Quote Originally Posted by Chrono View Post
Ah yes, indeed it is 12m/min, don't know how I have read that wrong every single time...

I have been using the spreadsheet to dimension all my motors so far. Is there a better way to do this, or will it all just come together in the final build? I am guessing there is no real way to account for all the variables the steppers will be influenced by when it comes to it, but I guess what I am asking is: Is it still a good idea to run the motors you can find through the spreadsheet to find the "best one" you can still drive?
Lots of things come into play, not all motors are equal for instance and same size motor can have ridicuously high inductance compared to another and the spread sheet doesn't and cannot really account for these variables.
Combine this with all the other variables and it's very much trial and error in some ways.

For instance I've helped folks troubleshoot machines with motors that would lift empire state building yet they stall and run slow because they wrongly sized components like ballscrews, gearboxs ratios etc or they did such poor job of building and allignment the machine is crippled.

The best advice I can give is to look around for similar size machine built with similar materials/components and copy what works.

Thru experience I can tell you that Single 4Nm nema23 with inductance around 2-3Mh wired in parallel running 4 to 4.5A with 68Vdc on 80Vdc Digital drives connected to 16mm Dia10mm pitch ballscrew with a Good motion controller (not parallel port) will easily and reliably reach 12M/min moving 40-50Kg.

For longer than 1200mm 20mm 10mm pitch screws you'll need to use nema 34 or use method like I suggested using larger pitch with ratio.
Same for dual screws you'll need 2 x Nema 23 upto 20mm Dia, Single 4nm Nema 23 won't drive 2 screws, even with ratio.

If you go to nema 34 then for better speeds you'll need more volts.