End Mill Extension - 1/8"

[BCRider]

This may sound crazy, but I have coworkers who use the camera function on their cell phones like that, to see in tiny places. One even has a magnetic holder for his phone: stick it onto the chassis somewhere and aim the phone at the area of interest. He works by looking at the phone screen at arm's length.

For in tight spots that could be a good idea. But maybe not the whole phone? Something more like this small ended camera on a USB cable?


I've had a number of times where small end mills used with my spindexer forced me to extend the piece out further than I wanted. To get around this to some extent I picked up a 3/8 size holder similar to THIS ONE . Paul, for your needs just to clear the nose of the spindle and let you see what is happening one of those might be just enough.

But it's still not all that great for small parts in the spindexer. The nose diameter still requires more stickout of the smaller items than I'd like. And I still can't reach in quite far enough if I were needing to put a slot through and out the bottom side of a small part. But the simple plain extension talked about earlier would be pretty much what I need to use with the smaller and shorter end mills.

I drew this up over my morning coffee and will make it a bit later today. It'll be done from 1" stock or some 3/4 hot rolled if it is big enough to finish to 0.750 after the scale is gone. It'll all be done in one holding so the OD and ID run true.

[frankie]

When I was employed we made end mill holders out of drill rod using set screws to hold the end mill in. I always ran a long taper on the business end so I could see what was happening in the cut. When I got laid off I took them along with me and I still use them from time to time
Frankie

[Paul Alciatore]

Thanks to all for the answers.

I have looked at all the holders suggested and am turned off by either the price or the shortness of the extension they provide. I mean, I can buy a three foot length of 3/4" ground round (that sounds like hamburger meat) and some set screws for about $25. That will make a whole bunch of extension holders for under $10 each. The time involved would be minimum, perhaps an hour tops. So where do they get those prices?

I am going to order some stock and make a couple of them.

Thanks again.

[true temper]

I could have used something like that the other day. Had to drill out 1/8” roll pin that I broke off in a blind hole. I got it out mostly dust when I was finished.

[Fasturn]

Paul- Yes the prices are ridiculous on extention. My guess, it a some what limited market. Putnum made them years back, but nomore. Like you said, 1 hour and you will have just what you need. We forget sometimes WE ARE MACHINIST, and can make just about anything. Your problem solved! Snap a photo and post when you make one.

Cheers ~

[psomero]

I have used drill rod to make extensions before. Did a shrink fit using a propane torch, but loctite 684 should work pretty well also.

There are a couple of companies that sell extensions with set screws, but the usual disclaimer re:weldon flats and set screws wrt/ runout apply. I am thinking of one company in particular that John Saunders did a tour of on youtube, but the name is escaping me. I think they also did a lot of oddball cutters including tapered endmills.

Quick googling yielded these guys, never heard of them: http://www.collistoolholder.com/cgi-...yp=CAT_0_TYP_H



That company I was thinking of was Harvey Tool, but they're a collet setup, not setscrew type: https://www.harveytool.com/products/...s/tool-holders
Never used their holders personally, but I think my machininst at a startup a while back had a bunch of their holders and he liked them. I have rando endmills and stuff from them and they're all great.

[psomero]

Thanks to all for the answers.

I have looked at all the holders suggested and am turned off by either the price or the shortness of the extension they provide. I mean, I can buy a three foot length of 3/4" ground round (that sounds like hamburger meat) and some set screws for about $25. That will make a whole bunch of extension holders for under $10 each. The time involved would be minimum, perhaps an hour tops. So where do they get those prices?

I am going to order some stock and make a couple of them.

Thanks again.

most manufacturers i've seen will certify their extensions to have a TIR of like .0002" from shank to the tool socket. I bet that ground rod you're referring to has a straightness tolerance in the neighborhood of .005" per foot, or about 10-13x what the stated value, assuming a 6in long bar, is from the tooling vendor guy.