Help Disassembling Leblond Regal tailstock - damaged nut

Greetings,
I have a 15 x 30 Leblond Regal Servoshift. I believe it was manufactured in the early 1970s (8C serial number) It appears to be in very good condition overall but there is a problem with the tailstock. The bronze or brass nut which engages the screw has been severely damaged and needs to be replaced. I have a copy of the military manual for this series which shows that the nut is replaceable but does not give a proceedure to disassemble the tailstock. The nut itself (#22) appears to be held in by two hex screws, but I'm not sure if the nut itself is threaded on the outside and screws into the tailstock spindle, if it is held in place with some sort of adhesive in addition to the screws, or if it is pressed in. I have removed the two hex screws but the nut is not free.

I was hoping that someone could instruct me in the recommended way to remove the spindle itself from the tailstock and the nut from the tailstock spindle. I have unscrewed the tailstock cap/screw/handle assembly and loosened the binder level assembly but there is a pin on the far side of the tailstock that I don't know how to remove (#7). Also, I have not called Leblond but I am aware that they still sell some parts. Is this part obtainable from other sources or from Leblond only? Alternately I could make one if a premade part is expensive.




I can provide a bigger picture from the manual or a picture of my actual pieces, I didn't want to upload anything too big...

Thanks in advance for any suggestions.

Jeff

Well I can't help with disasssembly 'cause I've never done it. But I do have a better idea of why we can't build a conventional lathe in this country anymore. If the the fucking R K LeBlond company didn't know a spindle from a quill then it is perfectly obvious why Harbor Freight and Grizzly are showing us how it's done.

tdmidget said:

Well I can't help with disasssembly 'cause I've never done it. But I do have a better idea of why we can't build a conventional lathe in this country anymore. If the the fucking R K LeBlond company didn't know a spindle from a quill then it is perfectly obvious why Harbor Freight and Grizzly are showing us how it's done.

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It might just be the particular year of manual I have, but that's what it's listed as: 18-20 Spindle, Tailstock.

Quill seems to be the more appropriate nomenclature, but I'm inexperienced so I just used what the manual called it. By either name...I can't get it out!

Thanks,

Jeff

Dont be cocky. In German most stuff that spins and has a special function is called a Spindel (yeah, the German word is that similar).
We have a Leadspindle and Feedspindle in our lathes , and i would not find it especially surprising some old fella called the quill a spindle, on some tailstocks it is essentially one, even though the nut revolves.

Funny how regional colloquialisms can creep into language, even funnier when one tries to convince others that a large machinery company, dated far earlier than he, therefore closer to the origin of the word, isn't as well versed in machine nomenclature as he is! Wouldn't be as bad if he didn't use a naughty childs profanity to puff himself up in front of an audience.

quill |kwil|
noun
1 (also quill feather) any of the main wing or tail feathers of a bird.
• the hollow shaft of a feather, esp. the lower part or calamus that lacks barbs.
• (also quill pen) a pen made from a main wing or tail feather of a large bird by pointing and slitting the end of the shaft.
2 an object in the form of a thin tube, in particular
• the hollow sharp spines of a porcupine, hedgehog, or other spiny mammal.
• ( quills) informal dated panpipes.
• a weaver’s spindle

Later, the term quill was adopted from the weavers nomenclature, to mean a rotating spindle, commonly with splines, that imparts torque while capable of lateral movement, like the quill of a milling machine or drill press. You see TD, RK knew what he was talking about, an industrial giant, not a midget!

By TD's reasoning, the part of his anatomy that he uses when he's demonstrating his naughty little word, is a quill but it just goes in and out, no torque, so it must be just a spindle!

It's OK to be wrong TD, just try not to let your loud mouth make it so hard to back out of.

Bob

My guess here is part #7 is an anti-rotate feature for the quill. You would know this if there's a corresponding keyway in the quill. If that keyway is not milled completely from one end to the other it could be a feature also preventing the quill from releasing.

My other guess is, if you can remove part #7, and you can remove hub #24 then you can sort of unscrew the acme rod from the quill.

So the quill exits one end and the handwheel/leadscrew asm, etc, exits the other end.

I could also be completely wrong Usually other confounding clues can lead you to some more understanding of the construction.

I looked at the manual. They did indeed call it a spindle.
As an apprentice I was taught that a quill extends. A spindle spins. They may be so proximitous that they appear to be the same as in a Bridgeport. If your tailstock quill spins you have a problem.

I tend to infer that the essence of "quillness" in the machinery world is hollow-with-something-spinning-inside, thus the drillpress and Bridgeport quills. A HBM does not have a quill because the rotating spindle itself extends, rather than being carried in a sleeve. I sometimes call the extending thing in a tailstock a "ram".

But we haven't helped the poor guy trying to take his apart.

If his trouble was not being able to take the round-sliding-thing out of the casting,perhaps (as suggested) the anti-rotation key runs in a keyway one end of which is blind,so perhaps the bearing assy for the screw has to come out and the ram then comes out the back?

That would seem bad design to me, as it is too important to be able to take the ram out easily in case the enter sticks in the taper.

Surely someone here has had one of these apart and actually KNOWS?

Not being a smart arse but have you tried just screwing the barrel out until its off the screw and then just pull it the rest of the way out.

Parts 34 and 35 appear to engage the quill somehow. Have they been removed?

Half way done:
Thanks to the suggestions and a re-examination of the problem in better light I was able to remove the, eh...part in question. The unit is keyed to mate with part #7, but not all the way to the end of the part, which stops it from being removed towards the rear. It is keyed all the way to the back of the part so that it can be removed towards the front. I missed this last night as rust and grime accumulated in the hole containing the "Binder" (spindle lock, quill lock?) and locked up the spindle/quill/ram. A soak in wd40 overnight along with re-examining the problem after reading these suggestions helped me get it out.

However, the threads in the nut are pretty mangled. Any suggestions where I can get a new one? The cause appears to be some damage to the front of the screw threads that turned the screw into a cutting tool. When the spindle was at it's full extension and the handwheel was reversed to retract it, the screw became an auger.

I could finish cleaning and installing the lathe and just make one, but as I said I'm inexperienced. An inside threaded acme screw nut seems like a challenging first part to make on a new lathe.

Any suggestions are welcome and all of you have my gratitude for all the help offered so far.

Thanks,

Jeff

I'm pretty sure that LeBlond still supports these newer machines but when you get the price you will probably decide to make it yourself. What better way to cure that "inexperienced" condition?

tdmidget said:

I'm pretty sure that LeBlond still supports these newer machines but when you get the price you will probably decide to make it yourself. What better way to cure that "inexperienced" condition?

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True, that. For reference, here's the damage:



My plan now is to grind the end of the acme thread to a less aggressive profile and make a new nut. I'm thinking it's pressed in so I'll push it out then get to work.

Still open to suggestions and if anyone has one of these nuts in their junk drawer let me know! I'll find out for sure tomorrow but I bet tdmidget is right...they're probably spendy.

Thanks,

Jeff

After you decide to make a replacement nut -- but before you actually start cutting the internal thread -- take a good hard look at the screw and remind yourself that it's left-handed, so the thread you cut probably ought to be left-handed too.

Yeah, don't overlook that detail. The hardest part will be grinding the acme thread tool and that's not too bad. You do have a mill, right? To cut those radii for the threaded antirotation holes you kind of need one- plunging with an end mill is the way to go.

Check Mc Master for the nut. They probably have one the correct screw size. It's easy enough to bore out the old nut threads, fit the new nut into the bore and soft solder into place. That's what I did to replace the cross feed nut on my B&S surface grinder. There is so much mating surface soldered that soft solder is way enough to hold.............Bob

It looks to me from your photo that you have several good threads left in the nut. If the machine were mine, I would make a drawing of the nut, so that I could make one later if needed. For now I would clean up the buggered threads on the screw with a file, "fix" the damaged threads in the nut by screwing the screw through from the other end of the ram, put it back together and use it.

magneticanomaly said:

It looks to me from your photo that you have several good threads left in the nut. If the machine were mine, I would make a drawing of the nut, so that I could make one later if needed. For now I would clean up the buggered threads on the screw with a file, "fix" the damaged threads in the nut by screwing the screw through from the other end of the ram, put it back together and use it.

Click to expand...

....And that's just what I did. Thank you Sir, it seems to be working fine. It'll probably need to be replaced someday, but for now it's working as it should.

Thanks again!

Jeff

You will find that LeBlond has what ever you need for your lathe. Some of the stuff is just stupid money and the rest is expensive, but if you need it now, they have it. They are friendly, helpful and easy to deal with....have your credit card ready!