JPG40504 wrote:I assume the quill is replaced for the same reason the main shaft and idler shaft is. Old(worn) bearings and 10k rpm are not a good combination(the idler shaft would run at 16K rpm).
Realize that also replaces the splined shaft and socket(nylon).
That makes the entire power train 'new')
I spent some time testing bearing RPM ramges over periods of time using a home made quill bearing test jig driven by a dc motor. I could test bearings up to 22,000 RPM with and without load. I found the single bearing quill bearing was rated up to 7,000 RPM without load. Even using TRBS3 bearings, I could only operate safety up to 11,000 rpm. TRBS 5 & 7 rated bearings was good to 17K TO 23k RPM but the bearing are many times more expensive.
I found most of the double bearing quill bearings faiiled around 7,000 RPM with the second smaller 32 mm OD bearing failing around 5,000 RPM.
Not all same size bearing will support higher RPM. I have built many difficult testing jigs/setups to test the maximum failure limits of various Shopsmith bearing and parts.
My testing of quill shaft runout (being bent) shows about 25% of quill shaft have a greater than .002" runout/deflection. I sell double bearing Gilmer and Poly-V quill assemblies with less than .002" runout or deflection as this is the maximum runout that I sell. I have dozens of quills with .003"-.033" deflections that I cannot use.
Contact me to see what tests and equipment and other information that I use for these tests.
Bill Mayo
bill.mayo@verizon.net
Shopsmith owner since 73. Sell, repair and rebuild Shopsmith, Total Shop & Wood Master headstocks, SPTs, attachments, accessories and parts. US Navy 1955-1975 (FTCS/E-8)