Looking For 90-1 Dividing Head Chart

I wrote a couple programs for machining, they are on my website. One is called "Index Table Calc" there is also a "Rotary Table Hole Index"

Both are free to use. (as well as a couple other programs there)

With "Index Table Calc" You enter the available holes (one per line) in all your plates you have available and what the gear ration of your index table is and then enter the number of holes/division you want and it will tell you all the combinations that will work and how many times you rotate the handle
example for a 40-1 ratio with a 18 and 27 hole plate wanting 18 divisions it would return these results

Plate: 27
Turns: 2 6/27

Plate: 18
Turns: 2 4/18

http://www.ltcomputers.com/software.cfm

Hope this helps.
 
hman said:
Just for fun, here's a pretty complete table for my own 90:1 rotab, which uses the same dividing plates you have.
Note 1 - All my holes are on two disks, which I've called A and B. Your diskss may differ, but all your hole sets are there
Note 2 - The 51 and 57 hole patterns aren't of any use that I can come up with
Note 3 - You CAN make a 127 tooth gear with minimal error (0.065 degree) by following the "recipe" on the third page. Just gotta pay attention, and do "something different" every 16th tooth.
Click to expand...
seasicksteve said:
I have a copy of the 90:1 table for a bridgeport rotary table. I would be happy to send you a copy if you would like it, send me a PM with your address and Ill get it in the mail
Click to expand...

Steve,

I appreciate your generous offer but several others have added some PDF files to this thread that will work for me.
This site is great in that there is help on most any machining subject if you ask.
Thanks for posting!

Burt
 
Hi Guys,

Two things:

1) I found another typo in the list hman provided.
For 290 divisions it says 0 full turns and 18 holes on the 56 hole circle.
It should be 0 full turns and 18 holes on the 58 hole circle!

2) I added more divisions to my list; version 3 is attached.

-brino
 

Attachments

  • dividing_90_to_1_simple_v3.pdf
    27.2 KB · Views: 66
brino said:
Hi Guys,

Thanks to hman, I had something to check mine against......and I found an error in the one hman posted!!!!
<snip>
In hman's version it looks like they dropped the "2"; must be a typo.
-brino
Click to expand...

OOPS!!! Thanks for catching that one, Brino! It was indeed a typo. The original spreadsheet had it correct at 28, and I copied it incorrectly when I made the printable version.
With great embarrassment, here's the corrected version:
PhII DivTable Print1.pdf
 

Attachments

  • PhII DivTable Print1.pdf
    36.3 KB · Views: 58
OK, brino, now ya really got me going!

I've gone over both of our tables with a very fine tooth comb, and checked out every discrepancy.
(1) As you'd pointed out, I'd made errors on the 19 and 290 entries. Lo and behold, I'd also made a transcription error on the 190 entry. I guess the number 9 and I just weren't getting along too well ;~) Anyway, I've made and double checked all three corrections.
(2) You chose to specify the 34 hole plate for all cases where there are zero holes to add to full turns. I've chosen to specify "Any" plate. No big deal.
(3) For several divisions (7,13,16,17,27,35,48,54,66,72,80,120,144 and 180) our solutions, though both valid, differ. The difference is due to my deciding to specify the lowest hole count row for all my solutions. Again, no big deal.
(4) You show solutions for 136, 200 and 250 divisions that make use of plates I don't have. I have no solutions for these .
(5) Initially, I chose to only show solutions to every 5th pattern above 180. You show several. Just for fun, I included as many as I could find. In addition, I'm including a second table ("~Print2"), which is organized a bit differently than "~Print" and shows all the solutions for zero turns and 20 or fewer holes for all of my dividing plates. It goes up to 5760 divisions (as if anybody would ever need that fine a sieve)!

For everybody else, the bottom line is that both our tables should match up pretty well now. As my friend, Rick Sparber has said many times, all of us are smarter than any one of us!

If you want to use my results, please be sure to download the latest version(s) - "~Print" and "~Print2", as the previous version, "~Print1" has some errors.

PS to Cathead - I've double checked that my plates/hole patterns are the same as yours. Please let me know if I've goofed here.
 

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  • PhII DivTable Print.pdf
    38.1 KB · Views: 62
  • PhII DivTable Print2.pdf
    55.2 KB · Views: 65
I don't have enough posts to post links, but I've written an online calculator to calculate index plate generations (no download necessary).

If you go to bilar.co.uk and click on the engineering page link, you'll find another link called "division calculator".

Note that the output is "full rotations and extra holes", not "full rotations and holes between arms". This is because I wanted to use it with my cobbled together rotary table setup, which doesn't have arms.
 
Also, not sure how useful the above is to the OP now that he has a full set already, but someone else might find it interesting.

There's a github project with the source code (ie GitHub.com forward slash hbilar)
 
cathead said:
Does anyone know where one could find dividing head charts for a 90-1 rotary table? I have been looking on the
web with little success. I found my original operating book and it has no charts......
Click to expand...
I have written a program for the workshop (ShopCalc) and one of the things it will calculate is dividing head solution in several ratios of the worm drive including 90-1. There is an option to print a chart of hole plates, turns and holes for use in your shop.

Download for free or just see what ShopCalc can do.
http://www.dogcreek.ca/shopcalc/WorkshopCalulator.html
 
I use the Shp Calc program a lot. It is an excellent program. everyone should download it
 
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