pic: Team 188 Teaser 2

[Bob92]

Originally Posted by Matt Adams

Consider that bolt not flush against the load.. such as a tiny "negligible" bending moment of only .25 inches....

Stress = M * y / I

Stress = M * y / I

130 lbs * .125 * .082 in / (3.141 * .164^4/64) = 75,500 PSI

Compound that with some shear stress... you're in a danger zone. Consider and extra load of an extra robot hanging with you... eek! In my opinion.. using a #8 bolt is definitely pushing a reasonable factor of safety.

However, the van door motor, being 11mm or so, should work out to be just fine.. but I'd definitely try to avoiding doing anything cantilevered... that freaks me out. Keep in mind that those bearing are bought from the cheapest bidder...

Nevertheless, good luck!

Matt

I doubt that there is a .25 inch gap. I assume this because most team dont manufacture parts like that to within 250 thousandths. I believe if there was "a tiny "negligible" bending moment" it would only be that of 1-2 thousandths. Especially considering that the nut on the end would hold it all flush.