Dividing Head Question

[papermaker]

I had a dividing head given to me today. It is 40:1 ratio and it has 6 plates and a tailstock with it. Does anyone know where you can find a table/chart that gives the basic information on use. Or can anyone explain the formulas to use for a 40:1 head.

 

[JPigg55]

I have literature for a Carroll dividing head in pdf format, not sure what yours is, but it may be helpful. It explains the formulas and has a chart it the back as well.
PM me your E-mail address and I can send you a copy. It's a 1 Meg file, I might be able to reduce the file size if you have a slow internet connection.

 

[Rbeckett]

Otherwise contact Chris at LMS and ask him where the dividing head tutorial is and he will hook you up. Most rotary tables larger than 4 inch are usually 90:1, but 40 to 1 is still doable if you are 1/2 decent at math. I don't have the exact formula, but it is pretty easy to follow once you get it. Good luck and dont forget to share it with us when you find it. That would be a nice thing to have as a general reference anyway.


Bob

 

[Terrywerm]

Your best bet would be a book on indexing. I have a very good one titled "Milling Machine Indexing" by Felker and Paine. It is a reprint from the middle of the 1900's that I purchased from Lindsay before he retired. There are new copies of it available on eBay for under $11 shipped, and I believe that 'Your Old Time Bookstore' (he bought out Lindsay's remaining stock) carries it also (www.youroldtimebookstore.com)

I have a copy of the book, and it is worth every penny that I paid for it. You won't go wrong getting a copy of it. Indexing can be a bit involved, so explaining it in detail here would be a tall order. It could be done, but a ready reference would be the best thing to have in my opinion.

Oh, and the usual disclaimer applies regarding the aforementioned bookstore. I have no connection to them, have not even bought anything from them yet, but am simply aware of their presence and am aware of the type of books they carry. I did purchase items from Lindsay, but since he has retired since my last purchase, I can't even put in a plug for him!

 

[papermaker]

Thank for the information everyone! Trying to read the Machinery's Handbook has some or I should say a lot but these tried old say have trouble reading it. I'm posting pictures of the dividing head The guy I got it from thinks it may be homebuilt but it seem a little elaborate for homebuilt but there are no marking on it anfd the indexing plates do look homemade.

 

[Hawkeye]

Going back a bunch of years, 40:1 was the common ratio. Shop Theory, the textbook from the Henry Ford Trade School (1934 - 1944), doesn't mention any other ratios that I've seen.

Here's a few pages from that book relating to the topic at hand.
View attachment Dividing Head Part 1.pdf

For a simple formula, take a look at this page from an old highschool text book.

 

[rgray]

Here's a chart. Looks daunting but not that bad. remember that the count on the number of holes to move in an indexing plate does not include the hole the pin is in.
For example if you want 15 divisions (Hole pattern, gear teeth, etc) chart shows using a 21 hole plate and turning 2 full turns plus 14 holes.
My dividing head literature shows using a 33 hole plate turning 2 turns plus 22 holes.
So if you don't have the plate with the number of holes listed you can search for a chart that has a different stratagy for the solution.