Lead screw setup is binding...need a new design
Lead screw setup is binding...need a new design
(OP)
Hi guys, I was presented with the current lead screw setup, which raises and lowers a platform with high precision. However, as you can see in the attached pictures, if the tolerances aren't exact, the mechanism easily binds. Assembly requires shimming, and the motor powering the mechanism is not very powerful, so it is easy to bind it.
I am looking for a way to make assembly easier and end any chance of binding. A complete redesign can be done if needed.
Thanks for your suggestions!
http://i51.tinypic.com/2hmh94i.jpg
http://i55.tinypic.com/28bza8j.jpg
http://i56.tinypic.com/33nf6uo.jpg
I am looking for a way to make assembly easier and end any chance of binding. A complete redesign can be done if needed.
Thanks for your suggestions!
http://i51.tinypic.com/2hmh94i.jpg
http://i55.tinypic.com/28bza8j.jpg
http://i56.tinypic.com/33nf6uo.jpg





RE: Lead screw setup is binding...need a new design
http://us.misumi-ec.com/mech/
Parallel linear bearings really need to be perfectly alligned. I few microns out and they wont run. The trick is to build some compliance into system. One rail fixed to give linear guidance. the other which allows relative movement between the carriage and bearing to compensate for out of parallel running.
Ball bushings are more tolerant.
Crossed roller slides allow easier adjustment.
Leadscrew offset looks too high for trouble free running. Closer to slides would reduce twisting loading of carriage. Also some compliance should be allowed between carriage and nut.
I would still favor a ready made over custom build.
RE: Lead screw setup is binding...need a new design
One flat "way" and one V "way" for the carriage, and another pair for the tailstock. The V does all the lateral guiding. If your "flat" way is vertical you'd need something to preload the carriage against it
The V (or equivalent) benefits from being long ( minimum 5 or 6) relative to its width.
Some of those roller/ball tracks come with slotted holes, and installation procedure includes locking them only when the carriage is near the screws to be tightened, thus ensuring the center to center is pretty close to the same.
RE: Lead screw setup is binding...need a new design