stepping motor

[hknisely]

stepping motor skips and needs replaced which one would be good to replace it mine is a vexta pk296a1a-sg3.6 2phase dc1.5

[bleeth]

The same one-available from Shopbot only as this motor is made only for Shopbot (unless you want to do a control board and full motor change or other extensive modification).
Are you sure it is the motor? There are a variety of reasons a motor loses steps and rarely is it the motor.
Might get some suggestions if you share more information. (Model SB, what you do when it "skips" like feed, speed, bit, what are you cutting, etc.)

Saw you have a PRT and wondering if you did the 4g upgrade earlier. Could be a gecko driver going bad. Check all your connections too.

[RUSSELL MC]

I have just spent the last 5 weeks trying to find why my X axis was skipping. I purchased a new Stepper motor from Shopbot and motor cable, It did not solve the problem. I tested the axis drivers by swapping x with y to check if it was the driver that was the trouble and it wasn't. I adjusted down the current to the stepper and this did not help. Finally after 5 weeks I found that I had reduced my Z plunge rate to low. The Z plunge rate I was using was to slow when used in conjunction with a relative quick x feed rate. When I increased the Z plunge rate the skip stopped. I was running a long 3D carving program on a BT48 Buddy standard with a 1500mm x 1500mm table. I believe an alpha machine would not give this problem.

[bleeth]

I'm glad you finally figured it out. This is a classic example of why the information of your cutting strategies is important in analyzing issues.

[Mayo]

I had a similar problem and replacement motors were not in stock at Shopbot.
There was also a long wait time from Oriental Motor.
I found a company that repairs stepper motors, servo motors and spindles - within 5 minutes of my home.
Works good now.
Another thing I found out was the recommended turnbuckle tension was causing my motors to sound horrible. Clickety clacking...
I dialed back the turnbuckle tension and the noise went away.