What are these off

[Mike LightfootParticipant @mikelightfoot72419]

• Good evening just found these i believe they are change wheels but dont match any machine dad had so does anyone have any idea
• cheers

[Mike LightfootParticipant @mikelightfoot72419]

Found while clearing dads workshop

[EmgeeParticipant @emgee]

Hi Mike

Could be Colchester Bantam, if you count the teeth and measure OD and post the figures, the DP can be calculated which will help identify which machine they will be suitable for. Dimensions of the centre and splines will also be helpful.

Emgee

[Mike LightfootParticipant @mikelightfoot72419]

Emgee, thanks will do that first thing tomorrow

[BazyleParticipant @bazyle]

Some Colchester info here though it is slightly confusing.

[I.M. OUTAHEREParticipant @i-m-outahere]

If they don’t fit any of the machines your Dad had is it possible he may have been using them for indexing purposes ?

[Clive FosterParticipant @clivefoster55965]

Looking at the labels on the dividers the gears mostly appear to be in steps of 4 or 8 teeth. If so they are a set of differential dividing gears for a dividing head as 4 (or multiples of 4) tooth steps are usual for the normal dividing head with 40 to 1 worm reduction.

The splines look similar to those used by Elliot / Victoria, Cincinatti, Edgewick, Hoffmann et al.

The Elliot set is 24, 24, 28, 32, 40, 48, 56, 64, 72, 86, 100

If the gears are for a spiral milling set up there will be a variety of other gears to generate the various leads.

For example Cincinatti supply 17, 18, 19, 20, 21, 22, 24, 27, 30, 33, 36, 39, 42, 45, 48, 51, 55, 60. But the Cincinatti heads have rather more holes in the dividing plates than normal, especially if you have the wide range set, so differential indexing is rarely needed. That set is more for generating leads.

Clive

Edited By Clive Foster on 09/08/2019 10:44:30

[John Paton 1Participant @johnpaton1]

I love the storage rack

With one like that you could have your lathe in the lounge!

Edited By John Paton 1 on 09/08/2019 10:27:40

[Tony Pratt 1Participant @tonypratt1]

Yes off a dividing head, used similar back in the 70's

Tony

[old martParticipant @oldmart]

The six splined shaft fitting should be a clue. A measure of the bore as well as the diameters/teeth count and gear thickness should do it.

[BazyleParticipant @bazyle]

Although the 86 is normally the indicator for a dividing head set the 48 is not normal for that so might be a set of pick off gears for the feed on a large mill. If they are 10DP and the splines are 1&1/8 at the max part then they are Kearney & Trecker and I would be interested if you want to sell them.

[Clive FosterParticipant @clivefoster55965]

Bazyle

I'm a little surprised to hear that 48 is an unusual tooth count for differential dividing gear sets as all the listings I have include it as do to the two sets of unknown origin I (should) have about the place. (I've not seen one set for 15 years but pretty sure I haven't sold it.).

Anyway I took another look at the numbers on the shelves of that very nice case and the contents are correct for Elliot / Victoria as there are two 24 tooth gears. So far as I'm aware Elliot and the associated companies were the only folk to use that particular duplicate.

Clive

[Mike LightfootParticipant @mikelightfoot72419]

First of all thank you all for your time, some more info, the larger inside bore is 1.04” the smaller is .85” .5 width

two pictures here of 64 and 24 tooth wheels and dia the first 64/4.123 is 15.5 second 24/1.615 is 14.8 since to calculate dp i believe they should be measured at the pcd and not the od would that be right for 15 DP?

[Mike LightfootParticipant @mikelightfoot72419]

My only other observations are even with a cabinet like that swmbo would not have the lathe in the lounge they were only allowed in for the picture, knowing Dad he just bought them because they looked nice he had two dividing heads so wouldnt really need them for indexing

thanks for looking

Mike

[not done it yetParticipant @notdoneityet]

For DP, add 2 to tooth count and divide by OD. They are 16 DP

[Mike LightfootParticipant @mikelightfoot72419]

Not done it yet, thanks i didnt know that one

[EmgeeParticipant @emgee]

My Bantam gears are 16DP.

Many years ago I had a 5" Victoria dividing head but the drive on that had a single keyway, not multi spline as these gears.

Emgee

[BazyleParticipant @bazyle]

Posted by Bazyle on 09/08/2019 17:30:26:

Although the 86 is normally the indicator for a dividing head set the 48 is not normal

Sorry, my mistake. It is the 44 that is 'off-key' and not listed in Clive's earlier list of the Elliott gears. The B&S tables also show you don't need 44 to meet all the necessary ratios. As an aside I've always admired the way some past engineer managed to work out the best set of gears for this application without any of the modern computing support.

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