Wuzzat?
Well-Known Member
- Joined
- Jan 20, 2010
- Messages
- 2,471
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I needed to adjust a timing belt tensioner to 33 lb-ft and there was no way my torque wrench would fit into the space available so I got two stiff springs from HD.
Filling a 5 gal bucket with water (2 lbs for the bucket + [5 gals x 8.3 lbs/gal]) = 43.5 lbs and stretched the spring 1.09" from its rest length so the spring constant K = 40 lbs/inch.
The spring was anchored on the wrench handle 7" from the center of the 3/8" drive stub so 33 lb-ft would need a right angle force of 33x12/7 = 57 lbs.
As it turned out the posted max force on the spring was 61 lbs (no max length given) so it was close. I should have done this calc. before I bought the thing but it worked out.
And with two springs in a package for $4 I could in principle go to 66 lb-ft or so.
Next is to check the K for my weaker springs from the basement.
Filling a 5 gal bucket with water (2 lbs for the bucket + [5 gals x 8.3 lbs/gal]) = 43.5 lbs and stretched the spring 1.09" from its rest length so the spring constant K = 40 lbs/inch.
The spring was anchored on the wrench handle 7" from the center of the 3/8" drive stub so 33 lb-ft would need a right angle force of 33x12/7 = 57 lbs.
As it turned out the posted max force on the spring was 61 lbs (no max length given) so it was close. I should have done this calc. before I bought the thing but it worked out.
And with two springs in a package for $4 I could in principle go to 66 lb-ft or so.
Next is to check the K for my weaker springs from the basement.
