I have the X servo mounted as part of the mounting blocks for the X gantry; it’s one integrated system. I have the Z motor mounted and a homemade loop of timing belt around the ridiculously large Z bed I saddled myself with. But for Y, I still have a short timing belt loop forlornly dangling off a torsion rod, just waiting for me to do something about it.
My initial plan is to use the same kind of servo motors for X and Y. The servo motor should mount at the top of the low voltage electronics bay, below the business end of the laser. My plan is to cut another piece of 2020 extrusion, and use the underside of the first mirror bed plus that additional piece of extrusion to mount the servo. I’ll use a similar set of straps to what I made for X, but designed to attach to extrusion.
Unlike the saga of redesigning the Z stage, this one ran smooth, it seems so far. Removed the first mirror mount shelf, installed some more t-nuts in the bottom, mounted the motor loosely to the bottom, put the shelf back, slid the loop around, slid the motor back to tighten it, tightened all the screws and pulleys, and it seems quite solid. Very happy so far with how this worked out.
Since that shelf also holds the first mirror (see the 4 empty t-nuts in the first picture), I need to make sure that this shelf is very stiff. I might use some openbuilds t-joining plates if I can fit them in with the mirror.
All I need now is to design mounts for limit switches and I’ll be ready to hook this up to a controller board and see how it moves. Hoping I can tune the Tarocco board without building new firmware for it; I didn’t realize until after I bought it that building firmware for it requires Windows, which I don’t have installed on my laptop.
Turns out there is room for a t-joining plate on only one side, at least lined up with where the tube is now. I think it will be stiff enough. If not, I can probably slide the laser tube a bit toward the front, move the first mirror to suit, and then put a second plate in.
I originally cut that corner notch when I thought this shelf might need to slide over between the 4040 corner uprights. I should consider cutting a new shelf, I guess.
When I was testing this, the servo motor worked great for a short time until the controller died. I ended up replacing the servo motor with a stepper motor (at least for now). However, the more I think about this, the less I like it. Vibration from the stepper motor is bound to cause the first stage mirror to vibrate.
It might not matter because the Y motor is mostly stationary during engraving, and it’s moving slowly when cutting, so it is possible that it will be OK. But also I am considering damping the shelf, and/or the stalk on top of it, especially if in cutting, my X-aligned cuts are cleaner than diagonal or Y-aligned cuts.
