Calculating Torque
I just stumbled on a google mystery. I tried this conversion via the google calculator and got,
1 (oz / inch) = 0.0111612296 kg / cm
But this was quite wrong. How did I know this? I happened to be comparing a Hi-Tech servo that a friend is thinking of getting with one of the Airtronics servos I have.
That said the page lists his servo as,
Torque:
106.93 oz-in at 4.8V (7.7 kg-cm)
133.31 oz-in at 6.0V (9.6 kg-cm)
Something was quite off here, and the google calculator was giving me gibberish. So i worked it by hand,
1 inch = 2.54 centimeters
1 centimeter = 0.393700787 inch1 kilogram = 35.2739619 ounces
1 ounce = 0.0283495231 kilograms1 kg/cm = 35.2739619 oz * 0.393700787 = 13.8894 oz/inch
1 oz/inch = 0.0283495231 kg * 2.54 = 0.0720 kg/cm133.31 * 0.0720 = 9.5994 kg/cm
200 * 0.0720 = 14.4016 kg/cm
Since I didn’t have a piece of paper at the time, a txt file had to suffice - problem sorted.
- Google Calculator Error…
Even though I posted this a while back and even suggested Google correct this error, it is STILL showing the same mistake, ...and to make sure that it isn't I that is making an error, I found t...
bsodmike.com » Google Calculator Error… said,
November 15, 2006 @ 3:30
[...] Even though I posted this a while back and even suggested Google correct this error, it is STILL showing the same mistake, [...]
Ian Patterson said,
June 25, 2008 @ 16:11
I believe that you are looking at this the wrong way.
The google conversion is correct. Just maybe not what you were looking for. They are giving you a conversion for oz*in to kg*cm NOT oz/in and kg/cm. They are a ratio representing a maximum value since it would have more potential torque closer to the servo.
Hope that helps.
Ian Patterson said,
June 25, 2008 @ 16:16
My bad, they were wrong but the logic in my explanation is true since servos have less torque as you move further away from the servo. I notice that they have corrected the value to 0.0720… which is correct.