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8 track player belt

G

Guscarguy

Member
I have a question about an 8 track tape player belt. I purchased an 8 track tape player with no belt on it. Can't find any information on it as well. I determined the size is 12.7" flat belt. I purchased a FRM 12.7 belt and works as it should good torque not too loose or too tight. I however did noticed the speed is slightly slow. I used an 8 track recorder that has a good stable speed and recorded a 440hz tone on it. (A note on guitar tuner). Played on this machine it's at G# (408hz).If I purchased a FRX 12.7 would that change the speed in any way or possibly another kind of 12.7 belt? I don't see any adjustment on the motor itself. Motor has a drop of oil in it and capstan has been lubricated as well with 3 in 1 oil (blue one). The motor is a Matsushita motor. Voltage is correct at just under 13 V. Motor is rated at 13.2 V
 
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Can you post a picture of the motor?

Some older motors had either a pot inside the motor or a weighted type of speed adjustment where it uses two screws on the rotor to set the speed and others had a speed control circuit on a separate board.

Also disconnect the motor and apply 13.2Vdc to it see if the speed is then right.
 
Would need pictures of your motor.

Some DC motors back then were installed in a housing with magnetic shielding inside the housing so that the motor wouldn't affect the head or tape.
 
I don't have any pictures of my motor for today but looks identical to that style in the photo. Would changing a different style of belt change the speed of the player?
 
It might, however if the speed is slow due to the motor speed adjust being off or the motor voltage being low then no belt will get the correct speed.
 
I'll have to look into the motor itself. When I replaced the gasket on the housing I don't recall seeing any screws when I took it apart but I could be mistaken
 
If the motor has a mechanical type of speed governor the adjustment is usually through a slot in the side of the motor, however before doing anything I'd suggest applying 13.2Vdc to the motor directly just to see if the just under 13Vdc motor voltage is the problem.
 
How thick is the belt that you got? A belt that’s too thick can run slow. Essentially it makes it act like the drive pulley is larger than it is. The first belt I got (from Amazon) for my Pioneer H-22 measured .042” thick. Unfortunately it was also only 12” long so way too tight. So I couldn’t run it long enough to see if it also ran slow. The correct belt for mine is also 12.7”. My original belt measured .026” thick but was badly worn. The second belt I got measured .030” thick. Got mine from West Coast Belts. Good luck!
Cheers……………………Todd
 
Yes, belt thickness has an impact on tape speed. Usually a DC motor will be fitted with electronic speed control, either in het motor housing itself or on whatever pcb it is wired up to. There is no service manual available?

On machines without any form of speed control or available information you just have to figure out thru trail and error how thick the belt should be to "land" on the right speed.

Although.. If it is a dc motor you might be able to replace a resistor somewhere, with either the perfect value one or just a trimpot.
 
As well as the "thickness" which was my thought as well, and you've used several tapes when testing, right? Some of those cartridges tend to bind up over years of use.

Check for PM.

Q
 
TConnelly said:
How thick is the belt that you got? A belt that’s too thick can run slow. Essentially it makes it act like the drive pulley is larger than it is. The first belt I got (from Amazon) for my Pioneer H-22 measured .042” thick. Unfortunately it was also only 12” long so way too tight. So I couldn’t run it long enough to see if it also ran slow. The correct belt for mine is also 12.7”. My original belt measured .026” thick but was badly worn. The second belt I got measured .030” thick. Got mine from West Coast Belts. Good luck!
Cheers……………………Todd
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The one I got is FRM 12.7. The length is right but if it could go a little faster that would be great. What kind of 12.7 would I need to make it go faster?
 
Guscarguy said:
The one I got is FRM 12.7. The length is right but if it could go a little faster that would be great. What kind of 12.7 would I need to make it go faster?
Click to expand...
Well you’ll need to measure the thickness of the belt you got first. Although I looked up FRM 12.7 and they seem to be about .030” thick. Unless yours is much thicker Than most of the ones I see, I think you’d be hard pressed to find one much thinner. I assume the drive pulley on your motor is a barrel shape. The FRM 12.7 I see is only .20” wide. The FRZ 12.7 is .23” wide. If it is barrel shaped and if there is room for a wider belt that may gain you something. But honestly it’s looking like a belt problem is less and less likely.

I think looking into a voltage adjustment is a better bet at this point. Good luck!
Cheers……………….Todd
 
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