Posted by Stephen Follows on 07/11/2017 22:34:37:
Upgrading the ML7 would till be my preferred option but not Paying over £300 for a pair of bearings and shaft.
Absolutely no need to. I just replaced the bearings and shaft in mine for pocket change. I bought four Oilite-type sintered bronze bushings from my local bearing shop. They cost about $5 each. 3/4" ID x 7/8" OD and about 3/4" long or so, IIRC. Knocked the old ones out and pulled the new ones in using a long bolt and flat washers to pull them in nice and straight. Cleaned them up with a reamer to fit the new shaft, made from 3/4" steel bar. (Yes, you can ream sintered bronze bushings, Oilite's literature says so.)
The shaft does not need to be hardened to run in sintered bronze bushings. The original was not hardened and lasted more than 50 years in service. I simply used a piece of 3/4" diameter bright mild steel, didn't even machine down the OD, just polished it with emery cloth. Turned the two grooves then milled in the flat and the keyway in the lathe using a vertical slide, but it coiuld be done by holding the shaft in the toolpost with suitable packing.
It's a low-speed, low load application, does not need anything fancy.
Edited By Hopper on 08/11/2017 04:42:16