More on belt tension
http://www.westerbeke.com/Online_Manual ... at_man.pdf Click on the link above and go to page
Page 46. It has a very easy to understand belt tension guide. I did find a technical engineering site from a belt manufacturer that provides an exact formula method of belt tension from many inputs such as pulley diameter, HP of load, number of belts, speed of belts, etc. I followed it through in my head and came up with roughly 1/2 inch deflection with a 28 pound force (thumb pressure) applied half way between the pulleys. I would use the Westerbeke drawing on page 46 of the link above and push with the thumb very firmly. I used my thumb to measure force on a scale and I was able to go over 30# but just barely, with my index finger I could not push down with more than 24#. I think the actual thumb pressure could be 20 to 30 pounds and still achieve proper tension, all I am saying is I think it is unlikely that you would be able to push too hard with a thumb. While looking around for this information, I notice that some belt manufacturers claim that recent developements in v-belts have increased the power transfer capability by 40% since 1980 when I presume the Westerbeke manual was written. Also note that in a properly engineered drive system, the belt, under proper tension, will "wedge" in the groove providing additional friction to power a load, but if the belt is not tensioned properly, centrifugal force of the spinning belt will lift the belt from the groove making the belt slip at high speed even if it appears tight when stopped.
Sam
Windfall #52