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Old Jan 09, 2008, 05:07 AM
Richard Bradshaw
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n/a Posts
Drawbar thread

Hi, I am new to model engineering, apart from some lathe practice at school
about 30 years ago so please be gentle with your replies.

I have recently bought an X2 mill and an ER32 Collet chuck. These are both
threaded M12 the same as the draw bar. Looking at some more items like a
slitting saw arbour I found that most are 3/8th or 1/2 BSW. My problem is I
only have a metric lathe so can't make a new draw bar with an imperial
thread. Is there someone who sells these or a soource that has M12 arbours
anywhere.

Or is there a configuration with the change gears where I can cut an
imperial thread on a metric lathe.


Old Jan 09, 2008, 05:42 AM
Charles Ping
Guest
n/a Posts
Re: Drawbar thread

On Wed, 09 Jan 2008 11:07:27 GMT, "Richard Bradshaw"
<richardt.bradshaw@tesco.net> wrote:

>Hi, I am new to model engineering, apart from some lathe practice at school
>about 30 years ago so please be gentle with your replies.
>
>I have recently bought an X2 mill and an ER32 Collet chuck. These are both
>threaded M12 the same as the draw bar. Looking at some more items like a
>slitting saw arbour I found that most are 3/8th or 1/2 BSW. My problem is I
>only have a metric lathe so can't make a new draw bar with an imperial
>thread. Is there someone who sells these or a soource that has M12 arbours
>anywhere.
>
>Or is there a configuration with the change gears where I can cut an
>imperial thread on a metric lathe.
>


M12 Studding

Charles

Old Jan 09, 2008, 05:44 AM
Jordan
Guest
n/a Posts
Re: Drawbar thread

Richard Bradshaw wrote:
> I found that most are 3/8th or 1/2 BSW. My problem is I
> only have a metric lathe so can't make a new draw bar with an imperial
> thread. Is there someone who sells these


Have you tried to get a long Allen bolt? I bought one for my Emco FB-2
mill, which uses M10 Allen bolt for its drawbar as standard. A 3/8 BSW
Allen bolt was necessary after I got some accessories with that thread,
so now I have both.
At a pinch, a length of threaded rod could be used.
Old Jan 09, 2008, 05:49 AM
Dave Baker
Guest
n/a Posts
Re: Drawbar thread


"Richard Bradshaw" <richardt.bradshaw@tesco.net> wrote in message
news:PV1hj.35106$745.5154@newsfe1-win.ntli.net...
> Hi, I am new to model engineering, apart from some lathe practice at
> school about 30 years ago so please be gentle with your replies.
>
> I have recently bought an X2 mill and an ER32 Collet chuck. These are both
> threaded M12 the same as the draw bar. Looking at some more items like a
> slitting saw arbour I found that most are 3/8th or 1/2 BSW. My problem is
> I only have a metric lathe so can't make a new draw bar with an imperial
> thread. Is there someone who sells these or a soource that has M12 arbours
> anywhere.
>
> Or is there a configuration with the change gears where I can cut an
> imperial thread on a metric lathe.


When the drawbar on my Holke broke I cut the old thread off and welded on
the threaded bit of a high tensile bolt. It's lasted 10 years. Might be
easier for you than making a new one piece drawbar and threading it.
--
Dave Baker
Puma Race Engines


Old Jan 09, 2008, 07:15 AM
Tony Jeffree
Guest
n/a Posts
Re: Drawbar thread

On Wed, 09 Jan 2008 11:07:27 GMT, "Richard Bradshaw"
<richardt.bradshaw@tesco.net> wrote:

>Hi, I am new to model engineering, apart from some lathe practice at school
>about 30 years ago so please be gentle with your replies.
>
>I have recently bought an X2 mill and an ER32 Collet chuck. These are both
>threaded M12 the same as the draw bar. Looking at some more items like a
>slitting saw arbour I found that most are 3/8th or 1/2 BSW. My problem is I
>only have a metric lathe so can't make a new draw bar with an imperial
>thread. Is there someone who sells these or a soource that has M12 arbours
>anywhere.


Alternatives:

1) Use lengths of studding (threaded rod) of the right diameter/thread
pitch

2) Get a couple of BSW threading dies to make your own
>
>Or is there a configuration with the change gears where I can cut an
>imperial thread on a metric lathe.
>

Depending on the change wheels that you have in your set, it may well
be possible to get a close-enough approximation to a 3/8" or 1/2" BSW
thread pitch. You aren't looking for extreme accuracy, so the pitch
error over the dozen or so pitches needed to hold the chuck may not be
a big issue. The "ideal" change wheel setup would need a 127T wheel,
but for this kind of application that may well be overkill.

Regards,
Tony
Old Jan 09, 2008, 07:42 AM
Mark Rand
Guest
n/a Posts
Re: Drawbar thread

On Wed, 09 Jan 2008 11:07:27 GMT, "Richard Bradshaw"
<richardt.bradshaw@tesco.net> said, amongst other things, that::

> Looking at some more items like a
>slitting saw arbour I found that most are 3/8th or 1/2 BSW. My problem is I
>only have a metric lathe so can't make a new draw bar with an imperial
>thread. Is there someone who sells these or a soource that has M12 arbours
>anywhere.
>
>Or is there a configuration with the change gears where I can cut an
>imperial thread on a metric lathe.
>


The suggestion of using studding would be good, except for the fact that you
would need either BSW spanners or to turn it down and put a metric thread on
the end. I would suggest getting hold of a 3/*" and 1/2" BSW die. Turning the
drawbars to the right diameter is not a problem (12.7mm etc :-). Then, having
put the BSW thread at one end, thread the other end to suit your existing nut,
or similar other metric one, eg. M10 or M12 as appropriate.

Alternatively, whereabouts are you?

HTH
Mark Rand
RTFM
Old Jan 09, 2008, 11:24 AM
Archie
Guest
n/a Posts
Re: Drawbar thread

>
> The suggestion of using studding would be good, except for the fact that
> you
> would need either BSW spanners or to turn it down and put a metric thread
> on
> the end.


Wots wrong with a shifter? -or am I showing my ignorance :-)

Archie


Old Jan 09, 2008, 01:17 PM
Mark Rand
Guest
n/a Posts
Re: Drawbar thread

On Wed, 9 Jan 2008 17:24:27 -0000, "Archie" <archie@nospam.com> wrote:

>>
>> The suggestion of using studding would be good, except for the fact that
>> you
>> would need either BSW spanners or to turn it down and put a metric thread
>> on
>> the end.

>
>Wots wrong with a shifter? -or am I showing my ignorance :-)
>
>Archie
>



Only major issue is that it's a pain to have to adjust one at head height,
against a mill head with little knuckle room, every time you use it.


Mark Rand
RTFM
Old Jan 09, 2008, 06:27 PM
Richard Bradshaw
Guest
n/a Posts
Re: Drawbar thread

Thanks for all the replies. The drawbar I have is literally a long bolt. M12
thread on one end and shaped for a 17mm spanner on the other so there is no
problem with trying to match to a metric nut. I was a little nervous of
using such a large die to create the thread but if you think it would work
that would be the most elegant solution. Otherwise I might be able to make
some stud work. Mark I live in Stansted Essex by the way.


Old Jan 12, 2008, 05:21 PM
David Littlewood
Guest
n/a Posts
Re: Drawbar thread

In article <uDdhj.59595$wD5.2590@newsfe3-gui.ntli.net>, Richard Bradshaw
<richardt.bradshaw@tesco.net> writes
>Thanks for all the replies. The drawbar I have is literally a long bolt. M12
>thread on one end and shaped for a 17mm spanner on the other so there is no
>problem with trying to match to a metric nut. I was a little nervous of
>using such a large die to create the thread but if you think it would work
>that would be the most elegant solution. Otherwise I might be able to make
>some stud work. Mark I live in Stansted Essex by the way.
>
>

Think the other helpful replies you got should have sorted you out.

However, FWIW, I had to make a 3/8" BSW drawbar to use UK made (Imperial
drawbar) 2MT stuff on my Emco FB2. For convenience, I wanted it to use
the same allen key as the Emco M10 drawbar (just a long M10 bolt). So I
turned down a short-ish M10 allen screw to fit in a suitable hole
drilled in the top end of a mild steel rod with a 3/8" BSW thread at the
bottom end. Loctited the two together, wasn't sure it would be strong
enough but it has functioned perfectly (with some pretty stiff releases
due to over-enthusiastic tightening!) for almost 20 years. Always nice
not to have to grovel around choosing looking for the right allen key!

David
--
David Littlewood
Old Jan 12, 2008, 05:47 PM
Steve
Guest
n/a Posts
Re: Drawbar thread


"David Littlewood" <david@nospam.demon.co.uk> wrote in message
news:WHPipHEEuUiHFw0O@dlittlewood.co.uk...
> In article <uDdhj.59595$wD5.2590@newsfe3-gui.ntli.net>, Richard Bradshaw
> <richardt.bradshaw@tesco.net> writes
>>Thanks for all the replies. The drawbar I have is literally a long bolt.
>>M12
>>thread on one end and shaped for a 17mm spanner on the other so there is
>>no
>>problem with trying to match to a metric nut. I was a little nervous of
>>using such a large die to create the thread but if you think it would work
>>that would be the most elegant solution. Otherwise I might be able to make
>>some stud work. Mark I live in Stansted Essex by the way.
>>
>>

> Think the other helpful replies you got should have sorted you out.
>
> However, FWIW, I had to make a 3/8" BSW drawbar to use UK made (Imperial
> drawbar) 2MT stuff on my Emco FB2. For convenience, I wanted it to use the
> same allen key as the Emco M10 drawbar (just a long M10 bolt). So I turned
> down a short-ish M10 allen screw to fit in a suitable hole drilled in the
> top end of a mild steel rod with a 3/8" BSW thread at the bottom end.
> Loctited the two together, wasn't sure it would be strong enough but it
> has functioned perfectly (with some pretty stiff releases due to
> over-enthusiastic tightening!) for almost 20 years. Always nice not to
> have to grovel around choosing looking for the right allen key!
>
> David
> --
> David Littlewood


My mill has a 3/8 BSW drawbar - for 12mm I just cut a length of studding
popped on two nuts and locked them together. Used for the last two years
with no probs.

Steve

 


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