Any suggestions greatly appreciated.
Belt driven Diode laser with laser side mounted on a Hobby CNC machine.
4000mm/m 100% (Should have backed the power off a bit).
It’s the “squiggles” in the circles where I am looking to correct.
Will re run when I get a chance at lower speeds.
Cheers,
Steve
how low is the module vs the X gantry
Seems what you having is just a bit of harmonic vibrations on your module
Assuming is hanging a bit “low”
4000mm/min on a cnc frame might be a little optimistic. They weren’t built for speed. they were built for rigidity on contact cutting forces and torque
Maybe a picture of the machine would give some additional clues
You may be onto something.
The Laser slide mount, custom made, does have a little movement in the Y axis.
Cheers
i thought so
Pendulum effect on high speed
Of course you can cut speed and power in half
if there is a significant improvement you found the “WHY”
Not much you can do on a CNC setup except LIFT the material as much as you can vs the center of gravity of the X axis. which in your case is above the module
test #2
Try nudging a chim there to put some pressure on the back of the slider just so it cant wiggle and vibrate
Was looking to “shim” it to stop that movement.
Good call.
Is this still the motor issue?
Have moved your post to this new topic to avoid cluttering the other one.
Thank you.
Apologies to all for getting off topic.
My first thought was my issue was related to motor calibration or the like.
Cheers
No, Re-tramming the router after removal is a pain.
Looking to add a second bracket or shims between the router and laser backing plate to remove possible harmonic movement and increase resistance on the slide to remove any Y axis movement.
I was also able to raise the laser by around 12mm on the slide plate. Hopefully will reduce X axis vibration.
Will be re running the tests @ 4000mm/m to judge any improvements.
Thanks all.
If they are harmonic vibrations, which did look like it, shimming might help but wont fix it. you will have to literally break the frequency. higher speed or lower
I would still do a half speed/half power test to have a comparative
No worries, it sounds like you are on track to reduce that wobble.
Overall your backlash test results were very good, but some noticeable play in the X-axis:
Working on the idea if i can reduce the “speed wobble” at high speed, at lower speeds will be perfect.
2000mm/m 30% after shimming, all is firm with the laser and mount.
But to me hasn’t changed the circle wiggles.
X axis backlash maybe? Since some circle ends don’t even meet up!
Thoughts?
In the process of calibrating the stepper motors… X was out by more than 5mm across 600mm of travel. Y wasn’t too bad.
Now i might be on track.
I have a cnc router/laser and I found that it was better to remove the router keeping the inertia down was worth the effort . Otherwise put up with less far speed.
I’d suggest a change of tactics.
A head with more mass takes more energy to accelerate it. Anything that hangs below the gantry/bearing point will act like a pendulum. Adding brackets may help but will exacerbate the original issue of increased mass. I have to assume you run the laser faster than your mill cutting wood or metals.
I would look at a change in acceleration values over all the other options you’ve tried.
It’s easy, quick along with it being at no cost. If you have the same issue, then you can return to this path, but I think you’ll see a change with a slower acceleration value.
Changing the acceleration values makes sense. Can you provide more info please?
