Small Collets, Snrink Fit, Etc

I'm looking for a tiny threaded collet. ER collets are fine, but you can't really use them to make long reach tooling. Shrink fit is an option I guess. My goal is to make my own mold making tool holders to use modest price proper geometry end mills in long reach applications to have greater rigidity than a long reach mill and better cost effectiveness than a tapered end mill to achieve that. I know. I know. It already exists in some types of tool holders,but I want to make something a little more universal to fit into tool holders I already have. Harvey tools makes an end mill extension, but their current version isn't tapered or designed quite right for what I want. I could buy them and maybe modify them, but they aren't cheap. Mostly I am just thinking out loud right now. I recently picked up a surface grinder, and I am making plans for making a cylinder grinding attachment for it. It would be ideal for finishing hardened tool holders like this.

Might actually use some of my grinder vises like they were intended. LOL.

Reply to
Bob La Londe
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I'm looking for a tiny threaded collet. ER collets are fine, but you can't really use them to make long reach tooling. Shrink fit is an option I guess. My goal is to make my own mold making tool holders to use modest price proper geometry end mills in long reach applications to have greater rigidity than a long reach mill and better cost effectiveness than a tapered end mill to achieve that. I know. I know. It already exists in some types of tool holders,but I want to make something a little more universal to fit into tool holders I already have. Harvey tools makes an end mill extension, but their current version isn't tapered or designed quite right for what I want. I could buy them and maybe modify them, but they aren't cheap. Mostly I am just thinking out loud right now. I recently picked up a surface grinder, and I am making plans for making a cylinder grinding attachment for it. It would be ideal for finishing hardened tool holders like this.

Might actually use some of my grinder vises like they were intended. LOL. =======================================================

If you make extensions with integral collets by slitting them crosswise, the closer nut could have tapered pipe threads.

Reply to
Jim Wilkins

On 4/14/2020 5:49 PM, Jim Wilkins wrote: > "Bob La Londe" wrote in message news:r74v76$p01$ snipped-for-privacy@gioia.aioe.org... >

The idea is to have maximal support for smaller mills when deep machining. I would prefer in internal draw bar to an external closer nut I think. I did a search for "straight shank end mill extension" just a few minutes ago and found quite a number. Most use set screws. One that came up in image search showed a collet, but when I went to their website it they just showed a set screw type.

These would only be useful for pockets with a lot of draft angle or a feature of the floor of a pocket, but I just finished an open casting mold with pretty deep pockets and tool deflection affected finish quality with a lot of tool stick out. I had to slow the job down a lot.

On the other screen I am working on a rough model. With a 3/8 Ball mill for the angle I needed with clearance I could have just one inch of stick out and be upto to 5/8 shank. Of course I could just continue the taper as far back as I want to fit into the largest tool holders I have.

Once I have it dialed in to make them I could make ones with a little more slender profile for tiny mills and less available angle clearance too. Of course its all a trade off.

I recently engraved the bottom of some deep pockets with a company logo using a 1/16 ball nose end mill. A tool extension sized for this application would have allowed me to feed much faster than I had to run with the ER collet tool holder and the long reach end mill I had to use to do the job.

They will not be a magic cure all, but they would speed up many jobs and improve surface finish doing it.

Reply to
Bob La Londe

On 4/14/2020 5:49 PM, Jim Wilkins wrote: .....

The idea is to have maximal support for smaller mills when deep machining. I would prefer in internal draw bar to an external closer nut I think. ==========================

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single 1/4" or 5/16" collet costs $18.

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#2 collets go up to 1/2", and you can buy a reamer for the female socket.

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drilled one for a drawbar to make a sliding and rotating end mill grinding fixture.

Reply to
Jim Wilkins

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