OK, we just finished our first plane and will be getting to the gym real soon. While practicing a dry run of the winding of the motor and attach it to the plane, we have a lot of difficulties. Does anyone have a tip for how one person can wind and mount the rubber motor onto the plane? Even with 2 persons the winding ring is so small, it is so hard to work with especially for a 6th grader (we have Ziegler kit). I think we are going to break a lot of planes doing this maneuver. Thanks in advance for any suggestion.
Try a little larger o-ring. Make sure the hooks are open enough.
Here's how I use them when winding
Take two o-rings and slide them onto the motor before tieing the knot. Weigh motor with rings and trim length till it weighs exactly 1.4999999 gm or so. Tie motor into a loop and lube it.
Now, you need to prepare the area you plan to wind. It helps to have a heavy table, but a heavy tool box, or door frame can work in a pinch.
- You need something to hook one end of the motor to. Preferably a torque meter, but until you get that advanced, a simple wire hook made of 1/32 music wire is fine. Clamp the hook to your anchor (heavy table, heavy tool box, etc...).
- Now you need some way to sit your plane aside, but wihin reach, and secure from being bumped accidently and broken. I use an old pole lamp pole because it has a heavy base so its stable and its a convenient height for me. I've stuck a piece of foam rubber on top with a slit in it, the plane sits in the slit secured by the friction of the foam. Easy to put in and remove one-handed and fairly secure. I set the pole (called a stooge) near the hook, about two feet to one side. In easy reach, but not likely to get bumped while winding
- And of course you need 10 or 15 to 1 winder. A typical Wright Stuff motor this year will be 3/32 inch wide and take 1000 to 1500 turns, you'll never get there hand winding
You are now ready to wind. Here's how.
- Hook one o-ring onto the anchor hook, and the other onto the winder. MAKE SURE THE RUBBER DOESN'T GO OVER ONE OF THE HOOKS. ONLY THE O-RING! I always slide the knot so its by the o-ring on the anchor for consistency as that the end I put on the motor hook. The winding
end goes on the plane.
- Now, strech the motor to about 3-4 times its relaxed length.
- Start winding
. Don't move in until you have about half the turns on the motor, 500 to 750 turns 50 to 75 cranks on the winder handle.
- Once you have half the turns, slowly start moving in to shorten the motor. You want to have the motor at about the prop to hook distance as the last turns are would.
- If you have the right kind of o-rings, they will still be open and the hooks free inside them.
OK, now here's where dexterity and care are called for, but nothing beyond most MS students.
- Take one hand and grab the o-ring on the winder firmly. DON'T LET GO!
- Remove the winder from the ring and set it down. Try to keep the motor still, don't let it stretch or shorten as you set the winder aside.
- With the free hand from setting the winder down, pick up your plane. Hold it by the prop so it won't turn. Hook the O-ring in your hand over the prop hook and let go with that hand. DON'T let go with the hand holding the prop and don't let it spin. Watch the tail of your plane, its easy to bump it into something at this point.
- With the hand you freed up, remove the other O-ring from the anchor point and hook it onto the tail hook.
That's it, you're ready to fly.
Like most things, this is much harder to explain than do. And it makes lots more sense once you've done it a couple of times.
Most motors break while winding
. Not how this method has the plane well away from the motor when its likely to break, reducing the likelihood of damage.
If you have two people, one can wind and handle the rubber and one can hold the plane. Just make sure the person handling the rubber doesn't grab the plane. They just need to put the o-rings on the hooks. An easy way to destroy a plane is two folks handling it at once. The plane always loses the inadvertant tug of war when person a goes one way and person b goes the other!
Finally, like most things, practice makes perfect. Until perfection is reached, don't risk the plane, set up a practice motor stick. All it needs is a prop assembly and tail hook. Make it out of balsa to about the strength of the plane, maybe attach skeletal wings and tail so the students get used to being careful, but don't spend any time building them. Practice just winding
and attaching the motors.