White Paper Discuss: Nothing But Dewalts

[Madison]

Originally Posted by techtiger1

Madison I respect your posts here on CD and I see your doing your best to try and make this work for your team. I don't think that using plastic as a key is such a great idea. This is coming from my background in machining and dealing with different types of plastic. I don't profess to be an engineer but my team has been machining plastic and using it for wheels,turrets and bushings for quite a long time. I have seen this set up and it just seems to me that in a application with the cim motor like you have shown the plastic keys just won't hold up through the whole season. I am only a first year engineering student but whenever there is metal on plastic, plastic usually loses no matter how strong it is after a certain period of time. I think your best bet would be to find someone who can make that size keyway which I believe is 2mm if your talking about the cim. Either that or make the Keyseat on the cim bigger and adjust the plate accordingly. Just a few ideas and I think aluminum would definitely be the way to go as far as the key. I like the idea it just doesn't seem efficient manufacturing wise and from what I read and I reread the post 3 times, that it just won't be durable enough.

Just some input and ideas like you asked for,
Drew D.

Drew,

Sorry if there was confusion -- I should've made this more clear -- but we'll be using a steel key seated between the CIM shaft and the plastic spacers. Last season, we built clutches for the 256:1 Banebots gearboxes that were delrin and acrylic and included the key in the delrin parts. Those keys didn't last very long at all and repairing them on the fly would've been impossible if we hadn't realized early on that we'd made a really dumb decision.

I'm not sure if we'd see better results with a steel key into a plastic keyway, though. It could end up being six of one and half a dozen of another.