Two extremes of chronograph movements

[nickelsilver]

Have these two on the bench this week, thought it was a funny contrast. The left is the Lemania 5100, perhaps the epitome of industrialization and use of injection molded plastic in a mechanical chronograph; almost the whole chrono mechanism is on the dial side, under an acrylic plate that supports the date rings. Vertical clutch with nylon gearing in it, plastic all over. Extremely reliable however! This one had suffered some sort of chemical exposure in the past, with pock marks in the rhodium plating and harsh staining on the barrel great wheel. Ended up running fine with 11 second delta in 6 positions.

 

The right hand one is a Longines 30CH, one of the most beautiful chronos ever made in my opinion. This one was in fine shape other than a non-original, ugly, and nonfunctional minute counter jumper. The one present in the photo is the replacement I made. This beauty had a whopping 16 second delta, and still hit near 270 degrees amp at 24 hours. Amazing.

 

 

[CaptCalvin]

Technically tissot has lemania beat in "industrialized" chronograph movement. C01.211 is basically the 5100 but takes the use of plastic even further by replacing the escapment with plastic. 

The longines is pretty. Job very well done on that minute counter jumper spring. 

Edited February 19, 2020 by CaptCalvin

[RyMoeller]

The minute jumper looks fantastic- I think you're a bit had on yourself there! 

The Longines chronograph movement is gorgeous.  They are rare thing today and I can only hope one crosses my bench eventually.  Lemania's 5100 is well loved because of it's bullet-proof nature.  I've worked on one and was amazed at how easy it was to assemble and also that it required no tuning to get the chronograph function working properly.  It's sad they don't produce them anymore.  The C01.211 is just a shadow of the 5100.

[nickelsilver]

36 minutes ago, RyMoeller said:

The minute jumper looks fantastic- I think you're a bit had on yourself there! 

The Longines chronograph movement is gorgeous.  They are rare thing today and I can only hope one crosses my bench eventually.  Lemania's 5100 is well loved because of it's bullet-proof nature.  I've worked on one and was amazed at how easy it was to assemble and also that it required no tuning to get the chronograph function working properly.  It's sad they don't produce them anymore.  The C01.211 is just a shadow of the 5100.

Haha, yes, that's the new one, the old one is here next to it! It's clearly from some lower grade pocket chrono or stopwatch. Way too big and too strong. And ugly.

Edited February 19, 2020 by nickelsilver

[teegee]

9 hours ago, nickelsilver said:

Haha, yes, that's the new one, the old one is here next to it! It's clearly from some lower grade pocket chrono or stopwatch. Way too big and too strong. And ugly.

Wow, beautiful work! How long did it take you to make that? 

[nickelsilver]

3 hours ago, teegee said:

Wow, beautiful work! How long did it take you to make that? 

About an hour and a half, but I have some helpful stuff like a toolmaker's microscope to get the position of the steady pins, screw, and point where it should sit between two teeth, a CAD program I can import an image of an original jumper, trace,  and then scale a traced drawing to size, and a little CNC machine that cuts out the part. The spring section still starts at around 0.15mm and gets thinned by hand to about 0.04 or 0.05, that's where the fun is.

[dadistic]

I'm curious about your toolmaker's microscope. Having worked in manufacturing for many moons, I'm familiar with optical comparators,  but they aren't typically used at the scales that are useful for watchmaking. 

Does the microscope use a reticle,  or some other measurement system? 

I also imagine it would be a quite pricey piece of equipment :-)

I'm still planning on what type of scope to acquire, and maybe I can spec something out that can also measure, and that is accessible by us mere mortals!

Thanks 

[nickelsilver]

The microscope is monocular and has a reticle with cross hairs and concentric circles. Objectives can be switched from 10x, 20x, 30x, 50x, and 100x. I use the 50x pretty much exclusively. It has an x/y table with very good micrometer heads on it, ball bearing slides. Easy to get down into the microns. It was a few hundred bucks, lucky find, but they are out there. Lots of different companies made them, Nikon (pretty sure), Mitutoyo, several I forget in the U.S., then the Swiss had Isoma, SIP, Hauser and others. It's super duper handy, I check my pallet stones on it before and after moving them, I find it faster easier and more precise than the escapement meters Bergeon sells.

 

For projectors, there are lots of small ones. Similar bunch of makers to above, in the pics are a little benchtop Hauser and a floor standing SIP. I use the SIP, the Hauser is just so pretty I keep it around for its looks. Projector gets used primarily for checking gearing profiles and choosing/making cutters, but it's also useful for getting forms and dimensions from existing parts.

[dadistic]

Thanks, I think I have enough info now to get on the hunt.

Really appreciate it.

 

[RyMoeller]

11 hours ago, nickelsilver said:

About an hour and a half, but I have some helpful stuff like a toolmaker's microscope to get the position of the steady pins, screw, and point where it should sit between two teeth, a CAD program I can import an image of an original jumper, trace,  and then scale a traced drawing to size, and a little CNC machine that cuts out the part. The spring section still starts at around 0.15mm and gets thinned by hand to about 0.04 or 0.05, that's where the fun is.

If you don't mind the prying, can you offer some details of the CNC machine you're using also?  I know Watchguy has been using a small CNC to produce parts for the past couple of years and I'm aiming to do the same in the near future.  He's been using an economical Chinese built system with some impressive results.

[nickelsilver]

 

 

 

 

 

If you don't mind the prying, can you offer some details of the CNC machine you're using also? 

 It's funny because a CNC is fairly simple in this day and age, but... complicated too, when you're seeking microns. My machine is shop built. The mechanical components are swiss, high precision stuff, the X and Y axis have high precision antibacklash screws, the Z slightly less but still high, spindle is a Gepy for 8mm collets, that spindle registers 0 runout with an Interapid 0.002mm test indicator. This is all stuff obtained second hand. The machine uses servos (no question better than steppers) with a control built by a guy in Hungary. The control software is Mach3.

 

I've made a number of complete prototype watches with it, the precision is amazing. But the software, running on Windows, bugs sometimes. It's an open machine so no oil flood (reduced cutter life). No tool changer, so you have to babysit.

 

It's in essence a "hobby" machine, but where it counts it's a serious machine. The cut time for that jumper was about 10 minutes for 2x pieces. I know the hole locations are correct. The jumper point is correct within 0.005mm and I used a dull end mill. The measuring, drawing, and handwork later (harden, temper, bevel, grsin, polish the functional bit, thin the spring) was much more work. Just making the steady pins is a task (short, polished ends). If I had done the dimensioned sketch, laid out the holes and point with calipers, it would have been an hour more. So the machine made me 100 bucks on this job (and a 0/6 sawblade or two). Maybe another half hour because the point position was perfect mostly because the hammer wasn't mic-macked and I zeroed it and found the "null" position of the minute counter wheel and it was good. When I say "a hundred bucks more" I mean in saved time. This is a 6-10k watch, great client, I charged 150 for the jumper. Honestly, would have done it on the house for this great watch, probably why I'm still not rolling in it! The "saved time" was probably wasted fluffing up my collar because it worked out so well!

 

 

[RyMoeller]

Thanks sharing about your setup.  I'm a way from getting there (I'm in the middle of a move right now so I have no workshop at all) but I'm looking forward to investing a bit of time and money into getting a proper machine shop going that works on the hundredths of a millimeter scale and you've given me some good ideas on what I should be looking for and how to approach the challenge.