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I need a little machining on a ER25 1 inch shaft

metron9

Aluminum
Joined
Oct 29, 2009
Location
Minnesota U.S.A.
I am in the process of completing my first 3 access CNC machine. At the moment I have a rotozip for a spindle. I have on order an ER25 chuck that has a 1 inch shaft. initially I thought i might use some 1 inch inside diameter angular ball bearings and the ER25 chuck and make a spindle that would be good for perhaps 1500rpm for cutting aluminum 6061. I see I can buy 25mm inside diameter and i am wondering if someone could trim down the 1 inch shaft to press fit the 25mm bearings.

Link to video of 270ipm ballslides and at the end is the CNC machine in process of being built.

YouTube - ballslides270ipm 2010_01_28_23_34_20.avi
 
Look harder.

the same bearing will be available with the Imperial size bore.


My bad, I should be more specific.

I have done some more research (on Practical machinist actually) And found that a "slip" fit is used for a spindle , my initial concern was that a slip fit using a 1 inch ID bearing would not work because I had mistakenly thought a press fit or heating the bearing and slipping it on was the only way to do it thus using a smaller ID bearing and reducing the 1 inch shaft to fit.

By the way, would it even be practical to reduce to 25mm if the tool has been hardened? This is just a question for my future reference, if hardened shafts can be milled or perhaps would have to be ground. Further, to get the tolerence needed for a press fit what would one have to use to do it?
 
Such a spindle should be ground between centers. A surface grinder operation.

The ER25 holder that I have is built on a 22 mm shank with a hollow end. I have not checked, but I would expect that such a tool could be fitted between two "regular" centers.

By the time you pay shop rate for such a modification, ........

At 1500 rpm, You could do just about anything as far as bearing fit and installation. That is not fast. Heck, you could use bronze bearings.

thoughts only....

ps to go from a tight to loose fit, some wet or dry paper while the piece spun in a lathe will do that. Slow, but you have time.....
 
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