Headstock Bearing Races

[Tomc938]

I got the new bearings and races for my 1440 rebuild today. Pretty excited as I can now start the headstock assembly.

Anyone have suggestions for getting the old races out?

And how about the new ones in? I'm thinking threaded rod and a couple of plates and the old races to pull the new ones in.

Any suggestions would be appreciated.

 

[Mcgyver]

I haven't had call to do so, but the usual advice is run a tig bead on the inside and as it cools it'll shrink and fall out. When I've had to, there were small holes you can get a brass drift into (protect the bored surface with you life lol). What type of bearings are they?

 

[Proxule]

tig bead on the inside and as it cools it'll shrink and fall out.

MIG or old smokey would work too.
YMMV but this is my exp!

I suppose if you had some dry ice cubes or nuggets you could use your needle nose pliers and grab some while you "rub" the race gently.

 

[Tomc938]

I haven't had call to do so, but the usual advice is run a tig bead on the inside and as it cools it'll shrink and fall out. When I've had to, there were small holes you can get a brass drift into (protect the bored surface with you life lol). What type of bearings are they?

They are tapered roller bearings. Also used in the from hubs of car wheels, so I like won't wear them out in my life!

 

[Tomc938]

MIG or old smokey would work too.
YMMV but this is my exp!

I suppose if you had some dry ice cubes or nuggets you could use your needle nose pliers and grab some while you "rub" the race gently.

I like the dry ice idea! And I know someone that just retired from Lindy, so can likely score a bit for near nothing.

And I bet it would also be good for installation too!

 

[Proxule]

I like the dry ice idea! And I know someone that just retired from Lindy, so can likely score a bit for near nothing.

And I bet it would also be good for installation too!

Normally cup and cone install isn't pressed fit. So the cup should slide out. But the ice and or weld would work. Access to the offending area is the tricky part.

Gluck

 

[mickeyf]

No harm in trying dry ice, but the temperature differential between that and room temp might not be enough to do it, depending on how tight the press fit is. The "put a bead of weld on it" technique seems to be tried and true, and since you won't be re-using the old ones there's no risk either. (Unless you are really sloppy handling your weld...)

For installing the new race(s), a simple jig made with a length of all-thread and suitable aluminum plugs/pressers at each end to press it/them in by screwing down is one possibility. I have used this approach successfully on other machinery.

 

[YotaBota]

If you're pressing the big thing is to support the opposite side of the casting you're pushing against. If you have a socket big enough for the race to fit into that works well. You can always build a socket if you have to, I've done that in the past.

 

[Tomc938]

If you're pressing the big thing is to support the opposite side of the casting you're pushing against. If you have a socket big enough for the race to fit into that works well. You can always build a socket if you have to, I've done that in the past.

I've used that process in the past. I will look, but I don't think I have a socket big enough.






(110 mm OD)

 

[Mcgyver]

They are tapered roller bearings. Also used in the from hubs of car wheels, so I like won't wear them out in my life!

Ah, so all the preload is from the spindle nut. I just did an account of replacing a taper bore roller bearing (taper on the shaft the inner race is drive up on) but that won't apply to yours.

 

[Susquatch]

I've used that process in the past. I will look, but I don't think I have a socket big enough.

The important thing is to remember that cast iron is very weak in tension compared to steel. If you don't have a socket big enough, do something similar to create a compression load. Perhaps a bar or individual feet to create a compression load. In the end though, some tension is ok, just not a lot. If you have to gronk on the threaded rod in tension, you are dancing in the danger zone.

 

[YotaBota]

So that's a bit bigger than I was expecting, lol.

Cap off a piece of pipe? Schedule 40 ABS might do it, there should be tons of force needed to take out a race.

 

[Downwindtracker2]

If the manufacturer was nice there could be cut outs for the brass drift. If not, curse the engineer who spec it. If you can get some lip ,work your way around slowly so as not to cock it.. We have frequently had to resort to welding to shrink.

 

[PeterT]

I've never done one, assume its this main spindle bearing? Does it remove towards the tailstock end? Wouldn't it be easier to make or scrounge a metal 'puck' or even a bar slightly under bearing OD & screw jack it out with standoff blocks - basically a bearing puller?

 

[Tecnico]

If the manufacturer was nice there could be cut outs for the brass drift. If not, curse the beancounter that wouldn’t let the engineer who wanted to spec it.

FIFY!

D

 

[Susquatch]

FIFY!

D

If not, curse the engineer who spec it.

I very much doubt they even paid an engineer to be involved.

 

[Downwindtracker2]

I've worked on too much machinery where no thought was given to repair. They seem to believe their designs were perfect, will work as they hoped and last forever. I'm not talking about throw-a-ways like cars and fridges.

Sorry, just a pet peeve from dealing with struggles. Good design was appreciated.