by 49-1183904562 » Sun Nov 16, 2008 7:05 pm
[color=#000000]WPH
OK,
If I were to do this conversion I would start at the rotating bearings first.
Is it bushing or ball bearing?
If bushing does it have play?
Is it easier to re-bush or convert to bearings?
Then I would look at the thrust aspect of the shaft, if the bushings are good can I convert the thrust to flat Torrington type roller thrust.
If I have to convert to bearing then I would use a precision angular contact roller like use in a Quill on a milling machine but smaller, this will give you both rotating stability and thrust all in one set.
Then if you look at MSC/JL they have a nice selection of Kenametal ER collet holders, you will need to choose one that will work for the range of valve stems you would work on and have an OD that will work in your set up. I/E the collet holder OD would either work as the ID of the bearings or a size you could bore your current heard to and then fit and weld etc.
The biggest problem here is this, the id of the collet holder must end up being true to the OD of the bearing mounting surface otherwise you will never be able to get total run-out below this machining error. I know because I am currently looking at doing this to one of my Black and Decker machines (I