What's new
What's new

Monarch Lathe Restoration Attempt (Fixing Someone Else's Botched Rebuild)

Jadams7

Plastic
Joined
Jun 18, 2019
Hello all,

I'm a young machinist starting his own job shop and have purchased some equipment. One piece being my beloved 1946 12 CKK Monarch Lathe. I have been researching this lathe and have learned it quite well. Been through the headstock and i'm in the process of rebuilding the apron. I plan to do a full restoration as it truly deserves.

While waiting on parts from Monarch I decided to disassemble the lathe so I could inspect the bed and saddle for wear. The bed isn't in the best shape but I feel that it is manageable. My real problem is that a previous owner has milled the under side of the saddle, the cross slide dovetail, the cross slide itself, and the compound. They left the milled finish and cut in very crude oil grooves. I'm in the process of learning scraping and acquiring the tooling necessary for the rebuild. I understand that I need to evaluate the lathe and correct the geometry problems. What I cant seem to wrap my head around is how much turcite i'm supppose to apply without knowing how much material was removed.

Any help would be greatly appreciated as I am eager to learn and I am without a mentor.

Apologies for the long winded opener. I feel that it is better to get the big picture out first so as to not spread it across the entire thread.

Thanks,

Jesse
 
Buy a pack of Plastic shim stock or use gage blocks or if you have some Turcite handy. Assemble the carriage with the feed shafts and rack pinion installed. Then block up carriage with wood blocks so it's level. Then set the saddle down on it and tighten the carriage to the apron. In the mean time slide in .030" under the saddle shim until the 6 saddle way ends and check the rack pinion in rack engagement. Add more or remove shims until it feels have a good idea. bedtime....Ill add more tomorrow
 
Hi Jesse, post some photos. I'm amazed at how much the experts here (Richard and others, not me) pick up from those. Cheers, Bruce
 
Richard,

Thank you for your reply. If I'm understanding correctly I need to reassemble the carriage and shim the underside of the saddle until the rack and pinion engagement feels right? I haven't had any luck coming up with a game plan. The only thing I could think to do was to measure the difference between the feed rod heights and the bushing block at the end of the lathe. Is there a standard I should be working towards with the rack and pinion engagement? Obviously wear would play a part and if I compensate for wear in the rack and pinion it could cause my feed rods to be out of alignment in the opposite direction. Or is this a non issue and I am over thinking?

Bruce,

I appreciate the input. I had thought to put some pictures up as well but didn't have any on hand. I will take some and post them up tonight.



Thanks guys,

Jesse
 
Last edited:
Richard,

Thank you for your reply. If I'm understanding correctly I need to reassemble the carriage and shim the underside of the saddle until the rack and pinion engagement feels right? I haven't had any luck coming up with a game plan. The only thing I could think to do was to measure the difference between the feed rod heights and the bushing block at the end of the lathe. Is there a standard I should be working towards with the rack and pinion engagement? Obviously wear would play a part and if I compensate for wear it could cause my feed rods to be out of alignment in the opposite direction. Or is this a non issue and I am over thinking?

Bruce,

I appreciate the input. I had thought to put some pictures up as well but didn't have any on hand. I will take some and post them up tonight.



Thanks guys,

Jesse

Racks are replaceable in sections, if need be. Pinions can be replaced.

Your leadscew and power-surfacing rod may have wear, but their centreline has not moved significantly. Bit of ordinary bearing-fu and they are back where they b'long.

"Whatever" has been either worn-off or milled-off from the COMBINED bed (if ground or scraped) and the underside of the saddle has to be restored to "come out" where the apron's guts are back in agreement with those rod centrelines.

No rocket science to it.

You can use makeshift screw-jacks to get the figure for how much you need to raise the saddle.

A "castable" miracle repair plastic, such as "Moglice" may be the faster way to then HOLD that height?

"NICE" if the bed has first been ground, but the saddle ordinarily has four or more TIMES greater wear, so yah get SOME benefit even if the bed's ways are still imperfect.

I leave that advice to those who use plastics.

I'm kinda "Bronze age" meself. Cheaper and easier when yah cannot AFFORD "perfection".

And/or found it faster and cheaper yet to just go and buy some other good lathe already in far better condition as doesn't NEED any such work. At all.

:D
 
The first thing I would do would set the saddle on the bed near the back of the travel and then mount a mag base on the bed where the carriage sets. this is before you install the feed shafts and carriage The attach a .001" dial indicator from the mag base and indicate the under-side of the saddle where the carriage bolts to and shim the front side of the saddle so when you push the saddle forward and back it reads zero or until the saddle bottom is parallel to the bedways. Lathe saddles are always worn on the front of the saddle. Make note of that number. Install the saddle back under bed way gib or hold down.

Then install the feed shaft, feed screw into the carriage, then slide under the saddle and use longer cap screws so it can be lifted evenly and carefully engaging the rack pinion into the rack. Then start to add shims until the pinion engages with a small amount of back-lash which done by feeler by eyesight once close to home slide the feed shafts into the quick change collars. Once home install the tail-stock end feed screw bracket. Once you think it is close add the shim thickness you found when you measured the saddle bottom. I use plastic shim to raise the saddle cut approx. 2" long and 1/2" wide. This is not an exact science as the V of the saddle is worn more and the front of saddle is going to use more shims.

The back flat is usually 1/2 the thickness of the front V's. To get that close you can depth mike to the bed way clearance area between the saddle carriage ways and tail-stock and the top of the saddle flat ways on the backside of saddle cross slide ways. Or mount a mag base on the tailstock base and indicate the top clearance surface of the cross slide. This should be with-in a .001" preferably front higher 1 to 2 thousands.

Once you know some thicknesses. cut some Turcite and slide it under there, I like to use super glue to hold the shims on the saddle. So you can crank the saddle to feel if it is slow. If you want to really over do this once the feed screw bracket is installed. Put a mag base under-slide sled and indicate the top of the feed screws and they should be parallel to the bed-ways. I hope I have explained this so you can see what I am saying. Rich
 
When I was first starting out I bought a Reed-Prentice that looked OK and functioned. As I got into a cleaning and paint job I figured out it was the victim of a botched bed re-plane and hack rebuild. It was frustrating to put many many hours into a project like that and around every turn I would find something else that was wrong with it.

To sum up quickly, I had a lot invested in that machine including a complete second machine for parts, completely rebuilding the headstock including all bearings, Bijur orifices, etc, etc. My business got to the point where I NEEDED that lathe running and I couldn't make the time or sink the money into finishing it. So I bought a great running, much better lathe for less money than I had into that R-P. I set that lathe on the floor. Wired it up and made parts. A few years later I slapped that R-P together and sold it for $1000. Probably a fifth of what I had invested into it not counting my time.

My point is make sure you really want to be a machine rebuilder instead of a machine shop. Because once you go down that rabbit hole there's a lot of potential for setbacks and not good odds the investment you will make in that machine will ever pay you back.
 
My point is make sure you really want to be a machine rebuilder instead of a machine shop. Because once you go down that rabbit hole there's a lot of potential for setbacks and not good odds the investment you will make in that machine will ever pay you back.

This one is "special".

IF, in fact, the bed was reground?

AND the saddle was milled to at least get slope and rockinghorse out?

It should clean up a LOT more easily than "average". Basically getting it back to height, per RK w/r Turcite, or RK and others who have used Moglice.

The "expensive", hired-out, or "third-party" work having been done?

What's left is seriously tedious for a non-pro, but it is mostly labour - not a lot of cash outlay left to put into it, and DONE.
 
This one is "special".

IF, in fact, the bed was reground?

AND the saddle was milled to at least get slope and rockinghorse out?

It should clean up a LOT more easily than "average". Basically getting it back to height, per RK w/r Turcite, or RK and others who have used Moglice.

The "expensive", hired-out, or "third-party" work having been done?

What's left is seriously tedious for a non-pro, but it is mostly labour - not a lot of cash outlay left to put into it, and DONE.

I guess my cautionary tale is suggesting that if someone was dumb enough to just mill and assemble carriage, cross slide, etc you should expect to find a whole bunch more stuff hacked up beyond common sense. For instance, lets say maybe they welded up and filed the pinion to fit the rack in the lower position better. Maybe they dropped the feed rod, leadscrew, clutch rods to line up with carriage, but didn't actually line them up at all and taper pinned them all crooked. Maybe they welded up the tailstock ram and turned it round again and re-bored the tailstock to fit, but nothing was in any sort of alignment whatsoever anymore.

You might think that's crazy, but I have seen some stupifying stuff on old lathes. Especially WWII era stuff that was probably whipped at the end of the war and somebody got it for nothing, fixed it for nothing and either used it for a bit or flipped it for a profit.
 
There are at least two classes of users, those that take a worn out machine and do as little as possible to keep it going and those that appreciate the ruggedness of these old machines. At the end of WWII and some of the other wars, surplus machines, worn out or not, were literally given away. Plenty of stock out there. Today much of that stock is cutting someones beard off so we want to take care of what we have and are aghast at what has happened to much of what is left. As the stock of good machines declines, this is what is left.

Tom
 
There are at least two classes of users, those that take a worn out machine and do as little as possible to keep it going and those that appreciate the ruggedness of these old machines. At the end of WWII and some of the other wars, surplus machines, worn out or not, were literally given away. Plenty of stock out there. Today much of that stock is cutting someones beard off so we want to take care of what we have and are aghast at what has happened to much of what is left. As the stock of good machines declines, this is what is left.

Tom

All-manual machines we are talking about, here. Mind - CNC rigs are being kept running long after anyone might have expected was prudent as well.

Much as I love 'em, it is nostalgia we are dealing with, not sound economics. The world moved on a long time ago.

Preservation, nostalgia.. of the same sort as inspires some some folks to restore old coaches.

Not Greyhound buses. Those pulled by horses.
 
Thermite,

What you said makes good sense to me. What I have had the most trouble with is figuring out how much has been taken out of the saddle. But like you said its not rocket science. Just figuring out what datum/ untouched surface to measure from and where to measure too seems to be my issue. I will admit I have never heard of Moglice. I'd imagine some form of castable wear compensation may be quick and easy. I know i'm not exactly using best business practices but scraping/machine reconditioning intrigues me. The thought of fully restoring a lathe of this caliber that is from the era where "they don't make them like they used to" satisfies me. I understand that I will probably never get my money back out of this machine considering my time invested. I suppose i'm riding the line of hobby and business. As much as i'd like to have more lathe work there has yet to be a lathe job walk through my door. So I reckon I can do without it for a bit. I sure do appreciate your input. Feedback from like minded people is something I severely lack.


Richard,

I think I understand what you're saying. I need to use the underside of the saddle to indicate and shim until parallel to the travel of the saddle on the bed ways. Then I need to install the apron to assess the position of the feed rods and add or remove shims accordingly. Which will in the end tell me how thick of turcite is needed. One question I have in which I may be misunderstanding you. You mention to do this indicating at the back of the travel which in my mind is the tail stock end. Wouldn't this be the most unworn section of the bed and shouldn't I indicate at the head stock end where most of the work will be happening. Regardless this gives me a game plan and I surely do appreciate it.

Garwood,

I completely agree with you. It would certainly be more economical for me to sell this machine and purchase another one that is ready to make chips. I just believe this process will teach me a lot of lessons which I won't have a chance to learn else where. I also feel that I will enjoy it. There's something about setting a large goal like this and achieving it. I don't believe restoring it will be to costly just time consuming and tedious. I've been through the head stock and only found one problem that was resolved easily. The head stock still looks brand new, the end gearing seems to be in great shape as well as the quick change gear box. Obviously there's no good way to confirm the condition of the bearings without taking everything apart but this machine runs pretty smooth.


I appreciate the feed back guys. All in all I may very well be in over my head but I have always been someone who learns the hard way. I'm gonna attach some pictures of the lathe itself and some of the wear on the bearing ways. Hopefully this will point out anything I may be missing.20200131_173458.jpg20200131_173503.jpg20200131_173815.jpg
 

Attachments

  • 20200131_173437.jpg
    20200131_173437.jpg
    87.1 KB · Views: 134
  • 20190427_222207.jpg
    20190427_222207.jpg
    90.7 KB · Views: 136
Thermite,

What you said makes good sense to me. What I have had the most trouble with is figuring out how much has been taken out of the saddle. But like you said its not rocket science. Just figuring out what datum/ untouched surface to measure from and where to measure too seems to be my issue. I will admit I have never heard of Moglice. I'd imagine some form of castable wear compensation may be quick and easy. I know i'm not exactly using best business practices but scraping/machine reconditioning intrigues me. The thought of fully restoring a lathe of this caliber that is from the era where "they don't make them like they used to" satisfies me. I understand that I will probably never get my money back out of this machine considering my time invested. I suppose i'm riding the line of hobby and business. As much as i'd like to have more lathe work there has yet to be a lathe job walk through my door. So I reckon I can do without it for a bit. I sure do appreciate your input. Feedback from like minded people is something I severely lack.


Richard,

I think I understand what you're saying. I need to use the underside of the saddle to indicate and shim until parallel to the travel of the saddle on the bed ways. Then I need to install the apron to assess the position of the feed rods and add or remove shims accordingly. Which will in the end tell me how thick of turcite is needed. One question I have in which I may be misunderstanding you. You mention to do this indicating at the back of the travel which in my mind is the tail stock end. Wouldn't this be the most unworn section of the bed and shouldn't I indicate at the head stock end where most of the work will be happening. Regardless this gives me a game plan and I surely do appreciate it.

Garwood,

I completely agree with you. It would certainly be more economical for me to sell this machine and purchase another one that is ready to make chips. I just believe this process will teach me a lot of lessons which I won't have a chance to learn else where. I also feel that I will enjoy it. There's something about setting a large goal like this and achieving it. I don't believe restoring it will be to costly just time consuming and tedious. I've been through the head stock and only found one problem that was resolved easily. The head stock still looks brand new, the end gearing seems to be in great shape as well as the quick change gear box. Obviously there's no good way to confirm the condition of the bearings without taking everything apart but this machine runs pretty smooth.


I appreciate the feed back guys. All in all I may very well be in over my head but I have always been someone who learns the hard way. I'm gonna attach some pictures of the lathe itself and some of the wear on the bearing ways. Hopefully this will point out anything I may be missing.
 
Indicating the underside where the carriage bolts to as that area is an original surface That the factory scraped in most precision lathes So your indication a surface with no wear. You indicate it before bolting on the carriage.
 
First you need to learn left end to right end from the machine operator stands. This is on all machine tools. So the chuck end is left and tail stock end is the right end. I'm telling you to indicate the surface where the carriage bolts on. You indicate it before you bolt the carriage on as this is an unworn factory surface. So it must be parallel to the bed ways after you shim up under the saddle to estimate the turcite. Oh and add .005" for the glue.
 
Take a look at this you tube show. I helped Keith Rucker figure it out. The surface is to the right of the V / Where the carriage bolts on. It starts around minute 14. YouTube

Here is another former student who is in Norway bonding, measure and scraping a a lathe saddle YouTube
 
Richard,

I believe we may have a misunderstanding. I assure you I know the anatomy of a lathe. And I understood what you meant by indicating the under side of the saddle and feed rod assembly. What I didn't understand is where on the bed should I be indicating all of this. Should it be toward the left of the bed (chuck end) or the right of the bed (tailstock end). I am assuming the bed wear will affect my indicator readings. As for Keith Rucker's Monarch restoration he is the main reason I even understand what I'm doing with this project. I also have another question. I finally measured my bed wear accurately using a version of your king way alignment tool and have come up with .020" wear in the inside v way. Which from what I understand is the worst wear point. It amazes me that hardened bed ways have scored/worn so much. Is this absolutely too much wear? Also when I scrape in the saddle after applying turcite and printing on the scored portion of the ways shouldn't I get false prints or damage to the turcite?
 
What I didn't understand is where on the bed should I be indicating all of this. Should it be toward the left of the bed (chuck end) or the right of the bed (tailstock end). I am assuming the bed wear will affect my indicator readings.

I don't see it "practical" to refer off the Vee way - or any OTHER "wearing" surface - once you've gotten indications of THAT much wear. if-even your measurements were perfectly done.

Other surfaces "may or may not" have been as precisely aligned, Day Zero, as the Vees and working flats. (As far as we know, they actually WERE). But the flats IN BETWEEN the "working" ways are probably the best and only surfaces surviving in close enough to as-built plane to serve as a reference to restore the rest.

See if there is any meat on that bone.

Compare the top non-working flat just "back of" the front inverted Vee way to the underside flat where the anti-lift rollers operate. It will need cleaned, then stoned. With some care in how you configure you "sensor shoe" you'll be able to avoid the worn area where the rollers actually ran.

Better yet, pull the longitudinal traverse rack segments and see if you can compare the top inter-way flat to the surface the racks were mated to.

That's also about as "relevant" a reference point as you will find for measuring what it needs to get the apron top to saddle bottom parting line back to the height where the leadscrew and power shaft are not being dragged-on.

Tedious? Surely! My age, yah just go and find another lathe in better condition. I have no interest in re-learning tedium!

:)

Your case, "sweat equity" and learning/improving skills may make it a far more worthy exercose? Your call. No one elese's.

But what else have you as isn't worn all sidegodlin and sway-backed?

I'd guess you are either up for a bed re-grind.

Or the TEDIOUS step-scraping the late, lamented Harry Bloom did - and documented so very well, "Right here, on PM" to put one or both of his "wreck" projects back to rights.
 
Richard,

I believe we may have a misunderstanding. I assure you I know the anatomy of a lathe. And I understood what you meant by indicating the under side of the saddle and feed rod assembly. What I didn't understand is where on the bed should I be indicating all of this. Should it be toward the left of the bed (chuck end) or the right of the bed (tailstock end). I am assuming the bed wear will affect my indicator readings. As for Keith Rucker's Monarch restoration he is the main reason I even understand what I'm doing with this project. I also have another question. I finally measured my bed wear accurately using a version of your king way alignment tool and have come up with .020" wear in the inside v way. Which from what I understand is the worst wear point. It amazes me that hardened bed ways have scored/worn so much. Is this absolutely too much wear? Also when I scrape in the saddle after applying turcite and printing on the scored portion of the ways shouldn't I get false prints or damage to the turcite?

JAdams, in a recent video on a large lathe Keith Rucker mentioned the same issue and decided to use the worn section near the headstock as his reference. His logic was that was where he was going to work the most as he rarely does long parts. It seems like a logical if not ideal situation and much cheaper than having the bed ground.

Charles
 








 
Back
Top