Thread: shaft couplers
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Unread 26-05-2011, 09:08
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Re: shaft couplers

We have used shaft couplers in the past, and they work fine, but can be very bulky. I would recommend having the last stage of gear or chain reduction outside the transmission, so it is not directly coupled with whatever you are driving. This makes transmission swaps much easier.

On our arm, when one of the 775 motor started self destructing by spitting out fan blades (surprise!) we simply took off the chain, pulled the gearbox, and dropped in a replacement.

In our drive system, the gearbox has a gear on the output shaft that engages with a gear on one of the middle wheel shafts, which stays mounted in the frame permanently. So when the shifter pin broke, we were able to pull out the gearbox and swap it very quickly.

A lot of designs use an extra long shaft on the gearbox to direct drive a wheel, but this makes it a real pain to take the gearbox out.

Obviously designing for quick replacement is a nice thing to have, but as Adam said, it might be more beneficial to find out what caused the problem in the first place. In our case, I think the shifter pin broke because we didn't limit the stroke of the air cylinder properly.