#5 Regulator progress

Discussion in 'Clock Construction' started by John MacArthur, Jun 18, 2018.

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  1. John MacArthur

    John MacArthur Registered User
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    Feb 13, 2007
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    Well, I have finally started another regulator, and as long promised, I will attempt to chronicle the progress.


    Movement front.jpg movement side.jpg
    We start with planning a more or less conventional regulator. This will have a jeweled dead-beat escapement, maintaining power, spiral-grooved barrel, and .6M high numbered train, with 12 leaf pinions. 12 s the lowest number of leaves that will give all the imparted motion from the gear to the pinion after the “line of centers”. The movement is “English style”, with center and third wheels behind the great wheel, and with six-spoke wheels. However, the dial will be supported on pillar extensions as in the continental style, rather than on individual feet.



    1 plate pins.jpg 2 Plate trimming.jpg 3 plate radiusing.jpg

    The taper pins hold the plates firmly in place, for milling the plate edges even, radiusing the plate arch tops, for drilling and reaming for the pillar holes, and for drilling the pivot holes later.




    4 pillar tapping.jpg 5 plates.jpg

    The front extensions of the pillars will become the dial mount feet, after the German tradition, making this somewhat a hybrid style.

    Next, I'll do the barrel assembly.
    Johnny
     
  2. John MacArthur

    John MacArthur Registered User
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    The barrel has a left hand thread, so that the weight, as it descends, moves toward the front of the case, and thus farther from the mass of the pendulum, eliminating possible gravitational interference.

    6 Barrel parts.jpg 7 barrel ratchet.jpg 8 barrel square.jpg 9 barrel soldered.jpg

    The ratchet cutter is made from an old Fiat valve shim. The barrel is complete after some tricky soldering.
    More to come,
    Johnny
     
  3. Phil Burman

    Phil Burman Registered User

    Mar 8, 2014
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    Hi John, looks Like a great start to number 5, it’s going to be interesting to watch the progress. Thank you very much for posting.

    What duration between windings have you planned, looks like it might be an 8 day?

    Isn’t the proximity of the drive weight to the pendulum an issue of variation in air movement rather that gravitational influence? I have a 4” diameter Perspex tube to run the drive weight in. It won’t eliminate air flow interference but it will keep it constant. I haven’t fitted it yet because I’m currently not sure the effect is detectable at 1 or 2 seconds a month with my pendulum bob, which is quite dirty with respect to air flow.

    Phil
     
  4. John MacArthur

    John MacArthur Registered User
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    Yes Phil, it will be an 8 day. I suppose you are right about pendulum interference - that it is more about air perturbations than gravitational effects. My pendulums, with glass cylinders, are obviously *very* "dirty".
    Johnny
     
  5. sharukh

    sharukh Registered User
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    Ok. I'll bite. I confess I have no idea about the use of the word "dirty" in this context.

    So, if you would be kind enough to elaborate ....

    Thank you,

    Sharukh
     
  6. John MacArthur

    John MacArthur Registered User
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    Yes, what Phil and I were talking about is air current disturbances between the pendulum and weight. We were using shorthand for "not aerodynamically smooth", referring to the pendulum bob. Mine is cylindrical, and fairly large.

    Johnny
     
  7. sharukh

    sharukh Registered User
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    Thank you John.

    And fantastic work by the way. Waiting to see more.

    Sharukh
     
  8. John MacArthur

    John MacArthur Registered User
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    On to the gears. This is the setup - the hub with a 3/16" dowel pin fitted in the center is bolted through the center of the dividing head. It is true within a tenth or two. The brass facing plate with 3 cap screws in it is roughly centered around the hub, and a little proud of it, so that the wheel blanks can be screwed down flat and true. The mounting holes will be cut away during the crossing out process, and so do no need to be particularly neat or accurate. The center hole, on the other hand, has to be concentric with the outside, and a nice snug fit on the dowel pin. The tips of the teeth will automatically be true with the center hole, as the cutter will even up any remaining inaccuracies in the circumference as the wheel is being cut.

    10 cutting gears.jpg 10.1 dividing head hub.jpg 10.2 hub in div. head.jpg 11 Gear teeth.jpg

    While waiting for the little mill to cut the gears, I relieved the centers of the pillars, and radiused the inner corners of the ends.

    That's it for now, I'll be working on the pinions soon.
    Johnny

    12 radius cutter pillars.jpg 13 pillars roughed.jpg
     
  9. John MacArthur

    John MacArthur Registered User
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    On to the pinions: Roughing the blanks, then cutting them in the mill in a good spin indexer. I did this in 3 passes. The steel is O-1, and I don't particularly like the finish after cutting. The British KEA-108 was better, but is no longer made.

    16 pinion blanks.jpg 21 after 3 passes.jpg

    Then turning away the excess arbor.

    22 turning arbor.jpg 23 completed blanks.jpg

    Finishing the arbor to shape

    23.1 finishing arbor.jpg

    Rough undercutting the pinion - this is supposed to help keep pivot oil from creeping up into the pinion leaves where it could accumulate grit. The pinion leaf faces and undercut will be highly polished after heat-treating.

    23.2 undercutting pinion.jpg

    Final roughed pinions. Next they will be hardened and tempered.

    26 pinions.jpg

    More as I progress,

    Johnny
     
  10. Paul Madden

    Paul Madden Registered User
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    Looking great John! Thanks for sharing

    Paul.
     
  11. Jim DuBois

    Jim DuBois Registered User
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    Here is one optimized bob design intended to lower air resistance and improve the "Q" of the pendulum assembly. This is from a clock made in his later years, by Eli Terry. There is a very complete article on it in an NAWCC 1971 bulletin by Elmer Kortin. The movement features a very interesting and well refined gravity escapement. If you have not looked at this article I highly recommend it. It is interesting that Terry had this degree of knowledge and expertise circa 1850. While the compensation remains a bit questionable, the shape of the bob, the escapement, and the degree of fit and finish of the movement itself are all first rate IMO.

    pendulum bob eli terry.jpg eli terry regulator clock.jpg eli terry regulator clock movement front.jpg eli terry regulator movement details.jpg
     
  12. John MacArthur

    John MacArthur Registered User
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    Thank you Paul and Jim. I knew that Seth Thomas made some exceptionally high grade gravity regulators in the mid-to-late 1800s, but did not know that Terry did also. That looks to be quite nice. I have known for some time that the "football" shape is likely the most efficient bob shape. I guess it has the least frontal and surface area per mass for the kind of velocities we are talking about. I already have the glass jar and mercury for this one, however.

    Johnny
     
  13. sharukh

    sharukh Registered User
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    I can't find the article. Besides, I've found that the archive of the Bulletin for the months of June for the years 1970 - 1976 are missing. Who needs to be informed about this ?

    Sharukh
     
  14. John MacArthur

    John MacArthur Registered User
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    I found it on the NAWCC site archive
    Johnny
     
  15. sharukh

    sharukh Registered User
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    Ok I found the article.

    The name is "An Elli Terry Regulator" by Elmer C Korten. The spelling threw me off and search results returned nothing.

    In case anyone is interested, its Vol 15 Issue 159.

    Sharukh
     
  16. John MacArthur

    John MacArthur Registered User
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    Now we harden and temper the pinions: This is one of those "on tenterhooks" operations. So much can go wrong. I wrap the pinions (W1 steel) and dip them into an anti-scale compound before I heat them to dull red, them plunge them into oil. Second photo is heating them to 510F for 30 minutes, which left them too hard. When I tried to straighten them, the first one broke. This is the first clock in which I have used W1 for pinions. The first two were of KEA 108, which is no longer made, and also stays very hard, but machined much better. The next two were 4140, which doesn't quite harden enough, but is a wonderful steel to machine. Some recommend 1045 or else A1, either of which I may experiment with. At any rate, the third photo shows all three (including a re-make) tempered to 610 F, and they are still very hard. If I use this steel again, I will probably temper to 650F or so.
    23.4 wrapped pinions.jpg 23.5 tempering.jpg 23.6 tempered to 610.jpg

    The W1 distorts somewhat when you quench it, and the arbors have to be straightened. More heart-in throat... but with care and fiddling, they come out good and straight.

    Check.... then whack....... repeat...... this took several days, and much swearing......
    23.7 checking straight.jpg 23.8 straightening apparatus.jpg

    The polishing is done by hand on a disc from some exotic hardwood, with 220 paste, and then handfinishing with Mother's Mag wax or Simichrome. I do have a jig for fast polishing, but it is pretty tough on the tips of the pinion leaves, and not good enough on the radial faces, where the action is. I may spend some more time on final polish - this was all I could take today.

    23.9 polishing.jpg 23.95 Mag Wax.jpg

    Johnny
     
  17. jhe.1973

    jhe.1973 Registered User
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    Having seen your prior clocks in person, I am well aware of what a treat it is for all of us here to have you share so much detail. I'm so glad that are finding the time to build and document #5.

    I am on pins and noodles now waiting to see your steps for shaping the pallet jewels.

    :)
     
  18. John MacArthur

    John MacArthur Registered User
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    Thanks Jim -- I appreciate the kind words. The jewels are a ways down the road, maybe this winter sometime. We'll see how it goes.
    Johnny
     
  19. John MacArthur

    John MacArthur Registered User
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    Crossing out the wheels is less arduous these days. I have done it with a coping saw, and more recently with a rotary table.

    This method is the easiest, and I've earned it. 25 crossing out wheel.jpg


    No matter how you cross them out, the spokes should be nice and square to the rim and hub. These files all have finely polished safe edges.
    I start making the safe edges on a belt sander, longwise, NOT crosswise. The crosswise sanding marks would make excellent miniature files. Then I polish them up on an Arkansas stone.
    The crossing file edges have a slight back angle; in other words they make less than a right angle.

    25.1 squaring spoke corner.jpg 25.2 squaring rim corner.jpg

    I like barrette files for most work.

    25.3 touching up spoke.jpg

    The hub corners of course need a square file, also finely polished on one edge

    25.4 hub corner.jpg

    The maintaining power wheel and third wheel, roughed out. We'll do quite a bit more finishing and burnishing of the spokes and rims later.

    25.5 M.P. wheel.jpg 25.6 3d wheel.jpg

    Johnny
     
  20. John MacArthur

    John MacArthur Registered User
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    Next come the small parts for the barrel/maintaining power assembly. They get roughed out on the little mill, and then I locate the holes by coordinates while still in the mill. The springs are O-1, and the screws are 1144.

    24 click spring.jpg 24.1 in the rough.jpg

    In this case, I got jumpy, and drilled out the holes. A better technique would have been, as I have done in the past, to drill out the screw hole, locate the springs on the wheel, mount them with temporary screws, and drill the steady pin holes through both the spring and the wheel, aligning them exactly. Here I had to make a tiny transfer punch, and locate the pin holes that way, after I had already hardened and tempered the springs. In either case, the holes are reamed until the pins are near tight before hardening. The steady pin holes are slightly countersunk, so that the shiny heads of the pins are below the plane of the surface.

    24.3 reamed for pin.jpg 24.4 countersunk.jpg

    The mill is tight enough to make beautiful screw threads, without any clean up to speak of. This is a HUGE advance over hand-finishing die-cut threads for hours and hours. There is still plenty of polishing to do.

    25 milling screw.jpg 25.2 ready for hardening.jpg

    The pieces are slightly heated and coated with anti-scale, then heated up to orange and dunked in oil, at which point they are very hard. Don't forget to bend the curve in the click spring before it gets hardened. Then they are heated in the little oven to a little over 500 deg. I broke one while driving a pin in, so I think they should have been tempered to 550 or so. The screws are heated in the tray until blue. Being 1144, they are a little softer, and none of the heads have snapped off, like ones made of W-1 are prone to.

    25.3 tempered.jpg 25.4 screw blued.jpg 25.5 screws.jpg

    Lots more to come,
    Johnny
     
  21. Allan Wolff

    Allan Wolff Moderator
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    Cutting screw threads on the mill; that is just too cool! When my wife yells at me for spending money on a CNC mill, I'm going to tell her that you made me do it!;)
    Excellent work as always,
    Allan
     
  22. John MacArthur

    John MacArthur Registered User
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    Thank you Allan. The mill wasn't up to it the way I got it. It had "anti-backlash" nuts. Which weren't tight enough by a long shot. I had to build a new saddle for ball-screws, and mount new stepper motors, geared down quite a bit. Then I had to upgrade the Flashcut to new version. None of this was cheap or easy, but the results are very cool. Here are some #0-80 screws.


    atiny screws.jpg atiny screws2.jpg

    Johnny
     
  23. John MacArthur

    John MacArthur Registered User
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    Mounting the springs, etc -- when reaming the holes in the wheel,
    do it one at a time, to get a good snug fit.

    26 one at a time.jpg

    The barrel assembly, roughed out. Needless to say, a lot of polishing of steel parts has
    happened between installments. A lot more will be done on the brass parts.

    26.1 M.P. assembly.jpg 26.2 ratchet.jpg

    A couple of special tools. After cutting the pins to length, the ends must be de-burred. The brass punch with a dimple in the middle is
    so that when you drive the pins home in the springs, you don't mar the heads.

    26.3 special tools.jpg

    Johnny
     
  24. Paul Madden

    Paul Madden Registered User
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    Hi John,

    Thanks for the great photos and descriptions of your latest work. Its really interesting to see the progress on the build!

    I have a question: You mention an anti-scale compound for protecting steel components during heat treatment. Is this a boric acid powder/denatured alcohol mix, or a commercial compound?

    I know many horologists who use a boric acid powder/denatured alcohol mixture, and this seems to work well for them. I'd be curious to know what you use?

    Cheers John, and keep us up to date with your progress!

    Paul.
     
  25. John MacArthur

    John MacArthur Registered User
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    Thanks Paul -- The anti-scale is a Kasenit product called "KeepBryte". I bought it probably 30 years ago, and don't think it is still available. It is a thin powder, and you slightly heat the piece, swirl it in the powder, and finish heating. There is probably something else available by now, or one can use the boric acid solution.

    Johnny
     
  26. Paul Madden

    Paul Madden Registered User
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    Hi John,

    Thanks for the explanation. Its interesting, because one of my friends actually heats up the component and dips it directly into boric acid powder. This forms a glaze which protects the surface from scaling up to a point. I have other friends who make a thick paste by mixing it with denatured alcohol. Both methods seem to work.

    Thanks once again John, and keep the photos coming!

    Paul
     
  27. John MacArthur

    John MacArthur Registered User
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    Will do, and glad you like it.
    Johnny
     
  28. John MacArthur

    John MacArthur Registered User
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    Here is my depthing tool, made many years ago. I make bushings for each wheel and pinion, for a good snug fit. Then I can use the pointed inserts to scribe arcs on the plates. This method has not proven as accurate as averaging the inside and outside dimensions of the inserts, applying these in CAD, generating coordinates of the arc intersections, and drilling holes in the mill by those coords.


    27 depthing1.jpg 27 depthing2.jpg 27 depthing3.jpg

    Then I have polished the arbors and pinion end faces in preparation for making the wheel hubs. I polish with a 1" disc on a flexible shaft, to a 9 micron finish. Then I polish the faces, starting with an iron lap and 500 grit carborundum, and finishing with 1200 grit diamond on the composite lap in the pic. These have come out fairly well, but I am more convinced than ever to use 4140 for the pinions, instead of O1. It will take a better finish straight off the engraver, as well as in the polishing, and not be so finicky to work with. This lathe is used exclusively for abrasive work.

    Johnny
    27pinion1.jpg 27pinion2.jpg 27 polishing rig.jpg
     
  29. John MacArthur

    John MacArthur Registered User
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    After locating and drilling the various pivot holes, and making, soldering, and truing a couple of wheel hubs, this is where I stand. The train runs very freely, even with the wheels only loosely pushed onto their respective hubs. Time to take a break and tend to some overhauls.

    Johnny


    27train.jpg
     
  30. Paul Madden

    Paul Madden Registered User
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    Nice work John. Thank you for sharing with us!

    Paul.
     
  31. John MacArthur

    John MacArthur Registered User
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    Thanks Paul, and you're very welcome.
    Johnny
     
  32. dandydude

    dandydude Registered User

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    Really great to see your work. And thanks for posting all the updates.
     
  33. John MacArthur

    John MacArthur Registered User
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    You're very welcome Dandy -- I'll be off for a few weeks, doing other stuff, but will be back.
    Johnny
     
  34. John MacArthur

    John MacArthur Registered User
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    #34 John MacArthur, Nov 30, 2018
    Last edited: Nov 30, 2018
    These next posts don't seem to show much progress, but represent a huge amount of hand-work. I cut and crossed out the escape wheel, drawfiled and burnished all the spokes, rims, and scape teeth for high gloss effect. The surface finish of the wheels will come later.



    28 cutting scape wheel.jpg 29 drawfiling spokes.jpg 30 burnishing spokes.jpg
     
  35. John MacArthur

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    At a friend's suggestion to use A-2 steel for small parts (air hardens, and he thought it machines better), I made this batch of 0-80 and 1-72 screws for holding the wheel to the hubs.

    31 slotting screws.jpg 32 first batch A-2.jpg They hardened and polished just fine, but wouldn't blue. Turns out A-2 has about 5% chrome in it, making it a variety of stainless, and so won't blue. Very disappointing,


    The next batch, of good old W-1, turned out fine. I then drilled holes in the wheel center to tap drill diameter by coordinate in the mill with the crossing jig, and counterbored the screw head seats by using the "wrong" end of the drill to hold the hole centered, using the micrometer stop on the tailstock runner to control the depth. Then I drilled the hub holes to the same pilot diameter, through the wheel holes. Finally I tapped the hub holes, and opened the wheel holes to clearance size for the screws. These last two posts represent nearly at least a week of finicky work, and I'm glad it's behind me. It's not very exciting progress. Now on to the pallets. BTW, I'll post a pic of the scape wheel tomorrow.
    Johnny

    33 second batch W-1.jpg 34 counterbore.jpg 35 drill hub.jpg 36 mounted wheel.jpg
     
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  36. tok-tokkie

    tok-tokkie Registered User

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    That is nice work. I particularly noticed the little chamfer on the screw heads.
     
  37. John MacArthur

    John MacArthur Registered User
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    Thanks Tokkie -- Yes, there's a lot of handwork there that is not entirely evident in the photos. I imparted a slight taper to the slots with a slotting file after cutting them, and then slightly chamfered the edges, to remove machining and filing burrs. This also reduces the chance of screwdriver caused burrs being raised if the screws soften too much during tempering. I had already run into this using 4140 steel - it machines beautifully, but doesn't retain good hardness. At least the W-1 does a fine job of staying good and hard. So that eliminates two kinds of steel for clock parts. These are very small screws, requiring several levels of magnification for these aging eyes.

    Johnny
     
  38. jhe.1973

    jhe.1973 Registered User
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    Hi Johnny,

    Not only is your hand work impressive but your photos are excellent and also absorb a lot of time too. Thanks so much for including all of us in your project. It may not be exciting but it is always a treat to see how others approach challenges - its what I miss the most about working alongside other craftsmen in a shop on a daily basis.

    Sorry to hear about your A-2 experience - another tip to keep in mind should I ever need to make anything requiring a blued finish.

    So........now you had to go and tease me with, "Now on to the pallets"...............I'm on pins and noodles waiting to see that process!

    :)
     
  39. John MacArthur

    John MacArthur Registered User
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    Thank you Jim - Yes, now the fun begins.
    Johnny
     
  40. John MacArthur

    John MacArthur Registered User
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    I've gotten a little behind. A while back I made these plate nuts.
    37 knurl nut blank.jpg

    This tool is just half of a pair of standard knurls, mounted in the end of a heavy bar. The rest is another heavy bar mounted in the four-way. THIS IS NOT OSHA APPROVED; Don't try this unless you are very familiar with your lathe, have a good slow back-gear, and aren't particularly afraid of bloody knuckles, etc. It takes a lot of pressure, and several tries.
    38 knurl tool.jpg 39 knurling.jpg 40 tapping.jpg

    This is a ground and polished radius tool, making a dished cut on the top of the nut.
    41 knob dish.jpg

    42 nuts.jpg
    42.3 nut in place.jpg

    I'll have the pallet jewel series very soon.
    Johnny
     
  41. John MacArthur

    John MacArthur Registered User
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    #41 John MacArthur, Dec 26, 2018
    Last edited: Dec 26, 2018
    Now to the pallets. After roughing them out, filing all corners square, and preliminary polishing, I cut dovetail slots in the pallet arms to hold the jewels. The dovetail is positioned to resist the continuous tiny scape wheel impacts or (more likely) the polishing of the dead faces from driving the jewels out of their settings. The hub is counterbored so that the screw heads will be buried flush.
    43 rough pallets.jpg 43.1 dovetail slots.jpg 43.2 counterbore pallets.jpg
    The synthetic ruby is adhered to a microscope slide with "dopping wax", a lapidary adhesive, so that it can be held easily while slicing it on a fine diamond wheel, shown in the next picture. The half-moon shaped pieces are then cut into smaller chunks. Finally, I draw pencil lines in the shape I want on the pieces, and cut them to approximately match the dovetails in the pallets. I charge the coarse lap (a copper disc in the lapidary lathe) with 320 grit diamond paste and a homemade charging wheel. This is just a dead-hard disc mounted in the forks of a bar handle. I after squeezing some onto the face, I start by manually turning the headstock for a few revs, then at the lathe's slowest speed.

    Two rules about grinding stones with diamond:
    1: Keep the piece moving back and forth, otherwise you get grooving. This will be much more important later.
    2: Keep the wheel and work wet with a special lapidary lube. I use a "Crystalube" from Rio Grande Jewelry, where all the diamond paste, dopping wax and epoxy comes from as well. You can see the little piece of sponge on the far corner of the table. At this stage, I recharge the wheel less frequently than I will when I'm actually forming the faces of the jewel. For now, I want a loose fit in the dovetails.


    44 pallets with rough jewels.jpg 44.1 rough shaping.jpg 44.2 charging lap.jpg 44.3 grinding to shape.jpg
    I use 220 epoxy; it's slightly harder than 330, but has a very slight color tinge to it. The fit definitely needs to be fairly loose, like 3 or 4 thou, to allow the epoxy some room to form a thin mass. I happen to think that JB Weld is stronger, but it is dark gray. The last step before gluing the jewels is to take a tiny cylindrical diamond grinder and carve vertical grooves in the ends of the jewels, and with a pointed graver, scribe some vertical lines in the inner sides of the pallet arms. This gives the epoxy something to grip on both mating faces. Otherwise, the jewel will probably get pushed out while grinding the narrow or non-contacting faces. This causes much frustration, vile language, etc.

    44.4 stone epoxied in.jpg

    Next, the forming of the acting faces
    Johnny
     
  42. John MacArthur

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    #42 John MacArthur, Dec 26, 2018
    Last edited: Dec 26, 2018
    OK, now the important part: Using the same lap and 320 grit, I rough grind the inner, outer, and impulse faces of the jewels. I use an old and somewhat funky compound with the cross-feed screw removed. I made a lever actuator, so that I can move the flat jewel faces back and forth across the lap face. Remember, keep it wet (cool) and keep it moving. You can see the sponge in old tweezers under the table. In this case, I'm not moving the slide, as I am rotating the pallets to grind the outer face concentric.


    45 outside face rough.jpg 45.1 keep it wet.jpg
    I use the tangent disc method - lines projected from my two impulse faces need to both be tangential to the same circle which is centered on the pallet pivot point. In this case, it is 0.911" in dia. This is the disc shown on the pallet stub on the table. I designed the escapement with 1/2 degree lock and 1-1/2 degree impulse (lift, to the Brits) I'm lining up the cutting face with the edge of the disc, just like in the drawing. Now I can slide the exit pallet impulse face back and forth on the lap, and keep it at exactly the right angle. The same disc and procedure applies to the other side of the lap for the entry pallet impulse face. This is all straight out of Gazely "Practical Clock Escapements" and adaptations from Daniels "Watchmaking".


    scape construction.jpg 45.2 aligning back face.jpg 45.3 exit impulse.jpg 45.4 entry impulse.jpg

    Finally I grind the inner concentric faces on the back of a special lap which has a slight curve on the back face, and the edge of which is somewhat tapered to allow the pallet to move far enough past it. On these inner concentric faces, it is crucial that the pallets sit exactly at the elevation of the center of the lap. Otherwise, the wheel will only cut on the top or bottom edge of the stone. These faces will, of necessity, be slightly concave, and the "dish" should be in the middle. This all gets repeated with new laps and 1200 grit after carefully cleaning all 320 grit off of the pallets and table. I just charge these laps by squeezing the paste onto the wheel, smearing it around with pegwood, and adding a drop of lube. This goes really slowly, as you have to stop and check the work, and recharge the lap every few passes. Each face get 10 or 20 of these. I check for pallet thickness and distance apart regularly with a micrometer, keeping me heading in the right direction. I can't imagine how this was done before CAD and micrometers.

    When it is all perfect, I polish the dead and impulse faces with 14,000 grit and yet again new laps. If I've done everything right, the pallets will allow minimal and equal drops, and approximately 1/2 degree of lock. In this case it looks good, and I don't have to do it over! Whew!

    45.5 exit dead.jpg 45.6 after all three grades.jpg

    On to the pallet arbor, and its and the scape pivot jewels.

    Johnny
     
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  43. Allan Wolff

    Allan Wolff Moderator
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    Johnny,
    Thank you for showing us how you make jeweled pallets. That is something I have always thought of as too difficult; but you make it look easy. Excellent work!
    Allan
     
  44. John MacArthur

    John MacArthur Registered User
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    Thank you Allan. Easy - not so much, there was a lot of back-tracking between the pictures, and the usual "vile language". But worth the effort.
    Johnny
     
  45. jhe.1973

    jhe.1973 Registered User
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    Gee, I thought that I was the only one!

    Yeah, I understand the not so much regarding the easy. I suspect that you are being gracious by not mentioning time consuming in both the work and taking such great photos. For all of that I can't thank you enough for including us in your project.

    But I can try.

    Thank you so much for all your contributions to this forum. Your insights and craftsmanship are greatly appreciated by many of us.

    :)
     
  46. John MacArthur

    John MacArthur Registered User
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    Thanks Jim - That part was a major steppingstone, and I'm glad to have it behind me. I'm making screws for various parts now (besides dealing with snow for a change), and will have more on pivot jewels pretty soon. Making this thread has a side benefit for me: I'll be able to remember stuff that I'd probably forget.....
    Johnny
     
  47. John MacArthur

    John MacArthur Registered User
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    Next installment: various small parts. First, the beat adjuster and crutch and various small screws to hold it all together
    46 beat adj & crutch.jpg 46.1 pallet parts.jpg 46.3 pallet assy.jpg

    The knurls for the beat adjuster
    46.4 knurls.jpg

    Then the maintaining power detent and arbor
    46.5 M.P. click.jpg

    The whole pallet assembly installed:
    47 pallets inst.jpg

    It's quite important to have the crutch limiting screws installed whenever the jewelled pallets are in place. Otherwise, the crutch assembly can swing to the point of damaging the tips of the jewels.

    There's quite a bit of work here, and not too exciting. Besides, skiing has gotten good and is interfering.....
    Now on to the hole jewels - can't put it off any longer.
    Johnny
     
  48. John MacArthur

    John MacArthur Registered User
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    On to the jewels. The rough part is done on a standard lapidary saw with a very thin diamond blade. The boules of ruby have already been cut by hand into slabs to a little thicker than the final thickness of the jewels. The resulting half-moon shaped pieces in this case have already been cut into smaller chunks, and now are mounted with dopping wax onto a microscope slide for holding in the diamond saw, and cut into blanks. Then I rough flatten them on the 325 wheel in the abrasive lathe, again keeping everything wet and cool.

    48 cutting raw ruby.jpg 48.1 rough flattening.jpg

    Then on the same table, but not mounted on a slide, I rough the blanks into a roundish shape.

    48.2 roughing round.jpg

    At this point I mount them onto brass tube mandrels, again with dopping wax, using a small alcohol lamp.

    48.3 dopping.jpg

    Then I mount the small grinding wheel, and grind the blanks flat and round. This must be done in very tiny increments, or the pressure and heat are too much, and the blank pops off. You can see the ruby mud, presumably along with diamond paste all over the place. This must be pretty tough on a lathe, but I wash the collets regularly, and the headstock spindle as often as I think of it.

    48.3 flattening.jpg 48.4 rounding.jpg

    Then I drill them with small diamond drills, again going very slowly, and cleaning the ruby mud out as it accumulates, and keeping the drill wet. The larger drill has paper towel dross on it, from cleaning out the hole.

    48.5 drilling.jpg 48.5 Drilling2.jpg

    This is just the beginning.
    Johnny
     
  49. tok-tokkie

    tok-tokkie Registered User

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    This is fascinating to follow. I don't have the equipment but seeing & learning how it is done is wonderful. In my working career I was involved in a lapidiary business so I have had exposure to the processes.
     
  50. John MacArthur

    John MacArthur Registered User
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    Thank you Tok - There's lots more coming.
    Johnny
     

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