Reeves Sheave Bushing Boring Question

[G-ManBart]

This is about a Clausing lathe with a Reeves variable speed system, but it could apply to other similar drives so I put it in the general section. I'm cleaning/sorting/fixing up a Clausing model 5904 lathe (12x24", 2hp) that I'm going to be selling soon. Overall, it's a nice machine with beautiful ways, minimal backlash in the screws/nuts, has a taper attachment and even a custom backsplash that was added at some point. It's cleaning up really nicely and everything is working properly with one slight issue. At certain speeds I noticed the lower (motor) variable speed sheave wobble a touch as I was running it. I took the lower VS system apart and found the bushing is a non-factory replacement (shop-made for sure) that's worn slightly undersized. The outer sheave itself is perfect. The inner sheave which has a shaft that is coated with epoxy is essentially perfect and under .001 for roundness and taper. I needed a few parts from Clausing anyway, so I ordered a couple of replacement bushings...partially as spares, and partially because these are sometimes known to crack at the expansion joint during installation. The expansion joint allows the sheave to compress and then slightly expand when it reaches a retaining ring in the sheave (bushing has a raised ridge to fit in this).

In the past I've read people saying these bushings (Clausing part 049-088) didn't come with instructions, but I got some with the bushings, and I'm not sure I agree with the process. The new bushings are pressed in place and wind up being undersized so you have to bore them to the dimensions of the opposing shaft to a tight fit...it should take a fair bit of pressure to move the sheave on/off the shaft. Everyone I've read describe fitting these new bushings seems to mount the sheave in a 4-jaw chuck, indicate it to zero as close as possible, then press in the bushing and bore to dimensions. The instructions from Clausing say to press in the bushing, indicate the bushing as close as possible to zero, then bore to dimension.

That's where my question comes in. Wouldn't it be more important to have the sheave zeroed before installing the bushing since the boring operation will make the bore of the bushing concentric with the sheave? The sheaves are balanced when manufactured (they all have different drill patterns for this), so if you zero using the installed new bushing before boring, and it's not quite centered, now you've thrown off the balance of the sheave. Am I over thinking it?

I will say the folks at Clausing might want to hire a new editor....see attached instructions. I think the last line is supposed to be "Note: Replacing the Delrin bushings will only work if the epoxy coating is undamaged."

I'll add pics of the sheave and bushing and how they fit together (or at least started) so it hopefully makes sense to those who haven't seen them before.

 

[G-ManBart]

Almost forgot....I know folks like pics!

 

[mmcmdl]

Can you get a better picture of the ring on the rear spindle Bart ? I think I have one from my 5917 but not sure . If it is , Ill get it up to NJ for the buyer .

 

[G-ManBart]

Can you get a better picture of the ring on the rear spindle Bart ? I think I have one from my 5917 but not sure . If it is , Ill get it up to NJ for the buyer .

You're talking about the aluminum hand wheel that you use to manually turn the spindle, right?

 

[extropic]

snip> The instructions from Clausing say to press in the bushing, indicate the bushing as close as possible to zero, then bore to dimension. <snip

\

View attachment 506322

I think you are misreading the Clausing instructions. They do not say to indicate the bushing. They do say to press the bushing in before mounting on the lathe, but your idea is better. indicate the pully first, then press the bushing in on the lathe. Be sure to indicate the cone of the pully as well as the bore. Wobble of the cone would be a serious problem.
In other words, the TIR of the circular elements of the cone is more important than the TIR of the pully bore. Hopefully they are coaxial, but if not, I would center the cone.

PS: Your new table is SWEEEET.

 

[G-ManBart]

I think you are misreading the Clausing instructions. They do not say to indicate the bushing. They do say to press the bushing in before mounting on the lathe, but your idea is better. indicate the pully first, then press the bushing in on the lathe. Be sure to indicate the cone of the pully as well as the bore. Wobble of the cone would be a serious problem.
In other words, the TIR of the circular elements of the cone is more important than the TIR of the pully bore. Hopefully they are coaxial, but if not, I would center the cone.

PS: Your new table is SWEEEET.

Once the bushing is pressed in place I don't think there's a spot to indicate the bore other than the bushing....hard to say. The bore the bushing fits in has a radius so I don't know if there's enough there for an indicator. Do you think they're suggesting to indicate the OD of the cone/sheave instead?

Last night I put the sheave (hub side in) in the 4-J and indicated the bore to right at half a thou. It's got some machining texture and the keyway to deal with so I think half a thou is about as good as I'm going to get. I then checked the hub OD just outside the chuck jaws and got around .002 runout. I checked the very outer OD of the hub and it was more like .006 or so (going off memory) but it seemed like there might be just one little high spot (maybe a ding). It's really narrow at the edge so I may try a different style indicator tip. At that point it was getting late so I decided to look at it today with fresh eyes.

I guess worst cast I pick a method, fit the bushing and see what happens. If it's not running smooth I can do it again with one of the spare bushings and only be out the price of one bushing. I plan to sell this so I want it done right and not pass along a possible problem to the next person.

Thanks on the table...I was pretty stoked to get it! It's overkill for most of what I do, but it was only an hour away and not terribly expensive (guessing, but probably not much over scrap price).

 

[extropic]

The TIR of the hub and OD are interesting, BUT I would be most interested in the TIR of the cone, I suggest you chuck the sheave (half) so that the circular elements of the face of the cone have minimal TIR. I suggest indicating the cone at about 1/2" larger diameter than the the hub OD, plus every additional 1/2" diameter increment until you get near the OD of the sheave (half). Minimizing the eccentricity and "wobble" of the cone is paramount.

That table is a beauty and, with the Fisher Body tag, has a great American industrial provenance. Things were built to last. You did great.

 

[G-ManBart]

The TIR of the hub and OD are interesting, BUT I would be most interested in the TIR of the cone, I suggest you chuck the sheave (half) so that the circular elements of the face of the cone have minimal TIR. I suggest indicating the cone at about 1/2" larger diameter than the the hub OD, plus every additional 1/2" diameter increment until you get near the OD of the sheave (half). Minimizing the eccentricity and "wobble" of the cone is paramount.

That table is a beauty and, with the Fisher Body tag, has a great American industrial provenance. Things were built to last. You did great.

I spent a bunch of time today measuring and checking zero in the bore, the face of the cone from center on out, the hub, the back side of the face where the weight dimples are, and the very outer edge on the rim.

After trying various combinations I found that if I had the bore down to around .0005 runout the face of the hub was at the worst .002 and at best .0005. At the same time the hub was slightly under .002. I can only imagine that the face doesn't wear in perfectly linear fashion since some speeds are used more frequently than others, so that might account for the difference. It's hard to describe, but I also thought that the bore looked to be more carefully machined while the hub looks like it was rough turned to dimension after casting. That might be why those two aren't exactly the same.

For folks who might tackle this job in the future and stumble on this thread I'll add a bit more detail.

I went with the setup above....honestly, I just got tired of trying different things and decided it was good enough, and if it didn't work I had two spares. I got the bushing started in the bore, heated it with a heat gun until it was pretty warm to hopefully soften the expansion joint and then pressed it into place with the tailstock most of the way and switched to a socket that was slightly undersized for the bore of the sheave for the last quarter of an inch...popped right into place just fine. It made a snapping noise and I thought it had broken, but that was just the retaining ring popping into place.

I spent a bunch of time measuring the epoxied shaft hub and kept coming up with exactly 1.750" using a good half a tenth mic, so that was the goal for the bore. I was using a 3/4" solid carbide boring bar with a CCGT insert, 32.50.5 insert (1/128" nose radius, uncoated), running 370rpm (wanted to keep the heat down) and a feed rate of .003" per rev on power feed. I went light on the cuts with most being .005 to .008 depth of cut, so .010-.016 off the diameter per pass. The last pass was .005 or .006 and then I did a spring pass just in case. The finish on the bushing was shockingly nice and super smooth. I honestly couldn't tell it had been machined it was so smooth...each pass I kept thinking I was going to mess something up because it was going too well! I measured the results for about twenty minutes and finally felt confident it was as close to 1.750 as I could measure and decided to test fit it.

It's supposed to be a tight fit, and it is...it took some pressure to get on the shaft, but nothing crazy...just have to sort of lean on it. I put the whole thing back together and it is running smooth, quiet and zero wobble. The biggest thing is how much quieter it is, especially at the higher speeds....it's really much better than before. I don't know if this was the best way to go, but I think it worked!

 

[G-ManBart]

Can you get a better picture of the ring on the rear spindle Bart ? I think I have one from my 5917 but not sure . If it is , Ill get it up to NJ for the buyer .

 

[G-ManBart]

I shot a quick video...it's running at 2,000 rpm at the beginning and I turn it down to 360 rpm (lowest in direct drive). No more wobble! At low speed there's a bit of a light rattle that I think comes from the clutch mechanism because it goes away when the drive is engaged....maybe clutch plates or something (both of my 6913s did this as well so I never tried to figure it out).

Now that I think of it, this also shows the new black colored slave cylinder cover I 3D printed for it. I have to tweak the program just a tiny bit and then I'm going to share the .stl file so folks can print their own.

View attachment IMG_6685.MOV