Stepper changes directions and has play in shaft

[Scheer]

Tore my mill down to upgrade some of it (Solsylva 13 w/ fully supported X) and everything worked perfectly fine before I tore it apart.

Got it back together and noticed that on my Z when I move up and down there was a delay, it turns out that the shaft moves about 1/4" thru the motor before it catches and then moves the axis, is there a way to tear into it and possibly fix?

Then on my X axis, the motor will stutter when you try to move it, I've tried every speed possible, and if you are manually controlling it and hold left it will move left, then let go and hit left again, it will go right, and you can hit left a third time and it will go left. Sometimes you can hit it two times and it will go the correct direction and on the third it will go opposite. At first I blamed the driver, but the motor will not work on a known good axis, and the X axis drives known good motors just fine as well.

Any ideas guys?

Thanks in advance,
Taylor

[vger]

Taylor,

Most stepper motors have a bearing cup on the back end that has one or more spring washers pushing the bearing against the rotor. If you push on the shaft, the spring washers flex and allow movement. Taking the stepper apart will most definately ruin it. The rotor will lose part of its magnetic strength and make the motor very weak.

Your lead screw should have it's own bearings set up to restrict linear movement of the screw. This way the motor only sees rotary torque and no linear force.

It sounds like your X axis may have TOO much friction to turn the screw. With the motor not mounted, you should be able to turn the screw with your fingers. Perhaps your nut is not aligned or too tight.

Steve

[Scheer]

Originally Posted by vger Taylor, Most stepper motors have a bearing cup on the back end that has one or more spring washers pushing the bearing against the rotor. If you push on the shaft, the spring washers flex and allow movement. Taking the stepper apart will most definately ruin it. The rotor will lose part of its magnetic strength and make the motor very weak. Your lead screw should have it's own bearings set up to restrict linear movement of the screw. This way the motor only sees rotary torque and no linear force. It sounds like your X axis may have TOO much friction to turn the screw. With the motor not mounted, you should be able to turn the screw with your fingers. Perhaps your nut is not aligned or too tight. Steve

That definitely explains the Z axis, but the X turned easy, I've been using a drill with the clutch set low as possible to verify it is not too tight.I assume thrush bearings are used with shaft collars to limit the linear motion?

Thanks for the help so far.