ER Collets: What's the Difference?

wrmiller

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What's the difference between the different numbers on collet sets, e.g. er20, 40, etc.?

Looking at these as a possible upgrade from R8.
 
As far as I know, the size is determined by the OD of the collet at its largest point. So an ER32 collet will have a 32mm OD. You get the picture.
 
The size is not actually the OD of the collet at the largest point, more like a nominal size. If you measure one it will be oversize. Perhaps they may measure on point when compressed to their nominal range. ER collets have a clamping range of .039mm/1mm, much wider than R8, 5C, etc.

Ultimately it's the max tool size that will base your decision on which size to buy. I have heard that the larger sizes don't hold smaller sizes too well, ie ER40 won't hold 1/8" shanks well, etc. Not sure of the truth in that but I use ER40 for 3/8" - 1" & ER16 for 3/8" & smaller. I like the ER16 for tighter areas where the ER40 won't fit with a smaller endmill. ER32 (max 3/4") is a good all around size for our size mills.

Technicks make the best quality ER collets you will find for an import & are all I use. Made in Taiwan. Hemly Tool & All Industrial on ebay have the best prices on them. Nemic tools has them cheaper so if buying a few at a time that's the place place to buy. ER collets were designed by Rego Fix & are the most used collet system worldwide. I have heard Glacern ER chucks are made by Rego Fix but I'm not sure of the truth in that. I do know they are very high quality though. For the mill I have an ER16 chuck from Glacern & I have 2 ER40 chucks from Bison/TMX.


IMG_8926.jpg

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And I also use ER40 & ER16 on the lathe.
Img_9141.jpg

IMG_8926.jpg

Img_8271_zpsc6ac4647.jpg

Img_9141.jpg
 
Thanks for the clarification, Will. I was basing my thought on the dimensions I have for some ER collet chuck plans. On those, the largest diameter of the taper matches the 'series' number (32mm for ER32, 16mm for ER16, etc), and the largest diameter of the compressed collet would then be the same also, or at least very close to that.
 
Thanks for the info guys (and the pics Will, very nice).

For those that do use them, how often do you run into clearance issues when up close to a part/vise/chuck? Reason I ask is I remember setting up tooling for my friends CNC and noticing rub marks (and worse) on some of the collet chucks where they've banged into stuff.

I can see one advantage though: Yesterday when I was doing my first cutting on my new mill I was having to move around quite a bit to see under the head and around the quill stop (or whatever you call that thing). A collet chuck would get the cutter down a bit further from the spindle so I could see it easier. :)

I would only worry about being so far from the spindle bearings if I was taking heavy cuts, but then if I have to do that I could buy a regular NT30 tool holder.

Every time I turn around there's more stuff that needs buying... :pondering:
 
What's the difference between the different numbers on collet sets, e.g. er20, 40, etc.?

Looking at these as a possible upgrade from R8.

Why would these be considered an upgrade? I ask because I got a complete set when I bought my mill. I've used them and much prefer the R8s. My brief experience left me unimpressed and wondering what the positive points might be. I found them to be somewhat cumbersome and as you mentioned I was unable to get close enough to my work piece at the time (2 x 3 aluminum angle). I realize I'm really green relative to many here but I've yet to have any issues with the R8s so why is it an "upgrade"?
 
One of the reasons I like them is using one set of collets for a lot of things. I have an r8 chuck, an mt2 chuck and a plate chuck like Dark Zero. I can use one set of collets in my lathe headstock with the ability to pass material/tools through the spindle and chuck,in the lathe tailstock, in my rotary table, and in my mill. That's pretty versatile. They are supposed to have less runout than r8 collets. I believe they have more holding power also. I bought a metric set of er collets that holds anything from it's lowest size to it's highest without any gaps in collets which is nicer than standard inch sizes that have gaps in the sets. I have some metric tooling projects and don't have to buy metric r8 collets that would only be useful in the mill. I can also swap mills/drills ect in the mill without climbing my short rear up on a step stool to fool with the draw bar. Within it's range, I don't have to swap out to a drill chuck to hold drill bits. That's what I can think of right off. I want to get a little set to complement my er40's, but that has to wait. Edit I forgot, I have no lack of vertical room on my Bridgeport to fight, and my chuck is scarcely bigger than my spindle, so no clearance issues for me. Those with mini mills would lose clearance in the Z using er chucks vs collets that fit inside the spindle.:))
 
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The size is not actually the OD of the collet at the largest point, more like a nominal size. If you measure one it will be oversize. Perhaps they may measure on point when compressed to their nominal range. ER collets have a clamping range of .039mm/1mm, much wider than R8, 5C, etc.

Ultimately it's the max tool size that will base your decision on which size to buy. I have heard that the larger sizes don't hold smaller sizes too well, ie ER40 won't hold 1/8" shanks well, etc. Not sure of the truth in that but I use ER40 for 3/8" - 1" & ER16 for 3/8" & smaller. I like the ER16 for tighter areas where the ER40 won't fit with a smaller endmill. ER32 (max 3/4") is a good all around size for our size mills.

Technicks make the best quality ER collets you will find for an import & are all I use. Made in Taiwan. Hemly Tool & All Industrial on ebay have the best prices on them. Nemic tools has them cheaper so if buying a few at a time that's the place place to buy. ER collets were designed by Rego Fix & are the most used collet system worldwide. I have heard Glacern ER chucks are made by Rego Fix but I'm not sure of the truth in that. I do know they are very high quality though. For the mill I have an ER16 chuck from Glacern & I have 2 ER40 chucks from Bison/TMX.


IMG_8926.jpg

Img_8271_zpsc6ac4647.jpg


And I also use ER40 & ER16 on the lathe.
Img_9141.jpg

Holding that little chuck in the big one is just cheating, I like:))

IMG_8926.jpg

Img_8271_zpsc6ac4647.jpg

Img_9141.jpg
 
Holding that little chuck in the big one is just cheating, I like:))

Haha. Originally I had planned on doing that for small stuff but I don't. I scored that ER16 extension chuck for cheap, it's Lyndex with the Lyndex ball bearing nut (I also use them on my ER40 chucks) so I just couldn't pass it up.

I use DA collets in the chuck when I need to work on small stuff, it's much quicker. I do have the collet chuck for the DAs also but I never use it since I use the collets for work holding & not tool holding. The DA collets clamp just like the ER, across the full range of the collet but I haven't had a problem with gripping short pieces.


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This was back on my mini lathe lathe with a 5" Bison but I do the same on my current lathe.

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Img_1254.jpg

Img_0098.jpg

Img_1390.jpg

Img_1388.jpg

Img_1254.jpg
 
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