Kram
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- Messages
- 6,177
- Location
- Sussex
I want to make a bigger collet chuck, not decided on the size but probably with a maximium of 60,75, or 100mm. There doesnt seem any standard I can copy, so I would like some advice on the design.
I'd like to hold short lengths, so compared to the ER type, the collet length will be much shorter, say 20mm. Its still much more engagement than Id get with 4 jaw chuck. That will mean increasing the taper angle from 8 degrees to 16-20 degrees. Looking at ER, the nose is a much shorter and steeper angle, but the collet still closes uniformly.
I have some large steel bar I could use, but I imagine mild wont be any good for the collets. Would an off the shelf en8, en16t or en19t have enough spring without heat treatment?
I'd like to hold short lengths, so compared to the ER type, the collet length will be much shorter, say 20mm. Its still much more engagement than Id get with 4 jaw chuck. That will mean increasing the taper angle from 8 degrees to 16-20 degrees. Looking at ER, the nose is a much shorter and steeper angle, but the collet still closes uniformly.
I have some large steel bar I could use, but I imagine mild wont be any good for the collets. Would an off the shelf en8, en16t or en19t have enough spring without heat treatment?