[cadmonkey]

Hackmax - Do you have any pics or drawings of what you ended up doing? If you could post them, or PM me for an email address to send to. If you don't mind I'd like to show some pics of how others have modified the plans to suit their needs - financial, phased implentation, etc. Thanks.

Also - with the ACME screws you can definitely go 1:1 on the Z, or even a step-up ratio. I know the 2.6:1 is overkill and I may end up going to a smaller ratio in the future to get better rapids. I rapid around 30 safely but that is a limit induced by my PC - it just can't send quick enough pulses for microstepping. With 16tpi ACME vs 5tpi Ballscrew, you've already got 3x the advantage. When you do install the ballscrew on Z if you go 1:1 then be conscious of backdrive when powered down - you may need to add a gas strut as I believe comes standard on the SuperX3 - this was part of my decision to go with the 2.6:1 - the natural cogging of the motor when coupled with a high ratio to the screw was sufficient to eliminate backdriving, even if I loosen the gib nearly to removed.

I toyed with the idea of doing Z on the ACME screw when I got the X and Y done since the Z didn't seem to all that have much backlash with the gearing of the front handle taken out of the equation, but since I had the Z ballscrew in hand since I had ordered a stock 6' length it wasn't worth the time to put AC bearings on the ACME. I do want to go to a preloaded double nut on the Z though - there's enough backlash with a single nut that I am not satisfied with and the best DIY double nut setup I can envision would loose some top end travel which I refuse to give up. The factory double nut is just longer than the standard nuts I used so it runs into the area that is at the bottom end of the travel that never gets used. That upgrade will wait for tax refund to come, doctor bills from the Cleveland Clinic to start showing up so I know how much they charge vs what my insurance covers and whether or not I am able to stay employed with my decreased performance under the diagnosis I have finally gotten from the high quality care in Cleveland. (eg - there are a lot of variables that need to be evaluated before I buy a $300 ballnut (IIRC) so that is VERY back burner). I am curious what size steppers you ended up using that are suited to ACME and ballscrew?

I know the stock 'adjustable' brass nuts were constantly in need of adjjustment while I was machining the parts and I ended up putting on digital scales to be able to machine accurate enough for the parts to come out with centerlines where they needed to be. And that was manual where speeds aren't as demanding as the speeds you'll see on CNC or loads with cutting forces involved.