# 12 sided R8 collet block



## Milt Able (Oct 28, 2019)

It will probably be awhile until I buy a proper 5C collet set and collet blocks, so I decided to make a collet block out of mild steel for my R8 collets. Instead of making square and hexagonal blocks, I reasoned that 12 sides would permit me the ability to machine six, four, and three sided objects. I didn't have the right size of bolt for the small draw bar, and I didn't have a collet block yet to quickly make a traditional hexagonal bolt, so I cut threads on one end, threaded a nut on and pinned it. It made a nice draw bar, but I will probably use my new collet block to make a bolt for my new collet block. (Kind of like how we all use our ball turners to turn a ball for the handle on our ball turners.)


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## Latinrascalrg1 (Oct 29, 2019)

Does the collet sit flush with the block?   Having 12 sides do you plan on engraving/stamping at least 1 of the sides to help with parts set-ups?


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## Canus (Oct 29, 2019)

Think I've found my next project.  Great idea!!


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## Milt Able (Oct 29, 2019)

Latinrascalrg1 said:


> Does the collet sit flush with the block?   Having 12 sides do you plan on engraving/stamping at least 1 of the sides to help with parts set-ups?


The collet stands proud a little because I wanted to be certain of solid work engagement. I hadn't thought about indicating a start side. I might do that, especially if I make a 12 sided object with multiple passes.


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## C-Bag (Oct 29, 2019)

Brilliant. A rough sketch with dimensions would be much appreciated if you feel like it. I've been putting off making a R8 collet block but this would certainly fill all my needs in one project. Thanks for posting.


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## Cadillac (Oct 29, 2019)




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## Milt Able (Oct 29, 2019)

C-Bag said:


> Brilliant. A rough sketch with dimensions would be much appreciated if you feel like it. I've been putting off making a R8 collet block but this would certainly fill all my needs in one project. Thanks for posting.


I didn't draw anything out. I just made sure the bored out dimension was a little more than the 4" I measured from the beginning of the taper to the end of the collet. I used 2" round stock. The length was chosen to allow the bolt head to recess to permit use in the vertical postion and give a solid shoulder to tighten against. I set the compound to the correct taper angle by inserting a quarter inch drill rod into a quarter inch R8 collet and suspending the collet between the drill rod in the four jaw chuck and a live center in the tailstock. Using a test indicator in the tool post, I dialed in the angle quite accurately.


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## C-Bag (Oct 29, 2019)

Milt Able said:


> I didn't draw anything out. I just made sure the bored out dimension was a little more than the 4" I measured from the beginning of the taper to the end of the collet. I used 2" round stock. The length was chosen to allow the bolt head to recess to permit use in the vertical postion and give a solid shoulder to tighten against. I set the compound to the correct taper angle by inserting a quarter inch drill rod into a quarter inch R8 collet and suspending the collet between the drill rod in the four jaw chuck and a live center in the tailstock. Using a test indicator in the tool post, I dialed in the angle quite accurately.


I don't usually draw anything out either. The one thing I was looking for was the stock OD you started with and you included that, thanks.


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