Mill Collet Mind-Meltdown

O

Old&Hammered

Registered
Registered
Joined
Jun 27, 2023
Messages
6
Hello all, and forgive my technologically challenged mind. It took me half an hour of fussing before I realized I was trying to sign into the wrong site, and another fifteen minutes here trying to figure out how to create a post; long story short I hope this is in the right place.
My question:
I have recently acquired what I believe to be an industrial size mill head. The brand is Acer, it looks like a Bridgeport knock-off. The mill included...nothing. Just the mill head and motor. I've spent the weekend mounting it to a massive floor-mount drill press stand (with a 4 3/4" column it's a beast, and I will be buying an xy table).
As I will be going through the workings of this mill and getting it up and running right and tight, I don't know much about buying the right collet/chuck. I'm guessing the arbor is an MT3? The arbor is hollow bottom to top to accommodate a draw bar, I assume.
I began some research before posting this, and was bombarded with ER32 and 40, several Morse tapers, adapters, collets, draw bar style, twist style, spring collets, R8....my internet search left me more confused than when I began.
I'd be greafull for a starting point, a link to some definitions or clarity, or anything anyone would like to offer to help clear things up a bit.
My other concern is that I haven't seen much information on the internet on Acer Mills. How do I know which type of arbor I have? I thought about taking some measurements with a bore gauge but I really don't know what I'm measuring?
I'm not planning on building parts for the Space Station with this mill. Just hobbyist, light automotive stuff. My collection of tools I expect, will be half a dozen or so.
Thank you!
Kevin
 
I assume it would be an R-8 . Did it come with a drawbar? If you have a neighbor or friend who has an R-8 tool holder, maybe try it before you pick any up to make sure.
Martin
 
If you could post some numbers from the head, we can probably help you out. Most likely R-8 collets.
 
An R8 socket has a short, fast taper and then about a .95" inch bore running about 3" in. The mouth of the socket is about 1-1/4" in diameter. There is typically an alignment key located part way up the straight section but a 1" dowel pin will insert about an inch into the socket. An MT3 socket is just under an inch at the mouth and a 1" pin won't insert any distane into the socket. Exact dimensions can be found online by searching for machine tapers.
 
Here are examples of the two most likely suspects:
You can see how different they look
R-8 vs Morse taper collets
R-8.jpgMT3.jpg
 
Can you post a picture of your project?
Sounds interesting...
 
Here is a picture of my DIY Mill stand/base that someone asked for. I greatly appreciate all the responses to my question the other day. I will investigate further this weekend, armed with the knowledge I've been provided with here.
IMG_0257.jpg
The photographer insisted I make the photo look like an OSHA educational picture. I did my best.
 
Did you buy that out of Montana? Something similar had been up for sale in the NW part of the state.
 
You must log in or register to reply here.
Back
Top