- NW Leicestershire, UK
Not sure about the bearings but you need a taper reamer to finish off the holes for the taper pins.Thinking things through aloud on line.. I have an antique back shaft lathe circa 1942/3
Recently I've become aware of the lathe chuck slowing & almost stopping even when under the lightest of loads .
I thought I'd cured it by replacing a known part shorted motor .
I've removed & part stripped the headstock shaft to clean out the old greased taper roller bearings that get a shot of grease out the hand held grease gun at the start of each lathe session . Happy to say in the dissolved grease no particles of metal or plastic were found. So binding problem is elsewhere.
The motor is still under warrantee but it runs so quiet you'd think it not on .
That only left the back shaft bearings which are sintered bronze bearing running on a mild steel 3/4 inch shaft . I'd ordered a metre of 3/4 inch drill rod several months ago so it was an easy change out . my biggest problem is that it's so easy to reassemble the simple shaft arrangement . I put one of the bearing mounts back on the wrong way so the oiler cap cannot be accessed to oil up at the start of each session .. will rectify that tomorrow . The old back shaft is full of groves where it's been scoured by something like cast iron dust or abrasive wheel grinding dust , they have both lost almost 2.5 thou on the mild steel bearing surfaces . ( It's not down to me yer Honour )
One thing that confused me is that two of the steel drive dog bosses are held on with tapered pins . I don't have a tapered 1/4 " drill so I step drilled the holes from 1/2 then down in 0.5 mm steps to the smallest size of the taper pin .. they nearly fit well. Might just drill right through them in the proposed future proper re-fit out & use rolled pins if I can get them long enough .
I've now got to consider either re-bushing the two steel phosphor bronze bearing sleeves with Olite bushes or try to accurately turn up two x two ( 4 x 3/4 ID " bearings in two carriers for proper sealed roller bearings .
My problem is that the drill rod is a very fine tolerance precision shaft and is exactly 3/4 of an inch in dia , the ID of the bearings being considered is also a precision 3/4 " which will be a hard interference fit on a ground to 3/4 " dia drill rod shaft . I have to mess around for a few minutes setting bearing sleeves precisely in there mountings so having them rock solid on the shaft is not going to work , grinding or turning off a thou or so on the shaft will also caused problems in a couple of places where precise bored to 3/4 ID driving dogs have to fit . They will slop about if I turn anything off the drill rod .
Hmm .... Just had a thought can you get 3/4 ID bearing plus 2 thou or so oversize ID for situations like this ?
Off to explore sintered phossy bronze , Olite and the Bearing Boys web site.