A few more lathe questions please...!

[RJSoftware]

Hello all;

I think I am making some progress now in understanding lathes. Lots and lots of options that add to this newbie's confusion.

Basically, I feel stuck in a catch-22. That is, I need to decide what kind of lathe I want before I can buy a book to study on the kind of lathe I want.

I say this because evidently there are no books available that cover all the different types of lathes, or perhaps they are not generic enough to apply.

(One would think they would be, at least with list of terminology so that I can relate).

The objectives:

1. Find lathe that has enough span and adaptablity to do both watch and average clock size repairs.

2. Repair broken pivots.

3. Cut gears.

Now my current understanding about cutting gears is that it is a job better left to a milling machine.

But, I think, I would like to try a lathe with milling attachment.

And here is a great point of confusion. Well, sorta. See, I have yet to see a milling attachment with a cutting device attached.

The photos I have seen so far, are just too hard to make out what is really going on. I take it to be a device that controls the amount of depth and location that the gear cutting wheel cuts. Obvious.

But, the problem here is money. I get the sense that I may be venturing into the deep bowels of my wallet and I get a little nervous.

Thing is, I have little to go on so I can price shop, compare etc...

I know also about the disk thing (terminology..?) that has many holes used to guide the cutting position. And that somehow attaches to the lathe so that the gear stock can be precisely cut and the gear comes out with correct number of teeth.

I think what would really be helpful here is to see a video. I'd like to see how the cutting device attaches to the milling attachment and how the disk is installed and used.

I think for now I would like to skip the computer controlled stepping system. I could advance into that later. Trying to shoot for most bang for the buck and keep things affordable.

A couple of questions about collets.

From what I see in pics on ebay. How does the collet clamp onto the object (pivot or arbor I guess in most cases)?

On my pin vice it has a collar that threads down and squeezes the collet cracks together to grip the object. But, I can't see if collets I see on ebay have the collar thing. Infact it looks as if they don't. Just the X crack.
How do they work?

Another collet question is, can they be applied/used on the tailstock. The reason I ask this is, if I put a collet in the headstock to hold an arbor, how does one hold the drill bit to drill a new pivot hole?

Does the tailstock hold the bit and slide up to the headstock which holds the arbor to be drilled?

Another question about this. Can I sink an arbor into the headstock/chuck/collet to hold the object, so it does not stick out too far.

I say this because I think holding an arbor by one end and drilling on the other does not sound well supported. If the headstock/chuck can accept most of the body of the arbor then the arbor would be rigidly held.

Or is this a job for the tool rest? To provide a shelf end to rest other side of arbor on?

Another question about the headstock. For pivot polishing I can see that holding an arbor in headstock alone would allow good access to polish pivots. But one does not hold the abor with just the other pivot, true?

I also wonder about how well the collets adapt to different arbor situations and how well they maintain center.

I could understand the wax lathe. That it could hold irregular object and be trued to center by manipulting the grip from heating wax and cooling. But I wonder if centering with the regular collets pose a problem.

Any help apreciated.
Thanks in advance.
RJ




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[al_taka]

RJ,
I've been clockrepairing for a couple of years and went thru the same questions. If I had to do it again I would have purchased a lathe that is supported today like a Sherline instead of a watchmakers lathe. Comes with a cross slide, can be ordered in MM or SAE and they sell accessories that allow you to use it like a 8mm WW lathe, graver rest, collects etc.

You can use it as a milling machine if you choose and you can add an extra motor and bed to use it as a lathe mill.

What I'm getting at is that it can grow with you. Don't need to spend a lot up front as your wants are different than your needs and the lathe can be added to as your knowledge level progresses. I'll be getting one this coming year.

You asked about gearcutting, this book will show what cutting is all about.

http://www.watch-clock-makers.org/ec...p?prod=book038

You'll see why a lot of people opt to find another gear or have someone else make one for them.

Lathes are made to hold collets in the headstock or tailstock making them very universal. The inventiveness that you will learn is how to adapt the tool to the job. It comes with time and experience and you will never stop learning. There are many books that show the usage of the many accessories for the lathe.
Your question about holding arbors, if the length requires support, a steady rest, purchased or a home made one takes care of that.

Collets are for precision work like holding and cutting pivots. The collets come in wide assortments. When a collet grabs the arbor it closes and grips the arbor flat and parallel holding the arbor straight and true. You must use the correct size collet or you risk damaging the collect. Too loose, and the closing jaws pinch the arbor but the back end is unsupported. Too tight and the arbor won't be supported where the arbor exits the collet. They are quite expensive. You have a lot of reading ahead of you.

I hope you can find a local horology club with members that can advise you through this time.

I can't speak for watch repair, the speciality of those tools need an expect to define them.

Al Takatsch
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[T.J. Kloss]

Originally Posted by RJSoftware

Hello all;


A couple of questions about collets.

From what I see in pics on ebay. How does the collet clamp onto the object (pivot or arbor I guess in most cases)?

On my pin vice it has a collar that threads down and squeezes the collet cracks together to grip the object. But, I can't see if collets I see on ebay have the collar thing. Infact it looks as if they don't. Just the X crack.
How do they work?

Another collet question is, can they be applied/used on the tailstock. The reason I ask this is, if I put a collet in the headstock to hold an arbor, how does one hold the drill bit to drill a new pivot hole?

Does the tailstock hold the bit and slide up to the headstock which holds the arbor to be drilled?

RJ

ICW this part of your post.

A collet grips the workpiece very much like a pin vice. The only difference is it is drawn tight onto the piece by way of a draw bar inserted into the end of the headstock. With an adapter a collet can be mounted in the tail stock of a lathe. When it comes to drilling with a lathe you either rotate the drill bit or, you rotate the workpiece. You can either set up to hold the drill bit in a chuck mounted in the headstock or the tailstock. It you choice as to how you want to do it.

Hope this help a bit.

Tom

"Hopefully, you learn something new every day."

[GeneK]

RJ, I second the recomendation for Sherline for the reasons mentioned. I have two Sherline lathes, Three mills, two WW lathes, and a 6" Atlas(in rebuild). I find that I do most of my work on the sherline, leaving the WW lathes on the shelf. Some times I'll use the WW lathe for pivot polishing because I have that set up on it. If the Sherline is set up for pivot polishing at the time I use it. I have found that my Sherline and the WW's all have about one and a half ten thousanths run out.
For gears I have dedicated a Sherline horizontal mill and cnc rotary table. To cut a wheel just poke in the number of teeth and punch the button. Since Sherline has a very good WW collet adaptor I can move work between the different machines easily.
What it boils down to is accessories. A WW lathe by itself is not worth much, the number and range of collets and other things are what makes it work, as mentioned Sherline is in production and has third party after market accessories.

GeneK

[Veritas]

RJ i dont really think there is any one lathe that can do watch and clock repairs.
I like the Sherline too, and would take it over some of the other lathes out there today.And yes depending on what you are buying for accesories for a lathe it will cost.But depends how deep you wish to get into. .Way before gear cutting you need to learn the basics of lathe work, it is the starting point for beginers.
A good book on basic lathe operation is where i would begin.
I am trying to show you that you need to basic skills and learn more as you go along.I am not 100 percent sure but i think there are collets for the Sherline. if you go to their website i am sure there is a lot of good information there.Another lathe i do like too is the older Unimats, they were well built and good prices for them.

[David Robertson]

RJ,

This may be the situation where you need to endure the pain of spending a few bucks to learn before potentially making an expensive mistake.

Someone mentioned Bob Porter's book on gear cutting. It is good and is around $35. In my (humble) opinion, though, if I was only going to buy one book on gear cutting it would be Malcolm Wild's book Click Here titled Wheel and Pinion Cutting in Horology: A Historical and Practical Guide. It is $44 but well worth the price if you are serious about wanting to learn about gear cutting and the various equipment configurations for doing it. Both books are good.

You mentioned wanting to see some actual gear cutting take place. A place called Smartflix rents technical videos for $10 for a week.

Bill Smith has two excellent videos that are relevant. One is Click Here called Wheel Cutting, Pinion Making, & Depthing.

The other is Click Here called Workshop Procedures For Clockmakers.

I have watched both videos numerous times (I own them both) and also have both of the books we have been discussing. I highly recommend them as a way to get your arms around this topic. In the end you may end up spending $65-75 on some education, but it could save some big bucks later down the line. Getting rigged up for gear cutting is not cheap. You are likely talking in the $500-1000 range to get started, so some money spent up front to learn is money well spent.

If you are an AWCI member, Jim Huckabee made a series of video tapes on making a regulator clock movement. It is not available anyplace other than the AWCI library as far as I know. It also shows a lot of gear cutting and quite a bit of information on tooling up for the task.

All gear cutting setups have: (1) a means of holding the blank with indexing capabilities (2) a means of rotating the cutter (3) a means of advancing the cutter past the blank for cutting and (4) a properly shaped cutter. All four of these components need a certain amount of rigidity and accuracy. Neither a lathe nor a mill has all three capabilities without something being added on.

[awolff]

RJ,
I agree that the best way to understand gear cutting is to see it done. I recommend the W.R. Smith video called "Wheel Cutting, Pinion Making & Depthing for Clockmakers and Modelmakers" You can purchase the video from W.R. Smith's web site, or rent it from Smartflix. The video will take you through the entire process and shows several different setups for cutting clock wheels.

Personally, I cut clock wheels with a Taig lathe. I attach a milling spindle to the milling attachment on the cross slide. The milling spindle is driven by a flex shaft and drives a single edge flycutter. The wheel blank is mounted to the headstock with an index plate on the outboard side.

The milling spindle is nothing more than a second Taig headstock. You could do the same thing with a Sherline headstock. I added a flywheel to the milling spindle to smooth out vibration from the single edge flycutter.

The milling attachment adjusts the depth of cut, that is, the tooth height. The cross slide is used to center the cutter over the wheel blank. Once these adjustments are made, they are locked by applying masking tape to the knobs and also tightening the gib set screws. This prevents any slippage or movement during the cutting process. The only piece left loose enough to slide is the carriage so the cutter can be moved towards and away from the wheel blank. I clamp the lever feed tailstock to the milling attachment so I can use the lever to feed the cutter rather than crank the carriage handwheel back and forth.

The flex shaft used to drive the milling spindle is a rather unique setup. It connects to the back of the motor with a homemade coupling. Variable speed drive is abolutely necessary when using a flex cable. To start the milling spindle, the motor speed must be set to zero and slowly increased to actual speed. Turning on the motor with the speed knob at cutting speed will twist up the flex shaft like a pretzel. (Done that!)

Notice that there are a lot of custom parts to be made to arrive at this configuration. Plan on spending a lot of time making the index plates, drive system for the milling spindle, wheel blank holders, flycutters, etc.

[terofpa]

RJ,

I have Unimat lathes. They have almost become a collectors item and is reflected in the prices. The watchmaker spindle alone for the Unimat is $400 delivered but if your paintent you can get a deal now and then. You'll find your best bargain with any used machine is to buy a package deal. You can often find a well equiped Unimat for around $1000.

Sherlines are a good machine and I heard of Taig lathes but know nothing about them. There is also a manufacture called Proxon but I know nothing about those either. So if you ever need advice on something I know nothing about, let me know. I'll fake it.

ter

PS I just stole this Watchmakers Unimat with a set of Levin collets, the power feed attachment and an extra head for the mill for $525, delivered.
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[Veritas]

That lathe Tera is a sweet deal for that kind of money.You wont buy one like that often for that price.Yes Unimats are old but good machines.My clock instructor has one and i wish i could get one like his.
Interesting postings on this question.

[John Echternach]

Okay, I have done this a few times before and all of you who have read my rant on lathes will have to hold your breath. Why does everyone have this love affair with the Sherline??!! PLEASE before you buy a Sherline please look at the Taig Lathe. It is every bit as accurate and versatile as the Sherline and a whole lot less expensive. I have been using mine for Clock repair for 3 years and am delighted. The runout is the same as a Sherline but neither one is really accurate enough to do fine watch work. Maybe for most pocket watch work, though.

You really need to search the archives for lathes and make sure you read Jerry Keiffer's posts. We disagree slightly on the accuracy issue on Taig but Jerry really knows this stuff inside out. I measured my runout and it's less than 3/10,000ths. I would be surprized if the Sherline actually was accurate to 1.5 10,000th.

The Taig accessories are much less expensive than Sherline and easier to use. I took the FSW lathe course and my Taig held it's own to all the Sherline and was much sturdier and versatile than the WW Lathes- they are hard to get accessories for and are awfully expensive.

RJ please do not hesitate to contact me if you want more info on the Taig. It is American made and Nick Carter is the dealer you want to use if purchasing- automatic 10% discount and Nick becomes an immediate resourse who is more interested in you than making a buck. John #0159010