ER16 Collet Size Problems

[Bob La Londe]

I picked up a Taig 2019 mini mill recently, and have been using it to do some CNC engravng while I learned how to use my software and get a feel for my machine. Mostly I used some 1/8" shaft stuff to do some engraving. Today I decided it was time to make some tight fitting solid t-bolt nuts and rails to fit in the table. Something a little better than the flat plates that came with the mill. Also helicoiled to a common size so I could pick up a variety of different length screws to use with clamping fixtures.

Thinking everything would be honky dory I sliced some 3/8" aluminum plate on the table saw to 5/8" wide strips So I could mill it down to 1/2" to fit the table grooves. Then I got it clamped up on the mill table with a couple welding clamps. I used the shaft of an 1/8 mill point to get the bar straight roughly to the table travel, and proceeded to swap collets to use a 1/4" flat end mill to rough material off of one side only to find out that my 1/4" shaft mill point would not fit in the 1/4" collet with the collet snapped into the nut. Then I tried with the 3/8" collet with a 3/8" shaft end mill and got the same results. The ER16 is what is supposed to be used in this mill, and the collets where clearly labeled for the size I was trying to install and use.

Am I missing something? If I took the collet out of the mill head nut I could force the shaft in, but then it would not snap into the nut at all. I measuered the shafts of the various mill points I was trying with a caliper, and the 3/8 measures .375 and the 1/4 measures .250 so I know its not that, but hey I had to check and make sure right.

Bob La Londe
www.YumaBassMan.com

[SpeedsCustom]

The mill end may be .250 or .375, but the shank needs to be .250 and .375. Make sure your shank is the right size.


Also! You put the collet in FIRST, then slide your tool into the collet.


-Jason

[Bob La Londe]

Originally Posted by SpeedsCustom The mill end may be .250 or .375, but the shank needs to be .250 and .375. Make sure your shank is the right size. Also! You put the collet in FIRST, then slide your tool into the collet. -Jason

LOL

I did measure the shank. I don't even know how you could measure the fluted cutting portion of the end mill with a caliper and expect to get an accurate measurement. And... yes I know that you are supposed to put the collet in the nut and then put the put the mill in the collet. I added MORE information to hopefully clarify that I tried every possible configuration of getting the mill point into the machine.

Let me try again.

1. The collets are labeled ER 16 1/4 and ER 16 3/8 repsctively.
2. The Taig 2019 is supposed to use an ER 16 collet.
3. The collets snapped into the nut.
4. The mill points would not fit into the collets of their respective sizes.
5. I tried 3/8 SHAFT in the 3/8 collet.
6. I tired 1/4 SHAFT in the 1/4 collet.
7. I measured the 1/4" shaft at 1/4 with a caliper by measuring the shaft not the cutter portion of the mill point.
8. I measured the 3/8" shaft at 3/8" with a caliper by measuring the shaft not the cutter portion of the mill point.
9. Know that the collet is supposed to be in the nut I tried inserting the correct shaft size mill point into the correct size collet when it was properly installed in the mill head nut. They do not fit all. They would not go in.
10. Then just wanting to see if it would fit at all I was able to FORCE the mill point into the collet when it was not in the nut, but because they are not supposed to be installed in the collet outside of the nut then obviously the collet would not go back into the nut with the mill point installed in it.

The ER 16 collets were purchased as a set off of Ebay from the seller doing business as 800watt. I have an e-mail into the seller explaining the problem.

[TOTALLYRC]

I have a Taig with the ER 16 system and I have none of the problems that you are having. The shank of the endmill slides in with little force regardless of the collet being in the nut or not.

I have read that the low cost collets are not worth the money. I went to the local supply house and got a 1/8, 1/4, and 3/8 and they all work really well.
I would estimate the insertion force at about 1-2 lbs.

Mike

[nicad]

A quick search on ebay shows 800watt selling er16 collet sets of 8 for $25. That is a little over $3/ea. They could be metric collets that are marked with inches. Have you tried measuring the ID of the 3/8" one? It has to be way undersized for it be behaving the way you are describing. That or the Taig collet nut is machined too small and not allowing the collets to expand at all, but I doubt that is the case.

My advice-- throw away the $3 collets and spend at least $10 on each one. I use 3/8" tooling more than everything else, so I bought a set of 8 ER16 collets for $88 and then one nice name brand USA made 3/8" collet for about $25.

[SpeedsCustom]

You get what you pay for, Er16 collets are not that pricey, but sometimes a set is useless. So buy some individuals ones, 12.00 bucks or so and cut parts!


-Jason

[Bob La Londe]

There is a ring inside the collet nut that the collet snaps into. This ring is off center. Is it supposed to be? My 1/8 inch collet snapped right in and worked fine. I have already cut a thousand inches of engraving with it with no problems and very good accuracy, but perhaps there is more room for manuevering the 1/8 collet since it has more grooves cut into it.

[SpeedsCustom]

The ring is suppose to be off-center yes.

Check the ID of your collets.


-Jason

[ikneb]

The nut might be damaged.

[Andre' B]

Originally Posted by Bob La Londe 10. Then just wanting to see if it would fit at all I was able to FORCE the mill point into the collet when it was not in the nut, but because they are not supposed to be installed in the collet outside of the nut then obviously the collet would not go back into the nut with the mill point installed in it. The ER 16 collets were purchased as a set off of Ebay from the seller doing business as 800watt. I have an e-mail into the seller explaining the problem.

Your collets are too small or they have been crushed by using them with a tool that was smaller then the minimum size the collet was made for, or they are just cheap junk.

ER collets are designed to be used with tools that are the same size as the collet (in its open state) or smaller, the collet should never have to expand to fit the tool.

Most cheap sets of ER collets being sold as inch sets are really metric collets that have been relabled.

You can get ER collets that were designed for use with inch size tooling.
http://www.royalprod.com/content/fil...Pgs_14_171.pdf
Note how the 1/4 size collet, page 3, has a size range of 0.250 - 0.211, ER collets work best (gripping power and concentricity) when used at their max size of that range.

A bit of info on how to get the most from collets.
http://www.rego-fix.com/colletcare/

[Bob La Londe]

I just got a new Taig ER16 closer nut from Super Tech and a set of Taig Collets. The collets from Taig work in the old nut and the new nut, but the generic collets also work just fine in the new nut. That tells me that there is a difference between the old closer nut and the new closer nut as well as a difference between the collets themself.

While the collets I had may not have been perfect, I have to also conclude that either there was a problem with the original closer nut, or there is a great deal of variance in their finished closer nuts.

Now I have two nuts and two sets of collets.

This is why I bought a new closer nut as well as Taig collets. Now I know.

[HuFlungDung]

Yes, I've seen some collet nuts that must be a tad off spec and will precompress the collet just enough that you cannot get full range use out of it. But, I don't toss 'em, I just mark 'em and use 'em for smaller diameter tools or drills.