18 Dec
2006
18 Dec
'06
8:38 a.m.
Over the weekend, I got out two old DC-600 tape drives out of storage
- a Wangtek and an Archive. Only the Wangtek has a SCSI-to-QIC24
interface board, but I think I can use that on either drive (the board
may in fact be originally from the Archive drive anyways).
Anyways, after a quick visual inspection and wiping some dust off, I
did try it with an old DC-600 tape cartridge - one that I knew was not
important. It loaded OK and I started an attempt to image the tape to
a file.
About 1/4 into the tape something started vibrating, quickly
escalating and before I could do anything, the tape stopped. Result:
rubber goo on the plastic roller that drives the DC-600 cartridge
drive belt, some on the tape itself, and the tape shows deformation
(wavy) on the top half. I had to toss it.
The drive itself: the rubber roller driving the aforementioned plastic
roller had melted. Clearly visible is the area where the rubber meets
the cartridges' roller - the rubber is notched. Furthermore the
rubber roller is no longer cylindrical. Luckily there seems to be no
other damage to the drive - no rubber seems to have been deposited on
the R/W head.
Any idea what could have caused this and how to prevent it? I now
have two options: I can move the SCSI-to-QIC24 interface to the
Archive drive, but I want to make sure that the same doesn't happen
there. The other option is to remove the melted rubber roller and
steal the one from the Archive drive.
The mechanisms of the drives are different (the Archive has a lever
mechanism, whereas the Wangtek has a spring-loaded push mechanism) so
it's hard for me to tell if I can even move the rubber roller. Is
this maybe a component that can easily be obtained elsewhere?
Any ideas?
Joe.
18 Dec
18 Dec
8:49 a.m.
In article <4affc5e0612180838l182c2bc0ra529b352cd6a65c9 at mail.gmail.com>,
"Joachim Thiemann" <joachim.thiemann at gmail.com> writes:
The drive itself: the rubber roller driving the
aforementioned plastic
roller had melted. Clearly visible is the area where the rubber meets
the cartridges' roller - the rubber is notched. Furthermore the
rubber roller is no longer cylindrical. Luckily there seems to be no
other damage to the drive - no rubber seems to have been deposited on
the R/W head.
Any idea what could have caused this and how to prevent it?
We've discussed the "rubber roller turns to goo" problem here a few
times since I've been on the list in the past couple years. There
isn't much you can do to prevent it other than don't buy old equipment
:-). The problem is that the rubber tends to break down with age and
turns to goo no matter what. Sometimes on old equipment the part has
completely turned to a puddle of goo without even attempting to use
it.
You can attempt to have new rollers manufactured; there are places
that specialize in this. However, the end results are mixed as the
new materials don't necessarily have the same friction properties as
the old materials. Sometimes they are too "grippy" and sometimes they
are too "slippy". You just have to try it and see.
I now
have two options: I can move the SCSI-to-QIC24 interface to the
Archive drive, but I want to make sure that the same doesn't happen
there.
The same could happen there, it would depend on the age of the drive,
the history of its storage (environment can affect material
degradation significantly) and the materials used on the roller.
The other option is to remove the melted rubber roller
and
steal the one from the Archive drive.
I don't know if I'd be brave enough to try that myself :-)
The mechanisms of the drives are different (the
Archive has a lever
mechanism, whereas the Wangtek has a spring-loaded push mechanism) so
it's hard for me to tell if I can even move the rubber roller. Is
this maybe a component that can easily be obtained elsewhere?
You can try Terry's Rubber Rollers & Wheels
<http://www.terrysrubberrollers.com/>
--
"The Direct3D Graphics Pipeline" -- DirectX 9 draft available for download
<http://www.xmission.com/~legalize/book/download/index.html>
Legalize Adulthood! <http://blogs.xmission.com/legalize/>
10:26 a.m.
On 18/12/06 16:49, "Richard" <legalize at xmission.com> wrote:
:-). The problem is that the rubber tends to break
down with age and
turns to goo no matter what. Sometimes on old equipment the part has
completely turned to a puddle of goo without even attempting to use
it.
Ya, the transport rollers in the tape drive for my Sharp MZ80B have wept all
over the metalwork. 'Tis a bit of a mess and will take some undoing......
--
Adrian/Witchy
Binary Dinosaurs creator/curator
Www.binarydinosaurs.co.uk - the UK's biggest private home computer
collection?
9:12 a.m.
"Joachim Thiemann" wrote:
The drive itself: the rubber roller driving the aforementioned plastic
roller had melted.
I don't think it melted. I would guess it suffered a fate oft spoken of
on this list - it "turned to goo".
My primitive understanding is that things like ozone and sunlight cause
the long carbon chains in the material to "relax". And, from the
discussions with a few chemists there is no way to reverse the process.
(keeping them in small plastic bags might help, but I am not qualified
to say, and only before the damage is done, not after)
I have found that various industrial tubing like neoprene, especially
those for food and medical uses, can be used to replace the old rubber.
I've done it with some success as have others here.
But I have not tried it with a dc600 viper. I do have a gummy viper
roller on my desk - I'd like to restore it at some point so if you do
let us know what worked. The trick is getting the diameter right...
-brad
9:42 a.m.
On 18 Dec 2006 at 12:12, Brad Parker wrote:
But I have not tried it with a dc600 viper. I do have
a gummy viper
roller on my desk - I'd like to restore it at some point so if you do
let us know what worked. The trick is getting the diameter right...
For those of us with machine tools, I wonder if a roller can be "fine
tuned" to the proper diameter by fitting an oversize piece of
neoprene tubing to the roller, cooling the whole affair in dry ice,
then machining it (on a lathe) to the proper size. I can't recall
where, but I seem to recall someone mentioning that if frozen hard,
neoprene is actually quite easy to machine.
Has anyone tried this?
Cheers,
Chuck
3:24 p.m.
For those of us with machine tools, I wonder if a
roller can be "fine
tuned" to the proper diameter by fitting an oversize piece of
neoprene tubing to the roller, cooling the whole affair in dry ice,
then machining it (on a lathe) to the proper size. I can't recall
I believe it can, although cooling to liquid nitrogen temperatures is
recomend (if only beacuase it takes longer to warm up again, so you have
longer to take a cut).
I've also heard you _can_ machine 'rubbers' at room temperature, but that
the tools are totally different from those used for metal turning. May be
worth investigarting.
I've not tried either though.
-tony
3:21 p.m.
The drive itself: the rubber roller driving the
aforementioned plastic
roller had melted. Clearly visible is the area where the rubber meets
Not really melted. The material decays (I am not sure what chemically
cuases this). It's a well-knwon problem for old compyter enthusiasts --
HP magnetic card reader rollers are well-known to suffer from this
Baiscailly you have to replace the roller. Replacements that have been
successfully used (depending on the machine, etc) include silcone rubber
O-rings (possibly with a grobe machined in the original hub, or a new hub
made), heatshrink sleeving, silicoe rubber tubing (fuel line for
glow-plug engines, for example), etc.
I've wondered if the 2-pack elastomer materials sold by e.g. Devcon would
work. Make up a mould and cast a new roller. A lot of work, but if it
does the job well it'd be worth it in some cases.
-tony
5:52 p.m.
Joachim Thiemann wrote:
Over the weekend, I got out two old DC-600 tape drives
out of storage
- a Wangtek and an Archive. Only the Wangtek has a SCSI-to-QIC24
interface board, but I think I can use that on either drive (the board
may in fact be originally from the Archive drive anyways).
Anyways, after a quick visual inspection and wiping some dust off, I
did try it with an old DC-600 tape cartridge - one that I knew was not
important. It loaded OK and I started an attempt to image the tape to
a file.
About 1/4 into the tape something started vibrating, quickly
escalating and before I could do anything, the tape stopped. Result:
rubber goo on the plastic roller that drives the DC-600 cartridge
drive belt, some on the tape itself, and the tape shows deformation
(wavy) on the top half. I had to toss it.
Another case of rubber rot... I haven't had it happen to me (except rubber
feet, etc... most recently on a Sun type 5 keyboard... half the left
foot had
turned to goo... the one thing I've found that acclerates this (and damages
some plastics too), is certain vinyl? cabling... this type 5 probably had a
keyboard cable wrapped and in contact with it's foot. I've had some plastic
on computer cases/etc similarly damaged by prolonged contact with cables.
If you are only looking to read... find a newer drive.... I use a Wantek
525Meg QIC drive... it reads DC6150 tapes... and I'm pretty sure DC600
too.
I have a bunch of QIC drives around... I'm going to have to start examining
the rubber rollers.....
I can imagine the old 45 meg ? drive for my Sun-2 is probably toast...
-- Curt
28 Dec
28 Dec
6:15 a.m.
Curtis H. Wilbar Jr. wrote:
turned to goo... the one thing I've found that
acclerates this (and
damages
some plastics too), is certain vinyl? cabling... this type 5 probably
had a
Many many years ago, one of the regular contributors to Television
magazine described how he'd managed to wreck the casing of a TV set he
had in storage by leaving it with the PVC mains cable coiled up on top
of the polystyrene cabinet. It seems the plasticiser leaches out of the
cable, and attacks the polystyrene. I wouldn't be surprised if it
attacked other plastics.
Incidentally, if you use expanded polystyrene wall insulation, this is
why you need to wrap up mains cables in polythene (which isn't
attacked). Otherwise the PVC jacket goes brittle and crumbly...
Gordon
10:21 a.m.
Gordon JC Pearce wrote:
Many many years ago, one of the regular contributors
to Television
magazine described how he'd managed to wreck the casing of a TV set he
had in storage by leaving it with the PVC mains cable coiled up on top
of the polystyrene cabinet. It seems the plasticiser leaches out of the
cable, and attacks the polystyrene. I wouldn't be surprised if it
attacked other plastics.
It's common on old boxed Acorn hardware; I've found a few where the mains
cable has steadily oozed its way through the polystyrene packaging.
Incidentally, if you use expanded polystyrene wall
insulation, this is
why you need to wrap up mains cables in polythene (which isn't
attacked). Otherwise the PVC jacket goes brittle and crumbly...
Interesting, I didn't actually know that - but I got into the habit of putting
the mains cables of aforementioned boxed Acorn stuff into bags as I figured it
would *probably* stop further disintegration (of the packaging; I'm less
worried about the cable as that's easy to replace!)
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9 comments
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participants (9)
-
ard＠p850ug1.demon.co.uk -
brad＠heeltoe.com -
cclist＠sydex.com -
gordon＠gjcp.net -
joachim.thiemann＠gmail.com -
julesrichardsonuk＠yahoo.co.uk -
legalize＠xmission.com -
rescue＠hawkmountain.net -
witchy＠binarydinosaurs.co.uk