DIVIDING PLATE ..DIY ..Help...!!

[Steamchick]

Hi Indian,
Please can you add a picture of the back cover of the Zeus book? - It may help for those of us without the copy you have.
Thanks,
Minh-Thanh, without CAD I find this of little use, as I can't make a picture (but can copy yours!), but you seem to have a method that works for you. (What is pamme? - or panme? you seem to use 2 spellings?).
Is this "by eye" - or is it by indexing on x-y coordinates? I wonder if it as accurate as indexing off gears? (Indexing by gears systems had been used for a century of more before Mr Babbage invented his calculating machine).
Of course, without the change wheels on the lathe an alternative to gear indexing is needed. - So I should like to understand your method. It looks - from my interpretation of the picture - as if you are indexing by using a stop on the workpiece and indexing 9.23mm at a defined radius? - I can't figure how to do this on a blank after machining only the first tooth gap?
K2

 

[indian]

sorry have tried photos and scanning but the condition is awful but to the rescue comes YouTube . just do a search for bolt hole calculation there are several and among the best IMHO is Joe Pie ,tom stikkelman or r. dean Odell

 

[minh-thanh]

Hi K2
I read your posts in this thread but they don't fit what I have : I don't have odd gears , but your comments will help someone so I'm silent .
my fault : PANME
This is my idea

 

[BaronJ]

Hi Indian,
Please can you add a picture of the back cover of the Zeus book? - It may help for those of us without the copy you have.
Thanks,
Minh-Thanh, without CAD I find this of little use, as I can't make a picture (but can copy yours!), but you seem to have a method that works for you. (What is pamme? - or panme? you seem to use 2 spellings?).
Is this "by eye" - or is it by indexing on x-y coordinates? I wonder if it as accurate as indexing off gears? (Indexing by gears systems had been used for a century of more before Mr Babbage invented his calculating machine).
Of course, without the change wheels on the lathe an alternative to gear indexing is needed. - So I should like to understand your method. It looks - from my interpretation of the picture - as if you are indexing by using a stop on the workpiece and indexing 9.23mm at a defined radius? - I can't figure how to do this on a blank after machining only the first tooth gap?
K2

Hi Ken,

Free Download !

Check out "https://www.presto-tools.co.uk/Downloads" Counsellor

 

[fvd]

Back cover of the zeus book

From the book Precision hole location, by J. Robert Moore (1947):
39 holes, page 320 and 321.

 

[ajoeiam]

Hi K2
I read your posts in this thread but they don't fit what I have : I don't have odd gears , but your comments will help someone so I'm silent .
my fault : PANME
This is my idea
View attachment 159971

Almost looks like someone is trying to create a vernier protractor.

https://ia904708.us.archive.org/11/...changability in toolmaking and production.pdf

If someone wants the complete reference that mr fvd referenced - - - here it is. (above)

Looks like in attached pics

 

[trlvn]

Stepping back a little, this is for a gear hobber, right? The 39 tooth plate will create a 39 tooth gear? So any angular deviation in the plate will be faithfully transferred to the gear? (As compared to a dividing head with a 40:1 worm gear. There, only 1/40th of any deviation in the plate ends up in the work piece.)

If correct, then accuracy in creating the plate is exceptionally important. Really, there are only 2 basic approaches:

1) Turn the work to the necessary angle and drill.

2) (Use trig to) determine the x y positions of each hole. Move the work and drill.

Even without a DRO, I think 2) will yield greater accuracy. Use a spreadsheet to determine the absolute position of each hole. Taking care of backlash and carefully counting turns, it should be possible to place each hole within a couple of thous (0.05mm) of the desired location. Tedious: for sure. Accurate: better than trying to interpolate factions of a degree over and over.

My $0.05 worth,

Craig
(Using a CAD-produced template for hole locations is, in effect, just another way of using trig. But with human error introduced in the centre-punching process.)