R8 end mill holder - 12mm?

[Alan H.]

Peter, you're correct in that I do not really want to mar or damage the shank on the Haimer. Any set screw would need to be nylon or brass tipped.

I always try to hang on to the assembly when removing it and the R8 collet from the mill. I am fortunate enough to have a power drawbar on my mill but there is still the risk of a "fumble" as Mark calls it.

I am now going to study the ER collet idea a bit deeper. I have wanted an ER20 or ER25 setup so now may be the time to get one.

 

[kd4gij]

Bore a 3/8" end mill holder to 12mm. and use a nylon tip set screw.

https://www.mcmaster.com/#set-screws/=1atvrvw

 

[spumco]

Maybe just put a short tether on the Heimer and a hook on the mill head. if you fumble it, it drops a couple inches and no broken tip.

 

[Ulma Doctor]

if you were so inclined, make your own R8 endmill holder 12mm bore.

 

[Alan H.]

Thanks to all for the wealth of replies here. I now have two options on order.

1. I bought the Arceurotrade 12 mm end mill holder. To conserve head space on my mill, I will remove as much off the bore end as possible with a KMG grinder and then finish it in the lathe. The Haimer's 12 mm shank is 25 mm long and I am betting the holder has a 50 mm deep bore thereby allowing for the reduction in length. I'll add a brass tip to the set screw so it doesn't mar the Haimer's smooth shank.

2. I bought this SOWA R8 ER20 collet chuck and a metric set of Techniks ER20 collets. I have wanted an ER20 set anyway to fill a gap in my ER collet kit. If the end mill holder doesn't work, this is another option.

Thanks again and I'll report back when I get all this landed and trialed.

 

[Alan H.]

Okay, I received the End Mill Holder and the ER20 holder and collets. I trimmed the End Mill Holder and it seems to be a fine soluton. I started a fresh thread on it all - https://www.hobby-machinist.com/threads/haimer-in-a-manual-mill-avoiding-fumbles.65131/