Rivett 1020S Spindle Bearings

I haven’t posted much but here it is. I’m replacing the spindle bearings on this Rivett and have a question about preload. The preload is set by the inner and outer spacers. The following is my method of determining preload clearance. My questions are does this method seem okay and do the following results of the original clearance seem reasonable.

* First I ground two spacers on both sides.
* Placed one spacer on a surface plate.
* Took the flanged angular contact bearing and put it face down so that the thrust was correct.
* Next placed the outside spacer on the outer race with the back angular contact bearing set so that when the last spacer I made is sitting on the inner race it is all in the direction of loading.
* Then I took gauge blocks to get the height checking with a .0001 indicator sliding back and forth between the stacks until it read zero. This is the total stack height.
* I subtracted the following from the total stack height: My two spacers, the spindle inner spacer and the inner races of the bearings.
* This gives me a clearance of .00235 using the original bearings.
* Used the same method with the new bearings and came up with a clearance of .00525.
* This means a difference of .0029 to be ground off the outer race.

Does the clearance of .00235 sound about right for the original clearance?
Does this method sound right for arriving at the original clearance?

The original bearings are New Departure 0L12DTX7038 and outer race is marked T3TT.

New bearings are marked: Front bearing 0L12DTX7. Back bearing is marked QN0L12DTX7. These are duplex back to back.

Any help or advice would be appreciated. Thanks.

Do you have a drawing of the spindle bearing arrangement?

Typically, the preload is built into the bearings. You don't have to set it, or even measure it. You just need to grind with spacers to be exactly the same length and put the thing together.

Maybe is machine is different, I don't know. I have heard of some applications like jig bores where people here claim that the spacers are ground to increase the pre-load, but I have not seen it personally.

Thanks for your response. On this lathe Rivett ground the inner spacer .0034 smaller than the outer. The two bearings’ preload offset isn’t the same. You would think the .0034 was the actual preload but when factoring in offsets it’s not. It is actually smaller.

I will get a diagram posted.

tailstock4 said:

I haven’t posted much but here it is. I’m replacing the spindle bearings on this Rivett and have a question about preload. The preload is set by the inner and outer spacers. The following is my method of determining preload clearance. My questions are does this method seem okay and do the following results of the original clearance seem reasonable.

* First I ground two spacers on both sides.
* Placed one spacer on a surface plate.
* Took the flanged angular contact bearing and put it face down so that the thrust was correct.
* Next placed the outside spacer on the outer race with the back angular contact bearing set so that when the last spacer I made is sitting on the inner race it is all in the direction of loading.
* Then I took gauge blocks to get the height checking with a .0001 indicator sliding back and forth between the stacks until it read zero. This is the total stack height.
* I subtracted the following from the total stack height: My two spacers, the spindle inner spacer and the inner races of the bearings.
* This gives me a clearance of .00235 using the original bearings.
* Used the same method with the new bearings and came up with a clearance of .00525.
* This means a difference of .0029 to be ground off the outer race.

Does the clearance of .00235 sound about right for the original clearance?
Does this method sound right for arriving at the original clearance?

The original bearings are New Departure 0L12DTX7038 and outer race is marked T3TT.

New bearings are marked: Front bearing 0L12DTX7. Back bearing is marked QN0L12DTX7. These are duplex back to back.

Any help or advice would be appreciated. Thanks.

Click to expand...

Why would you ever want clearance on a spindle bearing? The spacers should be the same thickness as the preload is normally built into the bearings.

The clearance I referred to could probably be better described as preload. What Rivett did was use bearings of unequal amount of offset. To achieve the preload they wanted, they ground the spacers of equal lengths. When I received the new bearings, this preload was different than the original. If I put it back together this way it would have way more preload than is needed.

I was able to talk to a spindle rebuilder who gave me the name of an engineer at a bearing manufacturer. After looking through some old New Departure books, he supplied me with the following. He came up with the preload in terms of newtons converted to microns and then into .0001’s. A light preload would be about .0008. The medium preload would be double (.0016). He said he would not go above a medium preload. Therefore, I’m thinking of using about .0015. It seems to be close to what Rivett had. This original clearance was difficult to measure because I could never get the bearings to track real true in their races.

Maybe I started this post out backwards and should have provided some background on this machine first. I picked this machine up near Kansas City. It was the partner lathe to the one that member X926629 posted about in “New to me Rivett 1020S”. The machine is actually in pretty good shape except for the spindle bearings. While the bearings weren’t completely trashed, they were getting a little noisy and rough.

This was due to their use of a Hardinge 5c collet chuck. Every time they tightened this chuck they went through high range to get to the low range back gear to hold the spindle. This repeated shifting caused a burr or blunting on the edges of gears that interact with each other. These edges were cleaned up with a small file and a lot of time. Apparently, Rivett did not use hardened gears in the headstock or for that matter anywhere else in the lathe. Anyway, these little burrs produced very small debris which found their way to the bearings. I guess the moral of this story is don’t bang gears when shifting a Rivett 1020S.

tailstock4 said:

I guess the moral of this story is don’t bang gears when shifting a Rivett 1020S.

Click to expand...

Besides which.. don't design so that bearing lube supply is shared AT ALL with gear, dog, or clutch lube supply.

We THOUGHT we had that on the 10EE with separate reservoirs and operating chambers even for front and rear spindle bearing sets.

Almost, but not quite.

There IS a way for lube from the upper central chamber where the dog clutches and input drive gear take-off for the threading gearbox live to get into (at least) the rear spindle bearing cavity. There are colourized diagrams in 10EE threads. The potential for contamination can be reduced.

I've no idea if Rivett 10X0 has similar info available, or if even any change is possible to extend bearing life on that score.

It could be worth some exploration, plotting, and scheming.

Replacing the spindle bearings on my 1020s

Monarchist said:

Besides which.. don't design so that bearing lube supply is shared AT ALL with gear, dog, or clutch lube supply.

We THOUGHT we had that on the 10EE with separate reservoirs and operating chambers even for front and rear spindle bearing sets.

Almost, but not quite.

There IS a way for lube from the upper central chamber where the dog clutches and input drive gear take-off for the threading gearbox live to get into (at least) the rear spindle bearing cavity. There are colourized diagrams in 10EE threads. The potential for contamination can be reduced.

I've no idea if Rivett 10X0 has similar info available, or if even any change is possible to extend bearing life on that score.

It could be worth some exploration, plotting, and scheming.

Click to expand...

I've opened this thread back up because I am planning to replace the 4 spindle bearings on my 1020s (1960). Before I get too far, is there someone who can briefly explain the process? I am more interested in any special precautions, and what might be involved with the press fits? Preferably I'd like to speak directly to one who has replaced theirs rather than typing.

Thanks,

Will

1020S#382 said:

I've opened this thread back up because I am planning to replace the 4 spindle bearings on my 1020s (1960). Before I get too far, is there someone who can briefly explain the process? I am more interested in any special precautions, and what might be involved with the press fits? Preferably I'd like to speak directly to one who has replaced theirs rather than typing.

Thanks,

Will

Click to expand...

To answer your question, I replaced the bearings the Rivet and was very pleased with the results. I used cold and heat instead of force to remove and install the bearings. I ended up with about twenty millionth of run out on Monarch 10EE and about thirty on the Rivett.

I have a CO2 fire extinguisher. I attach a pipe with several holes drilled in the side of it on the end of the nozzle. Cool the spindle down by putting the pipe inside of it. Put the nut on the back of the spindle to protect the threads and bounce the spindle on a piece of wood vertically. The bearings will fall off.
To install the new spindle bearings cover them in spindle oil, wrap them in tin foil and put them in an oven on a wood block at 220 degrees to heat and then install.

Depending on how nervous installing expensive spindle bearings make you, you can also cool the spindle before you install the spindle bearings which will give you more clearance. However, you will have to deal with the condensate this creates. To do that, when you are done stick the spindle bearing assembly in a bucket of oil to displace the water.

What makes the Rivett a little different from the 10EE which I also replaced the bearings on is that the Rivett uses a custom preload similar to the way a Moore jig bore uses.

I ended up using about .0008 of a preload which is on the high side of light. In contrast, the Monarch 10EE uses about .0005.

As an example, the Monarch’s new bearings had about .0004 preload. I ground the inner spacer about a .00015 for the additional preload. The original bearings in the 10EE had a total of about .0005 preload. Because Rivet didn’t use a matched set of spindle bearings, you have to determine what the original preload was, and then determine what the preload of the new set of bearings is, and then grind the spacers to get the preload you want.

There is a lot more to the measuring of all this. I’m not sure how much detail you want. You can PM with your phone number if you want to talk.

tailstock4 said:

To answer your question, I replaced the bearings the Rivet and was very pleased with the results. I used cold and heat instead of force to remove and install the bearings. I ended up with about twenty millionth of run out on Monarch 10EE and about thirty on the Rivett.

I have a CO2 fire extinguisher. I attach a pipe with several holes drilled in the side of it on the end of the nozzle. Cool the spindle down by putting the pipe inside of it. Put the nut on the back of the spindle to protect the threads and bounce the spindle on a piece of wood vertically. The bearings will fall off.
To install the new spindle bearings cover them in spindle oil, wrap them in tin foil and put them in an oven on a wood block at 220 degrees to heat and then install.

Depending on how nervous installing expensive spindle bearings make you, you can also cool the spindle before you install the spindle bearings which will give you more clearance. However, you will have to deal with the condensate this creates. To do that, when you are done stick the spindle bearing assembly in a bucket of oil to displace the water.

What makes the Rivett a little different from the 10EE which I also replaced the bearings on is that the Rivett uses a custom preload similar to the way a Moore jig bore uses.

I ended up using about .0008 of a preload which is on the high side of light. In contrast, the Monarch 10EE uses about .0005.

As an example, the Monarch’s new bearings had about .0004 preload. I ground the inner spacer about a .00015 for the additional preload. The original bearings in the 10EE had a total of about .0005 preload. Because Rivet didn’t use a matched set of spindle bearings, you have to determine what the original preload was, and then determine what the preload of the new set of bearings is, and then grind the spacers to get the preload you want.

There is a lot more to the measuring of all this. I’m not sure how much detail you want. You can PM with your phone number if you want to talk.

Click to expand...

Thanks for the clever idea for chilling the spindle. I’ll send a PM with my contact info.

My post from a couple of years back for my 10EE bearings.


Update on the spindle. I took a year off, not really planned, but life works out that way, but I recently got off my ass and started working.

I heated up the bearings in oil to 200 degrees in the oven, and then sprayed a can of R-134 down the inside of the spindle for some more Delta-T. The bearings slipped right on the spindle with no issues. Then I heated up the headstock with a 200 watt bulb for a day, and right before installing the spindle heated up the inner race of the rear bearing with a 150 watt halogen bulb. The spindle assembly slipped in easily to the rear bearing surface, and then I used a threaded rod to push the rear bearing to fully seated.

I had left the bearing lock ring slightly loose, and then tightened after the spindle was fully in, while the headstock was still heated. The SKF HN 12-13 wrench has to be purchased for this as the hinged type won't work.

The next morning after all the temps were back to normal I checked the runout and my test indicator needle moved about the width of a line on the dial, so I am going to say on the order of 20 millionths runout. Big "whew" here as I was paranoid about my $2400 of stuff!

Now on to tuning my Parker 514 and 507 drives. Life is looking up.