MARTIN Mickleburgh Posted November 30, 2016 Share Posted November 30, 2016 As a relative newcomer to model flying, and having cut my teeth on an E-Flite Advance 25, I decided to go for something a bit bigger and more powerful and invested in an AcroWot II and the relevant electric kit. I've gone for the motor and ESC recommended by Ripmax, a Quantum II 55 and 60A ESC. My problem is fitting the prop to the motor. This is the first time I've used a prop driver bolted to the front of the motor - previous electric models have used a collet attached to the shaft. I've hit two problems: firstly, the join between the prop shaft and the face of the driver has a distinct fillet of radius about 2mm, rather than a sharp right angle. That means that neither a prop or the backplate for a spinner will fit hard against the driver. Secondly, the boss of the prop (an APC 12 x 8 E) is shallower than the blades where they cross the edge of the washer that sits behind the nut that holds it al together, and where they cross the edge of the spinner backplate. Net result is that I can't get a tight, mechanically sound fit for the prop. Anyone have any suggestions? Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted November 30, 2016 Share Posted November 30, 2016 Hi Martin, I get those 2mm fillets turned down by a friend, but I have in the past resorted to a needle file, while turning the offending driver in my drill chuck. You can of course relieve the prop boss slightly at the rear face. You could put a suitable washer on the front that fits. This is an all too common faff Quote Link to comment Share on other sites More sharing options...
MARTIN Mickleburgh Posted November 30, 2016 Author Share Posted November 30, 2016 Denis - thanks for that. I rather suspected that a bit of fettling was going to be the answer. Hopefully somebody in our club (Woodspring Wings) has access to a lathe.....Frustrating though, isn't it: call me old fashioned but I expect things to work! Martin Quote Link to comment Share on other sites More sharing options...
Shaunie Posted November 30, 2016 Share Posted November 30, 2016 I would countersink the back of the prop driver where it bolts onto the motor. If you don't have a lathe put the driver in the drill chuck and turn it against a stationary countersink, it will be truer that way. Shaunie. Quote Link to comment Share on other sites More sharing options...
Chris Stevenson Posted November 30, 2016 Share Posted November 30, 2016 Hi Martin, I had the same problem with the recommended Quantum motor in a WOT 4. It was resolved by reaming the boss sufficient to clear the prop driver fillet. All has been well since. Chris Quote Link to comment Share on other sites More sharing options...
Maurice Harvey Posted November 30, 2016 Share Posted November 30, 2016 Please DO NOT remove the radius on the prop shaft. It's purpose is to blend in the change of section. Be guided by those that tell you to counter-sink the prop. Quote Link to comment Share on other sites More sharing options...
MARTIN Mickleburgh Posted December 2, 2016 Author Share Posted December 2, 2016 Chaps, thank you all for your help. I've worked out a fix thus: 1) Install a spinner with a thick backplate 2) Use a steel hand countersink to relieve the backplate of the spinner so that it fits flush with the prop driver 3) Use a thick stainless steel washer between the prop and the nut which is of smaller diameter than the supplied washer and doesn't touch the prop blades. Never had these problems with attaching a prop via a collet driver..... Martin Quote Link to comment Share on other sites More sharing options...
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