View Full Version : Adding drive dog to standard Jacot
04-28-2011, 03:22 PM
I am a considering adding a drive dog to standard Jacot tool.
It will ride on the latern side. (on right of pic below). I can carve a pulley out of wood. Put a brass sleeve inside pulley to act as bushing. I will turn a slot on latern just enough to put a snap ring on to keep pulley from sliding off.
But what would you suggest as the wire to drive a balance staff with?
I know a stiff wire would work, but should it be flexable too so as to avoid some kind of snag situation? I'm thinking some weed wacker lawn string. Stiff enough, but still flexes in case of emergency.
I think I will use a small dc motor for power supply.(any suggestions on the motor? )Standard rubber band o-ring to drive the pulley.
Your opinions apreciatd.
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04-29-2011, 01:51 AM
I think some music wire would suit for the drive. Weed wacker string will probably be too thick on some of the smaller wheels (or even a small balance). You should also include a plan to keep the drive pulley from walking down the shaft during use (that will cause trouble if it happens). Extending the brass sleeve to include a locking screw would probably work out OK.
04-29-2011, 04:46 AM
Hey Smudgy, thanks for reply.
Music wire sounds like a good idea. To keep the pulley from walking down the shaft I plan to turn a small groove on the latern, just enough so I can snap on a C clip so to prevent the pulley walking. You know those metal C clip washers that grip onto a slot.
The Jacot I won from ebay (in the picture) has no other laterns or heads (don't know what heads are called) so that it can do other sized pivots. I don't even know what size ranges I have on the current head. Crossing my fingers.
I guess I wil have to wait and see if the size range of pivots of the current head (what is it called?) will work with what I want.
I also wonder how it is that one latern can handle the different pivot sizes. Not sure how many sizes per head either -can't exactly see on mine. How many are there normally anyway..?
These are all questions I thought of after the purchase... :p
I may be able to turn some brass caps to put on the latern for different pivot sizes. Have those caps with correct sized holes to hold the pivots.
But I guess I will have to buy different heads, does Dashto sell them?
If not, who?
05-01-2011, 01:30 AM
You'll want to be able to set the drive pulley at different distances depending on the locations of the wheel (or balance) and pivot. Having the driver only be able to sit at one point will severely limit what you can do with the tool.
I just call it a runner, I'm not sure of the true name. It looks like yours has spaces for 8 different sizes. It handles different sizes because the axis of the two shafts are different. The one that takes the driver pulley centers on the edge of the one with the lantern end. The sizes are changed by pulling the runner with the lantern end and rotating it. I'm not sure about replacements as that will depend on the diameter of the runner. Steiner still produces these (possibly under the name Horia) and has replacement parts available (they can be bought through anyone that distributes Bergeon). Whether or not that will do you any good will depend on the hole sizes in the body of your tool. It's possible that Dash-To (or Uncle Larry's) has jacots with the same diameters, but I think they only sell as sets and you would need to get them to take measurements (which may not be greeted with much enthusiasm). Replacing the heads alone may be possible (some of the older type don't come apart as far as I know). You would need a similar diameter on the runner and the same diameter and taper on the mating piece.
05-01-2011, 07:04 AM
Thanks for info Smudgy. Meantime, I am crossing my fingers that it will work for pocket watches and men's wrist watch sizes. That's all I need for now.
05-21-2011, 10:12 AM
Got it this weekend.
Turns out, (no pun intended) that the disc side is broken. Has only 3 holes for working on pivots. Pretty sure it did not break in transit as it was packed well and I find no residual parts. It's a small piece so I think it would have been easily overlooked.
The other end to burnish looks good. So this is usable.
I seen no refference to the broken disc in sellers ad, also no pic shows it. So I wonder...
Anyway, instead of asking for refund and sending it back, I am hoping that I can negotiate some credit towards a good burnisher.
The seller wants to give me full refund including shipping and says I can keep or destroy the thing.
I am trying to be reasonable and dont want to hurt anyones hard earned reputation. I can respect that.
05-21-2011, 10:56 AM
On second thought I find it may of been my fault.
I was just tooling arround with it changing direction when I extracted the piece and the disc hit the edge of the Jacot body. The disc chipped even further and I noticed it is very brittle.
So most likely it was my fault as I was working on it to loosen it up. So the devices would slide.
I wrote to seller and explained this and also stated that I do not want refund or credit.
I wonder now if the disc is replacable?
05-22-2011, 01:43 AM
The disks are usually replaceable, but finding a replacement may be difficult depending on who manufactured it. It it is replaceable it will have a screw on the end.
The disk end is used to touch up the ends of conical pivots (the type that have cap jewels). They are easily broken, so if you do replace it you might want to fashion a tube to slide over that end to protect the plate.
05-23-2011, 01:42 PM
Thanks for info Smudgy.
Now re-reading my Fried book he also mentions same thing about a protective cover. Also slight mention of the disc being brittle.
Live and learn.
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