[glofuel]

Hi Guys,

I am using 22 gauge wires (7.02mm) on 1Amp stepper motors they are bi-polar. I have a twisted pair for each winding which are unshielded (not screened) (2 twisted pairs per motor).

Will this cause problems ? Because after running the machine for a couple of weeks with the driver boards and wires roughly hooked up on the bench which worked perfect I decided to re-wire the machine properly as it were and put the PSU and driver boards in a box.

But I am now experiencing strange results. The Y axis Motor and driver board seems to be getting much hotter than before and sounds if it may be loosing steps along with strange sqeeling noise which I did not have before. X and Z seem to be fine.

Only physical/mechanical/electrical difference is that the Y and Z axis twisted pairs are running next to each other in a loom with spiral wrap keeping them together, would they be interfering with each other ? Total length is approx 1200mm (48")

Any Idea's guys ???? (group)

[widgitmaster]

When I hooked up my stepper control box, I had lots of noise from the step & direction lines going to the motor leads, this made the motors do wierd stuff! One of the gurus on this site told me to use shielded cable for everything, and only ground one end of the shield! This has made everything run perfect, no hum, no lost steps, now radio voices from the motors! Yes, voices & music! I thought I was going bonkers!

Here is a greate site for getting multi conductor shielded cables!
http://www.action-electronics.com/cabl-prc.htm

Good luck, hope this helps!
Eric
http://kiersteadskis.com/cnc-router/cnc-router.htm

[NC Cams]

Take a cheap compass (as in direction finding) and place it near the wires while it is running. A cheap AM radio might work as well. Watch for compass going nuts or radio static.

The current flowing in the wire WILL cause a magnetic field in it which can induce a current in a surrounding/adjacent wire. Twisted connectors and shielding help prevent this BUT a 48" long parallel path is a long one.

You can't see electrons, therefore you can't trust them and there is no way to insulate for magnetism.

[glofuel]

Thanks for reply guys,

I guess I will have to try screened cables. I also thought it could have been the switched mode psu's to close to driver board's but it was'nt. I did move the wire's around a bit and it did seem to improve on the noise side of thing's, maybe I should drag my scope out and have a proper look.

As for hearing the radio coming from the stepper motors, this is not surprising when you think about it all driver/amplifier circuits suffer from interference and the motor has a coil just like a speaker. I remember some time ago building a PA amp for a band I used large resistors instead of speakers to test output power and they produced music sound clear as day - not much base though...

Cheers

[stdly]

Eric,
What gauge was that sheilded wire you used and what amp are your motors?

When I hooked up my stepper control box, I had lots of noise from the step & direction lines going to the motor leads, this made the motors do wierd stuff! One of the gurus on this site told me to use shielded cable for everything, and only ground one end of the shield! This has made everything run perfect, no hum, no lost steps, now radio voices from the motors! Yes, voices & music! I thought I was going bonkers!

Here is a greate site for getting multi conductor shielded cables!
http://www.action-electronics.com/cabl-prc.htm

Good luck, hope this helps!
Eric
http://kiersteadskis.com/cnc-router/cnc-router.htm

[widgitmaster]

My motors are 1.8A 144oz/in bipolar 8-wire, using Gecho 202's
My printer interface is the Combo board by Bob Campbell, its the best!
http://www.campbelldesigns.com/Combo-board.php
I have a 67VDC 6A power supply, by
http://transformertechnology.com/motorpowersupply.htm
I used 22AWG shielded cable for the motors, step/dir lines, and limit switches.
All multi-conductor plugs, sockets and panel meters came from Mouser Electronics.
http://mouser.com/

Hope this helps!
Eric