How to avoid an expensive mistake, Check your lathe's Spindle. 

Thanks very much for the instructive video and your analysis of the problem. I absolutely agree with your conclusions. Very sad to see such a great machine virtually destroyed by (probably) brute force. However I disagree with your remarks on electric "pulses" driving 3-phase motors and the resulting "unsmoothnes": basically 3-phase motors are driven by currents on 3 lines. The voltages are sine-shaped and there is a temporal shift between them - called "phase". The currents run through the coils of motor and create magnetic fields. If you add the magnetic fields of the three phases you get a perfectly "smooth" rotating magnetic field without any pulsation - as if you would spin a permanent magnet. The magnetic field drives the rotor of the motor which runs perfectly smooth. The electric sine waves of the current (which could be regarded as "pulses") do not cause any pulsation of the motor speed/torque. (To electrical engineers: sorry for my overly simplified explanation.) The description of your setup with a 3-phase motor driving a DC generator generating DC power for a DC motor sounds like a "Ward -Leonard" setup. The reason why this has been used in former times is the fact, that DC motors can operate at variable speed - in contrast to 3-phase motors (without VFD in former times). In former times Ward-Leonard converters have been used to drive very heavy machines e.g. electric winders in mines and motors in rolling mills. I have also seen surface grinders using the same principle to enable variable spindle speeds. (E.g. Jung HF50) Theoretically/strictly speaking I would even expect that DC motors run less smoothly than 3-phase AC motors because the current is "switched" between the coils of the rotor by means of the commutator. As you correctly state: nowadays you can overcome this problem by using solid state variable frequency converters (VFD). I hope you don't find my comment patronizing. Just wanted to clarify this. Keep up your excellent work!

Funny just before I watched this video I found a 10ee for sale. Thanks for the tips I will make sure I fully inspect that machine

In my 45 years as a tool maker, and machinist, I've never seen a spindle bent that badly. I can't imagine how that got bent.

Great video Steve thanks for the how too much appreciated.

Thanks a milling for making this video, ,, I will know what to look for at my next lathe purchase, You did a good job with this instructional spindle check,

Very nice work. Very interesting. Thanks

Very inforamative...Thanks for the explanation.

I worked in a local shop cleaning and repainting some of the older machine tools. One of the partners owned a Monarch 10EE. He was quite proud of that lathe. It turned a lot of repair parts for Parker Hannifin Hydraulics when they had a facility in Delaware, Ohio. AL B.

Looks like you have others problem children taking up a lot of shop space to me. Nice of you!

thanks for the video.......sad to see such a nice machine with so many issues....cheers from Florida, Paul

Oh my???!?!!? Interesting. Thanks for the advice.

I've so far resisted the urge to own one. We've had two come through the shop at work, both bought cheap(

Sorry to hear about the lathe. That’s gotta suck. I worry about that too. Thanks for the reminder. Happy machine hunting!

I’m living this very scenario on a different lathe. Pulled the spindle, had it chromed and ground concentric on the journals. Reinstalled new P5 bearings and now figuring on the grinding the D6 taper to match the bearings while installed, maybe cutting the face of the cam lock too. I need to work out the trigonometry if that’s going to be needed or not.

I'm always leery of machines that look too clean and pretty. Kinda like that Mexican Rebuild Bridgeport you showed a while back. Mexican Rebuild = Throw a coat of paint on it and call it rebuilt.

THANKS STEVE

Steve, I would like to see the owner give you permission to pull the spindle, clean good, set on vee blocks and check the runout from end to end as well as the face of the camlock to determine where the spindle is bent. Next, have the spindle either wet mag or dye penetrate done to see if any cracks started from the wreck the lathe got into. Last, any wreck that would cause this much damage has probably upset the alignment of the vee and flat the headstock sits on, too. So sad things like this happen. I've seen many machines in my past get into wrecks similar to this. Big machines! They patch them and keep running. Yeah, some day they get sold off to some poor guy and it turns into a nightmare for him. As always thanks for sharing, Ken

That is so sad it got crashed. Maybe take the 2 lathes and make one?

I'm thinking some one had a horrendous crash.

I do cnc field service, a customer bought a large horizontal mill at an auction, the B axis was bad, just the B axis bearing was $20,000, total repair just for the B was $56,000

Thanks. I had not thought to check the runout on the back end of my spindle. BTW There is something terribly wrong with your audio - stuttering - not heard in earlier videos.

Watching this, is like watching paint dry LOL

served a four year union apprenticeship in the early 70's and those double e machines were the only small lathe you would like to work on. they were better than any german or japanese machine. we had mostly monarch lathes and american pacemakers. i didn't realize how beautiful these machines were till i left the government lab where i served and got out in the real world. Some savage bastard really had to crash that monarch. poor little thing. take her to the scrap yard. it's only steel. and a seven thousand dollar mistake is par for the course in machine shop these days. I own a jet 13X40 for over 20 years that is in good shape only because i am the only one that runs it. the only jet 13X40 machines i have seen in shops i have been in had the carriages taken apart or the lid of the gear box removed, and covered with dust of long misuse.

if the electronics and drives are good.. i wonder if Keith Rucker would be interested as he just ripped the pre vaccum tube mechanical controls out of his 10EE. or if 4 ponds shop might have spare spindles from some of the many 10EE he has worked on.. but for the guy with the 9" south bend.. check ebay South Bend 9" Lathe Headstock Spindle

Are you using a noise gate on your audio track? Sounds like the threshold is set a little high.

I just bough a used haas cnc lathe. I paid some machine service company to inspect it. They told me it looks good. I get it here and the spindle has .010 end play. 6,000 to fix. waiting for haas to come and install the new spindle. I will have a nice lathe at the end of it, but i sure wish i would have known. I will know more next time

Make a custom backing plate to fit it, and move it off to a hobbyist so they can have bragging rights for owning a 10EE. They are nice lathes, but problem plagued electronics is a definite "buyer beware" .

Carbide reamer of whatever taper # it is? Just a quickey to see how long it'll hold the current spindle play with it running bent. good luck.

What a damn shame man I’d be absolutely sick if I was him whoever doctored that machine up and never said a word or whichever asshole withheld that information in the auctions description needs to suffer the same fate but karma has a way to deal with these kinds of assholes we just don’t get to see it

That sucks, I bought a 1917 Hardinge quick change with a bent spindle and bad bearing, luckily I was able to straighten it and make a new bearing.. (cast iron cone bearing) its a work in progress, but at least its spins true now.

Their is a saying not all things at auctions is junk but most of the junk is at the auctions.

Hi Steve 1967 I finished an apprentiship as a tool maker. Since then I have had a number of engineering jobs and Im not sure I fully agree with you conclusion that the main spindle is bent. I would put my money on somebody who didnt fully understand what they were doing , doing something stupid with a grinding wheel. That is the only explanition for the lack of concentricity between the OD and the ID at the stock end(chuck end) of the shaft. I would be tempted to re grind that inner taper. One way to check would be to put the DTI along the length of the spindle. Is that possible?.

What were the manufacturer's tolerances for the spindle? I used one of these for many years and don't recall ANYTHING locating to the I.D. of the spindle tube. The taper of the collet assy. would be pretty important as it is what really needs to run true, especially if you are not turning the O.D. of the pieces you are making. Trash? I think NOT!

I wasn’t aware that Monarch was still making these things, even as a custom order. I knew they rebuild old machines, at high prices. Real machine rebuilds are expensive.

There is a guy on youtube that completely upgraded the wiring on a Shalublin that had a lot of complicated electonics. RotarySMP. Maybe you can get some ideas from his videos on that process.

What would a similar cost in good condition? Both visual and mechanical? This do seems like it's being used, and not kept in clean condition. That often is a indicator of a previous owner not paying the needed attention to the equipment 😊

Steve, your Microphone has a bad connection or is clipping or something.

I am not sure it would even matter, if the spindle were to be wobbling as long as it rotated around the centerline correctly. If you chuck a part in your 3 jaw and it is .01" out 1 cutting pass and it is corrected. Part is rotating around the centerline of the bearings, going to finish round.

It might be worth checking the spindle bearings, maybe something is loose and the races spun a little, thus creating a parallel issue. Another issue may exist as high end bearings are marked with the high spot, they may be out of position. It has spindle issues grinding the nose speaks loudly. it is possible it was taken apart and then someone else re-assembled the spindle bearing wrong, maybe. My understanding is issues such as this, bearings improperly set parallel or not enough preload can skew a spindle. The nose issue can you chrome plate the nose and re-grind it. .005 Hard Chrome is attainable. I do like a machine that works right. Best of luck, either way it's a project.

What I want to know is how you go about BENDING the spindle of a lathe like a Monarch. Those spindles are manufactured of heat treated high alloy steel and ground to precise dimensions and tolerances. In order to bend it you need a bending moment applied either between the spindle bearings (fore and aft bearings) or you need a large force applied perpendicular to the face of the face plate or chuck which is mounted on the spindle. But that force needs to be in the neighborhood of multiple tons. How do you go about doing that? That's a deliberate sabotaging of the machine.

Just maybe it was hoisted up by the chuck neck, bad idea.

Ive seen plenty of bent spindles over the years, but never on a EE. Such a small machine, not sure how you could bend it.. The newer spindle drive retrofits are using servo motors, much smoother than a std AC motor, and no more $$$$ power vacuum tubes.

I'm having serious audio issues with these last two videos, very clippy

Hello Sir. Have you not rather established that the axle must be out of alignment with the bedways? If I understand your procedure correctly, you took a measurement at either end of the spindle. Between two points of measurement I suppose there to be a straight line and unless I can take a third in between that proves not to be on that same line, I think concluding that the spindle is bent is not justified.

Since it can't be used to any precision at this time I would still push the spindle straight with a hydraulic press. I could live with the bearings if everything stood to 1/2 ten thousandths after putting it back in after the push. That nose piece is useless.

Couldn’t finish it sound kept cutting in out

Pull the bearings out and post the numbers, I will see what I can find for you. Work at a bearing distributor.

Don't know if it is my hearing aids or your audio, but it is difficult to make out what you are saying.

Double EE's weren't that great IMHO when they were new. I served my apprenticeship in a shop and we had several. In 86 I went into sales and applications and have been in a lot of military shops that had them. The story is always the same...spindle drive issues. A Hardinge dovetail toolroom lathe is a better choice. Monarch is a company that should have been better but they disappointed a lot of customers.

sometimes it had to sacrifice 1 to make the others live. if that spindle is fubar. no replacement option. why not sell the other parts to other "monarch gangs" to fix theirs? may be a bit of here and there can fill a bit of that 6000 money pit too.

You could Repair the ground down spindle nose by welding and re grinding press the spindle straight ir as straight as you can get it ! get it out of your head that the lathe is junk...it's not fix the damn thing !

if you dont work in .001 plus or minus and not .0001 you could get buy with 1/2 the cost bearings, actually if you want .0001 and a 20 micron finish buy a new machine !!!

The audio is so bad that it is not worth watching.

And Don sys you lie a lot? Maybe your answers don't line up with his statements, recon? That is a bad deal BUT if it needs to be true, it blamed well better be. And yes, shafts are straightened every day BUT like you said, that one is shot. GBWYall!