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View Full Version : Ugh, setscrew on threads???!



tony ennis
11-11-2007, 04:52 PM
Ok, I started working on the opposite end of the spindle. I got a collar to move, but not far. Peering into the set screw hole, I see this:

http://home.insightbb.com/~antinice/images/hosed_thread.jpg

So, what do I do? I can't get the collar off... by twisting it...

John Stevenson
11-11-2007, 04:56 PM
Dimple it with a drill and when you replace it use a copper pad at the bottom of the hole and a cup screw, not a pointed screw [ or just grind the point off ]

.

Optics Curmudgeon
11-11-2007, 05:15 PM
Looks like the back end of an Atlas lathe spindle. There's supposed to be a lead plug protecting the threads, but any other soft metal will do. Wad up some solder, works fine.

Joe

dalee100
11-11-2007, 06:10 PM
Hi,

Pretty common cheap method to lock a collar to the shaft. I do it all the time at work;) .

The photo doesn't look too bad, I've seen worse. You stand a better chance of getting it off if you have a pin spanner wrench. One like this should do the job, [URL=http://www.grainger.com/Grainger/items/1FJ44[/URL]

They aren't cheap, but they do work well.

dalee

Charles Lessig
11-11-2007, 06:34 PM
Screw a bolt into the hole as a wrench but not against the threads.
Turn the collar until it starts to bind and tap it in all directions with a
small hammer. Loosen the collar and repeat. The hope is to hammer the burr
back down and not destroy the collar threads. This works quite well
much of the time. Best regards, Charlie

Oldguy
11-11-2007, 09:29 PM
How about grinding a 60 degree V on the end of a small rod (old drill ?) and using it to deform/reform the dimpled area so the collar will unscrew.

Glenn

S_J_H
11-11-2007, 10:19 PM
Tony, Grab a big pipe wrench if you have to for that collar. If you mar it then just re turn it to make it beautiful. It's just a threaded collar.
The threads will be very easy to restore with just a threading file if they burr up a tad during removal. Squirt a little oil into the threads beforehand.
And , you have to impact that chuck off. You are only dealing with a threaded nut in reality. Unless it has truly rusted tight it will come off with a very hard sharp rap by hand. No wood! Wood will absorb away all the impact.
I'll tell you what, this old artisan lathe with it's 2" 8tpi thread locks the chuck TIGHT as the face register fit is so good!. I can apply enough force by leverage alone to tip the near 400lb machine over before the chuck will even come close to breaking loose after just spinning it on by hand. But a sharp hard rap and it's loose instantly.
I have wrenched on cars for near 30 years. There is a definite skill to hand impacting. It's not about taking a 15lb sledge and following through like you want to destroy something. It's almost a wrist action type blow.
I wish you were local so I could help but best of luck as I want to see your machine restored!
Steve

BadDog
11-12-2007, 01:39 AM
My lathe spindle rear collar/nut was like that. I thought I would never get it off. When I did, I fixed the threads, but the Royal collet dog has to be locked on by that screw. So I did what I've done before and since. I took a piece of solid copper wire from a short scrap of 10-2 house wiring. Cut off a piece about 3/16 long, bent it about 90*, used a vice to fold it on down and sorta shape into a hocky puck, then put that beneath the grub screw. Had to take it apart again not too long ago. The collar scewed right off, a bit "stiff" to start, but that was from the copper deformed into the threads. It worked loose(ish) in about 1 turn and came off with no damaged threads.

torker
11-12-2007, 02:03 AM
I've used lead shot many times under those type setscrews.

Forrest Addy
11-12-2007, 03:51 AM
Don't go and bull moose the collar nut off with pipe wrenches. What's wrong with you guys offering advice like that? You watch too many Schwartzenegger movies. You'll damage the threads; quite possibly ruining them.

There's a better, gentler way one that uses intelligence and craft instead of raw brawn: put the deformed metal back where it came from.

Make up a little narrow cold chisel and use it with a light hammer to reach in and restore the damaged threads to form again by wedging them without actually cutting anything. Test the nut from time to time using the contact burnish to detect which raised surface need a little more attention. Be sure the exposed threads and are clean and you use plenty of extreme pressure oil (I like worm gear oil) when you unscrew the nut. If you meet gritty resistance stop instantly and cycle the nut gently to resistance and back. Sooner or later you'll get past the resistance without galling the metal. A good mechanic works wiithout unnecessary drama or causing damage to the parts.

Use a dog point or a cup point set screw to replace the pointy screw you have. Use annealed copper or a lead shot between the thread and the screw. A soft solder blob works fine too.

oldtiffie
11-12-2007, 06:05 AM
Most of the methods suggested for re-placing the nut are only variations of the method that caused the problem in the first place.

An old old method of making a "shake-resistant" (as opposed to a "shake-proof") nut is to cut/saw it half way through at right angles to the thread and then compress or close the gap made by the cut in one of several ways:
- close it in a vice until it "sets";
- hit it with a brass/bronze "dolly";
- drill the outer part to be a clearance fit on a selected thread, drill and tap the inner part, fit hex or socket-head screw and shake-resistant washer, fit modified collar onto its original thread on (lathe?) spindle to required "torque", tighten socket/hex screw to suit.

To remove, just slacken off tightening screw and use "C" spanner or similar.

And no more need for the original problem screw or risk of damage to the spindle thread.

These methods are "oldies" but they work!!!

S_J_H
11-12-2007, 10:02 AM
Don't go and bull moose the collar nut off with pipe wrenches. What's wrong with you guys offering advice like that? You watch too many Schwartzenegger movies. You'll damage the threads; quite possibly ruining them.

There's a better, gentler way one that uses intelligence and craft instead of stupidity and brawn: put the deformed metal back where it came from.
Forest, Perhaps you are right to advise as you did. But please do not call my methods stupid. Machining is relatively new to me but not wrenching and fabrication!
But I guess I have to agree if one is new to this type of situation then a little more careful method as you suggested is in order.
Steve

Forrest Addy
11-12-2007, 12:53 PM
S J H. My words were never meant to ridicule but to shock and cause reassessment. However you were correct in taking exception. I was unneceessarily offensive so I amended my post.

Here's your original words: "Tony, Grab a big pipe wrench if you have to for that collar. If you mar it then just re turn it to make it beautiful. It's just a threaded collar.

"The threads will be very easy to restore with just a threading file if they burr up a tad during removal. Squirt a little oil into the threads beforehand."

Please don't be upset with my lack of concurrance but I'd never reccommend a pipe wrench on a retainer nut except in the last extremety. Why risk damaging the threads in the first place? It's hard to reconcile your advice with damage free-disassembly possible with widely used methods. With a little care and technique, you don't need to risk damaging the threads or marring the nut. My words are but echoes passed to me by my mentors years ago. They are as apt today as they were then: there's no need to cause further damage with disassembly methind and adding to the work of repair if a little care can accomplish the task without damage.

In your post you go on to illustrate the proper use of a heavy hammer in dissassembly of precison made machinery. I prefer to use the word "nudge" in this connection but your words suggest the care necessary when using a big hammer to pursuade the movement of tightly fitted parts. I've used a big hammer in just such a way many times. One of my favorite mantras is "you can do more damage with a little hammer than a big one."

tony ennis
11-12-2007, 11:08 PM
Being a startup shop, I don't have a lot of tools capable of reaching into the small set-screw hole. I did have a small Craftsman screwdriver. I put it into the threads, pushed hard, and turned the collar. Repeatedly. This improved the threads. Finally with some force I was able to get the collar off. The spindle threads look ok.

Now there's the back gear. This is also threaded on, and held secure with a key. The key isn't a tight fit at all, but it seems captured. The gear turns a little before so it shouldn't be hard to get off once the key's out. The key is tricksie, I haven't figured out how to remove it. It's in a mating slot on the spindle and a slot on the gear, but neither slot seems large enough to accept the entire key and allow the spindle to turn.

But I'm not in the mood to fool with it tonight.

KiddZimaHater
11-12-2007, 11:23 PM
Never mind, you were too fast for my reply.

pressurerelief
11-13-2007, 08:09 AM
Forrest,
You would have gotten along great with my father. He always kept his cigars in the same tool box drawer as the hammers. He said he did this so when he got the urge to go to the hammer he would instead take a puff on a cigar. He would think for a minute and go with the hammerless alternative if one was viable.

Rick

Carld
11-13-2007, 09:48 AM
That's interesting. Your saying the gear is threaded on the shaft and there is a key in keyways to keep the gear from turning on the shaft. I have never seen a setup like that.

It is posible that the force of the gear doing work may have put thread marks in the sides of the key and that is holding the key in the slots. I assume the end of the keyway in the gear and shaft are cut all the way out. If you can grab the end of the key with vise grip pliers and twist the gear back and forth the key may come out while you are pulling on it.

I see you are in the Lou. Ky area. I know of about 4 of us that are here. There may be more.

tony ennis
11-13-2007, 10:12 AM
I assume the end of the keyway in the gear and shaft are cut all the way out.

Nope. The key seems captured. My suspicion is that it will come out but the slots have crud in them preventing movement, or the key isn't rectangular and you have to shake the spindle vigorously whilst doing the hokey-pokey. Then it will fall right out. If you're singing Kumbaya.

This is a Timken spindle, not quite the same as mine, but I bet the key to the left end is the same.

http://members.aol.com/tucker3579/ebay/tl102.jpg

Maybe it's the lighting, but that key seems not-rectangular.

Carld
11-13-2007, 10:23 AM
Tony, are you related to Wendel Ennis, in Nelson Co. I think?

tony ennis
11-13-2007, 11:39 AM
I do seem to recall the name, but I don't know if that's him.

Carld
11-13-2007, 12:06 PM
Wendel was on the Lou. police force and is retired now. He is a cousin of mine and a real nice person.

Peter N
11-13-2007, 12:14 PM
Nope. The key seems captured. My suspicion is that it will come out but the slots have crud in them preventing movement, or the key isn't rectangular and you have to shake the spindle vigorously whilst doing the holey-pokey. Then it will fall right out. If you're singing Kumbaya.

This is a Timken spindle, not quite the same as mine, but I bet the key to the left end is the same.


Maybe it's the lighting, but that key seems not-rectangular.

Perhaps it's a woodruff key.

Peter

gzig5
11-13-2007, 02:22 PM
Perhaps it's a woodruff key.

Peter

If this is an Atlas or Craftsman spindle, that is most likely a Woodruff key(shaped like half of a flat circle). The gear is not threaded on unless somebody modified it. The gear should slide off the end of the shaft and then you can lift the key out. If you need to press the gear off, make sure that it is fully supported. Those Zamak gears can be a bit fragile. Go slow and use lots of penetrating oil.

Greg

tony ennis
11-13-2007, 04:44 PM
Wendel was on the Lou. police force and is retired now. He is a cousin of mine

Well, hello cousin Carld! Small world!

tony ennis
11-13-2007, 04:51 PM
Gzig, I'll check that out tonight. That would certainly explain why the key is captured.

Carld
11-13-2007, 08:33 PM
If the gear is threaded on the shaft with a key holding it in place it can't be a woodruff key, unless a magician put it there. Some how the key must slide out.

Quote: Now there's the back gear. This is also threaded on, and held secure with a key. The key isn't a tight fit at all, but it seems captured. The gear turns a little before so it shouldn't be hard to get off once the key's out. The key is tricksie, I haven't figured out how to remove it. It's in a mating slot on the spindle and a slot on the gear, but neither slot seems large enough to accept the entire key and allow the spindle to turn.

Tony, do you have a digital camera to photo it and post it here?

J Tiers
11-13-2007, 09:36 PM
If that is anything like others I've seen, the threads go under the gear but it is NOT threaded on. Could be a first time, but .........

Look for any evidence of curvature to the key underside. If you see it, it's a woodruff key, and you can pull off the gear. My Logan has a trimmed woodruff key in that spot, the curved ends are trimmed off, but its a for-sure woodruff anyhow, since I've had it apart.

Pipe wrenches are just WRONG..... unless it's a tractor.

If you have a burr on threads, I'm not concerned about the bad spot in the burred thread, I'm concerned about what that burr is gonna do to the rest of the threads in the collar as they are forced over it..... that might hurt......

tony ennis
11-13-2007, 09:38 PM
Nailed by peter and gzig. The gear wasn't threaded. I assumed it was because, well, it looked like it. I worked it back and forth and it came of easily. And it is a woodruff key.

The improvised bearings came off next. They were a little rough. The first steel raceway and the bearing cage came off ok but the 2nd raceway wasn't coming off. Seems the spindle has a slight wide spot by the threads. I heated the raceway up with wifey's craft gun and it came right off.

The small back gear was next. It came right off and to my surprise rides on a brass bushing connected to the cone pulley. The gear sports 4 teeth that lock into the cone pulley. The cone pulley actually rides on two brass bushings, one fore and one aft. To my surprise, the cone pulley's brass bushing slide over a long steel bushing. All that's left on the spindle is the steel bushing and the bull gear. I removed the setscrew from the bull gear. There's probably another woodruff key too. I can get the bull gear to move about 1/4" down the shaft. Then it seems to hit something.

And now it gets interesting again, in the Chinese sense.

Scenario 1:
The steel sleeve runs under the bull gear and to the nose threads. The bull gear or the sleeve has a little rough spot and has trapped the gear.

Scenario 2:
Like the cone pulley, the steel sleeve is actually two sleeves, one fore and one aft. Something in the bull gear is intruding into the gap between them. This is a very bad scenario since the aft steel sleeve doesn't seem like it wants to come off and for fore sleeve is pinned on by the stuck faceplate.

I got farther than I thought I would. No need to rush now. I hosed the sleeve and gear interfaces with PB-Blaster. We'll see what happens tomorrow.

-=-=-=-

I notice some wear between the cone pulley and the bull gear - they rub towards their edges. If I put the right type and thickness of washer between them, there should be less friction when they aren't pinned together and they won't touch. Would I use brass? I don't think I'll have room for a moving bearing.


-=-=-=-

carld, we ought to figure out how we're related. Do you know of a Danny, Donald, Troy, Estelle, or Madeline Ennis? Evelyn or Russel O'Brien?

BadDog
11-13-2007, 10:14 PM
Pipe wrenches are just WRONG..... unless it's a tractor.
Or a pipe... <grin>

tony ennis
11-13-2007, 10:26 PM
Here's an image. Do you reckon that the silver ring that's in the red box is part of the spindle, or is it something that's been threaded on?


http://home.insightbb.com/~antinice/images/bullgear.jpg

lol sorry about the large image, should I resize it?

tony ennis
11-13-2007, 11:28 PM
Ah, most of my spindle questions are answered! (http://bellsouthpwp.net/t/h/thib9564/Atlas_Lathe_Spindle_Compare.htm)

S_J_H
11-13-2007, 11:38 PM
Pipe wrenches are just WRONG..... unless it's a tractor.
Yes yes I was wrong to suggest that to Tony and I apologize for posting such advice, especially to somebody new to working on machines in general.
I have many tools. But now and then I do break out a slip joint pipe wrench. It's a crude, mean looking brutish tool. But that does not mean it must be used in that fashion.
Anyhow, after thinking about it, I probably would not want to use it on my nice old Artisan either as you are right it just seems "wrong".
But on my 9x20 Chinese lathe, hell in a heartbeat I'd use it if need be. What's the difference, a pipe wrench was probably used to assemble that machine.:D

Steve

Carld
11-14-2007, 10:38 AM
Re: the pipe wrench. At times there is only the last resort to remove something. Pipe wrenchs, vise grips, heat and other means is many times the only way. Only a purist that has unlimited hours or weeks to spend disassembling things can afford to avoid those course, crude ways that are employed by working stiffs every day.

Many times when I have encountered a collar that is threaded on a shaft and locked with a set screw that damaged the threads I have resorted to a cold chisel. Yes, a cold chisel and hammer. With several judicious indentations of the cold chisel in line with the axis of the shaft the collar soon gives up and comes off or splits. It is easier to make a new collar than a shaft and spending to much time on a job will get me fired or chewed out. Now that I am retired fired or chewed out is not an issue but I still don't waste time on mundane things. My time is still valuable to me if no one else and I still do work for hire at home in my machine shop.

When you are working on something you have to stop and look for the trees in the forest. That is, how much is your time worth and can you make a replacement part if you destroy a part your taking it off.

Sometimes when posting a solution I forget that the thread starter may have overlooked an essential thing, such as, there are no threads in the gear, only on the shaft when he states the gear is threaded to the shaft. However, that's my problem, not his. I give Tony credit for not resorting to force right off the bat. Unfortunately that happens more offen than not. Many times when I get stumped on disassembly or machining a part I walk away, get some coffee and think. Many times the solution is there if you will only open your mind and eyes.