Need Help!- Motor Cogging

[offthewall]

I am new to this Forum, and was pointed here from the Mach3 forum.
I have been having some problems in my Z axis. I am running a Taig machine with a TurboTaig step & direction board added. My Z axis is running terribly, sounds horrible, misses steps, and hangs up. I looked at a thread about adding dampers. Seems like people add the dampers if they are having this problem at certain motor speeds, but I have it at all speeds high & low. Are there any other things I should be looking at before I invest time in making a dampener?

[tyty43086]

check for binding or misalignment of any components. is your z axis direct drive? if so what type of coupler are you using? try disconnecting the motor and turning the leadscrew by hand, does it turn free? even a very slight bind or misalignment can cause havoc

[offthewall]

Thanks for the info. My motor is direct drive. It uses the small nylon rods to drive the screw. I have removed the motor & the leadscrew turns very easily.
I’ll check a little better tomorrow.

[Monte]

Originally Posted by offthewall Thanks for the info. My motor is direct drive. It uses the small nylon rods to drive the screw. I have removed the motor & the leadscrew turns very easily. I’ll check a little better tomorrow.

Did you try running the motor while it was disconnected from the screw?

Monte

[offthewall]

Yes, it runs rough in either situation. I even switched motors, same thing on both. When I switch the plugs around in the controller box for the motors, the problem stays with the same port in the controller box. Thanks for the suggestions.

[Stepper Monkey]

Sounds like it could still be a lot of things, but if it is only on one port on the controller box and the rest function fine you have likely narrowed it down a lot. A damper will help with resonance but I think you have rightly guessed resonance isn't the case here if it is happening at all speeds and loads.
First and easiest is to check Mach settings for that specific axis and look at how the speed and acceleration functions and other settings on that axis differ from the rest. If that doesn't fix it start looking at possible RF interference from poor shielding, grounding, faulty wires, signal wires near power wires or power supply, etc. - all the usual suspects.
It could be other things as well, but you will likely find your problem in one of these two basics and even if you don't, you need know you have eliminated those variables anyway before going any deeper.

[Monte]

Originally Posted by offthewall Yes, it runs rough in either situation. I even switched motors, same thing on both. When I switch the plugs around in the controller box for the motors, the problem stays with the same port in the controller box. Thanks for the suggestions.

So you connected the X or Y motor to the Z output and it stayed rough? If it did that eliminated the motor as the problem.

How about this, I'm assuming the TurboTaig board is between the PC and controller, and I'm assuming you can change wiring a little, I don't have a TurboTaig or have I looked at it or a manual for it. Can you connect the Z motor output wires from the TurboTaig to the X or Y motor input connections on the controller?

Monte

[MonoNeuron]

These thinks can be a damn nuisance to figure out. Have you positioned the step and dir wires and also the motor wires as far away from the power supply wires as possible. This will eliminate any induced pulses in the wires. Check for a ground loop. You only want to have all your wires grounded on one end only (this is a very common mistake as some will ground the motor end as well as the case end and this induces noise in the circuit.) Mariss from Geckodrive is a legend on these things and even though he didn't make your machine he would probably help you out 'cause he's just such a nice guy.
Check and recheck. That's about all I can suggest you try. I'm just a hack but I get by.
Rich.