Tape machine - sticky rollers

[Martin]

dug out a Ta@#$% 16 track 1" that was lurking around the studio for a while dusted it down, cleaned the heads up and went to put the tape on... stopped it after about 2m of tape because of the strange noise of tape sticking to one of the rubber guide rollers..

question is, can this be remedied with some kind of chemical? or do i have to try and find a replacement roller? a search round the net supplied no answer!

[Howard Jones]

You need to clearly establish whether it is the roller that is sticky or the tape that is shedding, or both. Mind you, deterioration of the rubber compound on the roller isn't atypical nor unusual.

The solution is to replace the roller. If you provide the model number, I can look up the part number for you. You never know, we may have one in stock.

When these rollers get too far gone, they turn into complete gorilla snot. You will need to check that you don't have sticky deposits on your tape as a result.

Howard.

[Ausrock]

If it's an ATR-60 then pinch rollers are still available, Part # 580130640 from Teac Spares Ph: 03 96442466. From memory cost is approx., $180.00.

Of course, double check this info as things may have changed since I replaced mine late last year.

[Howard Jones]

No... Ta@#$% has been handled by Electric Factory for over a year now. No good contacting Teac Australia anymore.
Also, Martin didn't say whether it was the pinch roller or the tacho roller.

[Martin]

thanks howard and ausrock...

can't remember model number off the top of my head, but i dug out the manual (with full schematics!) as well and that will surely tell me

pinch roller i would assume as it pinches against another white small roller that is powered, but this roller is free spinning

some of the tape peeled off onto the roller! but the particular tape i used was the newest of the lot that i have so i'd assume it would still be okay, the roller is sticky to touch however

will get the info tomorrow and post it...

[Ausrock]

Howard,

At the time I was sourcing spares, Teac were still holding stocks of some parts.

Martin,

If necessary, I'll PM the name of the guy I dealt with at Teac.

ChrisO

[Howard Jones]

That's very interesting. The politics of the changeover weren't as smooth as they could have been. I'm intrigued that you were able to get Ta@#$% parts from TEAC late last year.

Howard.

[Adam Dempsey]

If it's just the pinch roller that needs cleaning (probably not by the sound of it) then luke warm water with a drop of washing detergent will do it without risking drying the rubber. Never head cleaner/isopropyl on the pinch roller.

There may be some non-rotating tape guides you can bypass the help facilitate play, if the tension is ok & depending on the machine.



The most boring video I ever saw... "The Head Cleaner".

[Martin]

Model of the Machine is a Ta@#$% MS-16

And yes it is the pinch roller... not sure how it got that way, it hasn't been used for a year or two, i learnt the 'don't let isopropyl near rubber' lesson at audio 'school' but its possible it did get alchohol'd (drunk?) in the past

cant find a particular model number in the manual for the roller itsself...

[mfdu]

i have had a shit of a time getting any info out of electric factory - dont bother with them.
the teac service guy (zoran) now runs his own shop in high st thornbury - ZM electronics. he's a gem. 03) 9482 2942.

chris s.

[Adam Dempsey]

Yeah, I can also recommend Zoran. Always helped us with DAT machine servicing..

[mark rachelle]

zoran is the man for Ta@#$%

[mfdu]

i hate to say i told you so.

he reckons he doesn't have anything for my 32/2 1/4" but anything newer and he can help out.

chris s

[Howard Jones]

I bailed when I saw that the model in question was an MS-16 and not something more recent. The problem with your machine is that the pinch roller has fallen apart with age. It's nothing to do with alcohol etc etc.

Naturally occurring ozone attacks the rubber compund and makes it go sticky and, eventually something like decayed liquorice. The same process also attacks capstan belts inside the machine.

All manufacturers have had parts that suffered from this phenomenon. Revox addressed this in over time by altering the compound from which their pinch rollers were made.

[Adam Dempsey]

It's not likely to have anything to do with ozone - that'd take decades. It is, however, likely that the pinch roller has taken in residue from past use of Ampex tapes. Same can happen (and has) with Otari machines, except those rollers crystallize.
The roller compound is a balance between the roller being resistant to absorbing tape residue under pressure vs the need for it to be pourous to maintain a minimum wrap with the capstan, for constant tape speed.

Best practise is to clean the pinch roller after each session.

Feel free to PM me, Daniel is restoring an 8 track AG440 & may have some MS 16 parts...

[Martin]

yeah it is a pretty old machine, its not exactly a piece of gear that we rely upon day by day but its better to have it as a different colour to use there rather than just be a piece of metal decoration

thanks for all the replys, very helpful!

[Howard Jones]

On the contrary, ozone decay is a significant contributor to rubber going off. As per rollers falling apart all by themselves even when machines are not used for many years.

Of course, all the various compounds and chemicals with which they are attached, such as isopropyl alcohol, also contribute greatly. However, as I say, capstan belts exhibit identical decay and they are inside the machine where no-one puts isopropyl or anything else on them.

Ozone is a highly reactive chemical, naturally occurring in small quantities in nature but generated in larger quantities by motors and the like. The peculiar smell associated with using a power drill is ozone.

Howard.

[Adam Dempsey]

We can agree to disagree & maybe it's greater ozone depletion here, further south?? ;)

Suffice to say it pays to clean rollers after sessions as they do absorb residue from tape & this is a greater, more accelerated cause of their decay.

I (and the boss here who's been servicing machines since 1979) have not known of a roller to decay without use.

[Howard Jones]

I'll reply to this in detail tonight.

[adamcal]

http://www.terrysrubberrollers.com/

[Ausrock]

Although I've heard positive comments about Terry and his rubber rollers from guys in the US, because Ta@#$% still have substantial parts support, I'd still recommend contacting, firstly, Teac spares, then Electric factory.

If those channels fail, then there is the option of sourcing o/seas.

8)

[rick]

i was using a mtr 100 ( otari) machine one night, the pinch roller was fine, i locked up the studio and went home, the next day the rubber was the stickest mess you have ever seen, i know nobody had touched it over night ,and i would like to blame alcohol and a careless operator but i had run out of alcohol and had the bottle had been dry for days...

my ampex atr 102 didnt get a whole lot of use for a few months and the atr service company capsten roller was fine one day and the next time i used it ( i week) it was cactus.

in my experience the rubbers reach some kind of critical mass then they melt

the atr service tech told me , they have a lot of problems with australian capstan rubber dying way too early , he said 5 years was a really good run for mine.

either we are all non compliant capsan trashing idiots or there is something in the air around here

most techs blame some substance or another but i dont think i have ever heard a reasonable explanation except they wear out !

btw
the mci tape machine capstan rubbers at festival were bathed in alcohol by mistake regularly by a certain not so with it engineer ( not me) , and i believe those machines are still fine ( twenty 5 years old...)

and finally i have (had) a mtr 90 capstan that has never been on a machine, never installed i went to sell it to somebody who needed a capstan in a hurry and guess what?
uninstalled but 8 years old .... it was like chewing gum to touch !

[mark rachelle]

rubber reaching a critical mass

kind of like extra chewing gum when you chew it for an hour or more its fine one minute and the next minute it just melts

off topic i know but i just thought i'd add it

[Howard Jones]

Hi Adam,

I suppose, as you say, we may end up disagreeing on the cause of sticky roller syndrome. However, I believe that you (and Daniel) are incorrect on this. I

[Linear]

I had a Studer A80 2" Pinch roller go from perfectly fine to green blob in about 4 months. At first it just got sticky and would make sticking noises when running tape.

Then, it just started to look like it was melting.

My brain is groaning, but I tried harking back to my 'materials III' lectures at uni. from memory, Ozone and UV exposure to vulcanised rubber leads to cracking (or crazing?) similar to what you see on a car tyre that's been exposed to the sun for 3 or 4 years. it only really affects the surface and makes a surface harder, not softer.

I suspect that what I and martin experienced was oxidation of the rubber, which is accelerated at elevated temperatures. This is why I think we get is worse than those in say europe or the US because of our hotter and more humid summers.

There is all this garb on what happens to rubber when it's oxidised (something about the covalent bonds forming rings or whatever) but I'd have to pull out the books for the theory.

i also believe that UV and other elements such as iron (!) copper and chromium can be a catalyst in this oxidation process which is why careful cleaning of the pinch roller is essential. i always use warm, mildly soapy water to clean pinch rollers and isopropyl alcohol for everything else. alcohol won't break down rubber but can, as howard said, lead to hardness for whatever reason. I always thoroughly dry the pinch rollers when I'm finished rather than let the water evaporate (or absorb) into the rubber.

I ordered a new pinch roller from Athan, they are recommended.

If one was to store a machine for extended periods, I would suggest removing the pinch roller, putting it in a vacuum bag, removing the air inside and sticking the thing in your fridge. low temperature + lack of oxygen would make it last a lifetime.

Cheers

Chris

* i just re-read my post and got confused. ozone is an oxidising agent (it's just O3) but it's also a catalyst for making the surface brittle. go figure.

[Howard Jones]

Part of the trouble with this topic is that probably no one of us will have access to a full knowledge of the chemical composition of the various rollers. One thing for sure is that they will be complicated compounds with various trade-secret additives. They will also probably be a mixture of natural and synthetic substances.

As to ozone leading to cracking rather than softening... some of the literature agrees with this, some not. Most writers on the subject seem to imply that hardening damage is caused by the effect of UV following up on the initial surface attack due to ozone. I imagine that UV is not a strong component of the light spectrum in most studios and that this part of the equation - which so strongly affects rubber compounds in automotive applications - is absent for our purposes.

I have bag of rubber bands kept in the dark in a filing cabinet that have tended towards cracking and breaking, rather than softening. I also tend to find that square and V-shaped drive belts harden and crack whereas flat belts tend towards softening. Just this morning, we have discovered that the 4 stick-on rubber feet on the bottom of a UPS have turned very soft.

It would seem to me that the nature of the compound from which the product is fabricated has a big influence in the nature of the decay process and whether the product goes soft or hard as it ages.

I was going to finish by saying "One constant in all this is that I have never seen a new, unused product go hard, only soft". However, it strikes me that the rubber band example I cited above may be a counter-example.

The US University Corporation for Atmospheric Research has a web project here http://www.ucar.edu/learn/1_7_2_28t.htm with the following design goal:

This activity is based on the high oxidation capacity of ozone, which causes rubber and plastic products to break down after relatively short exposure. By observing how rubber bands deteriorate and develop cracks or pits, the relative ozone levels can be determined for different locations.

Howard.

[mark rachelle]

seems a bit late to try and redesign the roller,

but why use rubber
its properties do not last, must have been the only thing available to use when they were deisigning the transports

looking at your post howard its made me think how rubber is the perfect bastard corporation product

i'm thinking about all of the rubber compound products i have owned over the years and not one has lasted.

god knows how many swimming goggles and flippers died

my cricket bat grips

rubber balls

my bike handlebar grips

to recently the bushes on my car

to the window wipers

and i'm sure i've missed a lot

so this post has really shown me that rubber doesn't really perform does and has failed the consumer!

[rick]

what about good old foam rubber ? or has anyone ever seen sonex acoustic tiles when the ozone turns them back into the slime they were made from,
or perhaps has anyone had a speaker cone surround just vanish into thin air.

the world can be a pretty hostile enviroment to things that just sit around.

i think we should thank our lucky stars this stuff does break down and doesnt just become another plastic relic of the 21 century for the great great great children to complain about.

btw. the binder agent that use to be in ampex tape that caused all the shedding problems of the eighties/ nineties tapes was created due to the fact that the previous binder (used from the 40s- 80s ) was made out of whale oil based products, save the whales and ruin the tape stock !
it took 5 to ten years to figure out what went wrong.

sticky rollers is nothing new.

[Adam Dempsey]

Howard, I'd have to say I concur with what you've said; certainly brittleness from improper cleaning is more common. Of course I was speaking from our experience and our MCI, Otari and Studer rollers have shown zero problems.
I'm sure it is agreed, however, that preventative maintenance, esp minimising absorption of shedding tape residue by cleaning pinch rollers after use, is the way to go.
Still, a good, detailed (however originally unintended) thread as always.

[Howard Jones]

Adam,

I'm a bit surprised that shedding tape residues have been causing you that much trouble with pinch rollers, considering that the roller contacts the backing, not the oxide side. I suppose that tape oxides can transfer to the backing side in the pack etc.

Howard.