HP-85 Belts needed/drive wheel repair

From: Stan Perkins <stan_at_netcom.com>
Date: Thu Feb 18 14:33:33 1999

To all,

I've found an easy way to replace the gooey drive wheels on the HP
cartridge drives as found in the HP-85, 9825, 9815, and other devices.

First, remove the drive motor/drive wheel assembly from the tape drive
assembly. Be careful not to break any of the wires going to the motor,
tape head, opto sensors, etc.!

Next, scrape of the goo remaining from the old hub. Once the majority is
removed, use an acetone-soaked rag to get down to the bare aluminum hub.

Next, cut three pieces of heat-shrink tubing whose diameter will allow
them to just fit over the bare hub (it's either 1/2" or 3/4"--I don't
remember offhand). Each piece should be about 1/2" long.

Slip the first piece over the hub and center it vertically. Shrink it
down with a heat gun or hair dryer. Slip the second over the first and
shrink it. Likewise with the third piece. Leave the "overlap" of the
tubing above and below the wheel. This helps to hold the tubing on the
hub and doesn't affect the operation of the drive.

Reassemble the tape drive mechanism.

After a bit of practice, I can usually get a tape drive rebuilt in 15 or
30 minutes. So far, they have all worked fine. The drive wheel is a bit
harder than the original rubber wheel, but it doesn't slip, as far as I
can tell. The only caveat is that it's probably not a good idea to leave
a tape in the drive (e.g., for autostart purposes) for long periods as
the harder drive wheel *may* dent the wheel in the tape cartridge.

Hope this helps!
Stan


Joe wrote:
>
> At 10:48 AM 2/18/99 -0500, you wrote:
> >On Thursday, February 18, 1999 4:58 AM, Joe [SMTP:rigdonj_at_intellistar.net]
> >wrote:
> >> At 04:09 PM 2/17/99 -0500, you wrote:
> >> >Michael,
> >> >
> >> >Are those belts problematic?
> >>
> >> Yes, the belts and the drive wheel for the tape drives disintegrate
> >with
> >> age.
> >
> >
> >Looking at my machine, I can see that the drive wheel for the tape drive is
> >pretty funky. I haven't tried to use it (don't have a cartridge) but, it'll
> >probably fail.
>
> Don't try to use the drive with a "gooy" wheel. The goo gets into the
> tape and sticks it together then when you try the tape in a good drive, the
> tape stickes to itself and the drive breaks it.
> >
> >Is there a common source for drive wheels?
>
> NO, but I've been working on finding a way to rebuild them. Partial
> success so far.
>
> >What about the cartridges?
>
> They can be found. There were some on E-bay recently. They turn up at
> hamfest and surplus outlets.
>
> Joe
> >
> >Thanks,
> >
> >Steve Robertson - <steverob_at_hotoffice.com>
> >
> >
> >
Received on Thu Feb 18 1999 - 14:33:33 GMT