Jacot tool; part names and their uses .... ?

[Endeavor]

Hello All;

I've read some of the recent replies of @JohnR725 and @nickelsilver regarding @VWatchie new Steiner Jacot tool, but it would be nice to get all the names of the parts, and their exact uses, in one place.

Seeing VWatchie's new shiny Steiner, I couldn't resist to search and stumbled over this Jacot tool, no it's not a Steiner, but it looks good none the less.

It has quite a few runners and some additional parts. The covered lanterns should be in good condition.

Could our experts on this forum be so kind to explain what the different runners are, why and when to use and what the parts 6 (?) & 7 (center broach) are / used for?

Thank you in advance

Edited June 3, 2023 by Endeavor

[nickelsilver]

The parts 1,2,3,4, and 5 are what Bergeon and Horia (Steiner) call broaches, or broche in French. In my schooling they were called runners, and most English speakers I know call them that. The main body of the tool is usually called the frame. Number 7 is also called a runner in English (Horia just calls it a cylinder, also in French), but specified as the headstock runner- the headstock being the end of the frame with the pulley.

 

The different runners are for different sizes and types of pivots. In the above (and most sets), the runners with caps on one end are for smaller pivots, up perhaps 0.36mm. The caps cover the fragile lanterns, which allow working on the pivot ends. The short runner, with no lantern (#2 above) is for long pivots on 4th wheels that carry a second hand. They have longer beds and naturally make a tapered pivot. In the above set it looks like #3 could be an additional 4th wheel runner.

 

The runner with beds on both ends is for center wheels i.e. larger pivots. You would choose between headstock runner #7 or the one currently in the tool according to pivot size, usually one will do the normal range up to 0.30-40, the other up to the limit of the center wheel runner.

 

Finally, #6 is a limiter for the burnisher. It clamps onto the runner (tailstock runner, with beds), and can be positioned so that the burnisher can't ride up easily over a shoulder on conical pivots for example. They aren't very common, and I have to say I've never used one, even on teeny tiny ladies sized balance staffs. But I would say a useful thing to have!

 

The pivot gage is something that has always terrified me, and I've never used one of that style. It seems like a good way to mark or break a pivot. But it was a standard accessory for most Jacot tools. I much prefer a jeweled hole gage.

[Endeavor]

@nickelsilver; Thank you very much

I'll print it out and stick it, once the set arrives, in the box

Indeed, I have had one of those (killer) pivot gauges before (throw it away, but now I'll receive another one ) and they are ideal for ruining pivots, hence my DIY pivot-gauge:

 

[Waggy]

On 6/3/2023 at 3:28 AM, Endeavor said:

stumbled over this Jacot tool

Can you let us know where to get this tool?

[valleyguy]

22 hours ago, Waggy said:

Can you let us know where to get this tool?

Waggy there is a ewus jacot tool on ebay at the moment, link below

 

https://www.ebay.co.uk/itm/285362345721?hash=item4270ebd6f9:g:AdQAAOSw3e5kotdN&amdata=enc%3AAQAIAAAA4BYHpC9E56bAVfuc5yybJFNslDAKrxTQCMKqQsALh1NxWcp6mdCFaX2pLuhSunoDP83bNbWa3JOVKH%2BWEnvZBBxFKna%2Bs9mtBu8y77wjnd8iaSbszYdW4tfekFbIFBbAUkZ5kAhPtfMk9iaQgMxf%2B6r3S1nlR2FOmrzvjTRtLD9datIumUOjZIj8c4ECb1UQ%2FKr68gj7qe6%2BFH0xwY%2FgB0Yc2vztiJSp6WVC2MN4vpfdBs90opxLONAzTaPadJLkIZHbjGglLzH8CYn0%2BTI5e9kGdcvQrWUfml9uDQwIaLBz|tkp%3ABk9SR_rhsuGkYg

[Waggy]

Thanks, I am already outbid for it 

[Endeavor]

@nickelsilver

I finally got around to start learning the Jacot tool skills

Starting off, I was puzzled which runner to use, so I had to re-read your explanations.

Thereafter I thought it may be an idea to put a "face" to each type of runner bed to clarify your explanations.

On 6/3/2023 at 2:08 PM, nickelsilver said:

The different runners are for different sizes and types of pivots. In the above (and most sets), the runners with caps on one end are for smaller pivots, up perhaps 0.36mm. The caps cover the fragile lanterns, which allow working on the pivot ends. The short runner, with no lantern (#2 above) is for long pivots on 4th wheels that carry a second hand. They have longer beds and naturally make a tapered pivot. In the above set it looks like #3 could be an additional 4th wheel runner.

The runner with beds on both ends is for center wheels i.e. larger pivots. You would choose between headstock runner #7 or the one currently in the tool according to pivot size, usually one will do the normal range up to 0.30-40, the other up to the limit of the center wheel runner.

Runner #1 and runner #4; (the runners with the caps) for smaller pivots. Runner #1 has the sizes: 5/6/7/8/9/10/11/12/13 and runner #2 has the sizes: 14/16/18/20/22/24/26/28/30.

Runner #2; for the 4th wheels with tapered end;

Runner #3; (like runner #2) is indeed an additional 4th wheel runner for tapered pivots;

Runner #5; with beds on both sides, for the larger pivots, i.e center wheels. Covering the sizes: 32/34/36/4045/50/55/60 & 65 on one side and 70/75/80/85/90/95/100/110 &120 on the other side;

 

 

Edited February 16 by Endeavor

[VWatchie]

On 2/16/2024 at 5:49 PM, Endeavor said:

 

Wow, I had no idea it existed runners taking those large centre wheels. The maximum size on my Steiner runner for the centre wheels is 76 and too often it isn't enough. @nickelsilver I know you have Steiner Jacots, is there a runner for it taking pivots with a diameter > 0.76mm?

[Endeavor]

BTW; the running in the box, numbered #2, turns out to be a (sellers?) "fill-the-gap-in-the-box"-runner. It has a smaller diameter and doesn't fit the jacot-tool at all.

However, if I take runner #3 out of the Jacot tool, then all the slots in the box are filled and my set seems complete ......., at least I think that everything required is present (?)

 

Edited March 25 by Endeavor

[nickelsilver]

1 hour ago, VWatchie said:

Wow, I had no idea it existed runners taking those large centre wheels. The maximum size on my Steiner runner for the centre wheels is 76 and too often it isn't enough. @nickelsilver I know you have Steiner Jacots, is there a runner for it taking pivots with a diameter > 0.76mm?

I have two large sets, both go from 0.38 to 1.00mm on the center runner. My colleague has a large set that seems a little older, but still new style frame with replaceable beds on the runners that goes from 0.35 to 1.20mm.

 

I think you could order these with a choice of sizes; I've seen a number that go to 0.07 as the smallest, others that go down to 0.04mm. Some go in steps of 0.005mm on the smaller sizes, others in full 0.01mm steps. The set I use daily has 5 runners, with the 0.005 steps on the small sizes. The other large set (with center runner) has 4 runners, with the 0.01 steps. That one also has the height adjustable "headstock" (which I've never used other than to get it aligned).

 

One of my small sets goes down to 0.07mm for the smallest size- but has doubles of 0.11 and 0.12mm- so yet another variation! I guess it was ordered specifically knowing they would do a lot of those sizes. I've owned a bunch of these (20?), but I'm not a collector, so I just "upgraded" as better ones came along and sold off or gave away the others.

 

Something to really check on these is the concentricity of the headstock runner. The tiny (1.95 total length) staff I did recently was being a pain with pivots breaking in the Jacot. They weren't ultra small either, 0.07mm, and it's rare for me to break a pivot in the tool aside from just slipping with the burnisher or something. If the headstock runner isn't perfectly aligned with the bed, on very short parts the error is magnified; though it had been checked in the past I re-checked the headstock runner and it had a whopping 0.10+mm of runout! Got it true, next attempt worked great no problem. No idea how it got knocked out of true, but I work in a shared workshop and everyone is allowed to use my gear, so who knows.

Edited March 25 by nickelsilver