Mounting in a lathe.

[Joe 90]

I have no lathe skills and am still learning. How would I go about mounting something like this on the lathe. A bearing is pushed into it but at one side it is worn a bit so when the bearing is pressed in full it goes loose. But it starts off tight so it's only worn on in. I would need to fill the worn side with weld and then lathe it off.
The hole passing right through it is not used and maybe not exactly but its damaged too so could be way off.
I dont know if the jaws go small enough to mount them in were the bearing goes and clean the back side flat and centre the through hole.
That'll leave me a flat side to mount against and a true centre hole to go by but I've still no idea then how to mount it again to machine where the bearing sits.
It's hard to explain what I mean.

 

[Pete.]

My first inclination would be to look at the option of fitting that bearing using Loctite 641 (bearing fit).

 

[Newlands]

I’d use a four jaw chuck. Do your weld build-up first. Then set it up so the face in the first photo is facing towards the tailstock, then use a dial test indicator to true up both the ID and the machined face. You have to go back and forth on this a few times - setting the ID first as best you can, then the face, then go back to the ID and so on until both are reasonably ok.
When you’ve machined all you can from that side, flip it round and true up the face showing in photo two.
the reason for doing it this way round is for your first setup you have a bore and a face that you can indicate off. It sounds from what you say that the outer bit of that bore is reasonably ok to work from.

 

[GraemeVW]

I am very much still learning, but I'd hold it from inside the bearing hole, face the back so it's true, then I'd use the 3 holes to bolt it to a face plate to machine the bore.

Personally I'd probably machine it out and sleeve it.

I am a complete amateur though, so there are probably better ways.

 

[GraemeVW]

My first inclination would be to look at the option of fitting that bearing using Loctite 641 (bearing fit).

This sounds like a very good idea to me.

 

[mike os]

Weld that and it will warp horribly I think ... I would bore out and sleeve (looks like plenty of meat so sleeve could be pinned too) or use Locktite 641 or similar

Depends what it's for and how it's loaded of course

 

[Newlands]

Weld that and it will warp horribly I think

Yes, it might well do, or worse if it’s cast. It would help to know what it does, (it’s not a lower link adjuster as I thought at first).

 

[Hopefuldave]

My thought is make a puck that fits to the unmachined side and drill and tap for the three existing bolt holes, bolt the casting on and grip the puck in the lathe chuck - may need shimming / packing where the bosses for the bolts meet puck to get it square - a 4-jaw's going to be essential so you can accurately centre the puck and thereby the casting's inside diameter.

Dave H. (the other one)

 

[Keithmac]

You can run round the inside with a centre punch then use bearing fit.

 

[Agroshield]

Since the existing bearing surface is the reference surface, do nothing to that surface until you have established another surface that is concentric to and co-planar with the bearing surface.

The bore out and sleeve is an excellent idea rather than welding.

The Midsummer Night's Dream above is a good idea but make it to suit the existing bearing diameter, face it square and ensure it is plenty long enough so the casting bottoms out on the base. Superglue the casting onto the puck and from the rear bore the ragged hole true and lightly face it. Use the three existing bolt holes to secure it if you do not trust CA.

Then make a smaller puck that fits in from the back. Again, superglue the casting on. There is enough room in there to put a thin disk, bigger than the small bore but smaller than the big bore. You can press on that disk with a rod held in the tailstock. Make the rod small enough so your boring bar fits in also.

 

[Shox Dr]

That looks like the bearing has been wobbling, it might seem like it not worn at the top. It might be its either material pushed up or its egg shaped. You'll end up having to reface the lot.
There is little material between the mounting holes, a Speedy Sleeve would fit.
Depending on the amount wear Id used Loctite 648.

LOCTITE 648

Retaining Compound - high strength. High temperature resistance. Ideal for retention of parts with a clearance or interference fit.

www.henkel-adhesives.com

 

[Sean]

Bolt it to a backing plate, 3 handy holes there.

 

[8ob]

The rough side would need facing off before bolting to face plate, may get away with an internal knurl to create an interference fit.

Bob

 

[graffian]

Tap a bit of steel for the three bolt pattern, bolt the thing to the steel and see how it sits, check how far
out the machined face is; or should I say how close. Might find bolting it on with lead washers or shims
holds it flat.


How would I do it.
I would stick something thought the hole that is parallel[is it?] to the machined face and using that and shims I would clamp it
so the machined bit is in the right orientation and central; hold it in three places. I wouldn't bother with the rough side.

 

[Turbo]

I've got stuff like bearing fit only for bigger gaps & have used it successfully in a similar situation to this. I'll see if I can get the name of it.

 

[Turbo]

I've got stuff like bearing fit only for bigger gaps & have used it successfully in a similar situation to this. I'll see if I can get the name of it.

It's called Loctite 660 Retaining Compound Quick Metal
https://www.henkel-adhesives.com/us/en/product/retaining-compounds/loctite_660.html

I had a gearbox that had spun the bearing. I used this stuff to repair it & the gearbox is still in use several years later.
On another repair job I used this stuff but had to take it apart again as I had assembled it incorrectly. I had a heck of a job removing the bearing just held in with the 660, before that it would literally fall out!

 

[Joe 90]

That's probably my best option. It fills up to 0.5mm. I think the metal is cast. And im just trying to source the bearing as its some strange self aligning bearing with 2 tracks around it.

 

[Turbo]

That's probably my best option. It fills up to 0.5mm. I think the metal is cast. And im just trying to source the bearing as its some strange self aligning bearing with 2 tracks around it.

Make sure you assemble it fairly sharpish with the bearing/shaft all aligned properly, it sets fairly quickly, especially in warm weather.