I seem to have just developed an issue with my Y-axis control - as you can see from the picture what should be a smooth engraving (settings I have used many many times in the past) now seems to be going wrong. It has also effected the cut round the outside of this disc - instead of a smooth edge is is bobbled / uneven.
Is this the sign that my y-axis stepper motor is packing up OR the y-axis controller has an issue.
I know it is not due to using a different material OR different settings for speed / power etc. as I have used this setting and material a lot.
Any help and suggestions will be greatfully received.
Slightly different artwork but same material (actually the same sheet) and the same settings. (this one is a bit battered as it has been in my son’s dice bag for a few weeks!)
Start by giving the machine a good mechanical inspection. Pay particular attention to the set screws in the pulleys and couplings. Also make sure the belts are fairly clean.
Hi Mike, I have checked all the coupling screws and there was nothing loose. I have given everthing a clean - there was a build up of muck under the sliders on the y-axis rails (there is still muck there) - is it worthwhile taking it all apart to clean these runners and the rails? Should the rails be greased / graphite lubricant etc.?
Are there pitfalls to watch out for if I did take it all apart to clean wrt putting it all back together? (apart from aligning the mirrors again.
If you tighten the set screw with the shaft in the position shown, it will appear tight. But it will still allow backlash. To make sure you are fully seated on the flat of the shaft:
Slightly loosen the set screw.
Twist the shaft back and forth while slowly tightening the screw.
Continue until you no longer feel any back and forth motion of the shaft.
Lock the set screw down.
For a coupling on the motor shaft, twist the coupling instead.
Check ALL set screws on all pulleys and couplings, starting at Step #1 above.
I used to be a Field Service Engineer for a urethane processing equipment company. Before shipping any machine I would be starting up, I would Q.C. the machine, including checking for lock washers and tightness of every bolt and nut on the machine. Even so, when it arrived on the flatbed truck at the customer’s factory, I would find nuts and bolts loose.
Moral of the story: If it came from China, expect to find things loose.
There is a backlash test file attached to this post that you can use to help identify/measure the issues:
Another thing to check is the focus lens, make sure it is not loose.
Less likely, but also worth checking, is for any small wobble or front to back pivot movement in the laser head, which can start to happen if the bearings in the x-axis carriage block behind the laser head/mounting bracket are wearing out (just try to physically try to wiggle laser head from to back as if the rail is the pivot point).
I have checked and tightened (and cleaned) everything and I am still getting the issue. I have also spoken to a techician who is saying that perhaps I could try replacing the stepper for the y-axis - I have seen this post Stepper Motor Identity and I have the same motor but later comments in this post suggest that a/ the stepper motor would be the last thing to break / wear out and b/ this issue was solved by a new / different controller.
How would I check for controller issues and would I need to replace both X and Y axis controllers? (Sorry if this is a dumb question but I have not specifically looked at the time of writing to see if both motors are controlled from the same board).
Did you try running it with a 90 degree scan angle? This should put the work load on the Y axes. Maybe it will be more visible as to what’s going on.
I haven’t seen anything, only a couple photos, that convinces me it’s the Y axes alone.
You can check the motor drivers for a red indicator light. This is usually next to the green one, which indicates power.
I don’t know Trocen controllers, so can’t really help you there.
There is no simple way to test any of the dsp type of controllers, other than swapping them out. But the reason, it’s unlikely is that it’s a computer, when parts in the controller fail, it’s usually more of a disaster and not bad steps… Same with motor drivers. They are tough as nails, many people have mis-wired them and they still survive. When digital equipment fails, it’s usually quite obvious.
I’ve never seen one that was intermittent in operation. Once they fail, they are generally not resurrected by a reset. So it the stepper was getting bad step commands, it would be continuous.
This is what we see, doesn’t mean it’s written in stone. I’d try to figure out a better way to determine the failure. That’s why I suggested a 90 degree scan angle, as a test.
At the controller board, swap the Xaxis and Yaxis plugs. If the issue frmains with the same axis, it is a wiring, drive coupling, or motor (in that order) issue. If the issue moves to the other axis, it is a controller board issue.
