Re: [GrizHFMinimill] chuck falls out

On Sun, 23 Oct 2011 18:48:05 -0400, you wrote:

>
>>
>>If the chuck falls off the taper itself, then it's not pressed on
>>firmly and properly. All the chucks (I assume you mean drill chuck)
>>are expected to come with a taper which matches the spindle in the
>>mill.
>>
>>The drill chuck taper is normally a Jacobs taper (JT-somenumber), or a
>>similar thing.
>>
>>However, the drill chucks generally are self holding, and you just
>>press them on (properly).
>>
>>The key is that the other chucks need a drawbar. The spindle is
>>hollow, and there's a threaded rod that pulls the taper back into the
>>spindle. Do not tighten it excessively.
>>
>> >
>> >What is the procedure for putting it on and having it stay?
>>
>>drawbar.
>
>Thanks Harvey. appreciate not being treated stupid!
>
>Yes it isn't pressed on tight and the parts are original. So the fit
>is correct. I did a google for a drawbar, but the results were not
>"enlightening" seems the drawbar is a threaded shaft that works like
>a bearing puller/inserter. I have those from years of auto work. The
>draw bar is a threaded shaft on one end and smooth with a shoulder on
>the other? Would be great if the drive shaft were center tapped , but it isn't

Oh, in that case, you don't really have a mill, you have a drill.

Mills subject the bearings to sideways thrust, and the flutes on the
mill tend to pull the mill *out* of the holder (which is why you get a
mill holder with a setscrew). With a drill, while you *can* use it as
a mill holder, the following things happen: 1) the mill pulls out, 2)
the bearing wear rapidly, and 3) the chuck can be vibrated/pulled off
the shank.

In your case, I'd clean the inside of the taper on the chuck
thoroughly, clean the taper on the shank thoroughly, make sure that
there are no scores or digs on either, *then* you put light dusting of
talcum powder (so I've heard) on the shaft.

Then you press the shaft on gently, making sure that it is properly
aligned. Then press it on firmly. The talcum powder makes it grip
better.

>
>How to find one and use one is a whole new issue. My drive shaft is
>tapered and doesn't seem to have a threaded center so i can assume I
>need to pull the drive shaft and do a bench press to 4 tons or some
>such? Is there some tutorial on how to change a taper tool??

The chuck is meant to stay on there, and if there is no center hole
for the drawbar, you may just have a drill press.


>
>Sorry to be so ignorant, but I have a bunch of books and this is not
>a covered topic.

Might be looking in the wrong place....

>
>I know how to put a taper in a dead center on the lathe but there is
>no rotary force there.

Not the same situation, I think.

Harvey

>
>- thanks again.

------------------------------------

Yahoo! Groups Links

<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/GrizHFMinimill/

<*> Your email settings:
Individual Email | Traditional

<*> To change settings online go to:
http://groups.yahoo.com/group/GrizHFMinimill/join
(Yahoo! ID required)

<*> To change settings via email:
GrizHFMinimill-digest@yahoogroups.com
GrizHFMinimill-fullfeatured@yahoogroups.com

<*> To unsubscribe from this group, send an email to:
GrizHFMinimill-unsubscribe@yahoogroups.com

<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/