Flat bottom hole

[bertterbo]

I want to drill a flat bottomed hole to accept a 608-2RS bearing, and then also a through hole for the 8mm center.

So 22mm OD, and 8mm ID. The flat bottomed hole would need to be about 7mm deep.

How would you do this with bright mild steel and only a floor standing drill press?

I'm assuming it's not really recommended and would be more of a milling operation?

 

[niall Y]

The ideal tool for this is a counterbore. And you can use these on the pillar drill The 8mm pilot hole would be drilled first and the counterbore is lined up in the guide hole to cut the outer diameter. But trying to find one with the exact dimensions you require is where the difficulty begins.

I do have a few useful ones I inherited from a neighbour but in the past I've spent many fruitless hours on the internet, searching for ones with the exact outer diameter and pilot hole I needed . There are sets available with interchangeable pilots but these would end up being quite pricey for just one hole

 

[TFrench]

Definitely a lathe or mill job. I wouldn't want to rely on a counterbore to get a bearing fit. If possible I'd also drill and tap two holes on the backside of the bearing housing so you can use 2 bolts to push the bearing out, should you ever need to in future.

 

[ChaiLatte]

Could you make from two parts?

Something 7mm thick with a 22mm through hole bolted, welded, glued, soldered etc. to the part with the 8mm hole.

Buy two bearings as they are very cheap and use (sacrifice) one to make sure the two holes are concentric while the weld dries or the glue cools.