I’m new to laser engraving and I have a 10w longer ray5 laser. It’s been working fine and all of a sudden when it moves on the y axis it makes a loud grinding noise, it doesn’t do it on the x axis. I checked the belts and they seem ok. Any ideas?
If you have checked the belts and they seems ok i would check the motor steps, rate and acceleration values.
What should the acceleration values be?
I now remembered that you should also check whether, with the machine turned off, the bridge slides smoothly or whether it is stuck.
Regarding values, each machine has its specifics.
Mine, for example, has the $121 parameter (Y acceleration) in the 2,000s.
If the steppers on your machine are identical, these values must be identical on both axes.
That is typically not the case, because the gantry (typically moving along the Y axis) is much heavier than the laser head (typically moving along the X axis).
The higher weight of the Y axis requires a lower acceleration than the lighter X axis, because the motors generally have the same current through their windings, which means they produce the same maximum torque.
If both axes have the same acceleration and the machine operates properly, the X axis acceleration is almost certainly set too low.
I agree with you @ednisley .
Identical is subjective…
What I meant was that they cannot be the same but they also should not vary much and when I say “much” I am referring to the level of units never at the level of decimal places.
It also depends a lot on each machine and what they have “hanging” on the gantry.
On my machine there are two motors for the Y axis, and that’s probably why the acceleration values don’t vary much either…
In principle, two motors should provide twice the torque to move the gantry, but its mass may be more than twice that of the laser head and the mechanism certainly has more frictional losses. If the motor windings are in series, then the stepper driver has less ability to change the current rapidly, which dramatically reduces the maximum step rate.
Although nobody runs the tests required to set the values correctly, a factor of two would be unsurprising.
Yes, no doubts about it.
The board I use is an MKS DLC32. It has a drive for each axis but two outputs for the Y that I think (this is what makes sense to me) are connected in parallel.
Between pros and cons, it may be better to have two steppers than just one. (This is as long as they work well) But it’s just the opinion of someone who has been discovering (very slowly) the “world” of these machines and still has a lot to discover and understand.
In the entire process of optimal adjustment of the machine’s operation, I went through the phase in which the movement was so sudden that the machine itself moved from place.
If they have separate motor drivers for the two motors, that’s fine.
If not, however, a parallel connection to a single driver does not ensure equal currents in the windings of both motors.
The motor winding resistance is on the order of a few ohms and, because manufacturers use the cheapest possible cables, the resistance of the additional wiring + connectors for the most distant motor adds up to a significant fraction of the total resistance, reducing that motor’s current by a similar fraction.
Which means the two motors produce much less than twice the torque of the closer motor, which should call for a reduced acceleration setting. It’s all deeply connected!
Newton figured it out long ago: every action has an equal and opposite reaction. 
Everybody is surprised when motion happens, because the laser head is a significant fraction of the total machine weight. Even for lighter heads, moving the frame by a fraction of a millimeter produces visible defects in the engraving & cuts.
That’s even more true with the recent and aggressively over-powered laser heads. I’d be unsurprised to find the head weighs half as much as the rest of the machine. 
Let’s shorten this because I believe it’s starting to be off topic (for which I apologize to @Trammell08 ) and a subject to be discussed in another topic. (which is most likely to already exist)
By chance, I already replaced all the wiring on my machine with stronger wiring. At the time I even considered maintaining the cable lengths precisely because of the ohmic resistance. But I believe the effect is so insignificant that I chose to place the cables with just a slight gap.
As I also never noticed a difference in heating in the drive cooler between the X and Y axis, I think the drives are well sized for the steppers and therefore don’t notice any difference in relation to torque.
Indeed!
We’ll meet again in another thread …