Keeping the Chuck on the mill

[dlavery]

Originally Posted by phrontist

We've got a rong-fu mill (purchased on the reccomendation of Mr. Lavery) and we're delighted with it. Save for one thing. It seems that no matter what speed we set it to, how fast or deep we cut, its only a matter of time until the chuck falls off, damaging our work and (once or twice) the table. The chuck, accoording to the manufacturer we just have to hammer it on the tapered drive shaft, but despite doing this really hard (and using an air-hammer to really drive it up there) it continues to fail. How do other teams deal with this. Why don't they have a screw or something to keep the chuck on?!

Any help would be greatly appreciated!

PM me off-line. C'mon by and we can take a look at it this weekend and see if we can fix it up for you. Or if that doesn't work, I have a spare chuck on an R-8 arbor that you can have.

-dave

[ginger]

Are you using a drill chuck to hold an end mill?

Please don t do that- drill chucks are made to hold drills, and to drill holes. End mill holders or colletts are made to hold end mills. There is nothing you can do to a drill chuck and its morse taper socket to make it hold well enough to use for milling.

In addition, drill chucks never run dead true, so holding an end mill in one causes it to become a one tooth cutter.

[S.Nickens]

I didn't even consider the possibility that you would be trying to mill with a Jacobs chuck. Ginger is right, doing this is a very bad approach, not to mention dangerous. End mills should always be mounted in the correct size R-8 collet. I know everybody has a budget, but you can start with a popular size like 3/8"or 1/2" for less than $20, and add to your collection as funds become available. An eight piece set will run you around $160 ( 1/8" - 1" by 1/8", most std sizes ), and you can always check E-Bay. SAFETY FIRST!

[ChuckDickerson]

As others have indicated it it a very bad idea mill with end mills in a drill chuck. The drill taper is not designed to hold with a side load. It is designed to drill (up and down) so the forces press the drill chuck onto the taper when drilling. You can get a set of R8 collets very inexpensively from ENCO (www.use-enco.com).

6pc R8 collet set DD231-4606 currently on sale for $19.95
11pc R8 collet set DD231-4611 on sale for $36.95
23 pc R8 collet set DD231-4624 on sale for $77.95

The $20 6pc set should serve you well and be much safer than milling with a drill chuck.