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Thread OP
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Zagi-bending motor shafts using Master Airscrew props on belly flops
The Gunther prop is no problem because it is so soft, but I like the MA 5.5x4 and if I hit the ground with the prop spinning (not recommended I know) I bend the motor shaft usually beyond repair.
Thought of a fin of plywood under the prop, but maybe there's a better idea (except "use a gunther" or"don't hit the ground", both of which I already thought of ) |
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I can't find the link, but there is a method of using a rubber band to hold the prop on. I think the set screws in the adapter were replaced with regular screws and the rubber band hooked to them. Maybe someone else will know what I'm talking about and post a link. In any case, that should prevent your bent shafts.
Randy |
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This is the first report I've ever heard of someone bending shafts on a Zagi. I used the same MAS props on mine and never experienced this, even with some spectacular crashes.
I guess you could add a small triangular EPP foam skid on the underside at the back to keep the prop from hitting the ground. |
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Your first thoughts was the best one. By glueing a 1/8" ply skid unter the tail of the zagi will do 2 things for ya.
1. Ptotect the prop when hitting hard 2. give a great hand hold for launching the Zagi into the air. Place 1 finger behind the skid and thumb and middle finger on each shide. Raise above head and throw. Have been doing this ever since I couldne figure out how to master the Thumb upside down fingers on the bottom launch. Larry |
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Thread OP
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Well I never heard of it happening either, but after the 2nd time I couldn't deny it.
I had an EPP skid for a while and that worked, but seemed pretty draggy, aerodynamically speaking. The plywood skid would be better, but might cut into our "runway" which is kind of rock hard dirt but the plywood could cut a groove. The rubber band thing I've read about somewhere and just couldn't figure it out. I've heard the saying "build to fly, not to crash". Either this doesn't apply to Zagis or to me or I can replace the motor if it happens again. |
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Does anyone make a 5 inch folding prop ? I've heard of 6 inch ones.... if put on backwards it should fold out of the way instead of breaking
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The rubber bands, work great. But instead of rubber bands, use o-rings or slices of latex rubber tubing. Seems the rubber bands are always breaking at the wrong time. I've never had a latex tubing slice break.
The long screws in the set screw holes is the answer. A very short stub on the adaptor shaft is needed so the prop can "bend" away from the shaft on impact. Means you'd have to cut off most of the adaptor shaft. hoppy |
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Just noticed that your origional topic stated MASTER AIRSCREWS props. Most of the Master props are very stiff and the blade will not bend and giveway when comming down hard, this will result in a bent shaft. The white plastic props that come with the zagi's will take some flex and not cause a problem.
as for a folding pusher prop, Gunther props does make a 5.5 x 6 replacement blades, these can be mounted backwards and be used as a pusher. I have tried this and found that it just wosen't worth the effort. A Zagi will fly great with the little whitte props and a good lightweight Zagi. My first one had so much added weight that I finaly converted it to a Cox .049 gas, pusing a 6 x 4.5 prop. Really try the 1/8 ply, it does not creat much drag, easy to make, and easier to launch a Zagi. Larry |
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