countershaft bearing replacement

The bearings on my vintage lathe countershaft have become noisy. I would think many lathes had this type of plain iron bearing but now there is a bit of play, This is worse at the end where the pull of the motor adds more pressure.

The spindle appears to be imperial 7/8" , I am thinking of perhaps using roller bearings if i can find a way to fit them.

The casting has inch & a half holes where the bearing fits and screw/nuts to centre it.

Has anyone replaced bearings in a similar casting to mine? and if so how did you do it?

Edited By vic newey on 01/09/2019 14:02:31

I used plain steel wrapped dry bearing bushes for a similar job on a one piece countershaft & motor mount casting. Something like this :- **LINK** . Albeit Glacier brand out of a box in the workshop!

Worked well although I really wanted bronze lined ones to run lubricated but such were not available at reasonable prices one off in those days.

As I recall matters I cleaned up the hole by bashing a wooden filler piece inane carefully drilling through with hole saw before final clean up with a reamer. If my recollection of sizes is correct, probably a king pin reamer to help get both bores in line. No chance of proper machine methods for me with something that size.

In your case probably easiest to make a new parts essentially the same as the old bearings with dimensions suitably adapted to take your chosen type and size of bearing.

Clive

Not exactly like that Vic - although I have replaced plain bearings with ball bearings in other applications.

I would alternatively suggest that it might be possible to sleeve your existing bearing with an Oilite bush, which would require a minimum 1" hole (or 1-1/8) for a 7/8th bush to be pulled into. I have done this in other applications, as well as the simple replacement of existing Oilite bushes. In all cases, I needed to make a custom 'puller' to remove and/or insert the bearings - not hard to do but extra overhead. An Oilite bush is usually easier to fit because they have a small ratio of ID to OD and can therefore be used where a conventional (ball) bearing might not fit. Kept lubricated, they last well and should work just fine for a countershaft (indeed I have a countershaft that uses them).

One other consideration is how badly the shaft is worn/scored. If it is, then you may need to machine the shaft ends down a bit and fit a smaller ID bush/bearing. This might make fitting new bushes (into the existing castings) easier but will also most likely have some knock on effects (like needing to sleeve any 'end' pulleys which will then be oversized for the shaft ends). It's a good idea to think these things through several times before leaping in, as sometimes other issues do pop up....

hope this helps..

IanT

Is that a Myford motor assembly MA97 from about 1947 ? I just got one last week myself but not penetrated the grime to see how it works yet.
I wonder if you could use a needle roller being lower profile at the motor input end and a smaller ball bearing at the other end with the shaft turned down at that end only. The ball bearing would provide the end float control not available from the needles.

Thank you Clive & Ian T

I think I would probably be better off making a roller bearing holder to fit in the casting aperture, this way I won't risk botching up the original one trying to bore it out for a bush.

The shaft is not scored where it passes through the bearing. The left hand side of the shaft runs on 4" past the bearing as there are two pulleys inc one for the overhead c/shaft, this is where the wear is most noticeable.

7/8" ring bearings are easily available so I'll look into it

Hello Bazyle,

no the lathe itself is a Pittler from 1898 and I have no idea whether the c/shaft is original, it has V belts but could still be the original cast bracket & shaft bearings

Edited By vic newey on 01/09/2019 15:28:29

Just been sent to do some jobs by SWMBO but very quickly checked Arc E/T Vic.

The 7/8th ID bearings they stock are 1-7/8 OD - so if the casting that holds the existing bearing is 1-1/2 at the moment, that may be a problem. You may of course be able to find lower profile bearings. Whilst I have needle bearings fitted in the Myford, I've no experience with using/fitting them myself - which is why I find the Oilite bearings useful for this kind of thing...

Anyway - duty calls. Good Luck

IanT

Thank you Ian,

yes that puts a doubter on a ring bearing unless a I can find a lower profile type, i don't want to risk trying to alter the casting apertures either so still considering what to do.

here is a pic of the actual casting

Oilite type bushes are easily available on ebay. They can be bored on a lathe without compromising the porosity, but reaming should be avoided.

Vic, I had a look at your albums What a lovely set up that Pitler is. It is the Myford countershaft assembly which you can see in a picture and a catalogue engraving on the Lathes page I linked. I think Myford must have seen a market in conversions to electric for treadle lathes or small lineshaft drives. In my case it seemed to be a solution after the Drummond lathe was demobbed from a navy boat.

Hello Bazyle,

your right, it does seem to be a Myford type countershaft assembly, there must be thousands of those around and no doubt many have found away to fit roller bearings.

You can see the problem with mine in that the pulley from the motor is 4" from the bearing. Ideally it would be better swapped around with the triple pulley but then it won't line up with the motor without major alterations down below.

The metal cupboard under my lathe is not original, it slides into original cast brackets that once held a wooden drawer. If I remove the cupboard then there is more room to move the motor over. I may well consider doing this

.

You might also consider the use of pairs of 'thin section' ball bearing units [one in each end of the existing holes]

**LINK**

https://www.carterbearings.co.uk/silverthin/thinsection-bearings

MichaelG.

Thank you Michael,

I think low profile ring bearings will be the answer, the holes in the casing are a bit rough, in fact one does not look properly round, presumably this is common as the original bearing is held by two bolts and made to swivel slightly. I can probably sort this out depending on the fit of the ring and how I keep them in place.

We have a bearing dealer nearby, the counter staff were most helpful when i went for bandsaw bearings a while back so I'll clean up & take the shaft & casting to get their advice as to what they have in stock

Vic

If you made a couple of tubes to carry the pairs of bearings, they could be fitted as 'casettes' into the rough holes in the casting, and the positioning screws used as-intended.

Admittedly it 'wastes' some available diameter, but it's worth pondering.

MichaelG.

a good idea Michael if i can get suitable bearings

I'll have to wait till I see what's available at the bearing shop, I'm busy fixing the garden fence first but I'll keep you posted as to what I end up with

I visited the local BRT bearings this morning and as predicted they were very helpful.

I'm ending up with a 1/1/2" OD needle bearing which fits the casting perfectly with a tight push fit! The two bolts can be lightly tightened onto it

The inner ring is on order as he had to ring around to find a 7/8 imperial which was not so easy,

I'm going to try this with just the motor end to start with so it leaves the other end in the original bearing so it has a bit of float if they don't line up exactly due to the castings

Edited By vic newey on 05/09/2019 14:53:22

Edited By vic newey on 05/09/2019 14:54:35