[suspension]

I wish to mill a PCB using a high precision er11 collect but my CNC has a 2.2Kw spindle which only accept er20 collects. I tried to find an adaptor for this but could not find any. Any suggestions?

[deadlykitten]

hy suspension, craft another shaft, with an er 11 chuck, then replace it using an adaptor will lead to more tir & overhang

if you wish, i can help you with specific details / kindly

[awerby]

The added precision gained by using a better collet will be lost by using an adapter, as deadlykitten is telling you above. Just find the right-sized ER20 collet for your PCB tool and use that.

[mactec54]

I wish to mill a PCB using a high precision er11 collect but my CNC has a 2.2Kw spindle which only accept er20 collects. I tried to find an adaptor for this but could not find any. Any suggestions?

There is no such adaptors, that I have ever seen, apart from a straight shank ER Collet holder, which you would not want to use in the ER20 Spindle, there would be no need for one. what ever size you want you can get it in the ER20 Size collet, with just the same precision, as the ER11.

[deadlykitten]

is there interference with the er20nut, while 11 may make it ? instead of other size, maybe is enough to use a smaller nut

[mactec54]

is there interference with the er20nut, while 11 may make it ? instead of other size, maybe is enough to use a smaller nut

When this happens you can just machine up a solid tool holder to fit what ever ER holder you have, to give the amount of clearance you need, I Loctite the cutter into the holder, you can buy these also, they are easy to make yourself though.

[Goemon]

They make screw-on adapters to go bigger and smaller e.g.

https://www.ebay.com/itm/15422087603....c101113.m2108

And

https://www.ebay.com/itm/35371366647...cAAOSwpOthYEMX

I don't know how small the end mill is but can't you just use a stepped end mill with a larger shank like this:

https://www.ebay.com/itm/33417734199...3ABFBMlKGbnZxf

Or V shape bits with a 1/8" shank and a 0.1mm tip:

https://www.ebay.com/itm/18510926519...UAAOSwzNRhal0N

I can't imagine any sort of adapter adding precision....

[MCImes]

Your best bet is to get an ER-20 Ultra Precision collet if you have a tool with at least a 2mm shank (the smallest ER20 goes I think?). A reducer doesnt provide any real benefit I can see here.
https://us.rego-fix.com/en/products/...ions?system=ER

But if you need more length for some reason, the regofix reducers linked above will take you down 1 size. I thought they went down more sizes than that, but dont see them in their current product list.