DIY surface grinder

[petertha]

Nice. You show 2 different spindles, the repurposed mill/drill & the other slender ?combo motor?. I'm looking to make a mini version for the lathe toolpost. Not a regular duty hp like a Themac, just a baby for small finicky parts. I have seen many versions of Dremels & Foredoms & other 'hand grinder' type motors adapted, but I always wonder about the bearings, both in terms of runout & heat. I do want to strive for accuracy over hogging material or just making it shiny. I have some plans using angular contact bearings that I can adapt & scale but requires detached motor & step up pulley.

Can you comment on yours? Does the all-in-one motor/spindle run quite accurate? What kind of rpm/watts is it? How are the bearings & how long can you run? I've seen some China cnc router ones but after about 500-700 watts they seem to have water cooling & many are VFD,

Sorry for all the questions, figured you would be a good guy to ask!