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John Stevenson
07-07-2007, 08:41 AM
As some of you may know I make dividing plates up for special applications and other uses.

Yesterday I had a pair of plates in that required two more to make the set up.
All plates follow roughly two standards, the Brown and Sharp standard which cover all holes up to 40 and the regular ones after that.
The second standard is the Cincinnati which uses a series of high number plates to get more divisions.
These were more of the Cincinnati type with high numbers but what made them special was some of the holes were bushed.

http://homepage.ntlworld.com/stevenson.engineers/lsteve/files/dividing%20plate.jpg

At first I thought this was to repair worn holes but a closer look showed that every 10th hole was bushed to make the counting easier. The two plates had also been screwed together, presumably to stop them being lost and keep them thinner as double sided plates are usually thick so the holes don't run into one another.

This is the first time I have seen this done and I have had some plates come thru the shop.

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oldtiffie
07-07-2007, 11:14 AM
Deleted/edited-out

moldmonkey
07-07-2007, 01:43 PM
My K&T Model K 5:1 dividing head has similiar plates. I had noticed the bushed holes at the start but hadn't noticed the every 10th one feature. That's nice. I got it a couple months ago, cleaned it up, & haven't used it yet.

lazlo
07-07-2007, 02:12 PM
All plates follow roughly two standards, the Brown and Sharp standard which cover all holes up to 40 and the regular ones after that.
The second standard is the Cincinnati which uses a series of high number plates to get more divisions.

John, I thought there were more "standards" than the Brown & Sharpe and the Cincinnati?

I thought the Brown & Sharpe dividing head, like my Ellis, was supplied with three plates that direct index up to 49 holes:

#1: 15, 16,17,18,19, 20
#2: 21, 23, 27, 29, 31, 33
#3: 37, 39, 41, 43, 47, 49

The Brown & Sharpe was a differential head, so the B&S tables assume you're using change gears for most of the hole numbers above 49.

The Ellis, Carrol and L & W dividing heads (and probably several others) can't do differential indexing, so they had a second set of "High Division Index Plates" for direct indexing up to 99. In fact, I was going to ask you how much you wanted for a set of these 4 "High Number" plates, plus an extra ring of 127 :)

Ellis Plates:
#4: 25, 61, 71, 83, 91, 93
#5: 51, 53, 63, 73, 81, 96
#6: 22, 57, 67, 77, 87, 97
#7: 28, 59, 69, 79, 89, 99

The Cincinnati dividing head was also differential, and shipped with a single double-sided wheel with up to 66 divisors:

Side A: 24, 25, 28, 30, 34, 37, 38, 39, 41, 42, 43
Side B: 46, 47, 49, 51, 53, 54, 57, 58, 59, 62, 66

The Cincinnati also had an optional set of 3 double-sided "High Number Indexing Attachment" wheels that had direct indexing holes up to 200 (!)

So your plate looks like the double-sided "standard" of a Cincinatti, but the holes (up to 99) look like they were from a non-differential dividing head like an Ellis or L&W.

Forrest Addy
07-07-2007, 03:31 PM
Bushed? Well I never reallry looked that closely. I was under the impression that the holes were circumsscribed, not bushed.

New stuff every day - even after 45 years.

lazlo
07-07-2007, 05:17 PM
Bushed? Well I never really looked that closely. I was under the impression that the holes were circumscribed, not bushed.

I think John meant circumscribed Forrest. If you look at the picture he posted, it looks like every 10th hole is etched. Nice touch.

John Stevenson
07-07-2007, 07:05 PM
Bushed? Well I never reallry looked that closely. I was under the impression that the holes were circumsscribed, not bushed.

New stuff every day - even after 45 years.

Forrest,
Now you mention that I'm not sure, trouble is the plates have gone back but I can get them again to look on the back to see if it is a bush but circumscribed does make more sense.

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