On Thu, Feb 15, 2018 at 8:06 PM, Gene Heskett <[email protected]> wrote:
> On Tuesday 13 February 2018 20:04:27 jeremy youngs wrote: > > > I had to service this motor today, as a previous technician had > > improperly installed the brushes and it would are off at speed. In > > doing so I removed the tach cover and found plenty of room for an > > omron encoder. So I will not likely try these for spindle encoder. But > > will be putting them in as home switches soon. > > > > Gene, you are absolutely right about the optos, the strongest and best > > these have performed today after I replaced the bob to a straight > > through board. However, I discovered my y axis ballscrews is bent. > > Ouch. Time to do it right. But how the heck did it get bent? I'd find > out why, and fix it. > If you have a massive machine and a powerful motor the motor can accelerate and produce a large force. The ball screw is no different from any other steel column and based on the ratio to length over diameter will buckle if enough force is applied. In other words nothing has to be broken to bend a ball screw. OK the CNC controller has the maximum acceleration set to high. To protect the ball screw the acceleration has to be limited based how far down the screw the nut is. From a mechanical engineering point of view a ball screw is simply an unsupported column. The force on the screw might be much more then the weight of the machine. -- Chris Albertson Redondo Beach, California ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
