View Full Version : What is the smallest series of ER collets?
02-27-2010, 12:37 AM
I see quite a bit of larger ones, but I thought there was a series that was rather small.
I'd like something that would fill the range of, and not be much bigger than, the Brown and Sharpe "stub collets" that were used in some of their turret lathe tooling.
The holders are no issue, I'd likely only use the cap, and make the base section.
I have a bed turret for the Logan, and making 17 million different bushings is not my idea of fun. If I already had a stub collet set, I could make lots of bushings fairly fast.... but then I wouldn't need them.
The stub collets each covered about a 0.4mm range, so they were somewhat like the ER in coverage. But they are not exactly common items now.
02-27-2010, 12:44 AM
ER 8 I believe...
They even have a straight shank holder...
02-27-2010, 01:03 AM
+1 for ER-8
02-27-2010, 10:18 AM
Ah, well that's even smaller than I need...... didn't know about those.
I'd be wanting something that accepts from a couple mm to about 14 mm, but that is the most minimal amount oversized from that in OD....
That does not seem to be possible. Looks like the ER20 is the smallest, and that is almost 30MM OD....with clamping nut etc. Considerably too big.
Maybe ER collets are not the most suitable item.
02-27-2010, 11:15 AM
ER 16 collets range is 1/32"-3/8".
02-27-2010, 11:17 AM
ER 16 collets range is 1/32"-3/8".
Yep. I have a set of ER16 extensions that I use in my mill. The shank fits in a 5/8 collet so the nut is just a hair bigger than that. Not quite as big as you are looking for but they do go down small enough.
02-27-2010, 11:52 AM
These DA100 collets?
.0495 - .5625
02-27-2010, 12:31 PM
Yeah ER8 is the smallest. I have a set of ETM ER-11's with a Craftsman Stub chuck with 1/2" shaft.
The ER-11's are next to a ER-32 in this pic-
02-27-2010, 12:58 PM
JT, If you need it for drill bits, you might want to consider a tiny drill chuck with a stub shank. I use a tiny Jacobs (#0 ?) on a 1/2" shank. This is very handy, but on a mill, when running a 1/2" tool normally.
If it's for boring bars, etc. then the collet is called for. You could still make your own nut with less OD. It only has to compress the collet into its taper although the extraction function makes the commercial nuts worth while. ETM nuts can be bought separately and they work great.
02-27-2010, 08:28 PM
it's for drills, reamers, hollow mills, whatever on 5/8" shank tooling. Boring bars? maybe.... depends on the way they are made... I'd probably want to do that differently to maintain similar 'stick-out" for all tools.
The "stick-out" issue is the problem with many drill chucks.... The small drills are fine, but even a screw machine 1/2" drill plus a chuck is basically huge compared to a box tool or knee tool.
02-27-2010, 10:39 PM
For a box tool or turret operation, you might want to consider making a bushing for each. I found something similar to that here except they are taper mounted.
Another option for a common shank on smaller bits is PCB drill bits, all with 1/8" shank. Some surplus places carry them although they are still pricey and are carbide. They also appear on ebay fairly inexpensive (for carbide) in assorted lots like this: http://cgi.ebay.com/50-Carbide-PCB-CNC-Micro-Drill-Bits-Assortment_W0QQitemZ380210366741QQcmdZViewItemQQpt ZLH_DefaultDomain_0?hash=item58864dc915
02-28-2010, 01:43 AM
For a box tool or turret operation, you might want to consider making a bushing for each.
Well, you have correctly identified the issue..... I'm tired of making sleeves and bushings.... There are a lot of drills I use, and a fair number of reamers etc. They all have different size shanks.
I'd rather have a collet or similar that fits a range of sizes, as the ER collet does. But they are somewhat 'clunky" for turret operations. The B&S stub collets are a bit more compact.
I want one type to cover from a mm or 2 up to 14mm. B&S made a V holder, that took a range of drills and could be alined to the spindle, and that's a possible, although the V would have to be filed, and each size drill needs to be alined separately.
The nice thing about a collet holder is that once you aline it one time, if you leave it set up, it's alined for any other drill or reamer also.
02-28-2010, 10:04 AM
Another option for a common shank on smaller bits is PCB drill bits, all with 1/8" shank. Some surplus places carry them although they are still pricey and are carbide.
Just a word of caution. These drills like to run fast. In fact the MINIMUM speed recommended is sometimes over 30,000rpm. Run them too slow and they're very prone to breakage. They won't tollerate much run-out either, which has been a problem with the Dremmel we use on the CNC-PCB machine at work.
There was a clever design in Model Engineer's Workshop for a vacuum driven turbine for PCB drilling.
02-28-2010, 11:30 AM
Just a word of caution. These drills like to run fast. In fact the MINIMUM speed recommended is sometimes over 30,000rpm.
They also aren't very good for 14mm holes ;)
02-28-2010, 03:39 PM
Here is the sort of thing I want to replace with a collet type holder, if possible.
02-28-2010, 06:56 PM
I am in the same boat. I have 2 second op lathes I would like collet chucks for but have yet to pull the trigger. I would also like to use them on other machines as I already have something like 7 different types of collets from auction & Ebay misadventures.
Heres one on sale at Enco:
Heres the search I did for 5/8" shank collet chucks:
SEARCH RESULTS (http://www.use-enco.com/CGI/INLMK32?PARTPG=INSRAR2)
It looks like ER-16 or DA200 collets, both 3/8" capacity, are as big as they go for 5/8" shank. It is quite easy to turn the drill shank down with carbide. I did that for some drills I was using in ER-16 collets on an CNC knee mill.
02-28-2010, 10:05 PM
The ones Enco sells in the link in the post above are really nicely made, right here in the USA, I've got one and like it a lot. However, they are fairly light duty as ER holders go, they have a smaller nut and body than ones like these ones:
These have a heftier nut and body, but need more clearance (probably more an issue when milling), so keep this in mind. I've got some of these ones also and they are also nicely made. Also even in these "heftier" style ones there is still a difference, the ones that use the hex style nut are a little beefier (both nut and body) compared to the ones that use the special "M" style nut (the nuts don't interchange).
02-28-2010, 10:06 PM
yeah, that first one has a 5/8 shank, and would be good, but I need the adjustability per the pictured holder, so I'd still have to adapt it or something.
If I luck into a couple three B&S #68-100 holders and a stack of collets for a song, I'd be fine. But I don't expect that this century.