Outer bearing diameter spec for 10L bronze split bearing

I have a bearing I measured and it seems that the outer bearing diameter is 2.5000".

Does anyone know if that is the spec ?

Maybe a better question would be what is the diameter of the bore inside the bearing caps/casting. Does anyone know what that should be ?

I realize it is probably not critical as the shims are supposed to take up and/or allow the bearing cap to be tightened so that it doesn't deform the bearings.

I asked the same question of Ted and he wrote back that it is 2.4985

karl said:

I asked the same question of Ted and he wrote back that it is 2.4985

Click to expand...

Awesome, thanks so much. Not far off from my guestimate.

I think I should measure the ID, inside the bearing caps and base, but my guess is that it is small to allow for the shims.

Thanks again for providing the "real number".

Now for the $64k question. Doesn't anyone know what the clearance needs to be between the bearing and spindle to allow the oil to flow and lubricate properly ? I know this is kind of arbitrary, since the spreader opens the bearing to allow for that clearance, however there must be an ID size to the bearing also. Did you get that also by chance karl ?

Regards,
Alan

Just a guess but note that the 2.4985" is .0015" less than the headstock bore.

So if the bearing was made on size to the spindle once it was in place in the headstock and the expanders tight you would land on .0015" max bearing clearance which coincidentally is the spec. max clearance for bronze bearings with expanders.

Theoretically that is..

iwananew10K said:

Just a guess but note that the 2.4985" is .0015" less than the headstock bore.

So if the bearing was made on size to the spindle once it was in place in the headstock and the expanders tight you would land on .0015" max bearing clearance which coincidentally is the spec. max clearance for bronze bearings with expanders.

Theoretically that is..

Click to expand...

Chad,

Thanks, I appreciate that. New bearings are going to be made for the spindle, and why I was asking. The machinist that is doing it has done this before, and I think is familiar with it, but I wanted to try and find out what South Bend numbers were also.

The new bearings will be lapped to the spindle.

Because I have quite a bit of material gone in the center, the bearing surface will be ground down on the front surface and new bearing will be made to fit that diameter. The other way would be to hard chrome the surface up, but that is exactly why Miller Machine doesn't do that work anymore...the hard chrome go so expensive they quit. I got a phone quote from someone near me and said it would cost anywhere between $700-$1200 to hard chrome it back up to 2.250"...

This is costing less hopefully, but going on time/material. Estimate was 4 hours.

Here's what I'm dealing with, I remember discussing this on this forum with you a while back. There is still slight tension on the bearing when inserted over the spindle, but it would be riding on just the outer areas of the bearing surface. Some material needs to come off to true it up. I would like to get a nice fit on this, the spindle and bearings are key to a decent lathe.

D1-4 spindle is soaking in the purple spooge as I type. It has a bunch of old hardened grease in the D1-4 cavities and spindle core...Gonna try and get it packed up this weekend to send off to the machinist.

karl said:

I asked the same question of Ted and he wrote back that it is 2.4985

Click to expand...

karl,

Wait, this can't be for the ID of the bearing. This must be for the OD of the bearing ?

Or you mis-typed that and it should be 2.2485 as that would be .0015" smaller than the spindle bearing surface.

If I understand iwannanew10 correctly .0015" is standard for split bearings, but I know the bearing is tight on the surface, and if it was .0015" smaller it would be 2.2485". (rather than 2.4985")

The spreader would open up the bearing to get the proper clearance of .0015.

Does that sound correct karl ?

Cheers,
Alan

I was just guessing,basing things on how I *might* proceed. , don't put too much stock in anything I say...I'm just shooting the bull, and I do get confused often these days... Although I do believe the 2.4985" is for the OD.

consider me the peanut gallery.

For the record:

Front spindle bearing
-ID...2.2500/2.2495"
-OD...2.4988/2.4983"

Spindle
-2.2495/2.2490"

Ted

iwananew10K said:

consider me the peanut gallery.

Click to expand...

I like having a peanut gallery to bounce things off of, and certainly value your opinions on all things South Bend.

I keep hoping to see a post from you one day that you found another lathe, and I probably won't be the only happy person when that happens.

SBLatheman said:

For the record:

Front spindle bearing
-ID...2.2500/2.2495"
-OD...2.4988/2.4983"

Spindle
-2.2495/2.2490"

Ted

Click to expand...

Ted,

You are a gentleman and a scholar!

Was just talking to the machinist and bounced these numbers around. This is good info as we're planning to take the bearing surface down and make a slightly thicker bearing to make up for that.

Regards,
Alan