Since I have acquired home bodged spoke tensiometer and a "conversion chart", I was wondering if the conversion chart is accurate. So, I reason, it should be easy enough so suspend a given volume of water from a spoke and measure the deflection.
My question is this, can I get away with say 5,10,15 and 20 kgs (about a bucket in 5 litre increments), or do I need to get closer to the 70-90kg that a spoke experiences.
In short, is it linear?
For those that are interested, the principle of the bodge job is the same as the DT Tensio
can we see a digital representation of this device?
the problem is? the tool samples a predetermined length of the spoke's shaft and relates that specific length bit by the tool to the tool's gauge whereas hanging weight from a spoke twists the spoke's complete length and twists the hub end. what that does to the measurement ? is trial and error on your end right?
Since I have acquired home bodged spoke tensiometer and a "conversion chart", I was wondering if the conversion chart is accurate. So, I reason, it should be easy enough so suspend a given volume of water from a spoke and measure the deflection.
My question is this, can I get away with say 5,10,15 and 20 kgs (about a bucket in 5 litre increments), or do I need to get closer to the 70-90kg that a spoke experiences.
In short, is it linear?
no it's most definitely not. your tensiometer is testing a material in 3-point loading, with both tension and bending being factors. you therefore need to be in the loading zone found in practice to have accuracy - extrapolation for lower tensions is highly unreliable.
Quoted message said:
For those that are interested, the principle of the bodge job is the same as the DT Tensio
Since I have acquired home bodged spoke tensiometer and a "conversion chart", I was wondering if the conversion chart is accurate. So, I reason, it should be easy enough so suspend a given volume of water from a spoke and measure the deflection.
My question is this, can I get away with say 5,10,15 and 20 kgs (about a bucket in 5 litre increments), or do I need to get closer to the 70-90kg that a spoke experiences.
In short, is it linear?
no it's most definitely not. your tensiometer is testing a material in 3-point loading, with both tension and bending being factors. you therefore need to be in the loading zone found in practice to have accuracy - extrapolation for lower tensions is highly unreliable.
Thanks for that, I shall find a bigger bucket then!
Since I have acquired home bodged spoke tensiometer and a "conversion chart", I was wondering if the conversion chart is accurate. So, I reason, it should be easy enough so suspend a given volume of water from a spoke and measure the deflection.
My question is this, can I get away with say 5,10,15 and 20 kgs (about a bucket in 5 litre increments), or do I need to get closer to the 70-90kg that a spoke experiences.
In short, is it linear?
no it's most definitely not. your tensiometer is testing a material in 3-point loading, with both tension and bending being factors. you therefore need to be in the loading zone found in practice to have accuracy - extrapolation for lower tensions is highly unreliable.
Thanks for that, I shall find a bigger bucket then!
what are you putting in the bucket? 100kg of water is quite a volume. 100kg of lead is not.
I haven't tried this exercise but its widespread fersure as several rube Goldberg devices ahhhh spring to mind. Yet I haven't read of one ??? is there a website devoted to gearloose tensiometers? but off course-at least 15 as of 9AM EDST
I haven't tried this exercise but its widespread fersure as several rube Goldberg devices ahhhh spring to mind. Yet I haven't read of one ??? is there a website devoted to gearloose tensiometers? but off course-at least 15 as of 9AM EDST
> > Since I have acquired home bodged spoke tensiometer and a > "conversion chart", I was wondering if the conversion chart is > accurate. So, I reason, it should be easy enough so suspend a given > volume of water from a spoke and measure the deflection. > > My question is this, can I get away with say 5,10,15 and 20 kgs > (about a bucket in 5 litre increments), or do I need to get closer > to the 70-90kg that a spoke experiences. > > In short, is it linear?
no it's most definitely not. your tensiometer is testing a material in 3-point loading, with both tension and bending being factors. you therefore need to be in the loading zone found in practice to have accuracy - extrapolation for lower tensions is highly unreliable.
Thanks for that, I shall find a bigger bucket then!
what are you putting in the bucket? 100kg of water is quite a volume. 100kg of lead is not.
Well, I was thinking of water because it's easy to transport in a hodepipe and easy to dispose of later. The current thinking is one of those "IKEA Bags", which look waterproof and will certainly hold the weight.
