubber,number of strands and date made up etc.I then keep them in a white polythene bag to keep the dirt out and the sunlight off.This then goes in my field box.
Stuffing sticks are easy to make if you are a woodworker.You can buy metal ones,but I am too mean.You can also buy an adjustable loop winder,
I use 2 dowels on a base,but one dowel and another sliding in a slot would be better as different batches of rubber produce different lengths for 10g.12/20/2009 at 10:50 pm #48329Bill ShailorParticipant
I make them a little differently. I take the loop, one end tied and make three loops in my hand. It is then a six strand motor. Then, I fold that in half when it it goes into the model for winding. Loops with the knot in back, fold at the bobbin. Twelve strands. Makes up real quick and easy.12/20/2009 at 11:51 pm #48330Norm FurutaniParticipant
I just re-read this thread – Andy, if you’re using 1/16th rubber, this should be 20 – 24 strands for a coupe? 12 or so for a P-30. A loop of rubber is two strands.
If using 1/8th, Bill’s method is what I use.
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