Thanks for the feedback. I’m not trying to suggest that there may be a issue with the Cohesion3D LaserBoard. I hear nothing but praise for them. I have only had mine a couple of weeks and am really impressed with it.
Perhaps I have a problem Y motor on my machine or there is some twist in the carriages that is causing an excessive load?
Jumping straight to external TB6600’s may have been influenced by very recent issue trying to upgrade my 3D printer from Pololu A4988’s to DRV8825’s. Where my Z axis parallels 2 motors off one driver I was losing a lot of steps. I modified this to drive two external TB6600’s to overcome this problem. The thing is though, the A4988’s used to work fine. I only switched to DRV8825’s for the higher current capability.
You have made a very good quality product with so many useful options. A great deal of thought must have gone in to designing such a versatile board. Thank you