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May 5, 2014 at 3:07 pm #49031
Am new to watches, have been practicing on some “dollar watches, now I have a few elgins and a couple Illinois. My question is. how do you figure what size jewel to get for a replacement and I have been looking at the tools on ebay, Wow, Pricey. Do I need a Jewel punch?. how about a pivot gauge?. I am finding watches are going to be an expensive venture if I include them with my clocks.. So what do I need for GOOD tools,, no china junk… I am really confused as how to buy the jewels. I notice you can buy an assortment, do you just test fit some???/ THANKSMay 5, 2014 at 4:39 pm #57562
First…. I recommend that you get a copy of the Chicago School of Watchmaking which was (I believe) and distance education course in the 50’s and 60’s. You can get it in hard copy at LuLu or on DVD on eBay which is cheaper. De Carle books are very good too.
Regarding jewels… there are rubbed in jewels (the most difficult to repair), friction fit (not difficult if you have a set of pushers or a staking set), and jewels set in bushings or “bouchons” that are held in place with a couple of screws (the easiest to replace). The simplest of tools that you will need are a set of jewels pushers (for the bouchon jewels) and a micrometer of caliper if you need to measure the outside diameter. You can measure the diameter of the balance staff pinion, add .01mm to the hole size and use that to order a jewel. However, a staking set is an important tool for many purposes. Bob’s videos provide a good guide to jewels.
If you replace the bouchon jewels, they are easy to find and you just need a jewel pusher to put them back in place. Friction fit and rubbed in jewels require a more expensive set of tools (unless you have excellent eyes and a good feel for this). I’m of the opinion that proper jeweling and timing issues are the most complicated things to master… at least for me. But you can start with a cheap tool like the following…
One last thing…. I’ve been working on jeweling for a while and I’m just now getting to the point where I believe that I can handle many of the jeweling issues that I face (except shock absorbing Incablok, etc.). You will find some great experience and comments here that will be superior to mine. However, I feel that we are kindred spirts on this issue.
TomMay 5, 2014 at 5:57 pm #57563david pierceParticipant
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While some of the low priced Chinese watch tools are not good there are others that are extremely good. A few of the better examples are the automatic watch winder from Sincere and the Sincere watchmaker lathe and accessories. Chinese collets are very good in both the ER and WW configurations. The Sincere watch lathe motor is by far the best watch lathe motor I have, and I have a lot of them. Stella brand tweezers are fantastic and only cost $30.00 for a full set. I have a small high precision drill press made in China that cost only $88.00. The dirll chuck that came with it was worthless so I replaced the entire spindle assembly with an ER-11 spindle and collets. Now it is a high precision, high speed small drill press that can hold carbide bits. On the bad end of things I bought a set of Chinese Watch screwdrivers for $12.00 which were not very good. I had to look at it on a product by product basis and judge for myself.
davidMay 6, 2014 at 4:03 am #57564
Hi Tom. I forgot to ask you what do you do when you can’t use the old jewel for measuring diameter ? This jewel was shattered…. Thanks… Oh, I won that action for the little jewel press on ebay… THANKSMay 6, 2014 at 4:34 am #57565
There are a few different ways to attack this.
1) Often, you can find a replacement jewelon the Internet by doing a reverse look up with the serial number to find a parts list, then try to find the correct replacement jewel by contacting a supplier to see if they have some new/old stock. Alternately, you can look for old movements or partial movements with that particular jewel intact and purchase that. Then you can push out the that jewel and press it back into the watch that you’re working on. Check the end shake to ensure that you have the jewel depth correct.
2) If you have a lathe, you can take a piece a brass or steel rod that is somewhat bigger than the jewel hole, and turn it down slightly until you have a tight press fit into the hole. Then, use you calipers to determine the hole size. Add .001″ to the order jewel diameter. (Someone check me on this)
3) if you have a set of pin gauges you can find the one that just fit into the hole. There are plus/minus sets for a go-no go arrangement. There is an excellent thread on this where Bob and David explain this better than I can.
4) I fyou have a set of the tools used to open the holes around rubbed in jewels, you can place one of those into the hole (if its one of the bigger jewels) and open it until it is a tight fit, then use your calipers to determine the hole diamter. NOTE! Take care not to clamp down on the tools as it will affect the accuracy of the reading which in this case won’t be all that accurate.
5) If you have a staking set with reamers and a lathe, you can ream the hole out to a known larger size, order a jewel with the correct inside diameter, then use a peice of brass rod or steel to create a bushing. Start by reaming out a hole in the watch plate somewhat larger than the original hole being careful to keep the center. Next select a brass or steel rod a little larger than the newly reamed hole in the watch plate. Place the rod into your lathe, ream out the brass rod to a press fit to the O.D. of the jewel, then turn the rod down to fit have a tight fit for the OD of the jewel before parting off to the correct depth (a little smaller than the depth of the watch plate). Using your staking set, press the new jewel into the bushing. Finally, again using your staking set, push the new jewel with bushing into the newly reamed hole in the watch plate. [This is not possible if you want to keep the watch in its original state.] Of course you need the tools to do this one.
I’m sure there are other methods that folks here can provide.
I hope this helps,
TomMay 6, 2014 at 7:14 am #57566
Oops.. I forgot that you can often find new replacement jewels too. Duh….
Here’s a link.
TomMay 6, 2014 at 9:24 am #57567
Wow, That’s a lot of useful information. THANKS.. As per your suggestions, I picked up the cd “Chicago School of Watchmaking”. Last night. I watch Bob’s video’s all the time, and each time I learn something. I don’t recall him explaining the sizing of jewels but I could of missed it. Sometimes I play the video while I ‘am working on a clock or watch and don’t catch everything. I think I ‘am getting hooked on watches. Although very similar to clocks, they are very different in a lot of ways. Have yet figured out how to time them but that’s another topic.. Again, THANK YOU SO MUCH for ALL the info,,May 6, 2014 at 10:36 am #57568
Not a problem…. I know virtually nothing about clocks. I might have to pick your brain one day.
TomMay 6, 2014 at 11:23 am #57569
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