8 track player belt

[Guscarguy]

I have some belts coming soon so I'll let you know how it goes

 

[borchee]

I think you’d be hard pressed to find one much thinner

He doesn't need to - he's running about 8% slow, not fast.

The rule of thumb is to add thickness of the belt to diameters of the drive and driven pulleys. Thickness of the slow belt is known, diameters of pulleys are known (or at least can be measured) - calculate the gear ratio, increase/multiply it accordingly (440Hz/408Hz) and deduct the thickness needed. Of course the lenght plays a role as well - stretching the belt results in smaller cross section, hence thickness.

I agree...adjusting speed with belts is a rather crude method.

 

[Okke 70s]

Oh, one more note! Assuming you won't get a perfect thickness/speed belt and will have to choose: Lean heavily towards "to fast" over "to slow". Our brain appears to be more sensitive to sloooww.. sound. Yeh, you'll have to do the sound effects yourself for now ;-)

 

[Guscarguy]

Hi everyone
I finally received some belts with no difference in the speed. Had to open up the motor and adjust the two screws on the centrifugal force and adjust it that way. Very time consuming but got to the correct speed. Was a little hesitant to open up a + 50 year old motor wondering if it was more harm than good but well worth it in the end. Thanks to everyone who commented and tried to help me out with my issue.