pinch roller to rc-m70 strange

[pap]

Hello to all
first of all ,
I wish you a happy holiday.
I have a pinch roller problem with one of the 3 jvc's!
it eats my bands!
at first glance it looks fine
I took it out and sanded it with 1200 grit sandpaper!
I'm going to use a dremel and try to keep a flat surface.
to keep a flat surface.
but all this was for nothing! the tape crumpled down and then crushed!
i don`t have a cross gauge! because of all the devices i have since 1982.
I have never had this kind of problem.
can you advise me?
I would like to point out that the 3 rc-m70s are all calibrated (new belts and idler, greasing, speed, azimuth etc..)
Thank you for your time in helping me.
greetings


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[pap]

this pictures

 

[pap]

And this

 

[BoomboxLover48]

Is the take up reel turning to wind the tape? In play mode the take up reel function is to wind the tape while the capstan and pinch roller pulls it at the correct traction and speed. If any of these two functions fail, tape will crumble and get all messed up. The contact wheels that move and help with the take up axle to function is interrupted in some way.

Without the tape, press play and see if you get good traction on the take up reel axle. If not that could be the cause of this problem you are experiencing.
It is the right axle on the M70.

 

[pap]

Is the take up reel turning to wind the tape? In play mode the take up reel function is to wind the tape while the capstan and pinch roller pulls it at the correct traction and speed. If any of these two functions fail, tape will crumble and get all messed up. The contact wheels that move and help with the take up axle to function is interrupted in some way.

Without the tape, press play and see if you get good traction on the take up reel axle. If not that could be the cause of this problem you are experiencing.
It is the right axle on the M70.

Hi
Bboxlover
thank you very much for your explanations,
I found them useful!
because I don`t have 95% of the ripped tapes anymore
I have also removed and lubricated the left one ( reel ).
I still have some weakness in reading?
I have some doubts about the motor! but the speed is well calibrated at 3000hz!
but the tape is running with sound waves?
the belts are 2 weeks old?
I don`t really understand!
I have 2 other rc-m70s that are excellent (mechanical)
if you have a new idea?
thank you for your time
Greetings from Spain (where it is a bit warmer than at home)
serge

 

[pap]

Hi

 

[Tinman]

Your take up reel is the other one with the counter belt on it.
You should be able to stop the take up reel from spinning with your fingers while in play mode but it should take some resistance to do so.
The take up reel needs to slip with a clutch mechanism because it will be turning faster than the capstan and pinch roller while they're pulling the tape between them at a constant speed.
If the take up reel is not turning fast enough or even intermittently skipping, the tape will get pulled around the capstan and/or pinch roller "eating" the tape.
Also, your pinch roller might need to be replaced if it's in poor condition (hard, cracked, etc.).

 

[BoomboxLover48]

Check if the contact wheel rubber shown with the red arrow is worn out. This must be slipping and making intermittent contact with the take up reel axle.
A contact wheel will make that axle turn and check the condition of it. Then see if the rubber on it is worn out or not.


View attachment 56228

 

[Tinman]

I agree with bbl48.
You should check and make sure all rubber is in good shape.
I find a magnifying glass helps when checking it.

 

[BoomboxLover48]

In play mode that tiny contact axle indicated with the arrow gets in contact with the take up reel rubber wheel to drive it.
So, check if there is dirt on that small axle. That axle is that of a pulley on the other side with rubber belt connected to the flywheel drive mechanism.