17 Jun
2005
17 Jun
'05
10:35 p.m.
On Sat, 18 Jun 2005, Tony Duell wrote:
Right.
Presumably the
roller is secured by a circlip and you can remove it for
No way... It's fixed to the motor spindle, and carries a
tacho disk (with clear
and black lines) at the lower end. This is hidden inside the plastic
chassis of the tape drive, between a light bulb and a phototransistor.
Ok, I didn't realize all that was going on.
I've not had my 9825 apart for some time, but I
can remember that you
take out the complete tape drive unit, and then remove the screws holding
the PCB and mechanism to the mouting bracket. The motor assembly is held
in place by screws from the 'bottom; (non-cartridge-side) of the drive,
but I can't remember if you have to desolder any wires to get it to come
free enough. Then you can remove the setscrew(s) that hold the roller to
the motor and pull it off the spindle. Problem is that the setscrews burr
the spindle, and often the roller doesn't want to shift...
My experience differs, but then I may not have been paying adequate
attention.
I had to remove the three screws holding the PCB to the aluminum bracket
so that I could get to the one screw (of three) that attached the tape
unit to the rest of the chassis. Then I could remove the tape unit (after
unplugging the cable). The aluminum bracket has two screws attaching it
to the body of the tape unit. Once those are off, you can extract the
aluminum bracket and get at the roller and read/write head. I couldn't
figure out how to remove the motor so I left it in place.
I couldn't find any of the recommended materials at the local hardware
store (never even heard of Tygon) but I did find latex tubing, and I
figured that would work just as well as anything. I cleaned off most of
the old roller material and decided to leave in place what I couldn't
scrape off to work as a sort of adhesive (that stuff is sticky). The
latex tubing had a 1/4" inside diameter and a 3/8" outside diameter. The
diameter of the spindle head is 3/8", so the tight fit gave it added
traction. The thickness of the latex tubing is of course 1/8", which is
about double the thickness of the original roller. But now the spindle
was too thick and was wedged against the read/write head. So I got some
sandpaper and attached a 9V supply to the motor and lathed it down about
1/32". Latex is difficult to cut straight so I also smoothed out the top
and bottom of the ring. Latex boogers were all over the drive mechanism
after that so I blew it out pretty good with compressed air. It now
looked pretty nice; a little rough--a finer grit sandpaper was probably in
order--but passable.
I re-assembled everything and tested it. It had trouble at first: the
drive would start up but then I'd get error 43 (unexpected BOT or EOT or
tape error). I kept re-trying and eventually it seemed to work, but then
I pulled the tape and examined it and it seemed like the tension loop
inside had come undone. I opened the tape casing and, being an idiot,
pulled it apart from the wrong side, and all the internal spindles fell
out. So now I have a thoroughly scrambled tape that I now need to figure
out how to re-assemble (I was supposed to be getting the data off this
tape).
Anyway, more work is in order.
--
Sellam Ismail Vintage Computer Festival
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