Has anyone done any independent load testing on HTD timing belts and pulleys?
The recommended ratings from Gates seem fairly conservative (which is fair for their target market). For example, a 44T, 15mm pulley (close to what’s on the AM14U, or the 2013 kitbot) would have a load rating of 17.7 Nm. Two CIMs without a gearbox put out 4.8 Nm, so a gearbox reduction of 3.6 would put the setup right at the brink of failure by the books (this is assuming a very worst case scenario of course… but bears consideration).
Is there an appropriate safety factor (which would be less than 1) to use with these numbers? Or are we just shooting in the dark?
Can we crowdsource a safety factor by gathering wheel diameter/pulley diameter/gearbox ratio/motor count on several datapoints? Fill out this survey, maybe we can!