3018-PROVer φ52mm Aluminum Spindle Holder

Great addition

Looks solid, Can’t wait to try it extensively!

z-axis upgrade (v2)

I recently purchased the z-axis spindle holder (V2) upgrade for my 3040 Prover. It is sturdy and well built. After adjustment, it is much more rigid than the original. I have only used it for diamond drag engraving (which is a good test for deflection caused by the spindle and z-axis assembly. Installation was obtuse, and I had to make two tries to get it right. One thing the manual didn't mention, but I had trouble with was taking the screws out of the linear rods, as there is nothing to stop the rod from spinning once you loosen the screws, nor was it possible to remove them because of the thread lock compound. I ended up having to make an aluminum collar for my vice-grips (no other pliers would hold it fast). This is not ideal for precision-ground surfaces. Not sure what the engineering fix for that would be, but I managed without obvious damage to the x-axis.

Not compatible with PROVer v2

Installation is straight forward. Once installed however it becomes aparent that this Z axis isn't compatible with the PROVer v2: the positive X axis limit switch cannot be reached and the Z axis collides with the X axis coupling nut. There doesn't appear to be a way around this other than substituting the X axis stepper for one with integrated lead screw. Such a stepper isn't available from Sainsmart so Aliexpress with a customised lead screw length seems to be one of the cheapest options. To their credit, Sainsmart recognised this and offered a complete refund for return, or a 50% refund to keep the Z axis. I took that latter, so I can use that to find a solution. Something to note also is that since this Z axis is made of metal it damps vibration less than the original plastic Z axis. In my case the vibration is transferred to the X axis linear guide rods. Precision machined collets and clamping nuts become more important now, particularly if you want to use the 20k RPM spindle motor which can transfer a horrid amount of vibration to the X axis guide rods. Sadly not the best upgrade experience for me, but I'm otherwise happy with the level of service from Sainsmart!