Building a Jacot Tool for your Lathe

Home Forums General Discussion Forum Building a Jacot Tool for your Lathe

  • This topic is empty.
Viewing 15 posts - 1 through 15 (of 17 total)
  • Author
    Posts
  • #48567
    tmac1956
    Participant
    • Topics Started: 171
    • Total Posts: 1259

    Here’s a project for the watchmakers here. I posted this because it looks as though (like many watchmaker tools) availablilty for purchase is virtually non-existent or cost prohibitive.

    http://www.davewestclocks.co.uk/making_a_jacot_tool.htm

    Thanks!
    tmac

    #53385
    arutha
    Participant
    • Topics Started: 85
    • Total Posts: 1536

    Hi Tmac,
    Much faster to use a block of hard wood in a vice and a pin chuck :)
    As you have rightly stated, the prices for lathe accessories is just going up and up, I dont think it will be long before someone with enough engineering sense starts producing this stuff again. I seem to remember David was considering making lathe accessories.

    #53386
    willofiam
    Moderator
    • Topics Started: 75
    • Total Posts: 1437

    the easiest and cheapest way I can see it is to have Paul buy me a rollimat for my birthday :D …..problem is I am getting so old I cant remember what day it originally was 🙄 , ….ssssooooo, lets just call it today :D , William

    #53387
    david pierce
    Participant
    • Topics Started: 90
    • Total Posts: 1360

    Paul,
    I haven’t forgotten, I am just trying to find the time to get around to it. I have some ideas for pivot runners and am confident they will work well but I need a block of time to make some prototypes. I have the materials and cutters and will get to them as soon as I can.
    david

    #53388
    arutha
    Participant
    • Topics Started: 85
    • Total Posts: 1536

    William, darn it, I thought you were buying me one for my birthday!

    David,
    I would be very interested to see how it turns out. I have spent some time on designing a jacot drum for my Wolf Jahn 6mm but decided against making one as I am just so used to polishing pivots by hand in a block of lignum vitae with the arbor held in a pin vice. I would have killed for one at the start, it took me a while to learn how to file a badly worn pivot straight and then to get a satisfactory polished finish with the pivot file/burnisher. If I was as rich as William I would have just gone out and bought myself a machine or the proper lathe attachments ;). As I go through repairing clocks I see some awful work that has been done to them previously, I think this could be on the rise again as people just cant afford the proper tools for the job and there isnt enough decent training opportunities in this country any longer to make sure work is done properly. Its ok reading books to get a general idea but having someone tell you how to do it or where you are going wrong is priceless.
    Seeing the prices pivoting attachments make on e-bay these days is a good indicator of where to start, along with the jacot drum, the most useful items that almost always seem to be missing from a used watchmakers lathe.
    Paul.

    #53389
    david pierce
    Participant
    • Topics Started: 90
    • Total Posts: 1360

    Paul,
    Lignum Vitae? That is the wood that used to be put on the bottom of wooden planes. Wow, I haven’t heard of that in a few years.
    david

    #53390
    arutha
    Participant
    • Topics Started: 85
    • Total Posts: 1536

    Its not so cheap, I bought a lump and cut a slice off now and again to make pivot beds for polishing them. Very dense wood, it sinks!

    #53391
    gerene
    Participant
    • Topics Started: 16
    • Total Posts: 377

    I believe it is not cheap and hard to find because those trees are protected species.

    Jan

    #53392
    achipo
    Participant
    • Topics Started: 4
    • Total Posts: 53

    Not sure about it being protected, but it is very heavy and a tropical hardwood from the rainforest, which means there are additional restrictions. I believe it’s still used for ship propeller bearings. You might try Gilmer Hardwoods as a source.
    https://www.gilmerwood.com/search_results.php?keywords=Lignum

    #53393
    arutha
    Participant
    • Topics Started: 85
    • Total Posts: 1536

    Here are a couple of links to Lignum Vitae being sold on e-bay uk.

    http://www.ebay.co.uk/itm/Lignum-Vitae-half-dowel-very-rare-Woodturning-cabinetmaking-clockmaker-/271185574632?pt=UK_Crafts_Other_Crafts_EH&hash=item3f23eb7ae8#ht_326wt_1255

    http://www.ebay.co.uk/itm/2-lignum-vitae-woodturning-blanks-/290894169912?pt=UK_Crafts_Other_Crafts_EH&hash=item43baa4c738#ht_234wt_1255

    I also have some “Vera” wood which has very similar properties. Ebony is also very tough and good for a pivot block but that is getting expensive, odd ebony piano keys come up on ebay from time to time.

    #53394
    tmac1956
    Participant
    • Topics Started: 171
    • Total Posts: 1259

    @Arutha wrote:

    Here are a couple of links to Lignum Vitae being sold on e-bay uk.

    http://www.ebay.co.uk/itm/Lignum-Vitae-half-dowel-very-rare-Woodturning-cabinetmaking-clockmaker-/271185574632?pt=UK_Crafts_Other_Crafts_EH&hash=item3f23eb7ae8#ht_326wt_1255

    http://www.ebay.co.uk/itm/2-lignum-vitae-woodturning-blanks-/290894169912?pt=UK_Crafts_Other_Crafts_EH&hash=item43baa4c738#ht_234wt_1255

    I also have some “Vera” wood which has very similar properties. Ebony is also very tough and good for a pivot block but that is getting expensive, odd ebony piano keys come up on ebay from time to time.

    Arutha:

    I just bought a couple of pen blanks approx. 1″x1″X5″ on eBay.

    http://www.ebay.com/itm/390530058710?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

    About how big are the slips that you use? I figure I can get each one of those little planks ripped into thirds.

    Your thoughts?
    tmac

    #53395
    arutha
    Participant
    • Topics Started: 85
    • Total Posts: 1536

    Nice find!
    as long as they are big enough to clamp in a vice, you can start your groove with a small rat tail file. When you file a pivot in one of these blocks you then need to give the groove a quick brush out with a wire brush as particles can spoil the finish when you then burnish it. If you want to make a bigger block you could inlay the lignum into the edge of a cheaper wood block as its only the edge you need.
    Hope that makes sense?
    Paul.

    #53396
    tmac1956
    Participant
    • Topics Started: 171
    • Total Posts: 1259

    @Arutha wrote:

    Nice find!
    as long as they are big enough to clamp in a vice, you can start your groove with a small rat tail file. When you file a pivot in one of these blocks you then need to give the groove a quick brush out with a wire brush as particles can spoil the finish when you then burnish it. If you want to make a bigger block you could inlay the lignum into the edge of a cheaper wood block as its only the edge you need.
    Hope that makes sense?
    Paul.

    Paul:

    I was thinking of holding the pivot in a collet in the 8mm lathe or a Jacot lathe and using this wood as a burnisher. In your example, does the groove hold the pivot which you then file with a metal burnisher? If so, that ia a much simpler approach. Simpler is usually better (david has taught me that). ;)

    Thanks!
    Tom

    #53397
    arutha
    Participant
    • Topics Started: 85
    • Total Posts: 1536

    Hi Tmac,
    I polish all of my pivots by hand, in a pin vice using the lignum as a bed held in a vice, the pin chuck is twisted back and forth whilst moving the metal burnisher in the opposite direction. It does take a little practice but the beauty of this method is it is very quick, you don’t have to keep changing the collets in your lathe to accommodate the different arbor sizes or the tailstock runners for different pivot sizes. Just use a little clock oil as lubrication. I do however polish the winding arbors in my lathe with buff sticks I have made from flat aluminium bar and then varying grades of wet and dry stuck to the bars with double sided carpet tape( I put a different grade on each side, so I have 3 bars with 6 grades of paper). They last much longer than cheap buff sticks and it doesn’t take long to replace the paper when it becomes worn. As winding arbors turn so slowly it is not so important for them to be burnished like a pivot, a good polish on them helps to stop them wearing through the barrel holes.

    You said you were thinking about using the lignum as a burnisher? Although it is hard I still don’t think it would work as well as a steel burnisher, remember some of these pivots are almost glass hard and no matter how hard the wood, I don’t think it would touch the surface. Embedding the wood with some form of media is also not the best way to go when finishing pivots as if any of the media ends up embedded in the pivot it will accelerate the wear of the pivot hole.
    Hope that helps?
    Paul. :)

    #53398
    tmac1956
    Participant
    • Topics Started: 171
    • Total Posts: 1259

    @Arutha wrote:

    Hi Tmac,
    I polish all of my pivots by hand, in a pin vice using the lignum as a bed held in a vice, the pin chuck is twisted back and forth whilst moving the metal burnisher in the opposite direction. It does take a little practice but the beauty of this method is it is very quick, you don’t have to keep changing the collets in your lathe to accommodate the different arbor sizes or the tailstock runners for different pivot sizes. Just use a little clock oil as lubrication. I do however polish the winding arbors in my lathe with buff sticks I have made from flat aluminium bar and then varying grades of wet and dry stuck to the bars with double sided carpet tape( I put a different grade on each side, so I have 3 bars with 6 grades of paper). They last much longer than cheap buff sticks and it doesn’t take long to replace the paper when it becomes worn. As winding arbors turn so slowly it is not so important for them to be burnished like a pivot, a good polish on them helps to stop them wearing through the barrel holes.

    You said you were thinking about using the lignum as a burnisher? Although it is hard I still don’t think it would work as well as a steel burnisher, remember some of these pivots are almost glass hard and no matter how hard the wood, I don’t think it would touch the surface. Embedding the wood with some form of media is also not the best way to go when finishing pivots as if any of the media ends up embedded in the pivot it will accelerate the wear of the pivot hole.
    Hope that helps?
    Paul. :)

    Yes it does. And would I be correct in stating that the bed depth for the pivot should be a little less than the radius of the average watch pivot?

    Thanks!
    tmac

Viewing 15 posts - 1 through 15 (of 17 total)
  • You must be logged in to reply to this topic.
tmac1956Building a Jacot Tool for your Lathe