MadModder
The Shop => Tools => Topic started by: Chuck in E. TN on August 11, 2013, 02:33:50 PM
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I have seen many extol the virtues of collets and collet blocks for various operations. I only have R8 collets. Quite a while ago I asked on several forums about the possibility of making R8 collet blocks for Hex and Square features. I mostly got giggles, ridicule, and in general laughed at.
Then, a fella called Davyboy just went ahead and made some. Some folks even applauded the idea. Then the subject of dividing/indexing heads cropped up. This reawakened in me the interest in R8 collet blocks, and spindles.
I decided to go ahead and make an R8 collet block for several reasons. I wanted to, I had a use for one, and making a collet block would be a good practice for making a spindle, whatever the taper.
So, over the last couple of days, I set about measuring, studying, researching, and finally making a R8 collet block.
My collet block started out as a piece of 1 ½” brass Hex. Why brass? I was the only material I had that was big enough to make a R8 collet with, that stood a chance of being useful.
First I cut a 4 ½” length of the brass hex, and faced the ends. As my 3” chuck was near its limit chucking the 1 ½” hex, and only with the outside jaws, I turned 1 ¼” of one end round, allowing me to use my 4” 4 jaw self centering chuck to hold it. I drilled it through 7/16”, bored to a close fit on the R8 collets, and then bored the 16° 51’ closing angle. I added a pin to fit the key slot on the collets. I even had to make the closing bolt as I didn’t have a 7/16 x 20 bolt in my collection, and I wasn’t going to town for one bolt. I turned down and single point threaded a bigger bolt I did have.
As I was drilling the hole for the key pin, I realized I would not be able to mill square from round stock. I milled ½” wide flats on 2 opposite sides of the hex, effectively giving me the ability to create squares on round stock.
All in all, I made a tool that may not last as long as I do, and may not get a whole lot of use. But, I did it. I gained invaluable experience to guide me in making an R8 spindle for the Dividing/Indexing head when I make it. It also showed me the limitations of some of my tools, and how to work around them.
Pictures here: http://s571.photobucket.com/user/chucketn/library/R8%20Collet%20Block (http://s571.photobucket.com/user/chucketn/library/R8%20Collet%20Block)
Chuck
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Hi Chuck,
This looks to be a great idea. I see now that you can get ER collet blocks which I have been thinking about but as I only have R8 collets at the moment I may have a go at this myself as I have a big chunk of hex brass too. I know I will be limited to bar that I have a collet for (unlike ER collets which have a range) but for most of what I do I have standardised on my stock sizes.
Matt
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I have been thinking about making a collet block for van norman 5v or 4ns rivett as they are the collets i have on hand have a van norman#6 mill and it came with both sets of collets
How well does the diy collet block work?
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I have been thinking about making a collet block for van norman 5v or 4ns rivett as they are the collets i have on hand have a van norman#6 mill and it came with both sets of collets
How well does the diy collet block work?
I'll let you know how well it works as soon as I get some 1/2" bar for my next project.
Chuck
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Similar project here.
http://madmodder.net/index.php/topic,4474.msg49168.html#msg49168
Works fine for what it was designed to do.
Joe
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Great job chuck!!!!!!
Personally i never realized they never made collet blocks for R8........ got me thinking about making a set myself...... i love the way R8 collets draw tight..
Very useful...
Anthony.
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I save all my various pieces of round stock. When they get real short, the R8 collet will be handy for using them!
Chuck