Another mystery object

Found this in a box of bits and pieces:

It has 60 teeth, about 65 mm diameter and is calibrated in degrees. It looks as if it is a brass die-casting.

Any ideas what it might belong to?

Russell.

Hello Russell,

I can't identify it but the gear works out to 24DP for the nearest whole number

Regards Brian

Perhaps its something to do with dividing?

Neil

With 60 teeth and something that resembles 360 divisions you could be right.Quite what the missing part or parts are is still a mystery to me. Thinking cap on.

Rick

Hej

Why not send it to mr Pete **LINK** and he will clure it out

Ulf

Yes,I thought that. The teeth are straight so it would not be too good with a worm but I guess it would be difficult to die-cast with the correct tooth form.

It must be from something that was made in big volume as die-casting tools are expensive. I can't figure out why the boss is like that although I guess that the part would have been drilled and tapped to take a clamping screw and the groove could accommodate that.

It will have to go into the box for things that will never be of use until they are thrown out

Russell.

Right, I will have a go.

The gear wheel probably sat on the shaft and did not rotate on it since there is no sign of a bush. The large slot on the boss has well rounded edges suggesting that something engaged (and disengaged) without too much thought (probably by hand). What every it was was probably also on the shaft and, obviously, did not rotate on the shaft. There is a dominant line at an angle of 315 degrees. Die-cast so plenty were made. Also, if made from brass, it would not have transmitted much torque.

Pure guess (from the 315 degrees) - part of the drive to a magneto on an IC engine?

JA

I have seen one of these, but cannot remember where or what, it' driving me mad, old age. Think the mag drive may be correct, . Bot it does look as if the hole is not on center line, is this just the photo angle? Is the hole tapered ?

coin operated Gas or electricity Meter Minute Timer?

Divisions are 5

It is pressure cast or sintered metal you can see the release pin depressions, so mass produced.

Regards
John

Edited By John McNamara on 04/04/2014 15:48:38

Like Gordon W, I have the impression I have seen one of these before, even if not exactly the same I am sure the slot in the boss looks familiar.

One thought thought I have is that the graduations look to be engraved after the part was cast as it would be a lot of hard work to create that profile in the die. Maybe someone modified an existing gear for some purpose we will never know.

Maybe the extended index line at 315 degrees was slip of the engravers hand? although it does just happen to be in line with the cast notch.

Ian P

I'm thinking war surplus, part for a gun sight, some sort of navigation instrument. Ian S C

45 degree as a a timing advance angle is a pretty compelling suggestion.

Neil

Hello Neil,

Yes, I agree but if that was it's sole purpose there are simpler ways of providing the information. My guess is that it had a wider use altogether than that [but what?] and with the gears at 6 degree intervals it would not be a precision piece.

Brian

With Graduations at 5° intervals, and Teeth at 6°

Might it be part of a "Vernier" setting-up-tool for Camshafts ?

MichaelG.

And another mystery object:-

Obviously a calliper, but one side is engraved in Millimeters/Centimeters the other in "inches", but not quite as each "inch" is 27.38 mm (1.078" ) and each "inch" is subdivided into twelfths. The overall measuring length is 13 Cm. Its rustic and has a lot of age to it (hardly precision). My other clue is that it was found in SW France. No prizes, but I will be interested in your thoughts.

Bob H

Edited By Speedy Builder5 on 05/09/2014 19:00:33

We blame the metric system on Napoleon, but apparently he hated it!

If they were 27.7mm they would be his post-revolutionary 'mesures uselles' equivalent of inches.

Units_of_measurement_in_France#Mesures_usuelles

"... the toise (fathom) was defined as being two metres with six pied (feet) making up one toise, twelve pouce (inches) making up one pied and twelve lignes making up one pouce."

If it's old enough to be pre-revolutionary, they may be the original pouce at 27.07mm.

Units_of_measurement_in_France_before_the_French_Revolution

Whatever it is, it's obviously of a good vintage.

Neil

Edited By Neil Wyatt on 05/09/2014 19:26:14

Thanks for that Neil - why is is nothing ever easy? Or simple?

My sources say that Neil is not quite there as 1 = 27.38 mm. Keep it going.

Pah! It's a typical French compromise made at roughly the half-way point between the long and short pouces!

Neil

P.S. I didn't know all this before, just had the memory that the French used to have a 'funny inch' of their own before they went metric.

Neil