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Hardinge Cataract BB59 rear spindle bearing

J Grainger

Cast Iron
Joined
Oct 12, 2006
Location
United Kingdom
Hello,

Some years ago I purchased a couple of Hardinge Cataract bench lathes, followed by a spare headstock and compound slide from a scrapped machine. Life kind of got in the way of doing anything with them but I've recently constructed a bench top, fitted original steam pipe legs, and put one of the lathes on it, using the spare BB59 enclosed headstock.

These two headstocks are the same model and type but the spare one has the brake intact, and having removed the chase threading spindle gear from the original headstock (with a bit of heat) it turned out to be missing a fairly important preload nut.

Running the lathe after oiling, I discovered the read bearing is intermittently noisy, it's been getting quieter with a bit of running - but it's still somewhat concerning. The front bearings seem fine.

Reviewing the headstock picture on the lathes website it seems that the rear bearing is just a deep grove ball bearing with the outer race free to float in the headstock bore - the lack of pre-load suggests to me that it's really nothing special.

Searching reveals there are a few threads on replacing the front bearings but little seems to have been said about the rear bearing. I wondered if anyone has replaced theirs or can offer advice on the sort of runout spec I'll need to look for in what seems to be a fairly (relatively speaking) non-critical bearing.

Thank you,

Jonathan
 
After receiving reading the PM sent by Irby I've spent some time today, disassembly and fitting a replacement bearing.

Having two headstocks I found that the spare one had a really good condition rear bearing, and that the headstock I've used had a bad bearing. The rear bearing had dried out, had a split cage, and the oil ways were blocked inside, to the extent that it was completely dry despite oiling for a week prior to some light use (to test and find problems). The front bearings weren't dry, but not too far off. The rear bearings got swapped after cleaning.

Curiously the spindles are actually slightly different between the two headstocks. The now running headstock has a taper which goes back to the rear edge, and the spindle tensioning nut has an internal clearance to fit over an extended bearing surface.
The spare headstock has a step in the spindle nose taper, just before the rear edge, and the tensioning nut is threaded all the way through and does not overlap the bearing surface on the spindle (it physically can't), as the nut is not relieved and the internal bearing registration surface is shorter.
Both spindles seem to protrude the same at each end of the headstock. I wonder if one was made in the UK and one the USA, or just a subtle update.

As the lathe became a project on the back burner I'll put up a few pictures in a sort of before and after thread. It's not finished yet, but is getting there.

Jonathan
 
Hardinge seems to have changed their headstock bearing designs almost continually over the years. You
may just have two different vintage items.

You are correct that the rear bearing is nothing more than a plain radial ball bearing, with the inner race
contstrained axially on the spindle and the outer race floating in a tight bore in the casting. This is
so the differential thermal contraction between steel and cast iron can be accomodated.

I suspect an electric motor grade bearign would work reasonably well for the rear bearing.

These are from an Elgin rebuild but the idea is similar:

BB59_1.jpg


BB59_4.jpg


The new front angular contact pair are from Alpine Bearing:

BB59_5.jpg


BB59_8.jpg


I didn't take any pics of the completely re-assembled spindle however.
You can see in one photo where the rear bearing seats in the cast iron
bore, and likewise the front pair in the front bore.
 
Thank you for responding with a few pictures. These lathes are a bit daunting at first but seem pretty straightforward once past the Hardinge fear factor.

Shall be nice once it's sorted.

Jonathan
 
Thank you for responding with a few pictures. These lathes are a bit daunting at first but seem pretty straightforward once past the Hardinge fear factor.

Shall be nice once it's sorted.

Jonathan

The lube question is always outstanding. They did not make up their minds about oil or grease?

That headstock had originally had oil cups, but a former owner got fed up I guess and put zerk grease fittings there.
I put oil cups back there, based on the gaskets and the shape of the oil grooves in the casting. If oil then you really
do need to put paper gaskets in there, it's designed to fill below the point where oil can spill out of the hole for the
spindle.

The two outer bearings need to be held in contact to develop the correct preload, the gaskets space the end plates
off the casting. The gaskets have to be thick enough to seal, but thin enough that the plates clamp the bearing ODs.
 
The two outer bearings need to be held in contact to develop the correct preload, the gaskets space the end plates
off the casting. The gaskets have to be thick enough to seal, but thin enough that the plates clamp the bearing ODs.

The gap there on my Hardinge ball bearing headstock measured .010" and a gasket made from a manila folder worked just fine. Here's an example of the manila folder gasket for an enclosed headstock on a BB4 mill. It uses the same bearings and same spindle configuration as the 5C lathes.

attachment.php


Also shown is the rear bearing that has been talked about. It was originally an open bearing but I wanted to eliminate the cork seals that had quite a bit of drag, so I made metal seals to press onto the inner bearing races where there was a place for them. It was really a relief for clearance for the outer seal but there wasn't an outer seal on these and no relief for one to be pressed onto. The seals rotate with the spindle, which is opposite to what normal bearing seals do, but these seem to work just fine. The mill spindle runs at 4000 RPM just fine and where the cork seals got the spindle quite hot, this seal doesn't heat the spindle at all. The mill originally had the open bearings at the front but a previous owner replaced them with sealed bearings, so I also removed the rest of the cork seals. I filled the rear bearing about 1/4 full with grease, so now the mill requires no oil lube on the bearings.

As a side note on the rear bearing specs. I measured the runout on one of the rear bearings I had out of a Hardinge enclosed headstock. The bearing inner race wasn't in great shape and the bearing was not always smooth turning even after cleaning it well. But when I found a smooth area on the inner race and the bearing turned smoothly the runout was as low as .0002", with no measurable side play. That doesn't sound like a run of the mill motor bearing to me, but I have never seen specs on the rear bearing. Here's that bearing.

attachment.php


Irby
 

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I need to sort out the sealing of the front bearings. On the inside, it looks like the cork seal is ok for now, but it's seeping at the spindle nose. Shall probably make a paper seal.

Here are a few pictures of progress so far.. I've plenty yet to do, including making little bits for the lathe.. as well as a proper toolpost. Being as there are 2 tailstocks I fancy scraping the bottom of a later one (same with zeroing dial matching toolmakers slide) which is a bit high and laterally slack, then converting the one in the picture to lever action.

Lathe Bench

lathe part way completed

lathe getting there

Jonathan
 
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Maybe everyone doesn't know this - but that particular lathe - hardinge split bed, with the two cast speed control levers - was the original logo for the PM site.
 
Thank you Irby,
I can't take full credit for it as most of the metalwork was there and just needed some cleaning and assembling. Beyond the top it just required some modification and fasteners (I made it about 6" narrower and reduced the depth slightly after some family questions about putting it in the garage).

Jim, I remember the old forum logo, was trying to remember whether it looked shiny or crinkle finish when deciding the colour for this machine.

Jonathan
 
I actually meant bench top. I'm fully aware of the Hardinge benches, and all the hardware associated with them. Making a laminated bench top like that isn't a trivial matter is what impressed me. It looks better than anything you could buy! :)

Irby
 
While not exactly work on the lathe, I have been busy and figured it was all BB59 related..

I haven't yet done any damage to the dodgy outer spindle taper - fortunately being busy with other stuff and not needing to mount the chuck make for a good excuse to put it off, for the time being.

The ability to cut small gears on the lathe is pretty important to me - even if my mill wasn't in storage, the lathe is more sensitive and it's pretty straight forward (and nice) to be able to turn a small gear then cut the teeth without removing from the machine. This would be handy to make the change gears for the chase threading (I'd like to be able to turn some watch screws without a die or screwplate), and to make some watch gears.

A while back I discovered a small ladies Fusee pocket watch needed a new ratchet wheel, so that was my more pressing concern.. it's pretty small for that type of watch and is also 3/4 plate which requires a more compact layout than the usual full plate design from the time. The ratchet wheel is 6.8mm and fits inside the bottom of the fusee cone.

I based the overhead drive on some pictures of a Schaublin design, it's powered by an old 1/3 hp fridge motor (eventually I fancy making a more heavy-duty Deckel-inspired milling spindle with ISO 20). The MDF mounting is an ongoing work in progress while I get used to how much space is required and get everything where it needs to be. The locking handles are missing while I decide between pressed in place / screwed, or sliding handles.. I'd have liked a longer belt to gain more height between the stationary pulleys and the WW style headstock but it was what I had handy.

Overhead Drive for lathe

Hardinge Cataract gear cutting in progress

A new ratchet wheel for a ladies fusee watch

Jonathan
 








 
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