Gummed encoders on Cipher Drives

[NeXT]

Both of my rackmount Cipher 9-track drives have a little arm with a wheel on the end that on one end has some sort of rotary encoder and on the other end rests against the take-up spool. Both of my drives it seems has an issue where the bearing or something in that assembly has gummed up resulting in erratic self-test failures (rear motor error) or failed reads/writes/advences. I can't figure out how to remove the arm to lubricate it. Was this a common problem? Both of my drives came from different environments. One was in a shed for 20 years and the other was taken out of use a month or two before I found it.

 

[Chuck(G)]

Might there be some rubber involved? Are these 990 drives?

 

[NeXT]

Indeed it's a 990.
The wheel is coated with something but it's definately not rubber. It makes it just grippy enough that it won't slip when in use. The rest of the assembly that I can see is anodized aluminum and steel.

 

[Chuck(G)]

See page 5-27 in the in the tech manual. I suspect a dry or gummy bearing (there are two of them).

 

[NeXT]

Ah, so there's a lock washer hidden underneath. Okay I think I know how to oil that up now.

 

[gslick]

Indeed it's a 990.
The wheel is coated with something but it's definately not rubber. It makes it just grippy enough that it won't slip when in use. The rest of the assembly that I can see is anodized aluminum and steel.

I had a nice M4 Data 9914 drive which had a similar issue. The tachometer roller had some sort of thin rubber layer around the metal core, which turned to goo. Removing the goo left a bare metal surface which would not grip the moving tape well enough to correctly sense the tape motion. I never found a working solution to that issue and in frustration eventually just gave that drive away. I wish I had been able to fix that drive as it had a SCSI interface (the Pertec interface was accessible too) and 800 bpi in addition to 1600 and 6250 bpi. My Fujitsu M2444AC doesn't do 800 bpi.

 

[Chuck(G)]

I've found that Tygon is my friend in the case of goo-ed rollers and capstans. Grippier than vinyl, and pretty much impervious to anything. Available in a pretty wide range of sizes, but not cheap.

I'd like to find an 800 bpi PE drive just in case I ever get a tape done with that. A 7-track drive would also be useful.

 

[CTM]

M4 tach roller

M4 tach roller

Did you ever find a way to restore the right type of friction to that tach-roller? (I just ran into a drive that had never been used, but that surface had turned to goo.)

I had a nice M4 Data 9914 drive which had a similar issue. The tachometer roller had some sort of thin rubber layer around the metal core, which turned to goo. Removing the goo left a bare metal surface which would not grip the moving tape well enough to correctly sense the tape motion. I never found a working solution to that issue and in frustration eventually just gave that drive away. I wish I had been able to fix that drive as it had a SCSI interface (the Pertec interface was accessible too) and 800 bpi in addition to 1600 and 6250 bpi. My Fujitsu M2444AC doesn't do 800 bpi.

 

[Al Kossow]

Did you ever find a way to restore the right type of friction to that tach-roller?

Surgical tubing mostly works.

The encoder wheel on the 9914 is EXTREMELY fragile, making it pretty much impossible to remove the shaft.
What is left of the M4 Data /STC product line was bought up by Pinetree Peripherals (they had a bunch of parts up
on eBay but apparently nothing sold) but they were pretty much a waste of time. I sent an entire head assembly
because I didn't want to risk taking the encoder out, and they just returned it without installing a new one (which
was going to be several hundred dollars WITH the other roller in exchange).