Connections on new Z motor

[waynec]

I have a new motor for my Z axis as part of my Shopbot PR upgrade. Its a larger Z axis motor with 4 wires that are connected to two separate windings in the motor. The stepper motor is from Tormach.

How do I connect these to the existing Z axis cable? This cable has a gray plug with several wires. If I knew the function of these wires or which colors to connect the coils to it would be great.

Thanks for your help.

Wayne from White Salmon

[richards]

Wayne, you have two coils per motor. There are two wires per coil. Use a multimeter to check the resistance on the wires. Low resistance will show which wires belong to each coil. Do the same thing with the original motor to find which wires go to the coils. Then just splice in the new motor. If it turns in the wrong direction, reverse the two wires on ONE coil.

[waynec]

Thanks Mike
I'm with you on finding the coils. But my shopbot Z motor has six wires, including a pair that are connected to the same post in the plug.

When I ohm them out, there appear to be two sets of three wires. Can I assume three of these are are ground, halftap, and full coil?

I guess I can just measure the voltages at the plug from the control box, and connect these voltages to the coils of the new motor, right?

Thanks for your help again.

Wayne C.

[richards]

Wayne, on an Oriental Motor 6-lead stepper motor, one coil uses the Black, Yellow and Green leads. The other coil uses the Red, White and Blue leads. Full-coil connections would use the Black and Green leads for one coil and the Red and Blue leads for the other coil. The Yellow lead and the White lead would be individually taped off and not used. When the motor is used in half-coil mode, then EITHER the Black and Yellow or the Yellow and Green leads would be used for one coil and EITHER the Red and White or the White and Blue leads would be used for the other lead. The two unused leads would be individually taped off and not used. If you used an ohm meter to check the resistance of the six leads, you would find that the Black to Yellow and the Yellow to Green readings would be about 1/2 the value of the Black to Green reading. In other words, the Yellow lead could be considered to be the "Center-Tap" lead. On the other coil, the White lead could be considered to be the "Center-Tap" lead.

On your replacement motor, you'll still have to determine which wires go to which of the two coils with an ohm meter.

[ljdm]

Wayne - you have mail

[waynec]

Mike, thanks again. This was what I was wanting to know. Now I can get the motor wired correctly.

Now on to figure out what's binding on my ballscrew mount. The travel has become very stiff, and I think I may need to shim or adjust the bearings at the motor end to line the motor axis up with the ball screw axis.

I'm so close to a working upgrade! Thanks for your help again.

Wayne from White Salmon

Lou - got the mail just this morning. I may need the same sort of documentation from Alan at Custom CNC for my Ascension box. Thats a few steps off yet. I want to get the mechanicals done using the PR controller first. Then introduce the Ascension.

But at least at this point I know my gantry moves, and the Y car works great. Its gonna work!

Wayne