Oh yeah! My new motor couplers have arrived. Several weeks earlier than I had feared they might.
They look great. Can’t wait to fit them and see how they run.
this type is shit
@Piotr_Smolucha I suspect that depends on perspective. Compared to the 3d printed plastic ones I was using that were not quite aligned properly, this is a definite step up.
@Piotr_Smolucha what is the problem with them?
Under what load and speed limits to they fail?
Lol Piotr. I put this type of solid coupler on my machine and it has made a world of difference.
I’ve used this type for coupling stepper motors to ballscrews on a cnc-mill and they work well.
I made a storm in a teacup. In Poland, for milling nobody uses this type couplings. I personally do not know why, I know that the Polish forum cnc from the guys who are already doing milling in dozens of pieces. All recommend this type of coupling:
Found the reason.
“The spring action of these chefs couplers is not only present radially, but also axially – they stretch and compress as the lead screw changes directions!” = Backlash
@Marcus_Wolschon so I’ve noticed when fitted. thinking I need to support the other end of lead screw such that there is no room to stretch into.
Don’t.
When you constrain both ends the axis is overconstrained and will lock up.
@Marcus_Wolschon I’m not sure I understand how. I was planning to put the other end into the inner portion of a bearing. And set it in a block that prevents the stretching. But would still be free to rotate. I guess I’ll find out through experimentation what doesn’t work.
@Daniel_Would only if that block is flexible in the other 2 dimensions because both sides will never face each other exactly.
If both sides prevent the axis from going up/down and left/right (with the axis pointing forward/backward) then they will bend the axis shaft and it will bind or break at some point.
@Marcus_Wolschon actually wondering today about just wrapping the couplers in duct tape. Just to resist the stretch enough that hopefully the force required to move the axis even under cutting force won’t break the tape. I figure it has to be worth a shot.
You need to have 1 thrust bearing on a ball screw. This will stop the lateral stretch of the coupler. There is nothing wrong with having another bearing on the other end of the screw. I have seen these couplers break, but under proper loading they work fine.