I am really struggling with the selection of ball screws. I would like to go with THK, because they have a wide range of options with online prices, but a few things remain unclear. My assumption is that I should go for the BIF set (Precision Ground Ball Screw-Non Backlash):
https://www.thkstore.com/products/fe...s/bif-set.html
And for reference purposes, the 3 axes of my machine are as follows:
# X axis:
Orientation: Wallmount
Stroke: 1000mm
Weight: 125kg
Rapids: 1,200ipm
# Y axis:
Orientation: Horizontal
Stroke: 600mm
Weight: 250kg
Rapids: 1,200ipm
# Z axis:
Orientation: Vertical
Stroke: 300mm
Weight: 75kg
Rapids: 1,200ipm
I went for 32mm shafts because this is what DamenCNC recommends for 1,500W servos:
https://www.damencnc.com/products/me..._314_2329_GB_1
Is that the right way of thinking about it? Most importantly, isn't it oversized for the Z axis? Ideally, I would like to use the same shaft diameter on all ballscrews in order to use the same mounts and brackets for all axes, but I want to make sure that oversizing a ball screw for a particular axis won't lead to a loss of precision.
In order to get 1,200ipm with 3,000rpm servos, I am planning to use screws with 10mm pitch. Would I get more accuracy with 5mm pitch models (in which case the rapids would go down to 600ipm of course)?
For the X axis, it seems that I would have to buy the 1,430mm version. And for the Z axis, the 730mm version. This seems like a massive waste of precision-grounded shaft. Am I missing something?
Also, what kind of service provider should I work with to finish the shafts for using BF20 and BK20 mounts in a supported/fixed configuration? Should I work with THK directly for the finishing, or am I better off working with a local shop?
Finally, where could I find a nut mounting bracket? The only one I could find is for the BNK line:
https://www.thkstore.com/products/fe...screws/mc.html
I am really sorry for all the newbie questions, but no amount of catalog review seems to provide answers to these.