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Motion control problem (Exlar - Parker - Galil)

Motion control problem (Exlar - Parker - Galil)

Motion control problem (Exlar - Parker - Galil)

I have an Exlar SR-series electric linear actuator connected to a Parker Aries (AR-08) type drive. This linear actuator pushes a table/cylinder assembly upward and downward for an additive manufacturing process. Anyway, when I tell my control software to move this particular linear actuator, it goes in the opposite direction that I tell it to go. It does this for about 10 to 20 turns of the screw mechanism then stops, at which point, a bridge fault registers on the Parker Aries drive and the actuator becomes unresponsive. I just had this actuator serviced, so I'm thinking Exlar switched some wiring around or something. Could I go into WSDK menu and just switch the polarity of the motor to make it go in the right direction? Also, is there a way to get rid of the bridge fault so that the actuator doesn't stop working. I've checked phases of the actuator and the drive as well as checked the integrity of all cables. I'm thinking it might be a software issue.

I am double-checking the wiring between my drive and my control card (Galil 17XX/18XX type) this afternoon. I just sent that card in for a service evaluation, and it came back negative. I'm just looking for any advice that might be useful in resolving this issue. Thanks.

I am by no means a controls expert as my expertise is in materials and manufacturing processes, so in response to that I say: I'm not worthy! I'm not worthy! I'm not worthy. :P

RE: Motion control problem (Exlar - Parker - Galil)

Hopefully you have the Users Manual. If not download it like I just did.

A "Bridge Fault" can be caused by two things. A screwed up bridge, (the bridge is what does all the power switching to the motor). Or, an overheating bridge.

I see things are moving in the wrong direction. While bad for your process it shouldn't be bad for your drive system. However for a bridge fault to come with it means they could be related. Once the fault occurs you should power off the drive wait for the capacitors to fully discharge(5 minutes) then see if you can turn the leadscrew further in the direction it was traveling when the fault occurred. A bind-up could be causing the fault.

If you can't continue to turn it in the direction check to see that you can turn it in the opposite direction. If you can move it back but not forward you likely have a mechanical problem that needs to be corrected.(as long as it didn't stop moving because it bottomed-out.

If you can easily continue the leadscrew in the direction the failure occurred in then mechanical issues are likely not the problem.

The motor will move in the opposite direction if you've accidentally reversed two of its power leads. Your linear drive likely has limit switches or an encoder that would expect the motor to turn a specific direction. If the motor is turning the wrong way you can have the drive driving the screw in the wrong direction until it bottoms-out or 'crashes' at which time you're handed a drive fault.

You should check for that possibility.

Keith Cress
kcress - http://www.flaminsystems.com

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