Thanks desertfox....I am going through the calculations again to add a little safety factor in there. You are right the deflection isn't hugely critical. I'm hoping to be around 20 degrees but +/- 1 to 2 degrees won't hurt anything.
In using the T/? = G*J/l equation I set that for 20 degrees and with my new force and shorter lever arm I have a torque of 11,670 in lbs from which I determined to use a 1" dia. bar based on the above equation.
Desertfox - I came up with a torsion stress of 357,706 psi....way to high so I did a little change of design and ran the torsion bar in line with the draw bar so I could get it about 30" long which gave me a shaft of 1" dia and a torsion stress of 59,438 psi so was thinking of using a 4140 alloy...
Desertfox - the tow bar would only go from where it is located down to the ground which around 10 degrees down and then it would probably only range up about 10 from level.
The way I have it set up now I actually have two torsion bars which are fixed at the ends and about 12" long with the other end free to rotate (the end the banana links are connected to are seperate torsion bars and both rotate at that end, they are just supported by a round bushing which the...
So can you use any material type for a torsion bar or does as long as it falls into range with the stress and deflection you need? Or does it have to be some sort of spring steel or something of that sort?
Thanks again desertfox for the response. I remember this stuff but its been a long...
desertfox - Thanks for the quick response. Yes the torsion bar is pushing the tow bar up to hold it in the air at a level position. The hexagon shaft terminates at the banana links like you assumed and that distance from my pivot to the rod eye link is 7" so I came up with a force of 3751 lbs...
I'm new to the site and so far have found alot of good info. I am working on designing a torsion bar to hold a tow bar of a trailer up. The tow bar pivots about two pins and I need a torsion bar set up to hold the tow bar in a level position when not hooked up. What I'm needing is a little...
