[Goodwood]

I am looking into watchmaking, making of small parts to bigger parts like watch case. What CNC mills are on the market that is at around a budget of $3000usd with accessories included ? I am looking into Sherline CNC mill, but have heard of the leadscrews causing backlashes and that there is a a2z monster mill upgrade. Are there any solid reviews on the a2z monster mill upgrade ? Are there better mill beside sherline at that budget ? Please help

[Winnfield]

Are you just making cases, or are you making movement parts? Either way, a Sherline will not be a suitable machine for that. Really, for good results, you'd be best off by picking up a used Emco F1 and swapping out the ballscrews. You won't find anything for 3K that will make a commercial quality watch, unless you get lucky at an auction with a Maho, Deckel, etc.

You need good axis perpendicularity, and a Sherline with a "monster" kit or whatever it is will not do what you need it to. You need a good sized hunk of cast iron for nice watch cases.

[Goodwood]

Hello, I want to make small dedicate watch parts measuring as small as 0.20 inches to as big as 3 inches. As thick as 0.40 inches. I am under budget, purpose of project is more for personal exploration less of commercial reproduction. Milling a watch case is good if possible, but not of the most priority. Probably spending 70% of the job making movement parts and plates. I have read in the forum, searching through some threads. There are many problems with backlashes solvable by changing the leadscrews, inaccuracy due to the overall weak structure of sherline being make in aluminium and inability to cut deep ( like milling 0.78 inches in one go ?) and fast on sherline mill ? Correct me if I am wrong based on my limited knowledge in this area.

My country has a sherline distributor hence it is more convenient, less of the shipping cost etc. I highly doubt there is a Emco mill around here where I stayed. I do notice Emco mill accessories are hard to come by ? Which CNC mill has as many accessories like what sherline has?

Can you throw me more brands/options so I can look around ? What about proxxon ?

[Ron Dunn]

Mike at SGTooling sells both Sherline and Proxxon machines.

SG Tooling

I think you'll find that the Proxxon machine is slightly larger and stronger, but also 3-4 times the price of the Sherline.

Ron.

[wildwestpat]

Hi Goodwood

Ok so you are gearing up to make a pocket watch. As Winnfield has said the task splits into case making and movement. Neither task INHO can be completed on a mill with or without CNC. Suggest you start if you have not already done so by reading some of the standard works on clock and watch making. A lathe with the necessary precision is going to be the first machine of necessity and again the spec for a machine to make a case and that necessary for movement making are very different. For example the case on a typical pocket watch is a metal spinning requiring some force to form the metal (to mill that case from solid is not on with a mill on two counts 1. the accuracy needed to machine both faces to a fine tolerance on thickness 2. the cost of the metal block and the high degree of waste if the case is any sort of precious metal) - to make the gears and balance wheel requires precision and high spindle speeds. Or put another way two different machines. The mill might be used to shape movement plates etc. The reason high class watches cost so much is the high degree of hand work required. Mass production can knock out movements by the million but the cost of the machines is out of the question unless you have millions of dollars to invest.

regards - Pat

[Winnfield]

Pat is completely right. Your lathe will be your primary tool. Making watches is a dying art, and I wouldn't ever discourage anyone from learning, but it is also not a tinkerer's endeavor - check this out:

LiveLeak.com - time piece-Switzerland

[FannBlade]

Amazing video. Made my hands shake watching (get it) it. Those screws are tiny I would need at least 60% over stock for the ones I dropped.

I agree...go for it. Looks like it would be very satisfying to see it work when finished.

[TarHeelTom]

Did you notice that each watchmaker in the video was wearing a white coat?

It's extremely common in Europe for blue collar workers to wear a work coat, no matter what field they work in.

When I was stationed in Germany, I was a member of a glider club, and one of the members had a factory in the ground floor of his house where he made these shop coats, and a few other types of coats, in large numbers.

I went looking once for nylon fabric to build a tent. One of the other club members took me to his shop and the shop owner gave me several rolls of rubberized nylon left over from making ski jackets. That tent served me well for many years, including living in it the first year, while touring Europe on my new motorcycle.

Tom

[wildwestpat]

Hi GoodWood

If you are starting out to make watch movements I suggest you cut your teeth on an over size pocket watch or clock with a lever escapement and balance wheel. The Watch and Clock Makers' Handbook - Dictionary and Guide written by F. J. Britten is one of many that will show the methods and types of machine necessary for hand work. Some of the tasks such as wheel cutting would benefit from cnc others would require production runs to see any pay off in time expended.

Ebay list a watchmakers lathe and most of the accessories to get started. (Enter search for watchmaker precision lathe a wider search will show various second hand machines.) I do not know what accuracy they are made to but the art of watch making is in the fitting of the bits together. As an example the gears are fitted by gauging their required centres and using a depth tool which allows the action of each wheel and pinion to be inspected for mesh and then to transfer the centres to the watch/clock plates. The precision required is such that it would be difficult if not impossible to pre drill the plates using a co-ordinate system with the X&Y axis of a mill table. This is due to the way the tolerances add up.

Hope thi

[FannBlade]

Watch maker Lathe. good price for all you get.

[Goodwood]

Hello, thanks for the help. I have a levin,lorch and boley watchmaker's lathe with limited accessories, and no milling attachment. Have tried cutting wheels and pinions of watches in watchmaking school with watchmaker's lathe as well as cutting wheels and pinions of clocks on sherline mill. Both machines required a considerable setup time. Hence watchmakers making considerable amount of wheels and pinions have a separate or second lathe specifically for cutting wheels and pinions only.

I am thinking of getting a chinese make milling attachment off ebay as it is rather hard to get affordable milling attachments and they are extremely hard to come by. The last levin milling attachment went to $1750 if I remembered correctly. Primarily I will be turning and cutting balance staff, wheels, pinions, ratchet wheels and stems on a watchmaker's lathe. By the traditional methods. But based on my limited knowledge, I think cutting bridges, movement plates and cases can be easier on a separate milling machine. I have cut bridges using file and saw only, but that is during schooling time. Would like to find an affordable milling machine that can do more things.

As I researched more, I have expanded my needs of a milling machine to cutting bridges ( about sizes ranging from 0.4 inches), to movement plates ( about 2 inches ) , watch cases ( 3 inches ) and making tools ( as big as 7 inches like a jacot tool ).

I have not spend too much time on lathe cutting after schooling, but thought a separate milling machine might be ideal and easier to make things. I might be wrong again, please correct me.

So far, from my limited knowledge and research. I have came about to 2 more machines beside Sherline. They are Emco CNC mill F1 and Mini x2. Probably going to buy them "used" but in good conditions. Please help me and give advise if this 2 machines are helpful in what I would like to do ? Namely "cutting bridges ( about sizes ranging from 0.4 inches), to movement plates ( about 2 inches ) , watch cases ( 3 inches ) and making tools ( as big as 7 inches like a jacot tool ). "

I am concern about the availability of accessories, knowing sherline has many accessories easily available but at costly price ? Knowing much of the tooling and accessories can be make if I am experienced and skillful enough. I know I am not there yet in terms of skills and experiences, but I am willing to learn. My second question is, what is the availabilities of accessories for Emco F1 and Mini x2 ? I suspect much toolings had to be brought or make to make small watch parts (bridges) and cases ? But I might be wrong again.

[Winnfield]

There is no EMCO "or" X2. They are very different machines with a great difference in quality. You can do a few of the things you mention on your watchmaker's lathe as long as it has indexing and you use a good milling attachment. You will find that the better the machine, the less time you will spend burnishing, polishing, filing, etc. Get one of the emco machines if you can. It will do a decent job. As far as a lathe for cases, unless you are using only precious metals, a watchmaker's lathe will not do it. You'll need a larger, more rigid machine to bore a titanium or stainless case.

[wildwestpat]

Hi GoodWood

Good work in getting started with those lathes. You are now on your way to be able to complete the movement. Making the tools necessary for wheel cutting is achievable on the watchmakers lathe. There are some very simple methods of making the necessary dividing plate which I would think you will have covered. Since there are only a few divisions required the time taken to make would be shorter than looking on eBay I suspect! Look at the old fashioned way wheels are cut. The wheel blank is mounted on a temporary shaft / pivot and supported by a hard wood disc. The shaft is then simply mounted in a collet with the disk containing the reference holes (dividing plate) firmly mounted on the other side of the head stock along with the index pin and its support. The motor is then used to rotate a simple form tool at high speed using some long lengths of belt or using a separate powered spindle. The rotating form tool then cuts the gaps between the teeth so it needs accurate depth control. Feed can be applied by hand with a simple lever. The link I have given you for a Chinese supplier has the necessary stand, belts and tool support / milling attachment.

Yes you are on the right track in aiming for a separate wheel cutting set up and another for general turning. However the set up / breakdown for the next task is not that great. Work flow planning helps by cutting all wheels in one session then switch to pinion making. It is the pinions that cause me problems as you want them to require the absolute minimum of polishing after forming. That brings us to the contentious bit about tooth form and there is a sharp division of opinion for cycloid versus involute. The point to keep in mind is that the movements gears rotate in one direction so backlash and slight irregularities in angular motion can be ignored. The important thing as I am sure you know is to have constant minimal friction as this impacts the going rate of the watch. Clocks can use gravity escapements and other doges to decouple the load on the pendulum. Tag have invented a magnetic pendulum for watches that replaces the hair spring and may be way less sensitive to friction changes. There is a video on YouTube which shows the action. I bet it is well protected by patents etc so is for academic interest not manufacture.

The plates, bridges and cock could be milled to outline bevelled. Planting the pivot holes will require a degree of precision in both the pitch circle diameters of wheels and pinions as well as actual co-ordinate measurements. IMHO start with the depthing tool and use that to establish the correct location of each pivot rather than milling machine co-ordinates. Co-ordinate tolerancing is difficult and requires some very fancy measuring equipment as well as extremely expensive machinery which is not necessary until you get in to real mass production. The problem is that there numerous movement supply factories from the cheap to the very best. These are then fettled by expertly finishing off and adjusting with remaking of some parts. These movements are made to recognised standard sizes. Finishing the movement and casing it can if expertly done give a very high quality watch.

This is getting a long way from a cnc mill conversion and you might get more watch orientated advice on a watch and clock forum rather than under benchtop machines.

You might like to explore this link as this about watch gear cutters for pinions amongst other things. Designing Cycloidal Gears and this is the main C.Sparks web site http://www.csparks.com/watchmaking/index.html

Good luck - regards - Pat

[ddk101]

Wow, he was asking about a cnc mill to cut watch parts. You guys waffle on about watchmakers lathes and cutting gears with them. You then tell him this is getting a long way from a cnc mill and advise him to look elsewhere for info? wtf?!

I'm pretty sure there are cnc mills out there you can cut watch parts out on, just not in the US$3000 mark..

[DRock]

You joined up and made an account just to say that...?

Thanks!

[ddk101]

Thank you for your valuable input to this thread.

Thanks!

[Winnfield]

Wow, he was asking about a cnc mill to cut watch parts. You guys waffle on about watchmakers lathes and cutting gears with them. You then tell him this is getting a long way from a cnc mill and advise him to look elsewhere for info? wtf?!

I'm pretty sure there are cnc mills out there you can cut watch parts out on, just not in the US$3000 mark..

That's because there is a presumption that he'd like information that will be of use to him. He didn't ask what 110,000.00 machine he could buy to do it. The guidance about manual watchmaker's lathes was just that - guidance - in case he is mistaken about how the watch parts are actually made (not on a CNC Mill, for example).

[Goodwood]

I know watch parts are mainly make on watchmaker's lathe just like in the old days when computer doesn't even exist. It was until recent time that most companies in production pursue cnc for massive production and cost effective measures. I am not running a production, just want to know more about cnc in case in the future there is another source of income for me in watchmaking field related.

Back to the topic, I read about do-it-yourself milling machines. For an inexperienced machinery like me, should I consider a diy milling machine? I have the thinking that it will not as accurate as any other commercial machines in the market considering how much millions are poured into building,researching those benchtop machines. But for my case, in watchmaking related I am interested to know if the accuracy is good enough ?

[wildwestpat]

Hi Goodwood

Accuracy is relative to what is required! An engineering approach is to consider the tolerance contribution of each part of the mechanism to give satisfactory operation and to include the spreads in tolerance. The errors arise from many sources including the instruments used to do the measuring as well as errors in the machining. The use of CNC is not a magic bullet and might best be regarded as automation of the manual process with consistency. You need to distinguish between made to fit and the problems of interchangeability required across a production run if selection of components is to be avoided. This is a very big topic and a bit off scope for your question I mention it as you would normally start looking for a machine by defining - accuracy in terms of repeatability - accuracy in terms of absolute size of part made - material to be cut - overall machining envelope - extra space required for jigs and fixtures.

IMHO a cheap vertical mill is capable of 0,001 inch with care in manual mode. To achieve 0.001 inch tolerance would require both ball screws and associated double nuts if the aim is to cut circles. Yes CNC software can achieve the same action as a manual control to avoid backlash by approaching consistently from the same direction but that implies the part has no direction reverses in cutting. (Yes the computer can make allowances but the errors with backlash also include the problems of tool load so that the actual part tolerance may not be as expected.) The problem comes in the scale of the parts compared to the machining envelope of X+Y+Z and the size of the cutter. The small diameter cutters used to make watch parts need high speed rotation and relative to normal milling a light feed. Small vertical mills commonly have a 3,000 rpm max spindle speed and this is too slow for making small parts with small diameter cutters. So my advice would be to get any small bench top mill and learn CNC and the way co-ordinate errors impact on overall accuracy. (for example how pivot hole to pivot hole tolerances build up and the impact on gear making tolerances.) This will give you a lot of CNC experience which can then be applied to what ever sort of instrument you wish to make.

The main thing is to gain practical experience of machining by cutting real metal to supplement your studies and above all have fun exploring the constraints.

Regards - Pat

[Goodwood]

Hi Goodwood

Accuracy is relative to what is required! An engineering approach is to consider the tolerance contribution of each part of the mechanism to give satisfactory operation and to include the spreads in tolerance. The errors arise from many sources including the instruments used to do the measuring as well as errors in the machining. The use of CNC is not a magic bullet and might best be regarded as automation of the manual process with consistency. You need to distinguish between made to fit and the problems of interchangeability required across a production run if selection of components is to be avoided. This is a very big topic and a bit off scope for your question I mention it as you would normally start looking for a machine by defining - accuracy in terms of repeatability - accuracy in terms of absolute size of part made - material to be cut - overall machining envelope - extra space required for jigs and fixtures.

IMHO a cheap vertical mill is capable of 0,001 inch with care in manual mode. To achieve 0.001 inch tolerance would require both ball screws and associated double nuts if the aim is to cut circles. Yes CNC software can achieve the same action as a manual control to avoid backlash by approaching consistently from the same direction but that implies the part has no direction reverses in cutting. (Yes the computer can make allowances but the errors with backlash also include the problems of tool load so that the actual part tolerance may not be as expected.) The problem comes in the scale of the parts compared to the machining envelope of X+Y+Z and the size of the cutter. The small diameter cutters used to make watch parts need high speed rotation and relative to normal milling a light feed. Small vertical mills commonly have a 3,000 rpm max spindle speed and this is too slow for making small parts with small diameter cutters. So my advice would be to get any small bench top mill and learn CNC and the way co-ordinate errors impact on overall accuracy. (for example how pivot hole to pivot hole tolerances build up and the impact on gear making tolerances.) This will give you a lot of CNC experience which can then be applied to what ever sort of instrument you wish to make.

The main thing is to gain practical experience of machining by cutting real metal to supplement your studies and above all have fun exploring the constraints.

Regards - Pat

Hi Pat thanks for the great information, when we are talking about spindle speed what is the maximum speed I should be looking at when making small parts ?

After thinking alot, I think sherline is really out of the picture. Accuracy in terms of repeatability always come to my mind as commercial sized machines that are big. Bench top mill might lack the size/mass and the ability to absorb vibration. I understand I need to start somewhere, and Pat and the forummers you had given me very important advise I must heed and sincerely thanks for the knowledge.

I am still thinking of Emco, but the availability of parts to repair if it breaks down still might be a cause of concern in the future for me. Though I am drooling over the wide accessories sherline had. I don't think sherline might be ideal. As much as I have hoped, if my budget is higher and my workplace alot bigger it might make decision making alot easier with so many good mills.

Bridgeport is too big, I can only aim for benchtop mills.