Repair of 10EE handwheel-style collet draw bar

Hey guys-

My 10EE has the old-fashioned Monarch 5C nosepiece with the handwheel draw bar. The threads in the drawbar have finally had too much use and the last nine of its sixteen threads have pulled out (these are the threads that engage collets). I am not sure how it was assembled, and therefore don't know how to affect a repair. It appears that the threaded tube section has been pressed into the larger multi-OD end piece. If so, I am thinking I might be able to separate the two pieces, then cut threads into the other end of the tube and press it back together.

Does anyone out there have experience solving a problem like this? I have attached some photos (I hope I have, anyway; I'm not too experienced at this).

Jim

It appears I'm not the first to have this problem, but this other thread does not answer my questions:

http://www.practicalmachinist.com/vb/monarch-lathes/monarch-drawbar-thread-replacement-302953/

I just bought a piece of 4130 tube 6 feet long. I'm going to thread a piece for me to repair my badly repaired tube. I will have enough left over I can thread a second tube. Bob

Jimbojet said:

It appears I'm not the first to have this problem, but this other thread does not answer my questions:

http://www.practicalmachinist.com/vb/monarch-lathes/monarch-drawbar-thread-replacement-302953/

Click to expand...

What is shown in this thread is probably a repair of the problem you have now.

I have repaired several over the years, including cut downs and extending to make it work on the machine at hand.

I prefer to put the male threads on the existing draw tube and make a short section an inch and a half long with internal threads all the way through.

You will need to relive the threads on the end that goes over the incomplete threads of the existing drawbar so it butts to the shoulder.

A little high strength loctite keeps it together.

When the repair wears out, just replace the end.

If you make a spare end, you will never need it.

Bill

Thanks for the info guys

hitandmiss said:

What is shown in this thread is probably a repair of the problem you have now.

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I agree, the other thread shows a repaired draw tube, not an original unmodified draw tube. It appears that guy swapped the internal/external thread configuration you said you prefer.

I could fix my problem your way, but I'd rather flip the existing tube end-for-end and thread the other side.

vettebob said:

I just bought a piece of 4130 tube 6 feet long. I'm going to thread a piece for me to repair my badly repaired tube. I will have enough left over I can thread a second tube. Bob

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Thanks for the offer, Bob. It looks like my tube is about 26.8" long, is that the same length as yours?

If you have the same Monarch draw tube, can you tell me how you separated the tube from the flange on the end? It must be stuck in there pretty good to keep from pulling free when you tighten down on collets.

Jim

Jimbojet said:

I agree, the other thread shows a repaired draw tube, not an original unmodified draw tube. It appears that guy swapped the internal/external thread configuration you said you prefer.

I could fix my problem your way, but I'd rather flip the existing tube end-for-end and thread the other side.




Thanks for the offer, Bob. It looks like my tube is about 26.8" long, is that the same length as yours?

If you have the same Monarch draw tube, can you tell me how you separated the tube from the flange on the end? It must be stuck in there pretty good to keep from pulling free when you tighten down on collets.

Jim

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Anyone in our craft "çan" 'DIY such goods, but what with the raw tubes already 5C threaded as cheap as they are from folks who do 'many', I'd rather put my own hands to work on stuff not as easily bought. A 10EE rod and T/A clamp from vettebob is a recent example that left me free to do stuff harder to substitute for or hire done.

There never seems to be enough time to catch-up on those other needfuls, anyway.

Monarchist said:

There never seems to be enough time to catch-up on those other needfuls, anyway.

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Well, that's not my situation, I'm retired and have nothing but time. And so I ask you directly -- can you tell me how this draw tube is assembled? To me it appears to be a very fierce press fit, probably done after heating one of the parts, maybe even after cooling the other as well, in the manner of how bearing races are fit into wheel hubs.

Jimbojet said:

Well, that's not my situation, I'm retired and have nothing but time. And so I ask you directly -- can you tell me how this draw tube is assembled? To me it appears to be a very fierce press fit, probably done after heating one of the parts, maybe even after cooling the other as well, in the manner of how bearing races are fit into wheel hubs.

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It COULD even be threaded, Jim. Plus Loctite or early-days equivalent. I have seen such.

I'd not bother to find out. Faster, and with a far more certain 'positive outcome' to buy a length of tube already 5C at one end, or fab such - turn your own arse-end hub for the spindles config, fit that however you please.

I last earned a crust with a handwheel closer when Ike was still Prez, counted it a PITA to use for speed, (NOT), so only have ever had a (Royal) rear-lever closer off some other shorter-spindle-bore lathe to adapt to my 10EE(s).

Gave it way rather than fit it.

10EE has a short ration of ID bore to begin with, so I went over to all nose-closers, D1 mount to steal back the tiny bit of it even a thin-walled drawtube needs.

Rubberflex & Sjogren. 'Loop' closer Burnerd Multisize & Hardinge, Even two each key-operated 5C, and wrench-operated ER, one of each on D1-3, the other bare plate so I can offset one of the 5C or ER in a 4J - or uber-center it - and/or migrate either to bench or other machine process without removing work from the collet and grip-position. Then put it back onto the 10EE, no significant loss of centering, the D1-3 is that good.

"To do" is to adapt a Hardinge threaded false nose closer I have to D1-3 mount. Nose spanner closes that for use with the 5C step and pot chucks that go clear up to 7".

Retired also. Twice.

Doesn't seem to have left me any more spare time than when I was still on someone else's payroll though!



To the good, eating my own cooking, no longer commuting, rutting and rooting, or dressing the part has put a fair chunk of what USED to be ..mortgages, auto loans, air travel, gasoline, clothing, shoes, booze, and.. other costs.. into some mighty fine steel and the Old Iron it tools-up, so...

"Keeps me out of the pubs and brothels"...

Monarchist said:

It COULD even be threaded, Jim. Plus Loctite or early-days equivalent.

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Yes Bill, it might be threaded and glued somehow. But I think I will try pressing it apart anyway, using a torch to heat the outer flange. What's the worst thing that could happen?

I sure wish somebody around here knew, though. The forum seems kind of dead these days.

BTW, did you used to use the name "Thermite" here? That guy was named Bill too, as I recall.

Jimbojet said:

Yes Bill, it might be threaded and glued somehow. But I think I will try pressing it apart anyway, using a torch to heat the outer flange. What's the worst thing that could happen?

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If you are going to heat it, twisting to unscrew won't hurt if NOT threaded. Pressing straight-line WILL hurt it if it IS threaded. JM2CW.

As said, I'd turn a new one faster than mess with it.

I sure wish somebody around here knew, though. The forum seems kind of dead these days.

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Spring is springing, lots of non-shop stuff to do in the rest of our lives. Some of the more fortunate folks are also busier making chips and such than in the past year or several.

BTW, did you used to use the name "Thermite" here? That guy was named Bill too, as I recall.

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Same person, common knowledge, I even posted about it somewhere.

Trying to stick closer to Monarch lathes, spend less time hands-on-keyboard, more time hands-on-projects.

Jimbojet said:

Yes Bill, it might be threaded and glued somehow. But I think I will try pressing it apart anyway, using a torch to heat the outer flange. What's the worst thing that could happen?

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Before you get real serious taking things apart, I would carefully review the obvious.
The tube is necked down where it goes into the part you are going to remove.
How much wall thickness do you have on the other end? After you go to all the work getting it apart and then you find that flipping ends won't work. Starting over with a new draw tube is your only option.

Ideas to check out before taking it apart.

Carefully inspect the inside 3" or so of the draw tube for a pin or two between the parts.
Monarch seems to like pins pressed in then filed off to hide them. The inside surface may be more revealing than the outside, any machining will be a clue for the hidden.
Two 1/4" pins would have plenty of shear strength for the job when added to a shrink fit and it never will move.

Bill

I haven't taken my draw tube apart yet as I'm in the middle of rebuilding my Bridgeport. Bob

hitandmiss said:

Starting over with a new draw tube is your only option.

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+1 Should be obvious that a 5C drawtube in the tight 10EE bore will have wall enough for ONE OF internal 5C threads, or 'whatever' external threads, never both, same place, lest it emulate that Frenchman so dehydrated they named him "Pee Air".

hitandmiss said:

Before you get real serious taking things apart, I would carefully review the obvious.
The tube is necked down where it goes into the part you are going to remove...
Bill

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Actually, on mine the tube does not appear to neck down. Do you have one of these handwheel drawtubes that does neck down? My tube is 0.350" in diameter, and fits into a larger diameter part. Thus there would have been no need to reduce the outer diameter of this tube, so I doubt that was the design. There is no way to know for sure, though, without taking it apart.

Thanks for the tips on inspecting the design. I see no trace of any dowel pins, either inside or outside. My guess is still a press fit assembly, although it is possible that the two do thread together.

Jimbojet said:

Actually, on mine the tube does not appear to neck down. Do you have one of these handwheel drawtubes that does neck down? My tube is 0.350" in diameter, and fits into a larger diameter part. Thus there would have been no need to reduce the outer diameter of this tube, so I doubt that was the design. There is no way to know for sure, though, without taking it apart.

Thanks for the tips on inspecting the design. I see no trace of any dowel pins, either inside or outside. My guess is still a press fit assembly, although it is possible that the two do thread together.

Click to expand...

Press fit ALONE of a thin-wall tube would not have been likely to win the hearts and minds of 'shall not break, ever' Monarch decision makers nor even Purchasing Agents of the era.

Simply test for threads by rotating before you push or pull.

That draw tube looks to have plenty of thickness on the inside. I would turn the OD and thread it the same as the 5c collets, then thread a section of good quality tubing on the ID, screw and loctite it onto the draw tube then turn the OD down flush. No need to touch the other end then and you get a choice of your material for a hard-wearing thread.

Although I see no signs of any other attachment method, I must agree that a press fit would not hang in too long -- it would probably pull apart fairly quickly with use.

Here's a new question for the board - are hand wheel closures stamped with a serial number matching their machine's serial number? Mine has a different 5-digit number on it, one that would match a much earlier 10EE.