Not being a mechanical engineer, I was looking at simple beam
deflection calculations in the machinery handbook and was wondering
why there seems to be a discrepancy from posted formula on various
sites.

For instance, for a beam with a single support and uniform load, the handbook states for maximum deflection:

ymax (at end) = (wl^3)/(8EI)

the formula ymax = -(w * l^4) / (8

from

http://ourworld.compuserve.com/homepages/MJVanVoorhis/T303.htm

agrees with the results from beamboy and other postings. I also measured it experimentally.

So I guess the question is l^3 vs l^4 unless E or I are calculated differently in the handbook??

thanks.

For instance, for a beam with a single support and uniform load, the handbook states for maximum deflection:

ymax (at end) = (wl^3)/(8EI)

the formula ymax = -(w * l^4) / (8

*** E ***I) at x = lfrom

http://ourworld.compuserve.com/homepages/MJVanVoorhis/T303.htm

agrees with the results from beamboy and other postings. I also measured it experimentally.

So I guess the question is l^3 vs l^4 unless E or I are calculated differently in the handbook??

thanks.