Shop Floor Talk  

Go Back   Shop Floor Talk > Welding and Metalworking Forums > Machining

SFT Search:   
Reply
 
Thread Tools Display Modes
  #51  
Old 11-25-2021, 10:57 AM
digr's Avatar
digr digr is offline
The Real Deal
 
Join Date: Apr 2005
Location: Duluth MN
Posts: 9,110
Default

Index plate hole calculator
__________________
Drawing by Smartdraw
Reply With Quote
  #52  
Old 11-25-2021, 09:07 PM
Ironman's Avatar
Ironman Ironman is offline
Iron Modification Investigator
 
Join Date: Feb 2008
Location: Warburg, Alberta, Canada
Posts: 16,788
Default

Quote:
Originally Posted by digr View Post
Using that calculator and displaying the table, it says:
To produce 51 divisions (7.059 degrees between divisions) using a 1:60 ratio rack, use the following combination of plates:

Plate Full revolutions Remainder holes
17 hole 1 3

So it's do-able, I'll have to dig them out.
Later.....
I dug out the dividing head and stuff and attached it using the plate with the 17 hole row.
I also went and re-calculated the ratio of the table. 1 turn is 4 degrees, so 90:1 ratio.

So with the 90:1 ratio corrected it now says:
Plate Full revolutions Remainder holes
17 hole 1 13

I'm going to read up on that bit, 1 full rev I get, but the 13 remainder stuff is a puzzle.
__________________
Gerry
You got freedom of speech, if you don't say too much.
Aaron Neville.

When a liberal screams racism, you can bet they were also born with white skin.

The countries whom the gods would destroy they first make green. Rex Murphy
Reply With Quote
  #53  
Old 11-25-2021, 09:30 PM
digr's Avatar
digr digr is offline
The Real Deal
 
Join Date: Apr 2005
Location: Duluth MN
Posts: 9,110
Default

One rev. + 13 holes then repeat one rev. + 13 holes
__________________
Drawing by Smartdraw

Last edited by digr; 11-25-2021 at 09:41 PM.
Reply With Quote
  #54  
Old 11-25-2021, 10:02 PM
arizonian's Avatar
arizonian arizonian is offline
Elite Member
 
Join Date: Jul 2007
Location: Tucson, Arizona
Posts: 1,954
Default

Quote:
Originally Posted by digr View Post
One rev. + 13 holes then repeat one rev. + 13 holes
Easy peasy.

90 turns x 17 = 1530 total holes

1530 / 51 = 30 holes

30 holes - 17 holes per rev = 13 remaining holes

1 rev + 13 holes will space out your teeth equally.

The light will come on once you play with the DH in your hands.

I assume there are two adjustable arms to use as stops on the plate surface. Set one of the arms 13 holes forward and you are in business. Don't forget to advance the PAIR of arms once you advance the dividing head crank to the next position. Lather, rinse, repeat.
__________________
Bill in sunny Tucson

I believe in gun control.

Gun Control: The ability to consistently hit what you are aiming at.

Weldor by choice, engineer by necessity.

Last edited by arizonian; 11-25-2021 at 10:11 PM.
Reply With Quote
  #55  
Old 11-26-2021, 01:44 AM
LKeithR's Avatar
LKeithR LKeithR is offline
Hey...wait...is there a prize?
 
Join Date: Aug 2011
Location: Langley, B.C.
Posts: 5,653
Default

It's been years since I played with a dividing head so my memory of how one works is a little dim. Never owned one myself but a good friend did and several times back in the 80s when I needed to create discs with multiple holes I borrowed it to do the job. You're pretty smart mechanically (trying to score some points here ) so, as others have said, once you're hands on it should become clear pretty quick. I know that's how I figured it out.

Machinery's Handbook has a pretty good section on indexing so if you've got a copy it would be a good place to look. I was just browsing through my copy and I noticed that--according to MH--you cannot achieve 51 divisions with direct indexing, you need to use differential indexing to get there...
__________________
Keith

Measure twice and cut once...or...wait, was that the other way around?
Reply With Quote
  #56  
Old 11-26-2021, 08:33 AM
greywynd's Avatar
greywynd greywynd is offline
I can dig it
 
Join Date: Dec 2005
Location: Wainwright, Alberta
Posts: 6,384
Default

It also depends on the ratio of the rotary table/dividing head. I’ll see if I can figure out what I have this weekend. I don’t have a dividing head, may be able to borrow one. I do have a rotary table and a simple indexer.


Sent from my iPhone using Tapatalk
Reply With Quote
  #57  
Old 11-26-2021, 08:54 AM
Ironman's Avatar
Ironman Ironman is offline
Iron Modification Investigator
 
Join Date: Feb 2008
Location: Warburg, Alberta, Canada
Posts: 16,788
Default

Quote:
Originally Posted by greywynd View Post
It also depends on the ratio of the rotary table/dividing head. I’ll see if I can figure out what I have this weekend. I don’t have a dividing head, may be able to borrow one. I do have a rotary table and a simple indexer.


Sent from my iPhone using Tapatalk
I have the dividing plate and the scissors installed, I still had all the parts and screws for it. Even the baby tailstock was still there. I found a pdf called 'How to Use a Dividing Plate" from Little Machine Shop.com. It made sense and so I'm ready to make chips when the cutter arrives.
__________________
Gerry
You got freedom of speech, if you don't say too much.
Aaron Neville.

When a liberal screams racism, you can bet they were also born with white skin.

The countries whom the gods would destroy they first make green. Rex Murphy
Reply With Quote
  #58  
Old 11-26-2021, 10:10 AM
Ironman's Avatar
Ironman Ironman is offline
Iron Modification Investigator
 
Join Date: Feb 2008
Location: Warburg, Alberta, Canada
Posts: 16,788
Default

Quote:
Originally Posted by LKeithR View Post
once you're hands on it should become clear pretty quick. I know that's how I figured it out.
you cannot achieve 51 divisions with direct indexing, you need to use differential indexing to get there...
Once it was installed it started to make more sense, you are right.
Is differential indexing a name for the remainder number?
__________________
Gerry
You got freedom of speech, if you don't say too much.
Aaron Neville.

When a liberal screams racism, you can bet they were also born with white skin.

The countries whom the gods would destroy they first make green. Rex Murphy
Reply With Quote
  #59  
Old 11-26-2021, 01:46 PM
GWIZ's Avatar
GWIZ GWIZ is offline
SFT Historian
 
Join Date: Feb 2006
Location: USA
Posts: 7,452
Default

see if this helps. pdf book
https://www.shopfloortalk.com/forums...9&postcount=24
__________________
*
*
The factory of the future will have only two employees, a man and a dog. The man will be there to feed the dog. The dog will be there to keep the man from touching the equipment. ~Warren G. Bennis
Reply With Quote
  #60  
Old 11-26-2021, 02:05 PM
LKeithR's Avatar
LKeithR LKeithR is offline
Hey...wait...is there a prize?
 
Join Date: Aug 2011
Location: Langley, B.C.
Posts: 5,653
Default

Quote:
Originally Posted by Ironman View Post
Once it was installed it started to make more sense, you are right.
Is differential indexing a name for the remainder number?
I never used differential indexing so I really don't understand it--I barely understood simple indexing and that was a long time ago.

According to Machinery's Handbook: "...change gears are used to transmit motion from main spindle of dividing head to index plate which turns (either in the same direction as the index crank, or in the opposite direction) whatever amount is required to obtain the correct indexing movement."

It's interesting to note that all divisions 50 and lower can be achieved by simple indexing. For divisions 51 and up, some can be achieved with simple indexing while others require differential indexing. The lowest number of divisions requiring differential indexing is 51. Aren't you lucky.

As I mentioned, Machinery's Handbook has pretty detailed info on how it all works...
__________________
Keith

Measure twice and cut once...or...wait, was that the other way around?
Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Web Search:

All times are GMT -5. The time now is 02:49 AM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2023, vBulletin Solutions Inc.