Thread: cnc not cutting like it should

There have been a lot of reports re cheap TB6600 drivers missing steps, incorrectly labelled DIP switches etc. but I would have expected those to show up from the beginning. Mine had cheap opto couplers as reported in a CNC zone thread and it was causing missed steps which changed with load, but it was evident from the start. I replaced the opto couplers as outlined in the same thread. Easy to check once the driver case cover is removed.

Check all couplers, set screws and bolts are tight.

Sets screws on couplers can work loose over time due to vibration and slipping can result (motor turns but ball screw doesn't)

Troubleshooting via forum is difficult. Best we can do is suggest common issues.

mechanical is a common start place.
you could try a pen and run without spindle to see if it is spindle noise.

This gives one method to check slippage.
An Aid for Troubleshooting Missed Steps - YouTube

Electrical Noise is a beast of a thing to sort if you have issues.

Hi
My advice in the first instance before you do anything is to right back to basics. First draw a square or a circle of a given size, put the allocated tool (make sure this is correct) and machine. If this appears to be correct measure it and compare it to your drawing. They should be the same.
Now if this is not working you could have a problem with the following, (I am now assuming you have used the correct tool).

1. You have a compatibility issue with your design(drawing)software and the post processor (some people call these drivers)
2. Your post processor is not compatible with your CNC for some reason
3. Your design software is not sending the correct file to the postprocessor to read. There are numerous file types so you must make sure you are using one (file type)that the post processor can read.

I have no experience with your stated software or the CNC pictured, as I use numerous industrial high end CNC machines, but the issue you have is typical across all machines/software/post processors.

Maybe you do have a lemon but try what I have suggested first before you have a panic attack.

Hope this helps

Kevin

The problem he has posted is not a postprocessor issue.

How would part of the circle / gear be ok and part messed up?

It's going to be lost steps / something slipping.

Hi

Fair comment, but as I teach CNC machining at a Melbourne TAFE college to apprentices, we start problem solving from the beginning. My comments are standard 101 machining problem solving, that's all.

This forum is here to offer advice, I have offered advice from my perspective as I see it. If you see different, fine.

Kevin

I think the important question is - Has the problem been there from the start or was it cutting fine for a while and is now causing what we see. If it’s the latter, has there been a change in equipment or software or settings?

Originally Posted by Lappa

I think the important question is - Has the problem been there from the start or was it cutting fine for a while and is now causing what we see. If it’s the latter, has there been a change in equipment or software or settings?

Thank you very much all you guys that have responded to my problem. Very helpful indeed. I have purchased new stepper motors, breakout board, power supply and would be replacing the ones that came with the machine. Will also check for any mechanical issues that is causing miss steps. Hopefully would resolve the problem. Thanks very much for all your help and suggestions. I am extremely grateful. Stay safe