What's new
What's new

Round Dial 10EE Tailstock clamp lever repair

Moddage

Aluminum
Joined
Jan 23, 2021
Hello fellow 10EE enthusiasts, owners, geeks?

I’ve been lurking this forum on occasion for a while now, not really sure why I never made an account until now... anyway, I acquired a 1942 10EE last year, and it’s in need of some love, but overall is in good condition and quite well equipped. I have to go through everything to be sure still, but it appears most of the original accessories are present as well, including the seemingly elusive and rather rare follow rest, and matching early style tool cabinet. I will probably make a separate post about the lathe itself and the journey of repairing it.

Anyway, I’ve been working on fixing the tailstock clamp lever, it’s been apart before me, what appears to be multiple times, and when I got it the tailstock wouldn’t clamp properly. I thought it was out of adjustment so I snugged the large nut a little and was greeted with the handle/lever slipping on the shaft...

Prior to the teardown and visual inspection I made a custom fastener out of a 5/16-18 socket head cap screw with a pin built into it that positively locates and retains the handle on the shaft, thinking the issue was the standard set screw that had been installed was simply slipping and didn’t belong. (Why else would the shaft have a locating/retention hole in it?). Upon installing the new fastener and attempting to clamp the tail stock, I learned that the eccentric isn’t able to rotate far enough toward TDC to actually lock in place and is pulled back down from the tension.

I dismantled the tailstock base and after searching through lots of photos/videos on here, google, and YouTube, I've managed to work out that the handle operation is unlocked when pointed up, and locked when pointed toward the rear of the machine, is that correct? I also noted that some machines seem to have the set screw or perhaps just a retaining pin like the knobs in a similar spot to my lever, and some seem to have it about 90 clockwise (where my shaft I think is lined up correctly but I'm also unsure). I even found a lower resolution and slightly blurry image that appears as though there may have been both a pin in one location (about where I think the shaft hole goes) and a set screw in another, but the resolution wasn't good enough to be certain.

Someone, or multiple people more likely, have had this lever off before, and there are marks from a set screw being tightened into it in several places around its OD and it's a little boogered up. I suspect perhaps the eccentric shaft and lever were not an original matched pair and that's why it doesn't orient and work correctly, but that's just a theory. My other theory is that the original lever and shaft fit were a press fit and at some point that got worn out and someone attempted to fix it by drilling a hole through the lever and shaft together as one, and pinning it or installing a custom fastener/pin hybrid like I made up, but wasn't paying attention and clocked the eccentric wrong. The hole in the lever and the shaft are both off center slightly, and I feel like Monarch would have had a higher level of precision for such an operation, but again that's just a theory.

IMG_9928.jpgIMG_9934.jpg
Picture of the tailstock disassembled, and a closeup of the damaged shaft.


IMG_9929.jpgIMG_9930.jpg
Shaft and lever hole aligned, the eccentric seems to point too far toward the front of the lathe.


IMG_9927.jpg
Shaft and lever holes clocked roughly 90 apart, eccentric seems to be oriented more appropriately.


Is 5/16-18 the correct thread for the retaining screw(if there was even supposed to be one), or has that been modified?

What is the correct orientation/indexing of the eccentric lobe when the tailstock is clamped, relative to lever position?

Is the original fastener some custom piece with threads and pin as one like I made?

Is there even supposed to be a pin?

Is there supposed to be a hole in the shaft?


Thanks in advance for any help, it will be much appreciated, and I plan to lean on the community for some other repairs I need to make as well, the threading gearbox has something wrong internally and won’t stay engaged among other little things. This machine came from a manufacturing facility and I believe was originally delivered there from new, and based on some things I’ve seen and “apprentice marks” in some areas where they have no business being, it was not serviced by persons who were very meticulous or came from a precision background... but now it’s safe and in my care and nothing major is damaged.
 
Last edited:
I have a theory. The handle you have is a replacement for the original lever. The original lever was indeed taper pinned and set screwed to the shaft. It was drilled by hand and eye just like mone was---not truly on center but good enough to work. Someone broke the original grey iron lever justr like mine broke. They bought a replacement and knew they could not hit the original shaft taper pin hole when drilling the replacement lever. So they tried to get by just tighjtening the set screw. Someone suggested in another thread that the main purose of the set screw was simply to hold the correctly clocked position of the handle while the hole was drilled for the taper pin.

You probably saw my active thread about casitng ductile levers as these levers break pretty easily. Mine will be in "break proof" ductile iron.

Someone also posted that the eccentric shaft can be swapped end-for-end and a new taper pin hole can be made. I havfe not yet checked that out. But, if true, you are golden. Figure out the correct clocking after wyou swap the pin direction. Lock its location and hand drill the taper pin. Sure, it would be nice to have it dead center and you could set the lever up in the mill and start the taper poion hole The taper pin will hold that lever very nicely.

One other consideration in finding the correct clocking could be that there may be uneven wear in the bed and the undersurface of the bed so that the tailstock cinches up well at one position near the less-worn outboard end of the bed and at a slightly different position in the higher wear areas.

I am betting you get better answers from folks more familiar with the tailstock issues than me. I've gotten to know the lever itself pretty well since I am casting it. But, I have not learned a lot about the nuances of the rest of the mechanism.

Denis
 
Last edited:
I went out to the garage and grabbed the handle and cleaned it up a little, I believe you are correct in that it's a new replacement Monarch handle that never had the taper pin hole drilled in it. I see no evidence at all of a taper pin having ever been in this handle, only the set screw hole. You'd think being that this lathe came from a small machine shop at a large company, in a building away from the other primary manufacturing machines, that someone who worked there any time since 1943 when it was delivered would have had the skills to drill the taper pin hole and hit the original location... But I guess not. Perhaps the handle was replaced long after the skilled machinists left. I don't think the general machine maintenance crew came from a precision tool making background, there are plenty of visual signs in places there shouldn't be to tell me that story...:angry:

IMG_9942.jpgIMG_9948.jpgIMG_9943.jpgIMG_9944.jpg


The damage on the pin end probably doesn't really affect the shaft adversely if I were to drill new holes in the handle and pin it in place. I don't presently have a mill in the home garage where this 10EE now lives, but I know someone who has access to a mill and is plenty capable of making a new taper pin hole.


Strangely enough, if I rotate the shaft so that my home made screw-pin goes into it and the eccentric is on the right(toward the back of the lathe) the eccentric points almost perfectly vertical with it's lobe peak right about TDC, and the tailstock seems to clamp firmly with minimal input on the lever, but the lever operates backwards from original direction, where lock is now up, and unlock is now down.

I also noted that the shaft hole for the eccentric is offset slightly toward the rear of the lathe, and the standard operation would pull on the clamping rod via the eccentric in a manner that it would be swinging closer to the centerline of the tailstock and the bed, I assume that's intentional to distribute the clamping force as evenly as possible. Does the eccentric ever actually reach TDC in normal operation? I couldn't seem to get it to lock in place and stay clamped without the eccentric lobe peak being near TDC.



I actually hadn't seen your post about casting these handles. I think search on mobile doesn't work quite right or something, I could hardly find any posts about these handles earlier, and now that I'm on the PC again suddenly I can find your post you mentioned and a few others. You wouldn't happen to have a pretty close angle relative to the center of the set screw hole of where the taper pin hole is would you? It visually looks close to 90 degrees if not 90, but I'd like to get the orientation as close to factory as possible if I'm going to drill a new pin hole, and I can only assume that Monarch drilled the set screw holes in the replacement handles in the same place as the originals. I'm also assuming the angles of the set screw hole and pin hole relative to the eccentric lobe were the same and set up with fixtures for production runs and then the pin itself was the hand fit piece during final assembly, but I could be wrong.


Thanks,

Moddage
 
I had a feeling that was the case, it did indeed come from a Union facility. Most of the repairs and maintenance had been done by what I assume was dedicated machine maintenance personnel, and eventually it had enough issues that the new ownership of the company decided it wasn't worth repairing and they were going to scrap it. Long story short after pressuring my dad to find out how to buy it and some time passing without hearing back, we ended up with it. I didn't even know it was a Monarch Model EE when I told him to try to buy it, I just knew an old lathe that once ran really well but now had some electrical issues(well within my wheelhouse to fix) was about to be scrapped, and dad and I have wanted a lathe for a long time now. Boy what a pleasant surprise this lathe has turned out to be, I call it my Holy Grail lathe, and aside from the electrical and some mechanical issues I still need to sort out, it's looking like it's up there with the best as far as complete Model EE finds go. I got the original order sheet from Monarch emailed to me, and most of the original order accessories seem to be present, though the taper attachment has been dismantled for some reason and is presently in pieces in a box, I'm not yet sure if it's missing any parts. It's had a few things retrofitted to it over the years, and they have been bolted on in places I would have never drilled into, which is irritating, but they don't really adversely affect anything except appearance so I'm leaving them alone for now. I sorted out part of the electrical issues and have forward, the reverse contactor is missing the pull down coil entirely. And the threading gearbox needs help internally, I think it's a relatively easy fix though, but have yet to take that apart.
 
Tailstock Base.jpgTailstock Body.jpgTailstock Clamp Parts.jpgRoll Pin.jpgTailstock Locked.jpg


I got the tailstock back together today and adjusted it, the clamp now works perfectly. While the tailstock was apart I cleaned and took a scotch-brite to the surfaces between the base and body to clean up the scale and rust and nasty old oil/grease residue from decades past. I also cleaned up all the clamp mechanism parts as they were totally disgusting and covered in a heavy film of what I can only assume is years and years of residue left behind from old way oil dripping down them. and there were a bunch of chips embedded in it. I also took apart all the pivot points of the clamp and cleaned them up and lubricated all the pivot points and the entire eccentric shaft with Super-Lube synthetic grease and reassembled it all. Man does it work nice now. It locks down tight with relatively minimal effort, and is easy to unlock without having to hit the lever and risk it slamming into the body and breaking.

We opted to put a roll pin through the lever and the shaft instead of trying to fit a taper pin to keep it like it originally would have been. I found a good clocking position for the eccentric and marked the lever and shaft and handed it off to my dad to set up and drill the hole on a Bridgeport. I also took the liberty to apply some Loctite 243 to the set screws during reassembly so they shouldn't come loose over time. I aligned the set-over at "0" but I'm not actually certain that is accurate, before I took it apart it was offset toward the front of the lathe by one mark or so. I didn't bother checking alignment today, that's for another day.

The position of the pin visually appears to be pretty close to where the factory one would have been, I just laser-eyeballed the position of the eccentric and the hole looked close enough to factory from the photos I've dug up, so we went with it. Man is it nice having a functional tailstock clamp and all the crusty/rusty/grossness cleaned up and oiled down. Speaking of oil, I was surprised the factory felt is in the oil reservoir that feeds the ways, and I cleaned both oil holes and the oiling grooves out while it was all apart too. Some day I'm going to give the entire carriage assembly the same treatment.
 








 
Back
Top