18 Apr
2010
18 Apr
'10
10:34 a.m.
I have a number of HP QIC tape drive units -- I think it's 2 off 9142, 3
off 9144 (1 3-board, the other 2 are single-board) and a 9145 [1] all
with hte same problem. The rubber capstan has turend to goo.
[1] There's a darn 68000 processor in that drive, unlike the 68B09s in
the other units. Eeek!
The capstan is a rubber 'tyre' on a metal hub, the latter being glued to
the motor spidnle. The diameter of the hub is around 12mm (but I wil
measure that accurately) and the overall diameter of the tyre is perhaps
18mm (it's going to be hard to measure, sure the fact I don't have a
solid one :-()
Anyway, does anyone have any suggestions as to suitable material that I
can obtain in the UK to repair this? Assume as ever I have a reasonable
workshop and am not affraid to pull the drives to bits :-)
-tony
18 Apr
18 Apr
10:50 a.m.
I too need some rollers, in a past life we had a company making rubber
rollers for us, they would mould the rubber on (neoprene iirc) and
then freeze then grind
Dave Caroline
On Sun, Apr 18, 2010 at 6:34 PM, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
I have a number of HP QIC tape drive units -- I think
it's 2 off 9142, 3
off 9144 (1 3-board, the other 2 are single-board) and a 9145 [1] all
with hte same problem. The rubber capstan has turend to goo.
[1] There's a darn 68000 processor in that drive, unlike the 68B09s in
the other units. Eeek!
The capstan is a rubber 'tyre' on a metal hub, the latter being glued to
the motor spidnle. The diameter of the hub is around 12mm (but I wil
measure that accurately) and the overall diameter of the tyre is perhaps
18mm (it's going to be hard to measure, sure the fact I don't have a
solid one :-()
Anyway, does anyone have any suggestions as to suitable material that I
can obtain in the UK to repair this? Assume as ever I have a reasonable
workshop and am not affraid to pull the drives to bits :-)
-tony
11:26 a.m.
I too need some rollers, in a past life we had a company making rubber
rollers for us, they would mould the rubber on (neoprene iirc) and
then freeze then grind
I am told that for most 'rubbers' you want to keep it at about the
temperature of dry ice (solid CO_2). At that temperature it can be
machinedrelatively easiy. Any colder, and it behaves like glass.
I don't have a soruve of suitable rubber compoind though. There are the
omes made by Devcon, but they are not cheap (particularly not if you
follow the instructions and mix the entire pack at one time!) I would
also have to make a suitable mould, but I think that is possible.
-tony
10:50 a.m.
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] Namens Tony Duell
Verzonden: zondag 18 april 2010 19:35
Aan: cctalk at classiccmp.org
Onderwerp: Suggestions for repairing HP tape drive capstans?
I have a number of HP QIC tape drive units -- I think it's 2
off 9142, 3 off 9144 (1 3-board, the other 2 are
single-board) and a 9145 [1] all with hte same problem. The
rubber capstan has turend to goo.
[1] There's a darn 68000 processor in that drive, unlike the
68B09s in the other units. Eeek!
The capstan is a rubber 'tyre' on a metal hub, the latter
being glued to the motor spidnle. The diameter of the hub is
around 12mm (but I wil measure that accurately) and the
overall diameter of the tyre is perhaps 18mm (it's going to
be hard to measure, sure the fact I don't have a solid one :-()
Anyway, does anyone have any suggestions as to suitable
material that I can obtain in the UK to repair this? Assume
as ever I have a reasonable workshop and am not affraid to
pull the drives to bits :-)
-tony
Tony,
I use rubber precision pipes (a special kind of rubberhose).
Diameters for the 9144 are inside 6/16 outside 7/16 inch.
I glue the with polypurethane glue and grind to the right size using
sandpaper 150 (3M wet or dry)
I finish the capstands with a sandpaper 400 so the surface is smooth.
For the HP85 / 9825 /9835 tapedrives I use a 6.5mm citroen hydraulic rubber.
-Rik
11:24 a.m.
I use rubber precision pipes (a special kind of
rubberhose).
Deoes anyone know a UK supplier of small-ish quantities (I do not want to
buy 100m of the stuff ;-)).
Diameters for the 9144 are inside 6/16 outside 7/16
inch.
Do you mean that? The roller is a lot larger than that. OK, it would
stretch onto the hub, but surely if the inisde diameter is 3/8" (6/16")
and the outside is 7/12", them the wall thicknerss is only 1/32". And
the old tyre looks a lot thicker than that.
I glue the with polypurethane glue and grind to the
right size using
sandpaper 150 (3M wet or dry)
I asume you run the motor off a bench supply and carefully hold the
abrasive againsit it.
I finish the capstands with a sandpaper 400 so the
surface is smooth.
For the HP85 / 9825 /9835 tapedrives I use a 6.5mm citroen hydraulic rubber.
Is that what I would call a 'sleeve seal'? That is the little rubber seal
you put ove the enf of the pipe before screwing the union down? IIRC they
come in 3 sizes, I assume you need the largest one.
-tony
12:08 p.m.
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] Namens Tony Duell
Verzonden: zondag 18 april 2010 20:24
Aan: cctalk at classiccmp.org
Onderwerp: Re: Suggestions for repairing HP tape drive capstans?
Oops, wrong notes :-(
It should be inside 1/2" outside 11/16"
I use rubber precision pipes (a special kind of
rubberhose).
Deoes anyone know a UK supplier of small-ish quantities (I do
not want to buy 100m of the stuff ;-)).
Diameters for the 9144 are inside 6/16 outside
7/16 inch.
Do you mean that? The roller is a lot larger than that. OK,
it would stretch onto the hub, but surely if the inisde
diameter is 3/8" (6/16") and the outside is 7/12", them the
wall thicknerss is only 1/32". And the old tyre looks a lot
thicker than that. I glue the with polypurethane glue and grind to
the right
size using
sandpaper 150 (3M wet or dry)
I asume you run the motor off a bench supply and carefully
hold the abrasive againsit it.
I finish the capstands with a sandpaper 400 so
the surface
is smooth.
For the HP85 / 9825 /9835 tapedrives I use a
6.5mm citroen
hydraulic rubber.
Is that what I would call a 'sleeve seal'? That is the little
rubber seal you put ove the enf of the pipe before screwing
the union down? IIRC they come in 3 sizes, I assume you need
the largest one.
12:18 p.m.
Oops, wrong notes :-(
It should be inside 1/2" outside 11/16"
RIght... See the other messages for what I believe are the right
dimensions of the finished roller.
[Sleeve seals for 98x5 tape drives)
Yes the sizes are 3.5mm 4.5mm and 6.5mm inside,
it's a special kind of
neopreen which is oil and wear resistant.
Having looked after a BX for 13 years I know them well....
-tony
13 Jun
13 Jun
8:01 a.m.
I use rubber precision pipes (a special kind of
rubberhose).
Diameters for the 9144 are inside 6/16 outside 7/16 inch.
I glue the with polypurethane glue and grind to the right size using
sandpaper 150 (3M wet or dry)
I finish the capstands with a sandpaper 400 so the surface is smooth.
For the HP85 / 9825 /9835 tapedrives I use a 6.5mm citroen hydraulic
rubber.
Someone should concatenate these tips on a web page :)
18 Apr
18 Apr
11:28 a.m.
On Apr 18, 2010, at 10:34 AM, Tony Duell wrote:
the overall diameter of the tyre is perhaps 18mm
(it's going to be
hard to measure, sure the fact I don't have a
solid one :-()
I put a micrometer on the capstan in my 9145A. It had turned to goo,
but not melted yet---so it was intact, but difficult to measure
without deforming. I got a reasonably accurate measurement off it.
Based on experience, this should be close enough to affect a workable
repair (though I haven't gotten to actually doing the repair yet).
HP 9145A 36 Track < 0.800"
That should be read as "just under 0.8 inch."
It was actually harder to clean all the melted capstan residue off the
motor spindle than it was to measure it in the first place. It gets
EVERYWHERE.
ok
bear
11:54 a.m.
On Apr 18, 2010, at 10:34 AM, Tony Duell wrote:
0.8" = 20.32mm Maybe the exact size is 20mm. Although I would normally
expect imperial measurements in an American device, I have noticed that
all the screws in this drive have metric threads. So perhaps it is a
sensible diameter in milimetres.
the overall diameter of the tyre is perhaps 18mm
(it's going to be
hard to measure, sure the fact I don't have a
solid one :-()
I put a micrometer on the capstan in my 9145A. It had turned to goo,
but not melted yet---so it was intact, but difficult to measure
without deforming. I got a reasonably accurate measurement off it.
Based on experience, this should be close enough to affect a workable
repair (though I haven't gotten to actually doing the repair yet).
HP 9145A 36 Track < 0.800"
That should be read as "just under 0.8 inch."
It was actually harder to clean all the melted capstan residue off the
motor spindle than it was to measure it in the first place. It gets
EVERYWHERE.
Indeed. The place to keep it well away from is the slotted tachomter disk
also on the motor spinde.
My method for cleaning invovles a bit of dismantling. Take off the top
cover and front pneal. Unclip and remove the tape door and its torsion
spriong. Remove the cotnroller board (athe tope of the unit), then the 4
screws on the bottom and take the drive mechanism out. Remove the
board(s) from the underside of the sdrive mechanism.
Take off the microswitch assembly (2 screws, but make sure you know which
switch goes on top!). Remvoe the optical BOT/EOPT sensor in a 9142. This
is not essentla but it's fewer things to get gunged up.
Now turn the drive ipside down. See the little plastic part in front of
the mtoor that hoos into the loading mechanism. Remove this (2 screws),
then loosen (or remove) the 2 setscrews holding the motor pivot spindles
in place. Slite out the spidles and lift out the motor assemlby. Recover
the spirng and 3 insulating bushes. Note that hte motor is insulated from
the drive chassis (the drive chassis is connected to logic groudn, the
motor to power groudn, these are connected in the PSU only). Remove the
tacho senso from the motor (1 screw).
Now clean off as much of the gunge as you can using kitchen paper and
propan-2-0;. Start with dry paper (it will remove much of the gunge),
then clean up witht he alcohol. Then connect the motor to a bench supply
anf give it about 12V (it's not critical). You can now clean it using
paper or cotton buds dipped in propan-2-ol. You won't get it perfect, but
it comes a lot cleaner that way.
-tony
12:11 p.m.
I put a
micrometer on the capstan in my 9145A. It had turned to goo,
but not melted yet---so it was intact, but difficult to measure
without deforming. I got a reasonably accurate measurement off it.
Based on experience, this should be close enough to affect a workable
repair (though I haven't gotten to actually doing the repair yet).
HP 9145A 36 Track < 0.800"
That should be read as "just under 0.8 inch."
0.8" = 20.32mm Maybe the exact size is 20mm. Although I would normally
expect imperial measurements in an American device, I have noticed that
all the screws in this drive have metric threads. So perhaps it is a
sensible diameter in milimetres.
12:58 p.m.
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] Namens Tony Duell
Verzonden: zondag 18 april 2010 21:11
Aan: cctalk at classiccmp.org
Onderwerp: Re: Suggestions for repairing HP tape drive capstans?
would normally
I could be wrong but my notes (about 2 years old) tells my 12.7mm (1/2")
inside and 17,5 (11/16) outside.
Tube thikness ~2.4 mm.
I used a 10/15 tube it has a tight fitting and I'm using it until today.
I use the same tube to fix the TU-58 works very well.
> I put a micrometer on the capstan in my
9145A. It had
turned to goo,
> but not melted yet---so it was intact, but
difficult to measure
> without deforming. I got a reasonably accurate measurement off it.
> Based on experience, this should be close enough to affect a
> workable repair (though I haven't gotten to actually
doing the repair
yet).
HP 9145A 36 Track < 0.800"
That should be read as "just under 0.8 inch."
0.8" = 20.32mm Maybe the exact size is 20mm. Although I expect imperial measurements in an American
device, I have noticed
that all the screws in this drive have metric threads. So
perhaps it
is a sensible diameter in milimetres.
Furter hto this. I've just put the micrometer on the
(cleaned) hub of the
9144 that's on my bench. It measues 0.5925". This is almost
exactly 15mm, and I suspect that's what it should actually
be. Which makes a metric dimension for the outside diameter
more likely.
So I guess the 'tyre' is 15mm I/D, 20mm O/D (which would give
a wall thichness of 2.5mm). Now to find some suitable tubing...
I am pretty sure that all these drives use the same size capstan, BTW.
-Rik
19 Apr
19 Apr
11:18 a.m.
HP 9145A 36
Track < 0.800"
That should be read as "just under 0.8 inch."
0.8" = 20.32mm Maybe the exact size is 20mm. Although I expect imperial measurements in an American
device, I have noticed
that all the screws in this drive have metric threads. So
perhaps it
is a sensible diameter in milimetres.
Furter hto this. I've just put the micrometer on the
(cleaned) hub of the
9144 that's on my bench. It measues 0.5925". This is almost
exactly 15mm, and I suspect that's what it should actually
be. Which makes a metric dimension for the outside diameter
more likely.
12:50 p.m.
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] Namens Tony Duell
Verzonden: maandag 19 april 2010 20:18
Aan: cctalk at classiccmp.org
Onderwerp: Re: Suggestions for repairing HP tape drive capstans?
I willcheck again. I doubt I was 0.1" out, but it's always
possibel I made an error reading the micrometer.
Of course a 1/2" I/D tube would be a tight bit on a 15mm hub
which could well be an advantage.
I will also admit I've not opeened all the tape drives
recently. It's possible I still ahve one good capatan that I
could measure. The 2 I've looked at so far (one 9142, the
other a 3-board 9144 have turend to goo, though).
-tony
I can't acces my HP 9144 at the moment but I opened up a 7946 whitch has a
9144 tapedrive build in.
And the sizes of the capstan are consistent with the ones you're measured.
So now it's for me the question where did I measured the other sizes
.................
-Rik
> > > HP 9145A 36 Track <
0.800"
> > >
> > > That should be read as "just under 0.8 inch."
> >
> > 0.8" = 20.32mm Maybe the exact size is 20mm. Although I
> would normally
> > expect imperial measurements in an American device, I
have noticed
> > that all the screws in this drive have
metric threads. So
> perhaps it
> > is a sensible diameter in milimetres.
>
> Furter hto this. I've just put the micrometer on the
> (cleaned) hub of the
> 9144 that's on my bench. It measues 0.5925". This is
almost exactly
> 15mm, and I suspect that's what it
should actually be.
Which makes a
metric
dimension for the outside diameter more likely.
I could be wrong but my notes (about 2 years old) tells my 12.7mm
(1/2") inside and 17,5 (11/16) outside.
20 Apr
20 Apr
11:21 a.m.
I can't acces my HP 9144 at the moment but I opened up a 7946 whitch has a
9144 tapedrive build in.
And the sizes of the capstan are consistent with the ones you're measured.
OK...
So now it's for me the question where did I
measured the other sizes
.................
Hmmm.. If it was HP, it's not something like the roginal size of the
HP98x5 capstan, is it?
-tony
3:45 p.m.
Hi
How is the speed controlled of the tape speed?
If it is a feedback of some type, the diameter may not need to be exact.
If not, knowing the linear speed of the tape and the
capstan rotational speed, one could determine the correct diameter.
Dwight
From: ard at p850ug1.demon.co.uk
_________________________________________________________________
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I can't acces my HP 9144 at the moment but I opened up a 7946 whitch has a
9144 tapedrive build in.
And the sizes of the capstan are consistent with the ones you're measured.
OK...
So now it's for me the question where did I
measured the other sizes
.................
Hmmm.. If it was HP, it's not something like the roginal size of the
HP98x5 capstan, is it?
-tony
21 Apr
21 Apr
10:58 a.m.
Hi
How is the speed controlled of the tape speed?
If it is a feedback of some type=2C the diameter may not need to be exact.
It is a closed-loop system (with feedback), but unfortunaetely the
feedback is not taken off the tape.
The drive motor is a permanent-magnet DC motor. The capstan roller is
directly fitted (glued :-() to the spindle of that motor, and below it is
a slotted disk (I have no idea how mant slots, but it's a lot, possibly
around 200). There's a slotted opto-switch fitted to the motor housing
that straddles this disk.
The electronics varies with the model of drive. But it's somewhat similar
in all cases -- there's a 6805 microcontroller that takes the input from
this sensor (in the 9144 for some unknown reason, the esnsor feeds a 2917
F->V chip, the output of that is fed into am ADC circuit, the 9142 does
things more coventionally, and I don't know about the 9145 -- yet). The
microcontroller drives a DAC which then drives a full-H driver that
feeds this motor.
So the spindle speed is regulated, but the tape speed also depends on the
diameter of the capstan roller.
If not=2C knowing the linear speed of the tape and
the
capstan rotational speed=2C one could determine the correct diameter.
I;'d have to measure a couple of rollers in the tape cartridge too (but
that would be easy enough). I could easily measure the rotational speed
of the spindle. All I need to find out is the correct tape speed for
these drives. IOt may be in HP Journal or soemthing like that...
-tony
18 Apr
18 Apr
3:15 p.m.
On Sunday, April 18, 2010 at 19:54, Tony Duell wrote:
Although I would normally expect imperial measurements
in an American
device, I have noticed that all the screws in this drive have metric
threads.
Is it an American device? I've never seen one, but all of the
9144/45/35401 manuals appear to have been printed in the UK. Does the
serial plate list the country of manufacture?
-- Dave
19 Apr
19 Apr
2:57 a.m.
-----Oorspronkelijk bericht-----
Van: cctalk-bounces at classiccmp.org
[mailto:cctalk-bounces at classiccmp.org] Namens J. David Bryan
Verzonden: maandag 19 april 2010 0:15
Aan: Classic Computing List
Onderwerp: Re: Suggestions for repairing HP tape drive capstans?
On Sunday, April 18, 2010 at 19:54, Tony Duell wrote:
Classic >1960 HP serials always mention the country of production.
Format XX (year +1960) XX (month) Y (country code) XXXXXXXXXXXX (serial)
2823G123456 made year 1988 week 23 in Germany serial 123456
A = USA
G = Germany
F = France
S = Signapore
B = Brazil
-Rik
Although I would normally expect imperial
measurements in
an American
device, I have noticed that all the screws in
this drive
have metric
threads.
Is it an American device? I've never seen one, but all of the
9144/45/35401 manuals appear to have been printed in the UK.
Does the serial plate list the country of manufacture?
-- Dave
12:11 p.m.
Classic >1960 HP serials always mention the country
of production.
Format XX (year +1960) XX (month) Y (country code) XXXXXXXXXXXX (serial)
2823G123456 made year 1988 week 23 in Germany serial 123456
Indeed.
A = USA
G = Germany
F = France
S = Signapore
B = Brazil
Some others that I have seen
E = England
J = Japan
K = Korea
(The last 2 I've seen on monitors made by NEC and Samsung respectively,
but badged HP. They have an HP style serial number.)
I've alsoe heard that 'Q' was used for England at one point, but I have
never come across this.
Getting back to tape drives, the units I'ev looked at are, indeed made in
England (with an 'E' in the serial number). I've also just stuck a ruler
on the metal hub of the capstan from the 9144, it measures 15mm, and is
considerably more that 1/2". Of coruse a ruler is not as accurate as a
micrometer, but it suggests that my measurements from the latter tool
could be correct.
-tony
12:26 p.m.
I don't think you can say with complete assurance that a device is or isn't USian
based on whether it has standard or metric fasteners. In the automotive industry for
example, it was very common (particularly on Ford cars) that all fasteners on the engines
were metric, way back into the early 1980s, whereas everything else on the car was
standard. These days I think most all car fasteners are metric.
That said, it is very common for standard measurements to be used in mechanical designs
these days.
________________________________
From: Tony Duell <ard at p850ug1.demon.co.uk>
To: cctalk at classiccmp.org
Sent: Mon, April 19, 2010 2:11:39 PM
Subject: Re: Suggestions for repairing HP tape drive capstans?
Classic >1960 HP serials always mention the country
of production.
Format XX (year +1960) XX (month) Y (country code) XXXXXXXXXXXX (serial)
2823G123456 made year 1988 week 23 in Germany serial 123456
Indeed.
A = USA
G = Germany
F = France
S = Signapore
B = Brazil
Some others that I have seen
E = England
J = Japan
K = Korea
(The last 2 I've seen on monitors made by NEC and Samsung respectively,
but badged HP. They have an HP style serial number.)
I've alsoe heard that 'Q' was used for England at one point, but I have
never come across this.
Getting back to tape drives, the units I'ev looked at are, indeed made in
England (with an 'E' in the serial number). I've also just stuck a ruler
on the metal hub of the capstan from the 9144, it measures 15mm, and is
considerably more that 1/2". Of coruse a ruler is not as accurate as a
micrometer, but it suggests that my measurements from the latter tool
could be correct.
-tony
12:39 p.m.
I don't think you can say with complete assurance that a device is or
isn't USian based on whether it has standard or metric fasteners. In the
True enough. However, the small-size UNC and UNF threads (things like
4-40 UNC) are very uncommon in non-US equipment.. And I suspect BA (or
for that matter BSF, BSW) are very uncommon in anything that wasn't made
in the UK. Apart from 1/4" BSW, of course.
automotive industry for example, it was very common
(particularly on
Ford cars) that all fasteners on the engines were metric, way back into
the early 1980s, whereas everything else on the car was standard. These
days I think most all car fasteners are metric.
I read somewhere that British Ford cards oold in the 980s over here had
mostly UNC and UNF botls, but the gearbox was built with entirely metric
fasteners. You needed 2 sets of spanners to work on the car.
I was also told by somebody who worked for Myford that they had saved a
fair amount of money by changing from BSW to metric bolts in some parts
of the Super 7 lathe. The point being that the metric ones were made in
much larger qunatities so they were cheaper. And of course it doesn't
make any real difference to the functioning of the machine
-tony
11:35 a.m.
On Sunday, April 18, 2010 at 19:54, Tony Duell wrote:
I thought the original 9144 was an American design/build, production was
later moved to England (Bristol) around the time the 3-board version was
introduced (that is, when the host interface and the device dependant
controller were all built on one PCB called 'SBcont'). I think 9145s were
all built in England, I am not sure about he 9142.
Certainly my 9144 and 9145 units are made in England (they say so on the
nameplate and have an 'E' in the serial number). On the other hand, I
would have expected the same screws and threads to be used throughout the
production run.
However, HP certianly did use metric threads. The Integral is full of
them, for example (the expansion PCB fixing thumbscrews are certainly
metric, I had to make one. As are most of the internal fixings. And of
course the HPIB jackscrew is M3.5
So perhaps I shouldn't have been suprised to find metric screws in these
tape drives.
-tony
Although I would normally expect imperial
measurements in an American
device, I have noticed that all the screws in this drive have metric
threads.
Is it an American device? I've never seen one, but all of the
9144/45/35401 manuals appear to have been printed in the UK. Does the
serial plate list the country of manufacture?
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22 comments
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