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Mar 8, 2021
Hey everybody. First and foremost Id like to say that I am finally registered on the site and look forward to being a member of the community. After having leached from here for many years I decided enough was enough. I look forward to sharing my knowledge and absorbing what I dont know from all of you. Anyway thanks to all who can help me with this problem.

I have an ht20sii spindle ( hitachi seiki hi tec turn 20sii) and I have very little knowledge with cnc lathes apart from running them in a factory setting. Anyway, I am building a lathe and designing the headstock out of epoxy granite to accept this spindle. It will have a precision drilled tube for a tap in fit. The issue is that this spindle I purchased came without the lock nuts, pulley/sheaves, and whatever else goes on it after the bearings. I did purchase two 90 x 2.0 nuts intending to double nut them after preloading the spindle. I will be making a rear mounting plate/flange with a lip since 8ts missing also. From what info ive gathered I can assume I need to draw the outer bearing races together when bolted to the headstock to keep everything in a fixed position. Do I need a wave washer or belleville washer on the outer race between the flange to allow for thermal expansion? Also a belleville or wave washer between the nut and inner race? I just don't have much info on this spindle apart from the very rough technical drawings with a few dimensions on it.. All I need to do is get preload in spec and install a drive pulley which.... I cant find anywhere. The spindle shaft goes from 90mm to 80mm and does have a keyway on the 80mm section, which I meant to also say because not having a keyway under the 90mm nut prevents locking the nut with a lock washer. Anyway I have a link here to a picture of it. I just recently bought it off ebay so this is an original link. Anyway... The bearings feel awesome but I will be cleaning everything completely and re-greasing.

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