(02-26-2014, 09:55 PM)Hawkeye Wrote: I think I tried to incorporate some of the features of that one, plus some from other sources. I tried injecting air, but it didn't make the spindle move any easier. I haven't seen any plans for an air spindle.
Making an air bearing is pretty much beyond the reach of the home machine shop. Clearances are on the order of 5-50 microinches and the air must be clean, dry and well regulated for the bearing to function. Too much or too little air pressure will move the shaft off center so it binds on one side.
(08-10-2014, 01:18 PM)TomG Wrote: Making an air bearing is pretty much beyond the reach of the home machine shop. Clearances are on the order of 5-50 microinches and the air must be clean, dry and well regulated for the bearing to function. Too much or too little air pressure will move the shaft off center so it binds on one side.
Tom
Are you sure Tom , Philip Duclos has made one "Floating end mill sharpener" described in his book "The shop wisdom of Philip Duclos" floats on an air bearing .
I should have said "Making an air bearing well is pretty much beyond the reach of the home machine shop". Two thousandths clearance is going to allow the spindle to move around a lot more than I'd like to see for sharpening end mills. I suppose if one was willing to invest the time, the spindle could be lapped for a closer fit.
08-10-2014, 06:34 PM (This post was last modified: 08-10-2014, 06:35 PM by stevec.)
Tom, I sorta agree with you.
This "Asian" machine's spindle is on an air bearing .
It gives me the impression that the "air bushing" can deviate depending on the operator's influence as the spindle is drawn back.
Even the "needle" that the flute follows allows for inaccuracy.
I generally relegate the re- ground mills to less than precise work, (which ,sigh, is what most of mine is).
This cat over on Mad modder done an excellent job at making one designed by Duclos, his thread was exceptional, read the whole thread you will enjoy it.