I just learned a lesson the hard way: MAKE SURE YOUR SLED IS MOVING FREELY BEFORE YOU START A JOB.
I had screwed my sled onto my temp frame so that it was nice and flush so I could set zero on the z access reliably. In my haste to get started, I forgot to unscrew it and started running a job. I realized it very quickly but not before the right motor tensioned its chain a lot. I hit stop and disconnected everything and recalibrated my chaines, but noticed the right chain wasn’t loading into the motor properly. In fact, it appears that I bent the motor shaft on the right motor, so the sprocket is no longer perpendicular to the body of the motor
I moved the chain on the right side down to the lowest point on the bracket and this helped a little bit… but the chain is still jumping because the sprocket isn’t pointed in the right direction. New motor on order… but wow, that was careless and unnecessary.
Are you sure its not just the motor bracket that twisted? It looks cockeyed in the picture. Personally I would have expected the screws to give in the plywood rather than twist the solid motor shaft. Check closely. Regardless, I feel for you.
I’ll be completely happy after I get this thing back together and see that it works correctly! Was it you who had your sled fall off the table? I was glad to see it still works!
Yes, I am the guilty party. I will be building a new frame soon (I need put it on the other side of the shed and my sled is to small to allow me to turn it around inside of it) and I plan to incorporate some of the suggestions for a sled hanger in the design.
I was thinking that it would be unlikely to bend the shaft before burning something out in the motor or driver board. Glad to hear that it was just the mount. Guess that makes for a nice re-settable failure point
I picked these motors because they have have high quality ball bearings on both sides of the shaft and the shaft is high quality steel from Japan (which is why it takes approximately a million months for them to arrive ). A lot of the cheaper ones will use bushings on the output shaft
). A lot of the cheaper ones will use bushings on the output shaft