How do you get 600 ft/lbs torque on a rotary cutter blade nut?!?

[4570Man]

It doesn't matter what orientation the bar is in as long as the force is applied 90 degrees from the bar. Now, if you wanted to hang a 100 pound weight from the end of the bar it would need to be level to accomplish maximum toque.

 

[rbtjr]

My spec was 480 foot-pounds. I used a 6' piece of iron pipe--3/4" pipe, as I recall--run down over a 24" breaker bar. Then I put a scale on the end of the pipe and put 80+ pounds of force on the end of the pipe.

To clarify my prior post above, my helper (my son) and I took care to get the lever--the pipe we sleeved over the breaker bar--as close to perpendicular to the centerline of the bolt as possible. I agree with the prior post to the effect that to the extent to which the lever is not at a 90-degree angle to the bolt the nut is on, the torque on the nut is reduced. I think that is correct from the physics perspective and also based on our everyday practical experience. If we are going to loosen a nut on a bolt, we try to get the handle of the ratchet wrench as close to being perpendicular to the centerline of the bolt as possible, in order to reduce the force on the end of the handle that will be required to loosen the nut. I would be interested in any and all disagreements and the basis for them.

 

[MESSMAKER]

If you weigh 200lbs, put all your weight on the end of a 3 foot bar. It's that simple.

That is how it's done. Almost nobody has torque wrench that will measure that high anyway.

 

[Mace Canute]

I bought a torque multiplier a few years back when on sale, 1/2" to 3/4" drive, less than $40, and is rated to a maximum torque of 730 ft-lbs.

Only used it once to remove the rear duals on an old Dodge truck. Wouldn't have been possible without it due to confined space. If you have anything around that has fasteners that require a large amount of torque one of these is the way to go.

 

[Klcflyer]

I have a Bush Hog RD5 but found this in the manual for a model 12 with regards to tightening the blade holder nut:

"REPLACEMENT
A. Replace blade holder and tighten the lower shaft nut to 600 ft./lbs. If a torque wrench is not available, the nut should be tightened with a wrench having a three foot handle, or a section of pipe over the wrench handle, if a wrench of this size is not available.
B. Strike the blade holder several times with a heavy hammer and retighten lower shaft nut. This should be repeated several times."

My blade carrier slips over a splined shaft. I had to use a two jaw gear puller to get it off. Today I'm putting on new blades and using an impact wrench to seat it. I can pretty much tell if it's seated by how far the splines meet.

 

[searcyfarms]

with an impact wrench that puts out 650 ft. lbs and hammer on the nut ;-)

or a 6 foot cheater on a 3/4 or 1 inch drive breakover bar w/socket and a lotta grunt

 

[Zebrafive]

I bought a torque multiplier a few years back when on sale, 1/2" to 3/4" drive, less than $40, and is rated to a maximum torque of 730 ft-lbs.

Only used it once to remove the rear duals on an old Dodge truck. Wouldn't have been possible without it due to confined space. If you have anything around that has fasteners that require a large amount of torque one of these is the way to go.

For $40, I am guessing it was not new, sounds like a super deal.

 

[WranglerX]

I bought a torque multiplier a few years back when on sale, 1/2" to 3/4" drive, less than $40, and is rated to a maximum torque of 730 ft-lbs.

Only used it once to remove the rear duals on an old Dodge truck. Wouldn't have been possible without it due to confined space. If you have anything around that has fasteners that require a large amount of torque one of these is the way to go.

Got one good for 1000ft-lbs (4:1 gear ratio) for $10 at yard sale.... Better than any pipe or cheater bar or "hammerology"...

When up to those torque levels be very careful... Something breaks (yes you can break 3/4 inch drive breaker bars) and sudden you are moving "freely" thing get ugly fast...

Dale

 

[Zebrafive]

Got one good for 1000ft-lbs (4:1 gear ratio) for $10 at yard sale.... Better than any pipe or cheater bar or "hammerology"...

When up to those torque levels be very careful... Something breaks (yes you can break 3/4 inch drive breaker bars) and sudden you are moving "freely" thing get ugly fast...

Dale

The price you paid is even better! WOW!

 

[Mace Canute]

For $40, I am guessing it was not new, sounds like a super deal.

No, it was new but on sale at Princess Auto.