Buy a tapered reamer
You’ll find plenty of uses for that afterwards
Drilling a hole with a 0.01mm tolerance is not something you can do with a drill bit… a 10mm drill bit is usually at least + - 0.2mm especially if you are drilling by hand or with cheap machinnery. But then do you really need that tight fit? @Thomas_Sanladerer is as usual on to something, use loctite.
Drilling a hole with a 0.01mm tolerance is not something you can do with a drill bit… a 10mm drill bit is usually at least + - 0.2mm especially if you are drilling by hand or with cheap machinnery. But then do you really need that tight fit? @Thomas_Sanladerer is as usual on to something, use loctite.
I am planning to drill with 10mm, test the fit, then if necessary let the bit at 1/3 of its length rotate inside the hole to enlarge it due to wobbling, then again, if necessary let the bit at it’s half wobble in the hole, test again, etc, until I reach the tip of the drill bit … until I feel I am closing in. Then measure with calipers in the process to make sure I am where I want. I will see from there. If I reach to 10.5 or more maybe even with rough sandpaper I’ll be able to shave off the remaining few tenths of mm.
Suggestion #1: There are tools for widening a hole without changing its centre or roundness. (Though 10-11mm is teeny)
They are basically a few pieces of sandpaper wrapped around a spring-loaded part, attached to a drill.
You could jury-rig something similar; drill 10 or 10.5mm hole, wrap a small amount of sandpaper around the bit (with some extra paper forward as a taper) and shove in to widen the hole. Repeat with more and more sandpaper.
Suggestion #2: What about shims? Drill 11mm hole. Calculate difference between OD and hole diameter. Get pieces of aluminium sheet about the right thickness. (drink can?) Insert bearing and shim material into hole, checking for tightness. Trim excess off afterwards with side cutters or etc.
@Patrick_Barnes It’s a possibility but the bearing are so small I’d have a hard time inserting shims around them.
@Florian_Ford You mentioned using the non uniform nature of a drill bit to create a larger hole which in my experience usually ends up being a triangle, I meant use it like a die grinder and rotate it around in the hole while moving it up and down. It’ll chew out the aluminium quite easily and is how I’ve made slotted holes in aluminium many times.
@Steve_M Yeah that’s what I did in a scrap piece, it worked out pretty well, together with a mouse tail file… it was some work nevertheless, not very straight forward
not complaining, just reporting it did take some elbow grease 