Useful “lathe” from bench grinder

Salsagev

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Hi, I am very satisfied with my setup when it came to this - I actually bought this cheap 40 dollar adjustable speed bench grinder with a handy little flex shaft rotary tool. I just used a harbor freight squeeze clamp to secure with the chuck key hole up. Very nice setup, although the chuck size it came with was quite tiny. I am thinking of using their other rotary tool (under ?10? dollars for kit) chucks and cutting them down to size because they don’t quite fit. I think I could create some sore of pivot support thingy? Any ideas for a support? I think once I get the chuck inserts to size, I can do any sized pivots. I set the “lathe” to 5000-10000 rpm and it spins really fast. This might seem very effective as it sounds but I almost forgot about the main thing - the buff and the grinding block! I can polish the pivots using the :???:Tripoli and buff:???: OR I can even attach a smaller buff (from the other cheap rotary tool) onto the rotary part of the setup. The grinding block can be used for various things in or out of clock stuff!

Any suggestions, complaints, or questions? Thanks! 9408A819-2561-41F9-8358-28A83FC0363A.jpeg E9A8DD1B-D55B-4A28-B90E-3649A5A64D52.jpeg A7423078-2AD0-41E7-874C-EA27E59FE965.jpeg
 

bruce linde

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you might want to do some reading on the MB on 'pivot polishing' (or 'polishing pivots'). there is a lot of previous discussion available along similar lines.

these two articles were a bit of an eye opener for me and might be of interest.



and, it might behoove you to check the runout on your setup... if the pieces aren't spinning totally true, that would be an issue.
 

Salsagev

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and, it might behoove you to check the runout on your setup... if the pieces aren't spinning totally true, that would be an issue.
This is an issue if you sharply bend the shaft but clamping it down completely will reduce this. Now that I’ve bought myself a Vallorbe Burnisher, I will learn how to use that.
 

Willie X

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Look up how to make and use a: steady rest, Jacot tool, and a throw. This will give you some ideas but you will have to work out the details on your own.

Willie X
 

T.Cu

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...And speaking of cheap tools: Salsagev I love my Harbor Freight! It's so much fun to go in there and buy all that cheap junk.. er, I mean, stuff! But..their "Dremel tool" that comes in that cheap eight dollar kit you mentioned, is no good. It's one of only two things from HF I actually thought was so amazingly bad I went and returned it just on principle. (They have an "upgrade" one now that might be better. And you can get used real Dremels on Ebay.)
But If I understand you, all you are wanting from that kit is the thing called a "collet", and that collet nut you show in your third picture holds the collet in, and adjusts the size of its hole. Tightens it down on whatever you put in it.
So.. I am wondering if you can use one of the things ebay lists as "keyless chuck for Dremel tool" on your setup. I'd show a picture but they are currently for sale and maybe that's against message board rules.
It's like a mini adjustable keyless chuck on a drill. Might save you using a collet and collet nut. These mini chucks are currently selling for about six bucks apiece, I have two for my two Dremels.
I love your fun setup. And you'll find tons of uses for a bench grinder even without the flex shaft. (Don't bend that flex shaft in too close an arc when you're using it. If you do it binds, heats up, wears out whatever lube's in there, puts a strain on the system.)
if you're like me, you'll soon have another bench grinder, as I also find it really convenient having a cutting wheel set up on one side and a wire wheel set up on the other side of a bench grinder, I use them both all the time as well as the other bench grinder with the stones.
Carry on! :)
 
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Salsagev

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Thanks for all your replies! I will be looking around for the keyless chuck adapter and looking into making some fancy schmancy tools!

Musta had a cheap drill.
Once tried to make a lathe with a variable speed drill. Worked quite well for a while until the thing burned out from running at too low speeds.
This is one situation why you always need a DeWalt! I will not turn down a good DeWalt drill because they are simply so powerful!
 

R. Croswell

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I am thinking of using their other rotary tool (under ?10? dollars for kit) chucks and cutting them down to size because they don’t quite fit. I think I could create some sore of pivot support thingy? Any ideas for a support? I think once I get the chuck inserts to size, I can do any sized pivots. I set the “lathe” to 5000-10000 rpm and it spins really fast.
It will be difficult without a real lathe to 'cut down to size' a chuck or collet and have it end up running true. Things can get out of hand very quickly at 5000 to 10,000 rpm. but you will probably find that out the hard way like I did years ago trying to use a Dremel tool to hold an arbor for pivot polishing. Vibration caused the part to come loose and it went wild. Bent the arbor, slung the part across the room, and as I recall sliced me on the way out. At that speed there is a lot of energy stored in the rotating part and you won't believe how much until something goes wrong. I suspect that your setup might have some runout issues but it may work our OK if you support the pivot and keep the speed down to a few hundred rpm instead of a few thousand rpm and work the pivot a little more slowly.

Perhaps the simplest support could be made by placing a drill bit the size of the pivot in the chuck, then advance a block of wood toward the drill making a hole in the wood block in line with the drill. Cut away the top part of the wood block leaving half of the hole. Fasten the wood block in position to cradle the pivot in the half-hole. It would be helpful if you have a foot switch to start and stop the motor. You don't want the pivot to hop out of the cradle, so make sure it turns true at slow speed first and control it.

RC
 

Kevin W.

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Sals have you considered the door hinge tool for polishing clock pivots?
 

Salsagev

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I have not- I never heard of that before.


It will be difficult without a real lathe to 'cut down to size' a chuck or collet and have it end up running true.
I see what you mean, i am thinking of just finding a suitable chuck online?

hings can get out of hand very quickly at 5000 to 10,000 rpm. but you will probably find that out the hard way like I did years ago trying to use a Dremel tool to hold an arbor for pivot polishing. Vibration caused the part to come loose and it went wild. Bent the arbor, slung the part across the room, and as I recall sliced me on the way out. At that speed there is a lot of energy stored in the rotating part and you won't believe how much until something goes wrong. I suspect that your setup might have some runout issues but it may work our OK if you support the pivot and keep the speed down to a few hundred rpm instead of a few thousand rpm and work the pivot a little more slowly.
The lowest RPM on this is 1000 on the lowest setting. I am thinking of using this only for American pivots that are thick instead of small and fragile ones.

Perhaps the simplest support could be made by placing a drill bit the size of the pivot in the chuck, then advance a block of wood toward the drill making a hole in the wood block in line with the drill. Cut away the top part of the wood block leaving half of the hole. Fasten the wood block in position to cradle the pivot in the half-hole. It would be helpful if you have a foot switch to start and stop the motor. You don't want the pivot to hop out of the cradle, so make sure it turns true at slow speed first and control it.
Would making this but without cutting it be possible but the hole is large enough to support the arbor itself and the pivot is free hanging?
 

R. Croswell

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I have not- I never heard of that before.



I see what you mean, i am thinking of just finding a suitable chuck online?


The lowest RPM on this is 1000 on the lowest setting. I am thinking of using this only for American pivots that are thick instead of small and fragile ones.


Would making this but without cutting it be possible but the hole is large enough to support the arbor itself and the pivot is free hanging?
OK for polishing, but if you plan on burnishing that requires a lot more pressure.

Most chucks that you find on line - adjustable 3-jaw like on a drill - are generally not going to have the precision you hope for. Some from China will be awful.

Most American clock pivots were never burnished and it is debatable whether burnishing really helps that much. Abrasive polishing can produce the same surface smoothness as burnishing. Theoretically burnishing, if done correctly with enough pressure, is believed to harden the pivot surface to some degree.

Keep it around 1000 and you should be more safe.

I would not spent too much time and money on contraptions to avoid buying a lathe. Save up and drop some coins on a new Sherline lathe and get a decent machine that can do a lot more than polish pivots. Most of the neglected American clocks that I get have at least one pivot that is too far gone for polishing or burnishing and needs to be turned down in the lathe, or replaced.

RC
 
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Salsagev

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I would not spent too much time and money on contraptions to avoid buying a lathe. Save up and drop some coins on a new Sherline lathe and get a decent machine that can do a lot more than polish pivots. Most of the neglected American clocks that I get have at least one pivot that is too far gone for polishing or burnishing and needs to be turned down in the lathe, or replaced.
I am guessing the other side of my Vallorbe burnisher can file pivots?

Most American clock pivots were never burnished and it is debatable whether burnishing really helps that much. Abrasive polishing can produce the same surface smoothness as burnishing. Theoretically burnishing, if done correctly with enough pressure, is believed to harden the pivot surface to some degree.
Does the pivot itself need support or just the arbor?
 

Kevin W.

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Yes a good lathe is a great investment, you wont be sorry getting it.
 

Salsagev

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Oh my gosh - 140 for that baby piece of metal?:eek:

I think since I am just chucking pivots, I think I will get something cheaper! :O:
 

Schatznut

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Some random musings after reading through a lot of good conversation and ideas on this thread... This is from the perspective of a dedicated but still fairly green amateur, not a professional horologist.

I've got a couple of keyless chucks for my Dremel tools and I've found they have unacceptable runout for very precise work. Maybe I've just been unlucky. I seem to do better using collets.

I share the common suspicion about Chinese tools, but making generalizations that all Chinese tools are junk is a good way to spend money unwisely. I have an inexpensive Chinese lathe/mill/drill combination machine. It's not great quality but I've spent a lot of time dialing it in and it's dead nuts true. It was all over the place when I got it, having been banged around how many times in shipping and whatnot. It's way too big for clock work but it's what I have so I'm finding ways to make it work. A 1/4" carbide turning tool set shimmed up in the tool holder to hit the workpiece on the tangent allows me to turn diameters down to about 0.5mm repeatably. A MT2 carbide-tipped dead center in the tailstock allows me to hit the ends of arbors, well, dead center, in preparation for drilling holes for new pivots. The precision 13-mm chucks coming out of China for less than $25 are absolutely amazing - how they can build something with that degree of precision for that little is astonishing. They'll hold a drill as small as 0.5mm securely. I have these for the lathe tailstock and both drill presses (my big one and a little one I use for bushing work). Latest addition is an ER11 straight shank collet holder and collet set. Once again, ridiculously cheap and when set up correctly, runs dead nuts. The only problem with them seems to be that the finish on the outer surfaces of the collets and the inner surfaces of the holder and clamp nut is pretty rough and the collets tend to stick in the holder when trying to remove them. Oil doesn't solve the problem so I'm going to polish the surfaces to see if that helps.

*Don't* scrimp on measuring tools. Used tools from Starrett, Browne & Sharpe, Mitutoyo and Lufkin (yes, Lufkin!) can be had reasonably if you can't afford new ones. A test indicator with a +/- 0.030" range and 0.0005" divisions is a must; you can easily read tenths of thousandths. Using it and the collet holder clamped in my lathe chuck, last night I straightened a bent arbor that had almost 30 thousandths of runout to where it was running true within +/- 0.0005".

And amplify your eyes with a microscope - even one of the inexpensive USB units plugged into your computer will allow you to climb inside these tiny dimensions and see how well you're doing.
 

Willie X

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The set up you have there would be more like a stationary handpiece (Foredom), or collet motor (Dremel). Useful, but not as a lathe. You will always have a free end, sometimes more than others depending on the wheel and pinion placement.

Go back to RC's post #9 & 12.

Willie X
 
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Kevin W.

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I fully agree with what Bob said. He gives great advice.
 

R. Croswell

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I am guessing the other side of my Vallorbe burnisher can file pivots?


Does the pivot itself need support or just the arbor?
Yes, one end of these file/burnisher combinations can be used to file pivots.

If you were using a lathe and had one end of the arbor in the lathe chuck or collet, you would usually (not always) have the option of employing a steady rest to support the other end of the arbor just behind the pivot you plan to work. That would ensure that the arbor will run true and so will the pivot it it is true to the arbor. With the arbor supported just behind the pivot it will usually not be necessary to support the pivot directly. If you use a wooden runner (the half-round hole in a wood block) you can press the pivot against the half-hole in the runner and because the runner is stationary, when the pivot is pressed against it you essentially have zero runout at the pivot. If you were using a lathe you could make the runner from a wood dowel and chuck the runner in the lathe's tail stock. I believe some folks use brass runners as well.

There is no one setup that's going to work for every pivot. The most difficult cases are where the wheel is right up close behind the pivot and there is not enough arbor to chuck. One thing for sure, if the pivot is not running true and you try to file it you end up with an oval pivot that will be useless. Once you get a pivot off center or oval, it is near impossible to get it true with a hand-held file or buff stick.

RC
 

R. Croswell

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Oh my gosh - 140 for that baby piece of metal?:eek:

I think since I am just chucking pivots, I think I will get something cheaper! :O:
It is not the price of metal, it is the price of precision machining. But I agree, it's probably useless to spend that kind of money for a precision chuck if you don't have a precision machine to mount it on.

You say, 'I am just chucking pivots' like that is somehow not very important or doesn't require a great deal of precision. Nothing could be further from the truth. Pivot and bushing work is the most critical part of most clock repairs. If your pivots end off center, tapered, oval, or crooked, even a small amount, things will not go well.

RC
 
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Salsagev

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You say, 'I am just chucking pivots' like that is somehow not very important or doesn't require a great deal of precision. Nothing could be further from the truth. Pivot and bushing work is the most critical part of most clock repairs. If your pivots end off center, tapered, oval, or crooked, even a small amount, things will not go well.
Is a Jacob's chuck accurate enough? I think I got what you mean because some cheap chucks have off center jaws.
 

Altashot

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Collets are far better than a Jacob chuck, quality collets that is.

In my opinion, home made contraption will never replace a proper lathe. It might get you by and do ok work but...

Lathes have been around for a long time and other than modern electronics, have remained mostly unchanged, because they have proven themselves to work.

You’re eventually going to need one anyhow...

M.
 
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R. Croswell

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Is a Jacob's chuck accurate enough? I think I got what you mean because some cheap chucks have off center jaws.
Some Jacobs chucks are better than others and the good ones cost more, but that's only half of the equation. You have to attach that chuck to something to turn it so even if the chuck is 100% the total runout at the pivot being worked can still be out if the driving machinery is not 100% true.

As M said, quality collets properly mounted in a good quality lathe give the truest run. But collets are expensive and have a very narrow size range so you would need a bunch of them. Force the wrong size into the collet and all bets are off. A self-centering lathe chuck is somewhat like a Jacobs - not so perfect and somewhat dependent on cost and quality. I like my 4-jaw independent chuck on the lathe. Requires a dial indicator and some time and patience to get zeroed in. Remember, if the driven end of the arbor perfectly true running, that is no guarantee that the work end will run true. Soft steel arbors are springy and it is not unusual to find irregularities, especially in cheaper clocks. You need to consider the entire system and the work piece.

RC
 

Salsagev

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I remember getting a box of stuff and there were these things I just found again. Are these relevant or useful?

8F093512-A370-4CEF-B625-5003D152BE28.jpeg
 

Altashot

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That’s the tail stock of a watchmaker’s lathe.

I am not sure what the other things are but I can see a collet.

Useful? Absolutely, if you have the rest of the lathe.

M.
 

D.th.munroe

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Other than the tailstock theres a door latch for a mantle clock, I have a bag of these from merrits antiques somewhere, a handle for a K&D (robbins type) watch mainspring winder, a watchmaker s lathe collet and a the piece of brass I'm not sure about.
Dan
 

shutterbug

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The brass piece is an anvil from a bushing machine I think. Used to seat bushings.
 

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