On 23 February 2015 at 08:54, Viesturs Lācis <viesturs.la...@gmail.com> wrote:
> I would appreciate, if someone could share a source for torsion > springs, moment needed is 70 Nm, when there is 90 degrees still left > to reach max angle (for 270 degree max angle that would be ~105 Nm max > moment). > Lets take the example of a straight torsion bar and see where we end up. Springs typically go to about 80% of UTS, so lets guess at 1GPa. The stress on the outside of a solid shaft in torsion is... http://www.engineeringtoolbox.com/torsion-shafts-d_947.html Torque_max = (pi / 16) stress_max * D^3 so you would need a solid shaft of 7mm dia. So it sounds possible. But you need 70Nm at 90 degrees rotation and safe stress at 270. Angular deflection theta of a shaft (radians) = 32 L T / (G pi D^4). G for steel is 75GPa. You want to solve for L and D at T = 70Nm and theta = pi/2 T < Tmax and theta = 3pi/2 Which, is, err, left as an exercise :-) -- atp If you can't fix it, you don't own it. http://www.ifixit.com/Manifesto ------------------------------------------------------------------------------ Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server from Actuate! Instantly Supercharge Your Business Reports and Dashboards with Interactivity, Sharing, Native Excel Exports, App Integration & more Get technology previously reserved for billion-dollar corporations, FREE http://pubads.g.doubleclick.net/gampad/clk?id=190641631&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users