[modeleng] Re: Releasing chuck taper

Hi Jem

I too have a Dore-Westbury, and like yourself, I had to make a special 
drawbar with a step in it.  In fact I had to make two, because some of the 
2MT attachments I use have an M10 thread in them.  When I want to release 
the tool I'm using (usually a flycutter) I just give the top of the drawbar 
a smart smack with a copper mallet and the whole thing drops out into my 
other hand.  The problem comes when I've been using a Jacobs chuck because 
there is no ejection slot and no drawbar.  In this case I just drop a length 
of brass rod down the spindle and give that a smack.

I've never had a taper stick, but then all my tooling tends to be covered in 
WD40 to keep rust at bay.

I don't use a milling chuck. I tried a thing called a Pozilock (a poor man's 
Clarkson) but found it too unwieldy, I much prefer to use Myford collets to 
hold my milling cutters.  With the sort of cuts I take, they never slip and 
the whole thing is much more rigid because the head is nearer to the job. 
Horses for courses, I suppose.

Regards
Ron from Oxford

----- Original Message ----- 
From: "JEM HARRISON" <jemharrison@xxxxxxxxxxxxxx>
To: <modeleng@xxxxxxxxxxxxx>
Sent: Sunday, February 18, 2007 1:27 PM
Subject: [modeleng] Releasing chuck taper


> Gentlemen
>
>  Yesterday, I thought that I would try to make a simple (!) drilling jig, 
> by drilling some holes accurately in a piece of 6mm thick mild steel that 
> I had machined in the ML10 to fifteen-sixteenths of an inch square.  The 
> next step would be to hold that piece of steel in the nippy vice on the 
> old, very old, Dore Westbury mk.1, but before I could do that, I had to 
> remove the Clarkson type milling chuck so that I could install the drill 
> chuck that is normally installed on the tail-stock of the lathe.  The fun 
> is about to start.
>
>  The Clarkson type milling chuck, a Vertex, is on a Morse Taper No.2, and 
> has a tapped hole in the end, 3/8" Whitworth for a drawbar.  As the bore 
> through the spindle of the DW is smaller than 3/8", I had to make a 
> drawbar from 5/16" ms, plus an adaptor (5/16" - 3/8").  I had removed the 
> milling chcuk from the DW once before, and it had needed some persuasion. 
> Even more persuasion was needed this time.  I tried hitting the top of the 
> drawbar (protected with a piece of wood) with a small hammer, then I tried 
> a bigger hammer, then i tried hitting the drawbar directly with the 
> hammer, only to damage the thread on the end of the drawbar.  After 
> re-cutting the thread with a 5/16" die, I put extra nuts on the top of the 
> draw bar, and belted these with the heavier hammer.  The morse taper would 
> still not shift.  Finally, I took the drawbar out and squirted WD40 around 
> the top of the milling chuck and down the bore of the spindle.  After 
> leaving the WD40 to penetrate for five
> minutes, I put the drawbar back in, gave it a tap, and the chuck morse 
> taper released quite easily.
>
>  Is there an easier way to remove a stubborn morse taper?
>
>  Jem Harrison
>  battling with basics in Basildon, Essex, UK !
>
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