a Steel Box Section Build with SBR20 & Ballscrews Plus a few questions

[Lee Roberts]

Typically you would spot drill the hole first with a spotting drill bit (like a normal bit but shorter and so stiffer) or a center drill bit, a smaller diameter drill bit maybe used as/or well, just take your time as they snap easily at those sizes.

I can't see this would be a problem with your bench drill though, would continue to use it instead of going free hand personally.

.Me

Edit: Not sure if you've settled on a Z Axis design yet but here is a link to how I've done mine using 20mm plate and TBR16 round rails:

Link: http://www.mycncuk.com/album.php?albumid=387