Dragging Cassette tapes

[wlgrant6]

I find that a lot of older cassette tapes are dragging, sometimes to the point
of stopping completely. When you spin the reels in the cassette, they turn
freely, but when the tape is pushed against the pressure pad that keeps the
tape pressed to the head, then there is excess friction. It isn't a weak motor
in the deck, as I have 5 decks, and they all do this. Has anyone else observed
this, and does anyone have a solution?

 

[oldvinyldude]

Great question-just picked up a 1980 release, and it squeals and drags like crazy. I wonder if putting the tape in a good shell would solve it?

 

[wlgrant6]

I'm sure that would help, but then you would lose the song info on the old shell. A bit of powdered graphite applied judiciously about the reel pivots might cure the dragging in this case. Good luck

 

[1tumbleweed]

The old standby cure was to rap the cassette against a table a time or two - that would flatten out the tape pack. Winding from one end to the other works sometimes too.

As far as squeaking: If it's the tape against the heads, you're out of luck - the lubricant in the binder has dried out. Happens a lot with old prerecorded tapes. Crappy "duplicator grade" tape. If it's one of the guide wheels squeaking, then yes, a touch of graphite will quiet it down.

 

[oldvinyldude]

The old standby cure was to rap the cassette against a table a time or two - that would flatten out the tape pack. Winding from one end to the other works sometimes too.

Tried that-rapping did not help. Fast winding would halt mid way through, as if end of tape was sensed. Different shell might help there, or the graphite trick might, but I am concerned about loose graphite in the headblock area.

As far as squeaking: If it's the tape against the heads, you're out of luck - the lubricant in the binder has dried out. Happens a lot with old prerecorded tapes. Crappy "duplicator grade" tape. If it's one of the guide wheels squeaking, then yes, a touch of graphite will quiet it down.

Not sure if it's the tape on the head or the shell, or both-a veritable 'symphony of squeals coming from the deck! Oh well-it's a $.75 tape, so not going to ruin my day.....

 

[Numistrek09]

How does your head and guides look after playing this tape? Though not as common on cassettes as in R2R, sticky shed syndrome has been known in the cass world too.

 

[BruceRPA]

The old standby cure was to rap the cassette against a table a time or two - that would flatten out the tape pack. Winding from one end to the other works sometimes too.

As far as squeaking: If it's the tape against the heads, you're out of luck - the lubricant in the binder has dried out. Happens a lot with old prerecorded tapes. Crappy "duplicator grade" tape. If it's one of the guide wheels squeaking, then yes, a touch of graphite will quiet it down.

Agreed, especially the part about winding the tape in both directions from end-to-end without stopping. That, after a good sharp rap or two on the edge of a table for good measure may help as Mr 1tumbleweed suggests will solve many tape handling issues with cassette tapes.

The symptoms also suggest that the drive belts and/or idler wheel surfaces are getting old, hard, and worn out. A LITTLE bit of belt conditioner may solve the problem temporarily. Sometimes temporarily can be quite a long time. Try something like this stuff: http://www.mcmelectronics.com/product/20-230

 

[dr*audio]

If these are pre-recorded tapes, throw them out. Many are made with inferior tape or housings. That's the reason for the excessive tension. You will ruin your heads with tapes like this and there is no fix for them.

 

[perryinva]

The old standby cure was to rap the cassette against a table a time or two - that would flatten out the tape pack. Winding from one end to the other works sometimes too.

As far as squeaking: If it's the tape against the heads, you're out of luck - the lubricant in the binder has dried out. Happens a lot with old prerecorded tapes. Crappy "duplicator grade" tape. If it's one of the guide wheels squeaking, then yes, a touch of graphite will quiet it down.

+1 exactly. I have all new rubber, fully restored Nakamichi decks that will not drive a bunch of old pre-recorded tapes with the exact same symptoms. It's the tape dragging, but not from the pressure pads, as the Naks have pad lifters. In fact, the problem is far worse with dual capstan decks, and MOST times a good single cpastan deck has no problems with the same tape, which lends me to think it is indeed the loss of tape lube and the noise/binding is from the tape not slipping between the supply capstan and pressure roller.

 

[vidguy]

I have had the occasional issue with my Dragon not wanting to play a tape, FF or RR for a few seconds always cures it.

Is it not an issue the slip sheets in the shell?

 

[goldear]

It sounds like you are talking about sticky-shed to me. Most R2R people are extremely familiar with this, but the cassette crowd not so much.

Throw the tape into a food dehydrator at 130 degrees F, for two hours, and let it cool for another hour, and I'll bet that your problem stops for about 1 month.

 

[eclectik]

. In fact, the problem is far worse with dual capstan decks, and MOST times a good single cpastan deck has no problems with the same tape, which lends me to think it is indeed the loss of tape lube and the noise/binding is from the tape not slipping between the supply capstan and pressure roller.

Agree. I have numerous prerecorded tapes from the early 1980s which presumably have lubricant (and in some extreme cases, binder) breakdown. The spools turn freely but there is excess friction against the heads, slowing it down in play. Often there is audible squeal; sometimes the deck just stops.

As mentioned above, on borderline tapes, decks with the fewest components in the tape path usually work best: i.e. cheapo boomboxes with a permanent magnet erase head which swings out of the way in playback, single capstan, no tape end tension arm etc. However, even these will eventually succumb to the tape friction problem and grind to a halt.

Another problem is if they won't even wind properly, try gently squeezing the hubs and try again. If this cures it, a new shell may help.

 

[Wilhem]

There are a number of causes for excess friction within the cassette. The most common one is uneven tape winds that have multiple layers of uneven tape contact the slip sheets to such a degree that motors have difficulty pulling the tape. Deformed slip sheets also cause this problem. The solution in these situations is to fast forward/reverse the tape packs end to end in order to redistribute the pressures and evenness of the winds. Rapping the cassette sometimes works, but at the risk of damaging a tape edge.

Another cause is layer-to-layer sticking in the tape pack itself. This is caused by intense internal pressure from sudden and dramatic changes in temperature and humidity during the storage of the cassette. The fast forward/reverse solution works in these cases unless the oxide layers are damaged by adhesion to the base film. Cross-linked formulations are more likely to face the problem of oxide being pulled from the base film.

Oxidation of the metal pins acting as roller guide shafts can be another cause. Improper storage and insufficient lubricant on the pins contribute to the oxidation. Fast forwarding/reversing does not help much, and the squealing of the rollers over the pins is evidence of this problem. The solution is a transfer of the tape/hubs to a better housing.

None of these causes fits the symptoms described here. It sounds as though the tape coating has released some its chemical formulation as a sticky, invisible waxy substance on the heads. (This is NOT the same thing as what is referred to as "sticky shed." For one thing, there is no shedding. For another, the notorious polyurethane binder that was the cause of the breakdown in open-reel formulations was not used for audio cassette dispersions. Suggesting the "cure" for one illness that is not related to the present illness is akin to suggesting penicillin for a broken arm.) In this case the tape is permanently damaged, but it might be recovered by heating it enough to disperse the surface wax. On the other hand, heating may release more of the substance and worsen the problem. Symptoms of this kind of problem are inability to get the tape to move across the heads or terrible squealing--audible both from the machine and through the speakers as the tape creates awful modulation distortion through the playback head--as the motor pulls the tape across the heads while it sticks, releases, and sticks again.

In any case, the tape will leave invisible residue on all the heads that will require thorough cleaning because that residue will pass the stiction problem on to the next tape that is used in the transport. You might want to blame the second tape even though it is innocent. The problem is the residue left by the first tape. This is a defect known to a number of different formulations over time and has nothing to do with the "duplicator" tape category by itself.

 

[eclectik]

The problem is the residue left by the first tape. This is a defect known to a number of different formulations over time and has nothing to do with the "duplicator" tape category by itself.

You are spot -on with the description. There just does not seem to be any 'shedding' with these tapes, just the horrible modulation noise as they stick and unstick many times a second as they pass by the heads.

I have had problems with quite a few USA -made cassettes on Warners/Elektra and MCA labels. Also with some UK tapes: Epic/CBS, WEA and EMI /Harvest. All from roughly 1979-1983. I have to say, I haven't ever had this to anywhere near the same extent with off the shelf blanks, so it does seem like there was some bad duplicator tape about.

 

[Bob]

My experience is that the slip sheets on either side of the reels are bad. you can either open them (break the glue/heat seals) and replace the sheets or move the reels to a different cassette shell.

Most of the recordable cassettes have screws that allow this transfer.

Just keep the two shells the same for recording types and if its a
pre-recorded then break off the tab that allows recording.

Bob

 

[Cadillac Kid]

My experience is that the slip sheets on either side of the reels are bad.
Bob

I was going to post that but got lazy and distracted.

 

[eclectik]

We still have not ascertained whether this problem is mechanical (shell, slip sheets, jamming spools etc) or tape-based (binder/lubricant breakdown, wax etc) in origin. Perhaps the OP can do a few more tests.

 

[Wilhem]

When you spin the reels in the cassette, they turn
freely, but when the tape is pushed against the pressure pad that keeps the
tape pressed to the head, then there is excess friction.

This symptom rules out bad slip sheets.

In 1979-83 the chief source of ferric duplicator tape were, in order: Agfa, Capitol, BASF, Audio Magnetics, Ampex.

 

[oldvinyldude]

I have had problems with quite a few USA -made cassettes on Warners/Elektra and MCA labels.

Yes-my recent example is an MCA tape.

Good to hear described symptoms on the topic, so I can decide to transfer the tape to a better shell, or in my case with the MCA tape mentioned, I will look for another copy on different media.

 

[santacruz360]

I find that a lot of older cassette tapes are dragging, sometimes to the point
of stopping completely. When you spin the reels in the cassette, they turn
freely, but when the tape is pushed against the pressure pad that keeps the
tape pressed to the head, then there is excess friction. It isn't a weak motor
in the deck, as I have 5 decks, and they all do this. Has anyone else observed
this, and does anyone have a solution?