Boxford Headstock bearings ME10 and AUD etc2788-2720-TIM 2788-2720-TIM

This is around on some web sites but can be hard to find

The "original" bearings were by Timken

Front bearing cone 2788, cup 2720

Back bearing cone 19138X, cup 19283X (35.00mm=1.378" 72.00mm=2.8346" 17.02mm=0.6700".

The front makes up a standard imperial bearing so can be bought complete or like that for more or less the same cost.

The rear one is an odd metric bearing that SimplyBearings list as being imperial and costs £300 plus. It can be replaced with a standard metric bearing but it's slightly thicker. This doesn't cause any problems for me as I did replace it but on some of the lathes the dust cap might need relieving by about 1/2 mm. I think Boxford switched at some point. There is something about this on lathes co uk.

So front 30207-TIM 30207-TIM - Single Row Taper Bearing

Rear 2788-2720-TIM 2788-2720-TIM

Some people have ordered the front bearing and had a UBC delivered instead (China)

Or

Front Timken 2788-2720-TIM - 1.5" x 3" x 0.936" (SKF788/2720)

Rear 35X72X17 (Nachi 30207 Bearing - 30207 SKF) metric

This timlken bearing and the other isn't actually 0.936 wide, more like 1.010 so assume that figure is just the shell. I'll check the sizes of what comes off.

There is a need to turn up discs to use a draw bar to press the new shells in and get the spindle out. That ideally needs a spacer but I use a large tool makers vice as it was handy. Discs were aluminium and circa 5/8" thick. It sometimes takes a lot of force to get the spindle out by driving it through the rear bearing. It would be worth making a sleeve to go into the spindle to make sure that the draw bar is central when this is done. Sometimes it's fairly easy which probably means it's been done before and the spindle dia lapped a little. I did that on mine before fitting a new rear. My front bearing cone was so tight I didn't even try to get off. I'm going to take it to some one with a bearing press. I suspect Boxford used bearing heaters.

There are provisions for using a drift to get the old shells out of the headstock. Tap on either side to keep them square and removing the other parts from the headstock before doing anything else is pretty straight forwards. There are parts breakdowns for all of the lathes on the boxford Yahoo group or I could post one some where else if any one needs it.

There preload setting method is shown in the parts break downs. be interesting to see if it works with new bearings. I've noticed that they allow a little axial movement. This may be when there is no grease in them and might be a better method. However I suspect after the lathe has been run for a while they will need adjusting again anyway. Too much grease in new bearings will mess the settings up. I'm going to try a generous smear / 1cc

John

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