Prime number division without gearing?

I do have a Cincinnati high number dividing plate I scored off of eBay years back that has a row of 127 holes. Haven't mounted it to my rotary table yet.

It would be nice to get someone here to offer to make a 127 hole plates for their dividing head using their CNC mill. Any offers?
 
4gsr said:
I do have a Cincinnati high number dividing plate I scored off of eBay years back that has a row of 127 holes. Haven't mounted it to my rotary table yet.

It would be nice to get someone here to offer to make a 127 hole plates for their dividing head using their CNC mill. Any offers?
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That is a good idea, Ken. Keith Rucker had a set of plates made on a CNC machine for his K&T horizontal mill. A friend of Keith who is a manager in a machine shop did the work for him. I am not much into CNC in home shops (old fart), but for making stuff like dividing plates, it is the only way to go! You could spend most of a lifetime doing it manually, even with using a DRO for the hole locations. Without any electronic assistance, the job is likely to end in mistakes and failure.
 
Karl_T said:
Tell ya what. If somebody will give all the holes in an X#.### Y#.### format, one hole per line, with the center of the plate at X0.000 Y0.000 I will run it.

karl
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I guess I could take the plate I have and overlay it as a template on top of a new plate and drill those holes by hand. Ooh! 127 holes to drill by hand! I'm going to think on that!
On CNC mill, there's got to be a subroutine that could be plugged into the programming to locate 127 holes on a circle, without hand cranking coordinates and programming.
 
4gsr said:
I guess I could take the plate I have and overlay it as a template on top of a new plate and drill those holes by hand. Ooh! 127 holes to drill by hand! I'm going to think on that!
On CNC mill, there's got to be a subroutine that could be plugged into the programming to locate 127 holes on a circle, without hand cranking coordinates and programming.
Click to expand...
Aren't the Cincinnati plates drilled on both sides? Could complicate that approach.
I made a 127 tooth by differential indexing with my B&S dividing head, of a pitch that fits my automatic gear cutter, then cut a gear of a pitch to fit my 19" Regal Leblond that requires a gear of a smaller numbered pitch; the dividing head would not accommodate a gear that large of diameter without raising blocks, which I do not have, besides which, the larger the blank the more tendency to chatter; the gear cutter has a back rest to address the tendency.
 
4gsr said:
On CNC mill, there's got to be a subroutine that could be plugged into the programming to locate 127 holes on a circle, without hand cranking coordinates and programming.
Click to expand...

Nope, CNCs are not that smart. you have to tell it exactly what to do.
 
A few decades back, I wrote some g-code to scribe 360 degree marks on a disk. I believe that I did it with the conditional programming. It cut four 9 mm lines for degree positions, 12mm lines for five degree positions, and a 15mm line at every degree position.

It was actually my first attempt at writing g-code. I used polar coordinates and left it to the machinist finish filling out the code. We had a CNC machine but the machinist had never written any code. He only used conversational programming or some simple routines that came with the controller. I don't recall what the machine was or how this would relate to other machines.
Here is the code:
Degree Marking G- Code.JPG

Other than that, it would be a simple matter to create the model in SolidWorks or Fusion and let the CAM program write the code.
 
Karl_T said:
Nope, CNCs are not that smart. you have to tell it exactly what to do.
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I'll check with my brother. I bet he has something in his bag of tricks that would work without having to calculate and type out every coordinate point. Of course, it may require buying a half million dollar machine to do it on too.
 
A dividing plate is just a series of bolt circles, basically, just multiple circles. That is a very common task for both manual and CNC equipment. I am certainly not a CNC programmer, but cannot believe it is that difficult to drill multiple bolt circles on a flat plate. I think doing it manually would be the challenge (drudgery caused mistakes), but suppose lots of them were done that way, at least the templates for the production runs.
 
Yes, I know it could be a new and challenging frontier for some. It kinda was for me. But, I now have stepper motors on my dividing head and Levin lathes. I can now punch in any divisions I want. And no more turning that handle. And easy to run, hard to make a mistake, I just push the button. I do have a very minor error on some divisions, but it’s very small…Dave.
 
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