Old Monarch Lathe Help

Hello everyone - I have some issues with an old monarch lathe. One of the gears is stripped partially of the teeth and I would like to find a replacement for it. I attached a photo of the gear in need of replacing and a couple pics of the whole lathe. Anyone have a parts manual/service manual - even if it's a photocopied version??? I have not had this running and either has the previous owner. Does anyone have any clue on the age or model of this. It appears as the lot # is 819 machine #1. If anyone that can help me with this I'd sure appreciate it. - Jeremy



lathe - http://i41.photobucket.com/albums/e258/centralminnesotablacksmiths/Jeremy K/DSCN2664.jpg

lathe - http://i41.photobucket.com/albums/e258/centralminnesotablacksmiths/Jeremy K/DSCN2665.jpg

bad gear - http://i41.photobucket.com/albums/e258/centralminnesotablacksmiths/Jeremy K/DSCN2667.jpg

Could someone tell me why this old lathe is such a dead horse? What is the major defect in these styles, that the Monarch company will not supply any info on them at all? Just curious because.... Am I wasting my time triing to get this thing back running? - Jeremy

From the photos it looks like you have a CK, which is actually a old work horse, especialy for a 60 year old lathe. There are many of them still running. To strip out a gear like this, it either had one heck of wreck or it had a stupid operator. If the damage came from a wreck, there could be damage through-out the machine. Do you have other problems with you lathe?

Hopeful others in the group with these type of lathes can tell you more about them.

Much older than CK. This is a plain bearing helical gear head from twenties/early thirties.

John Oder

I'd be inclined to bet on an operator attempting to shift gears while the lathe is running. It'll be a pretty big job to repair that, probably you'll have to work out how to make (or get made) a replacement. Its a great lathe and I think it'd be well worth fixing as long as the effort isn't intended to be a paying proposition- meaning it'll be a lot of time into the job and probably some money. Monarch had really good taste in gears, a comparable replacement will not be a usual off-the-shelf item, unless you're lucky enough to get one from a parts machine.

Regards,

Greg

Almost impossible to say without a complete strip of the headstock whether small chunks of the teeth did any other damage. One thing is sure- after the damage they didn't stop using the machine- only that speed.

Helical geared headstocks are quiet and smooth, but almost preclude finding an off the shelf gear in a catalog. To make one will require a universal horizontal mill with a geared dividing head.

It's been said before, but bears repeating------NEVER buy a geared head machine with out taking the lid off and having a good look at the gears

Herb Kephart

This is the way this machine jumped into my shop. I didn't even think to look at the gears before hand. I was just looking for a small lathe to make some bushings and spacers as needed in my welding shop. I did find a shop that would or could make one - as they do repairs on lathes and machines. They just do not have the prints on this particular gear so I'd have to remove it and then they could reverse engineer it. when I seen the damage on this gear I looked at the one that rides with it and did not see any teeth gone on it. I'll do a better visual inspection today. The original motor was supplied with this lathe but the motor mount has disapeared - no problem - I can fab one up. If it is just one speed and the rest of the gears look ok - would it hurt to use it if I drained and cleaned the oil from the gearbox to keep the small parts of the damaged teeth from getting pulled back up into the rest of the gears? I got it because it had clearance for 1-1/2" barstock through the gear head. Maybe I just drug home an anchor??? - Jeremy

Supposing that I do not find any other visable damage.... who knows the process of actaully removing this gear? Does anyone have a manual on dis-assembly/re-assembly??? Can someone walk me through it so I can posssibly get another made? Or would it be better to clean it out good, get the motor on it and run it to see what else may be wrong? I know this is a chore to do via. not being right in front of it to look at it with your hands, but that's what these forums are for right . If someone has experience with this I'm more than willing to get my hands dirty - mainly because I really don't want to move it again, the little bugger was a bit heavy but not outside my means of moving things though. - Jeremy

Excellent advice on inspection of a geared head machine Herb.

My understanding is that Monarch has no documentation on these old machines, that's why they can't help you.

Monarch made their own very high quality helical gears, it was part of their contribution to the art of the lathe to manufacture gears good enough to minimize/eliminate gear noise effects in the workpiece. Although a "similar" gear could be produced with a universal horizontal mill with a geared dividing head it would not be an equal gear. It will require additional operations such as heat treatment, and shaving, grinding or honing to achieve the accuracy of the original. It won't be inexpensive unless you can do all the work yourself.

There might be relatively easy and cheap workarounds if a teardown shows the rest of the gears and bearings are servicable. Perhaps you don't need that particular speed(s) (haven't studied the photo sufficiently to know exactly what that gear does in the overall speed selection geartrain). Cut the teeth off that gear so it's a spacer and use what's left of the speed selections. That way if you ever found a proper gear you could easily put it back right.

There might be a parts machine out there somewhere, there's one of those gears/lathe.

Better yet, drive the motor with a VFD to vary speeds between the gear selections you have left.

Anyway, good luck with it!

Edit: Wrote this post before Jeremy's last two posts arrived here.

Dave - good idea on the VFD and the stripping of the rest of the teeth or use of a spacer so that gear will not be an issue anymore. That may be the most sensible repair for now - as I'm a bit of a nostagic person and would like to get this one back into operation so it does not end up in the forbiden death zone of the scrap yard. - I'm not going to give up easily on this one - Jeremy

I just looked at the rest of the gearbox and only found one other partial bad spot as show in the attached picture. This is on the headstock engaging tabs(forgive me for not knowing the correct names). The main gear that is broke is a 40 tooth gear with 5 broke then 1 good then 5 broke then 1 good then 7 broke and the rest around the gear are good. The teeth that are broke are broken from the bottom of each tooth edge at an angle up towards the middle of the top of each tooth. So the gear that meshes with this broken gear still has engagment with the good half of all the broken teeth (am I making it clear how the teeth are broke?). Everything else looks or appears to be in great shape - maybe 1 or 2 of the very corners of a tooth is slightly chipped off on one of the other gears. It just appears as the 2 shown spots are very isolated damage. - Any more thoughts on this....anyone - thanks to those who have replied already - Jeremy

detailed bad spots in gearbox:
http://s41.photobucket.com/albums/e.../Jeremy K/?action=view&current=DSCN2667-1.jpg

From your fracture description the teeth failure description is consistant with a very high torque overload. Continued running of this broken gear will damage its mating gear even under no load, they are constant mesh gears. That will put additonal wear particles into the gearbox, not good. They may always be turning depending on the details of the gearbox.

#2 are clutch dogs, parts of a "dog clutch" shifted into and out of engagement by sliding one member axially on the shaft. Can't make out enough detail in the photo to see if it's OK. It's common to see some damage to the corners of these in mistreated machines (shifted while things are still rotating). If there's adequate parallel to the shaft axis contact faces remaining they often have servicable life left.

Drain the oil and look in the bottom of the sump. What do you see? Just big chunks or chunks and lots of fines? Only big chunks is much better.

What is the condition of the rest of the machine? Is it worth the work to make it servicable?

Dave - The clutch dogs do appear fine with the exception of the one missing(broke off) in picture labled #2 w/ circled area on the headstock. This next week I should have time to drain and check out the gearbox to see what types of particles are in the bottom of it - like what was said - hopefully larger pieces vs. small fines.
Is it worth it - well I guess that's kinda what I'm triing to find out, even though being it's in my shop already, I'd like to get it back into usable shape. I know that's a fine line of a decision and I will know more when I get the motor mounted and new oil in the gearcase and run it to see how everything works.
I'd say yes it has some wear on it due to its age. Is it not usable anymore? - that I do not know. Why was it not being used anymore? - again I do not know. I do know that it has been move into 3 different buildings for storage without being run at all.
I could probably buy a brand new lathe in the price range of $3000 to do what I may need( of course it would be an import). I would rather not do that even though it'd be quicker I suppose. I've always been told that an old lathe is better than a new one?? That is another topic for discussion that is is not what I'm looking for. This will not be used as a full machine shop would as far as time running. The purpous would be having a lathe accesible for conveinience instead of multiple trips into town and a waiting period from a regular machine shop and cheaper than buying a new lathe. I'm sure people have restored far far worse shape lathes than this one and got them back into working condition.
I'll post my findings in the bottom of the gearcase as soon as I get it cleaned out - Thank You - Jeremy

A machine that size can be handy, but everything you do to repair it will be large, heavy, with lots of parts. I'd agree with the other suggestions, check the sump for extra parts, and decide if to proceed ahead, or move to another machine. Good Luck

Jeremy-

Looking at the picture of the broken gear, it appears to me that- as far as gearing goes- the three gearsets on the spindle are- left to right -medium (the broken one), high and low. It appears that the most useful is the one that is broken. While the broken dog was probably caused by shifting while running, the teeth being broken would probably caused by torque overloading, as DaveE907 said, unless the missing dog clutch, or pieces of it, got picked up by the oil and tried to go through the mesh. If you can get the chuck off, indicate the spindle, to make sure that it didn't get bent. While controlling the speed electronically is a useful and viable fix, it is not an inexpensive one, and some motors don't take kindly to the pulses.

I am from the school that believes that all things considered, a good used US lathe is a better deal than most foreign ones- but I would part the old gal out. If you spend a little time looking, you will find another old lathe that needs a lot less work

Herb Kephart

Jeremy I will gladly take that old gal off your hands and restore her back to her once youthful condition. Or you can keep it and just let me know when we start her make-over.

Machinsts built it once and it can just as easily be done again.



Another possible cause of similar gear destruction that I have seen over the years is caused by power feeding the carriage into the rotating chuck; machine fighting itself scenario. I have a W&S 3A that had gears as bad or worse, caused by that situation by a previous owner. She looks and runs great today after a little makeover.

Your call pal, you know were I live!!!

I used to have one of these and might have a few parts kicking around. Like the thread dial, collets, collet closer maybe a steady or maybe that went to the bone yard. Anyway fell free to send a PM or mail if you decide to keep the machine. That head looked like it would be a real bear to dis assemble, never tired it but it looked tough. Mine was a 16 inch.