Quote:
Originally Posted by Argess
Patrick, it doesn't look to me like your math matches your intent. Yes, hanging in the air, the side force on the quickjacks is about 722 lbs for a 2500 lb car. but the sling tension of 1443 lbs needs to be added as you've looped the sling rather than using two straps and tying them off seperately. Neglecting friction, the tension in the sling is constant all the way around. So you may be looking at about 2165 lbs pulling the quickjacks together.
Your quickjack rods may not fail in tension or shear, but what you have here is a bending moment. If the rod length is 8" long, that's 1443 ft-lbs of torque. They will bend.
Might be a good idea to recalculate for that towing forced of 750 lbs. and look into the bending force for those rods.
Of course I could be wrong. It's 4:00 am here and I can't sleep for some reason.
|
You are correct I think. They bend like a garden hose.
This video of a homemade bender, bending 3/8" all thread rod shows it.
https://www.youtube.com/watch?v=cNToITxxVp0