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Monarch 12CK 1942

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Plastic
Joined
Oct 3, 2019
I am setting up a 12CK in my shop from my dad's shop. I have a lot of MT4 & MT5 tooling and drills. From what I can tell the head stock in the CK is a Jarno #12(short) and the tail stock is MT3. Has anyone bored the headstock out to an MT5(short) and the tail stock to an MT4? If I bored out the whole length of the headstock spindle to 1.5" would that weaken the spindle too much? Any thoughts would be greatly appreciated. Thanks
 
I am setting up a 12CK in my shop from my dad's shop. I have a lot of MT4 & MT5 tooling and drills. From what I can tell the head stock in the CK is a Jarno #12(short) and the tail stock is MT3. Has anyone bored the headstock out to an MT5(short) and the tail stock to an MT4? If I bored out the whole length of the headstock spindle to 1.5" would that weaken the spindle too much? Any thoughts would be greatly appreciated. Thanks

Ive no direct experience with the monarch, but my DSG 13z is a similar class machine from 1930/40s era. It has a Jarno 13 in the spindle that im thinking of taking out to the next Morse size.
A lot of folks frown on boring the spindle for various reasons, in a manual ive got for the DSG it actually talks about just that, unless you can find similar info then its a judgement call on your part. Maybe you could find the minimum od of the spindle and and make a decision from there. Monarchs usually aint short of 'Meat' are they :)
As long as youre comfortable doing a decent job you could bore/ream the spindle and TS quill tapers, provided they are arnt too hard. MT stuff is easy to come by and will suit your tooling, is also just nice to have fresh sockets. You might want to add a couple of set screws to engage the tang if yours is currently a bare socket.

Cheers
D
 
Spindle nose hardened and ground - like all D type Monarch spindles. Good luck on cutting on it with any accuracy - unless set up in a suitable ID grinding machine
 
I think there is a theme here.Just leave it alone! Using 3MT to a 4MT adapter in the TS shortens up the 30" quite a bit. The 5C draw tube won't fit through the spindle but I could get a D1-6 5C chuck $s. Is the run out on that type of chuck as good as the Jarno to 5C sleeve ? This lathe is really tight and I am looking forward to doing a lot more accurate work with it. I appreciate the advice.
 
Get a 4mt tool holder to hold your drills, feed with carriage.

No, I'd not go about cutting on either of those features on the lathe unless absolutely necessary.

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Wow, I am new to forums. That is a lot of good information I guess I need to get out of the shop/ranch and see what's going on out there. I will keep my old LeBlond flat belt Babbitt 22" set up for the occasional big stuff and be happy with the 12CK as is. Good point on the speed though. This one is 700rpm top speed. Has anyone sped one up with a pulley change or a vfd? If I run it up to 1400 will it shake apart? I use my 5MT stuff on a 13"x 4' radial drill so I don't have any trading stock. That er40 collet suggestion might be pretty handy for the radial press.
 
Of course a 12CK has D1-6, it is meant to take a chip

It also has a multi point oil pump in the headstock, should show a regular bloop bloop of oil in the sight glass

I think mine is oversped through pulleys but never checked it out.

I bought a Sjogren chuck since the headstock is so long it would take two steps to reach the lever on a collet closer.


I don't think 1000-1200 rpm would be crazy given the quality of the gears and bearings.

The levers get loose tho, and the brake might have other ideas, so if doing it with a VFD, braking with that might be a better idea.
 
Its my understanding the 12CK could be purchased with spindle speeds up to 1000 RPM. I wouldn't be too worried with running one that fast by playing with the motor pulley. Mine is setup for 800 RPM top end with a drive shaft speed of 822. However I'd run it as is for a bit and see what you think. With any Monarch this age I would confirm the lube pump and Bijur meters in the headstock are working correctly.
 
Its my understanding the 12CK could be purchased with spindle speeds up to 1000 RPM. I wouldn't be too worried with running one that fast by playing with the motor pulley. Mine is setup for 800 RPM top end with a drive shaft speed of 822. However I'd run it as is for a bit and see what you think. With any Monarch this age I would confirm the lube pump and Bijur meters in the headstock are working correctly.

Pulling the headstock cover is a trivial, if heavy, matter and is definitely worth the effort.

IMAG0334.jpg
 
Also well-worth the very modest cost to fit a sheet of clear Lexan across it, run it with a strong LED light to-hand - eyeball it all to make CERTAIN lubes are going where they need to go, and nothing is bent, wobbling about, etc.

Never even thought about that, I just let the oil fling. :)
 
HOPEFULLY.. you meant "pulling the headstock TOP COVER"... only?

And, yes. Well-worth it. Any used geared-head.

Also well-worth the very modest cost to fit a sheet of clear Lexan across it, run it with a strong LED light to-hand - eyeball it all to make CERTAIN lubes are going where they need to go, and nothing is bent, wobbling about, etc.

A bent shifter fork, my 10EE, held dog clutches mis-positioned.

WELL worth that sort of inspection, cheap as plastic is. Also wipe rags, of course!

:)
I'm also gonna take your advice on this. Thank you.

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About testing oil flow... Running the machine with the head stock open will create an world class oil spill in an instant. Even in low gear that input shaft is turning its normal 800+ RPM. The way I tested mine was to stick a socket in the chuck and power the lathe spindle with a cordless drill with a socket adapter. Just slip a dog clutch to the center (neutral position) so you are only spinning the spindle and not the whole gear train. The oil pump is cam driven from the spindle so you just need those parts moving.

Mike
 








 
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