DIY - alternator belt tensioner

[mottofreee]

The idea was taken, not original (minus for me).
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From a 17mm thick plate textolit I cut two jaws.
The one I drill a 5mm drill bits and threaded with the M6. In it I put a M6 bolt that I am stuck with a nut.
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In the second, we drill it with M6,5.
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A butterfly nut M6 completed device.

[tolsen]

All fine but how do you intend to measure tension?

[mottofreee]

Acoustic ,240Hz@Conti belt .

[markinnz]

Acoustic ,240Hz@Conti belt .

So you are going to twang the belt and listen for a 240hertz sound ?!? :-)

[mottofreee]

Frequency will be recorded with a microphone.
The frequency generated depends on belt use and span length.
The method appears in the video below:
https://www.youtube.com/watch?v=KNG9fmwW8vw

[tolsen]

Belt vibration theory:

f = v/λ

v = sqrt(T/µ)

f = sqrt(T/µλλ)

T = ffλλµ

S = λ/2

λ = 2S

T = 4ffSSµ

f = sqrt(T/4µSS)

Vibration frequency (f)
Velocity of the wave (v)
Tension of the belt (T)
Wavelength (λ)
Free vibration span (S)
Linear mass density of the belt (µ)

All we need do is to measure the span (S), weigh the belt, measure its length and calculate its linear mass density (µ). Plug the figures into the last of above formulas and out pops vibration frequency, easily measured.

A small spreadsheet is attached. Might be useful for those among you that want to maximise the life of drive belts and bearings.