G203V Random Direction

[bdring]

I have a G203V that has suddenly started going in random directions.

I was cutting the fourth piece of a set of parts. The Z was supposed to rapid up to my clearance height which was over an inch to clear some clamps. Instead it went the wrong way and dug into my part past the spindle nut. It did some serious damge to the z axis. I got everything repaired, but the Z is now totally random.

I have isolated it to the G203V. If I swap control wires with a different axis. The problem stays with the G203V and the other axis works fine. The voltages all look good on the control wires. I have a Smoothstepper, but I also verified the problem with a std parallel port.

I have heard others talk about optos going bad. Is this my problem? Is this user seviceable? I have an SMD rework station.

[LeeWay]

I had a problem similar to this before. After a week or so of frustrating trouble shooting and elimination, I got ready to tear the entire box up and start all over. The first thing I did was to unplug my motors from the box. It was there that I found the problem. One wire was not making connection. Repaired that connection and all was well.
Good luck with it.

[jhowelb]

Originally Posted by LeeWay ...........One wire was not making connection.

Good thing it was a 203V, bad connection will lunch many drives!

(LOVE those 203V's!!!)

[bdring]

I doubt it is a wiring problem, because I moved the wires to a different G203V and they worked on that one....moved them back and the original G203V and the problem was still there. I checked continuity to all the way to the terminal block screw heads.

[LeeWay]

Don't I know it. I burned out my first Xylotex with a very incidental grounding of one motor wire. Crap!.

It was actually on two axes that this happened. These were brand new connectors and I had no reason to think they would screw up like that. One of the spades in each plug just bent over instead of going into it's receiver.

I now use Trailer connectors.
The first ones on this page. These are made to be plugged and unplugged multiple times and still connect well. Pretty heavy duty. You can shop around and get a set for about $3. They also come with about 6" of wire already connected and ready to splice.
You can choose the 5 wire if you want to run your shield or 6 or 7 if you want to run an encoder or limit switch with the wire.
I've never had one of these fail......yet.

http://www.accessconnect.com/trailer_wiring_diagram.htm

[LeeWay]

Here is a troubleshooting guide that may help you figure out whats up.

[jhowelb]

I just lost a G251 because of an intermittent internal problem with a Kelling motor.

Was never able to find the short but the 251 sure did. A 203V would act up while connected to that motor but only on occasion.

Like chasing ghosts!!

[bdring]

More Info....

The problem appears to be in the cable to the Z stepper. The Y and Z have the same motors and drives. There is a connector right at each motor. They are AMP/TYCO plastic circular with high current pins (13amp). If I swap the cables to the motors, the problem moves to the other motor. The Z cable is about 15' long and the Y cable is about 9' long. Both are 16 amp high strand cables. I cannot find anything wrong with the cable. There are no shorts pin to pin and no opens. The resistance is less than 0.1 Ohm on all wires. I wiggled any tight bends or possible kinks when measuring. The setup was working perfectly for about 8 months.

Connector

http://catalog.tycoelectronics.com/T...&RQPN=206060-1

Contact

http://catalog.tycoelectronics.com/T...4&RQPN=66400-4

[bdring]

The problem was an intermittent open connection in the cable. I am surprised a stepper can still turn with an open.....anyway problem fixed...thanks for all the help