Source/s for Metric ER20 collets? I know one that does NOT fit!

[carolinasmith]

Eager to try an inexpensive bit that was mentioned in another thread, I decided to buy a metric sized collet first for the Desktop MAX (ER20 size).

I tried a source from Amazon that had many favorable reviews, unfortunately, they don't fit so they're going back.

Did NOT fit: Zchao ER20 Precision SPRING COLLET set 13 pcs (1mm-13mm) CNC MILLING LATHE CHUCK TOOL for $37.49

Looks like the ShopBot store only carries Imperial. Where have you found ER20 Metric collets for the Desktop series? Thank you.

[Gary Campbell]

https://www.maritool.com/Collets-ER-Collets-ER20-Collets/c21_56_62/index.html

[garyb]

ER metric collets are available from Onsrud or any full Onsrud distributor.

I would expect you got a metric size collet set, the problem here is your sizing what most don't realize is metric collets are sized with overlap
eg 1-2mm, 2-3mm, 3-4mm and so on
So when you look at the sizing a 1-2mm collet it will be .039-.079". A 2-3mm will size .079-.118" with a collape range of .039"
Now in this example they are both 2mm collets, so what was the tool diameter sizing needed ?
Gary

[Burkhardt]

You can try these guys in the UK. They ship to US and have good quality collets. I measured the runout to be comparable to my inch sized collets from Precisebits. http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collets/ER20-Collets/ER20-Collets---Metric

They also have the highly desirable ball bearing collet nuts. They are easier to tighten and hold big bits much better: http://www.arceurotrade.co.uk/Catalogue/Collets/ER-Collet-Nuts-Wrenches-and-Spanners/ER-Collet-Nuts-with-Ball-Bearing-Type-A

[scottp55]

What bit Carolina?
scott

[carolinasmith]

"I bought mine a few years ago for $6 but it looks like similar ones are nowadays only $1.58 with free shipping. http://www.ebay.com/itm/60-Degree-Router-CNC-Engraving-V-Groove-Bit-6mm-x-22mm-1-4-Shank-22mm-Tool-mw-/322349768719

Quite ridiculous but the one that I bought back then works absolutely fine. Sharp carbide, maybe 15/1000" tip width and no unbalance. That said I do not run it over 12krpm due to the heavy head and slim shank.
(That quote, Scott, was from the Redwood V-carve bit discussion this past weekend (14 Jan 2017)

They say 1/4" shank but it is actually 6mm and a 1/4" collet will not work well."

[Burkhardt]

Carolina, the link that I posted is not the one I bought the bit from a couple of years back. But these bits from all of the ebay sellers look quite alike (except some are red and some are blue...) and I suspect they may come from the same factory. If you want to experiment they are fine.

I did an extensive v-bit comparison test with 6 different brands/types (I believe I posted the results with pics here somewhere). This did not include Onsrud, but some other highly recommended types like the CMT Laser Point bit, Whiteside and Amana In-Groove. The cheap China tool cut about as well, had a wider tip than the CMT but smaller than e.g. Whiteside. I am not sure how the durability compares but at that price and my rare usage this is not an issue.

My real concern (and why I don't run them over 12krpm) is as mentioned the heavy head on the flimsy 6mm shank. I really don't want that breaking off and shooting across the shop while spinning.

[scottp55]

Thanks Carolina:)

Found it Gert... I remember test carving that shape as a brand Newbie:)
http://www.talkshopbot.com/forum/showthread.php?18914-Need-Some-V-Carve-Advice

Also a couple others on VBits;

http://www.talkshopbot.com/forum/showthread.php?20631-quot-Waterline-quot-marks-and-VBit-angle

http://www.talkshopbot.com/forum/archive/index.php/t-20346.html

Wish they'd give us back our linking:(
scott

[carolinasmith]

Are there other metric sizes folks here have found useful? I'm going to try Gary's suggestion and order from Maritool. It seems that the $8.95 shipping cost holds for one product or more (I tried up to 3 collets in the shopping cart with no increase in shipping), so I'll order more than the 6mm size if other sizes have proven useful to have. Thanks for everyone's comments.

Garyb, if I understand your comments correctly, it was not about the collet not grabbing a bit, but about the collet nut not accepting the collet at all. I tried two different collets in the Chinese imported set, and could not get either one to snap/click in the Desktop collet nut, like the collets from ShopBot easily do.

[Burkhardt]

Are there other metric sizes folks here have found useful?....

Not really. Besides that 6mm collet I got a full complement of metric collets with my spindle and the only other one I use occasionally is 2mm one for 2mm drill bits.

As for the collet/nut fit I did not have a problem with that but getting cheap Chinese stuff to fit is always a hit and miss. At one point I had a different Chinese spindle and the collet nut would not go onto the spindle thread. It took me half an hour back and forth and some diamond honing paste to make the nut work smoothly. While this stuff usually works, at the end you get what you pay for. I can live with that as a hobbyist but if I would use the machine professionally I would surely have a different attitude to such quality issues.

[carolinasmith]

Thanks and agree with the sentiment. Since Amazon (Prime member) is good about returns, I was ok with trying an unknown source once. I have placed an order through Maritool for just the one 6mm collet to trial their fit and service.