Hello,

I have a question about the Unimat SL/DB headstock stem -
I wander how it is attached to the body of the headstock?
I want to reuse the stem but don't want to ruin the headstock.
I assumed that connection is threaded but weren't able to
unscrew. What else could it be - there is significant force
pulling stem out when you tighten the locking bolt. What could
you suggest to detach the stem?

Thanks,
Archi

Archi wrote:

Hello,

I have a question about the Unimat SL/DB headstock stem -
I wander how it is attached to the body of the headstock?
I want to reuse the stem but don't want to ruin the headstock.
I assumed that connection is threaded but weren't able to

Wow, nice pattern! Unintentional...

Archi

Archi wrote:

I have a question about the Unimat SL/DB headstock stem -
I wander how it is attached to the body of the headstock?

Don't know how it's connected, but it could be cast in place?

Jordan wrote:

Archi wrote:

I have a question about the Unimat SL/DB headstock stem -
I wander how it is attached to the body of the headstock?


Don't know how it's connected, but it could be cast in place?

It's different metal. So did you mean that stem (provided it has
some 'fins') had been placed into the mold and the possible used
as the mandrel to machine the bottom of the headstock (for
example)? Then it means that there are no ways to extract the
stem w/o destroying the headstock By the way stem looks
heat-hardened - doesn't it suggest it wasn't heated later
even to the AL temperature?

Thanks,
Arcady

Archi wrote:

Hello,

I have a question about the Unimat SL/DB headstock stem -
I wander how it is attached to the body of the headstock?
I want to reuse the stem but don't want to ruin the headstock.
I assumed that connection is threaded but weren't able to
unscrew. What else could it be - there is significant force
pulling stem out when you tighten the locking bolt. What could
you suggest to detach the stem?

Thanks,
Archi


Archi:
What part of the Unimat head stock are you calling the "stem"? I have
my owner's manual here and once I figure out what part you are referring
to I might be able to help.

Jim Chandler

Jim Chandler wrote:
Archi:
What part of the Unimat head stock are you calling the "stem"? I have
my owner's manual here and once I figure out what part you are referring
to I might be able to help.

The round one going down from the main casing - to be clamped to the
base. This is the e-bay picture of it -

http://cgi.ebay.com/365-Unimat-SL100...pho tohosting

or here if long link would not survive -

http://www.podzam.com/images/3d88_1.jpg

Thank,
Archi

Archi wrote:
Jordan wrote:

Archi wrote:

I have a question about the Unimat SL/DB headstock stem -
I wander how it is attached to the body of the headstock?


Don't know how it's connected, but it could be cast in place?

It's different metal. So did you mean that stem (provided it has
some 'fins') had been placed into the mold and the possible used
as the mandrel to machine the bottom of the headstock (for
example)? Then it means that there are no ways to extract the
stem w/o destroying the headstock By the way stem looks
heat-hardened - doesn't it suggest it wasn't heated later
even to the AL temperature?

Thanks,
Arcady

Things are sometimes made that way. My MZ motorcycle for example had an
iron brake disc, but the centre of it is aluminium alloy - must be cast in.

Here's a blow up from a DB200 parts list. It shows the stem as a
separate part, and the method of holding it with a pin in a groove.
Note that the SL has a different method of clamping the headstock/stem
assembly to the bed, but it's likely the DB method is the same as on the
SL, as regards the stem to headstock question. Worth checking?

http://tinyurl.com/2pagpr

According to Archi :
Jim Chandler wrote:
Archi:
What part of the Unimat head stock are you calling the "stem"? I have
my owner's manual here and once I figure out what part you are referring
to I might be able to help.

The round one going down from the main casing - to be clamped to the
base. This is the e-bay picture of it -

http://cgi.ebay.com/365-Unimat-SL100...pho tohosting

Note that this is only one of the two styles of mounting pin for
the Unimats which you mentioned in the subject line. The one shown is
the one with the SL-1000. The DB-200 (based on what I have read and
seen) had a different system. The pin has a tapered hole which is
encounted by a tapered pin with a threaded straight section on the small
end. It is installed/removed by the same metric Allen wrench, but the
two are not interchangeable -- and the base into which the pin is placed
is also sufficiently different so you can't interchange any of the
headstock, the base, or the screw between the two styles.

And I would be willing to accept that the pin (on the SL-1000 at
least) was machined, probably with fins for gripping, heat treated,
placed in a mould, and the headstock casting poured around it. I'm not
really sure whether the headstock casting is Aluminum or Zamac (zinc
casting alloy which pours at a lower temperature)).

In any case -- instead of trying to extract it from the
headstock, I would measure the part which extends from the headstock
casting, and then machine my own replacement for it. That replacement
could attach to whatever you want to use it on in whichever way is
convenient for you. I would probably thread the hidden part.

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Archi wrote:
Jim Chandler wrote:

Archi:
What part of the Unimat head stock are you calling the "stem"? I have
my owner's manual here and once I figure out what part you are
referring to I might be able to help.


The round one going down from the main casing - to be clamped to the
base. This is the e-bay picture of it -

http://cgi.ebay.com/365-Unimat-SL100...pho tohosting


or here if long link would not survive -

http://www.podzam.com/images/3d88_1.jpg

Thank,
Archi

O.k. I thought tht as what you were referring to but I wanted to be
sure. The manual won't be of any help here but tomorrow when I get home
from work I'll take a look at mine and see what i can come up with. I
have to say that I have never thought of taking it off so I haven't
looked too closely at it. I'll let you know what I come up with.

Jim

Jordan wrote:

Things are sometimes made that way. My MZ motorcycle for example had an
iron brake disc, but the centre of it is aluminium alloy - must be cast in.

Thanks. Looks like I am out of lack.

Here's a blow up from a DB200 parts list. It shows the stem as a

Actually I mislead you by the subj - mine is SL - with grooved pin
and w/o hole. Looking on the pictures I got an idea that this part
was common for both SL and DB.

separate part, and the method of holding it with a pin in a groove.
Note that the SL has a different method of clamping the headstock/stem
assembly to the bed, but it's likely the DB method is the same as on the
SL, as regards the stem to headstock question. Worth checking?

I checked. It does not have any clamping pin. And looking at the
entry point at the bottom and all this webbing around it - there is
no space for any pins. Even thread is very questionable - no any
traces of threading on the visible part of the stem as well as no
traces of machining around the entry point in the casting. I think
that suggested groove/fin and then molding as one piece is the case.

Thanks,
Arcady

DoN. Nichols wrote:

According to Archi :

Note that this is only one of the two styles of mounting pin for
the Unimats which you mentioned in the subject line. The one shown is
the one with the SL-1000. The DB-200 (based on what I have read and

My wrong - I have SL, but got incorrect idea that this part has been
shared among SL/DB.

In any case -- instead of trying to extract it from the
headstock, I would measure the part which extends from the headstock
casting, and then machine my own replacement for it. That replacement

Do not have a lathe It is 20 mm so I could use the drill rod (If
I got lucky with it in this non metric country) but there still be
question of groove (as well as good enough threading).

Thanks,
Archi

PS Which model has been first - SL or DB?

Archi wrote:
Jordan wrote:

Things are sometimes made that way. My MZ motorcycle for example had
an iron brake disc, but the centre of it is aluminium alloy - must be
cast in.

Thanks. Looks like I am out of lack.

Here's a blow up from a DB200 parts list. It shows the stem as a

Actually I mislead you by the subj - mine is SL - with grooved pin and
w/o hole. Looking on the pictures I got an idea that this part was
common for both SL and DB.

separate part, and the method of holding it with a pin in a groove.
Note that the SL has a different method of clamping the headstock/stem
assembly to the bed, but it's likely the DB method is the same as on
the SL, as regards the stem to headstock question. Worth checking?

I checked. It does not have any clamping pin. And looking at the entry
point at the bottom and all this webbing around it - there is no space
for any pins. Even thread is very questionable - no any traces of
threading on the visible part of the stem as well as no traces of
machining around the entry point in the casting. I think that suggested
groove/fin and then molding as one piece is the case.

Thanks,
Arcady

I found a parts list for Unimat SL, and it indicates that the headstock
and stem has only one part number for the combined unit. This may well
mean the stem is cast in place.
Curious: Why did you want to remove it?

Archi wrote:

Which model has been first - SL or DB?

DB came out first.

Jordan wrote:

Curious: Why did you want to remove it?

Wanted to reuse it for some other type of headstock. But if it's not
going out then I have to change my plans

On Wed, 24 Oct 2007 23:24:51 GMT, Archi wrote:

Hello,

I have a question about the Unimat SL/DB headstock stem -
I wander how it is attached to the body of the headstock?
I want to reuse the stem but don't want to ruin the headstock.
I assumed that connection is threaded but weren't able to
unscrew. What else could it be - there is significant force
pulling stem out when you tighten the locking bolt. What could
you suggest to detach the stem?

Thanks,
Archi

Why don't you sign up on the Yahoo Unimat SL/DB group.
A lot of good information there and a nice files section as well.
Dave Foreman

David L. Foreman wrote:

On Wed, 24 Oct 2007 23:24:51 GMT, Archi wrote:


I have a question about the Unimat SL/DB headstock stem -


Why don't you sign up on the Yahoo Unimat SL/DB group.
A lot of good information there and a nice files section as well.
Dave Foreman

Sure thing, Dave! Where was my head - if there is something, then
there is Yahoo group (possible more then one) about this something!

Thanks,
Arcady

Archi wrote:
Jordan wrote:

Things are sometimes made that way. My MZ motorcycle for example had
an iron brake disc, but the centre of it is aluminium alloy - must be
cast in.


Thanks. Looks like I am out of lack.

Here's a blow up from a DB200 parts list. It shows the stem as a


Actually I mislead you by the subj - mine is SL - with grooved pin and
w/o hole. Looking on the pictures I got an idea that this part was
common for both SL and DB.

separate part, and the method of holding it with a pin in a groove.
Note that the SL has a different method of clamping the headstock/stem
assembly to the bed, but it's likely the DB method is the same as on
the SL, as regards the stem to headstock question. Worth checking?

I checked. It does not have any clamping pin. And looking at the entry
point at the bottom and all this webbing around it - there is no space
for any pins. Even thread is very questionable - no any traces of
threading on the visible part of the stem as well as no traces of
machining around the entry point in the casting. I think that suggested
groove/fin and then molding as one piece is the case.

Thanks,
Arcady


It wouyld appear that your question has been answered. I checked mine
and came to the same conclusion. I agree with the person who suggested
machining your own for the other application. good luck.

Jim Chandler

According to Archi :
DoN. Nichols wrote:

According to Archi :

Note that this is only one of the two styles of mounting pin for
the Unimats which you mentioned in the subject line. The one shown is
the one with the SL-1000. The DB-200 (based on what I have read and

My wrong - I have SL, but got incorrect idea that this part has been
shared among SL/DB.

A lot of things were shared between them, but not all, such as
the headstock/pin design, and the mating base. (And, presumably, the
milling adapter.)

In any case -- instead of trying to extract it from the
headstock, I would measure the part which extends from the headstock
casting, and then machine my own replacement for it. That replacement

Do not have a lathe It is 20 mm so I could use the drill rod (If
I got lucky with it in this non metric country) but there still be
question of groove (as well as good enough threading).

That does make things more difficult. Do you have friends with
a lathe of sufficient size? BTW -- you could use inch drill rod say 1",
or as small as 13/16" if you can find that -- and turn it to the needed
diameter -- once you find a lathe to handle it.

[ ... ]

PS Which model has been first - SL or DB?

The DB is first. And it needed the two-part arrangement of
headstock and pin so the headstock could swivel (when loosened) in spite
of the transverse screw through it.

FWIW -- the SL-1000 is the easier to machine without production
fixtures and jigs. That tapered transverse hole -- with threads perhaps
in the base, or perhaps in the pin -- would be more difficult to make.

Good Luck,
DoN.
--
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---