Compound indexing for 127

Smithdoor

Smithdoor

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Has any one else use compound indexing for making gear like the 127 tooth gear or 157 tooth gear using a BS-0.
I just working some drawing and have not seen any one even taking about compound indexing, hard to find any data today.

Dave
 
Hi Dave
No, but I needed to make a 44 tooth change gear for my mill and the the rotary table and plates I have could not handle that number. I made an arbor that would hold the gear blank and a 44 tooth gear from my South Bend change gear set. I set that up between centers on the rotary table and mounted a spring latch to the mill table to index the arbor. The project worked great. Maybe you could borrow the gears with those numbers and finish your job also. Good luck.
 
Are you referring to compound indexing or differential indexing? There is a big difference.

Compound indexing is an old method using two separate simple indexing movements to create an index movement of a specified amount. It is seldom used anymore because high number plates are easily found or made, allowing the necessary divisions to be created.

Differential indexing requires an indexing head that also has the change gears with it, known as a Universal Indexing Head. It cannot be done with a rotary table or with a semi-universal indexing head. The gears are set up so that the number plate is also rotated a certain amount as the indexing is done. It is complicated, and is beyond what I can do with my rotary table, thus I have not learned how to do it.
 
Compound indexing Not differential indexing NO GEAR TRAIN

Dave

terrywerm said:
Are you referring to compound indexing or differential indexing? There is a big difference.

Compound indexing is an old method using two separate simple indexing movements to create an index movement of a specified amount. It is seldom used anymore because high number plates are easily found or made, allowing the necessary divisions to be created.

Differential indexing requires an indexing head that also has the change gears with it, known as a Universal Indexing Head. It cannot be done with a rotary table or with a semi-universal indexing head. The gears are set up so that the number plate is also rotated a certain amount as the indexing is done. It is complicated, and is beyond what I can do with my rotary table, thus I have not learned how to do it.
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It is easer than trying to set up gears. I had a dividing head back the 70's that was very old that did the dividing not hard to do just have not seen since, I had the chart in a Machinist Hand I used

Dave

terrywerm said:
Okay. Compound indexing it is!

It can be done, but it is a bit complex as well. I have never done it, but can see where it might be useful. Here is a link to where you can find the information you seek: http://babel.hathitrust.org/cgi/pt?id=mdp.39015002958927;view=1up;seq=79
Click to expand...
 
terrywerm said:
Okay. Compound indexing it is!

It can be done, but it is a bit complex as well. I have never done it, but can see where it might be useful. Here is a link to where you can find the information you seek: http://babel.hathitrust.org/cgi/pt?id=mdp.39015002958927;view=1up;seq=79
Click to expand...

That link made me go cross eyed when I tried to read it :dunno: :nuts: It's definitely a "bit complex"

I think I'd find a buddy with a cnc to make a new 127 hole plate. You could make a new plate with a rotary table, it would be tedious, but could be done.

Mike
 
FYI Most CNC indexers only have accuracy of ± 20 sec a dividing head is less than ±0.1 sec on a cheap one.

Dave

Reeltor said:
That link made me go cross eyed when I tried to read it :dunno: :nuts: It's definitely a "bit complex"

I think I'd find a buddy with a cnc to make a new 127 hole plate. You could make a new plate with a rotary table, it would be tedious, but could be done.

Mike
Click to expand...
 
Look up oxtool on YouTube spindexer he does a video series on making indexing plates and mods for a 127 hole plate on a spin indexer might be worth a look
 
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