We talked about all the things that you could make that would mount on a receiver hitch a while back. I think we talked about hitch mounted BBQ grills, picnic tables, hoists like that. If not somebody else had the same idea.
I hope they make a fortune at it, thing with this idea is lifting to much weight might actually flip the truck and I am no engineer but I think this one should have been made to use with the tailgate up, or off and closer to the truck to help solve the balance problems of to much weight.
Steve
------------------ Technology is great when it works, and one big pain in the ass when it doesn't
Well, if you base it on the tongue weight rating of the hitch:
A standard class 3 hitch, like most pick up trucks have, has a tongue weight rating of 600 lbs. The ball where the load is applied is approimately 6 inces out from the hitch. That puts a torque of 300 ft pounds on the hitch approximately. Any torque greater than that would be beyond its rated capacity. If you are 4 feet out, which is close to the picture, you can only pick up 75 pounds before you are over the rated capacity of the hitch.
From the ad he says its rated for 2 tons. Is he a PE, or has he had it checked by a PE? If not he is opening himself up to lawsuits. He probably buys cheap cherry pickers from harbor freight and reuses the boom part. The cherry picker he starts with probably is rated for 2 tons.
Well, if you base it on the tongue weight rating of the hitch:
A standard class 3 hitch, like most pick up trucks have, has a tongue weight rating of 600 lbs. The ball where the load is applied is approimately 6 inces out from the hitch. That puts a torque of 300 ft pounds on the hitch approximately. Any torque greater than that would be beyond its rated capacity. If you are 4 feet out, which is close to the picture, you can only pick up 75 pounds before you are over the rated capacity of the hitch.
From the ad he says its rated for 2 tons. Is he a PE, or has he had it checked by a PE? If not he is opening himself up to lawsuits. He probably buys cheap cherry pickers from harbor freight and reuses the boom part. The cherry picker he starts with probably is rated for 2 tons.
Yeah that is why I was asking. Well that and I have to admit I like the idea and wanted to adapt my own HF cherry picker to do double duty on the back of my tiny Toyota. But it didnt come stock with a hitch mount and instead has one as part of an aftermarket bumper which bolts to the frame. I was hoping to establish a kind of reference point from which to asses any of my own plans against.
Of course in the picture he is clearly well beyond the "rated" capacity. Anyone have any experience with an easily removable bed hoist that does double duty as a shop hoist?
These "professional" made ones made to mount in the box are only rated at 1000lbs, so I have to agree that guy is just looking at making a quick buck (hopefully not at the expense with someone getting hurt). He probably didn't even consider the amount of weight the hitch can hold.
A standard class 3 hitch, like most pick up trucks have, has a tongue weight rating of 600 lbs. The ball where the load is applied is approimately 6 inces out from the hitch. That puts a torque of 300 ft pounds on the hitch approximately. Any torque greater than that would be beyond its rated capacity. If you are 4 feet out, which is close to the picture, you can only pick up 75 pounds before you are over the rated capacity of the hitch.
The moment at the hitch is going to be way higher than that. The effective moment arm is from the hitch receiver to the tip of the hoist's boom ... which looks to me to be at least 8 feet.
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From the ad he says its rated for 2 tons. ... He probably buys cheap cherry pickers from harbor freight and reuses the boom part. The cherry picker he starts with probably is rated for 2 tons.
Exactly! Not only that, but the 2 ton rating is with the hoist's boom fully retracted (essentially the length of the orange portion); the weight capacity with the boom fully extended (as in the photo) is usually no more than a quarter of that.
Run away!!!
[This message has been edited by Marvin McInnis (edited 04-30-2015).]
Originally posted by Marvin McInnis: The moment at the hitch is going to be way higher than that. The effective moment arm is from the hitch receiver to the tip of the hoist's boom ... which looks to me to be at least 8 feet.
Exactly! Not only that, but the 2 ton rating is with the hoist's boom at its shortest setting (essentially the length of the orange portion); the weight capacity with the boom fully extended (as in the photo) is no more than a quarter of that. Run away!!!
You are correct if it is 8 ft that would drop the capacity even more to under 40 pounds. If you were to put a 2 ton load on it at the shortest setting of the boom at say 4 ft that would put a moment on the hitch of 16,000 ft pounds. There is no way the hitch could take that.
Now, if you had a hydraulic jack under the boom that you could put in place after you park the truck you could provide the support under the base of the boom and not put a torque reaction onto the hitch. You couldn't pick up something over water but could pick up something on land. With this setup you are only using the truck to stabilize the load.
Now, if you had a hydraulic jack under the boom that you could put in place after you park the truck you could provide the support under the base of the boom and not put a torque reaction onto the hitch. You couldn't pick up something over water but could pick up something on land. With this setup you are only using the truck to stabilize the load.
I like that idea. I think something that flips down and ratchets like a Hi-Lift could work well. Now if the whole thing attached to the hitch and then were to fold transverse to the vehicle axis staying on the truck below the tailgate when not in use that would be a winner.
I wonder, at what point, the front tires of the truck comes up off the ground?
wish I had a camera there then
at a boat ramp a big semi- truck sized crane was pulling old rotten pilings guess he pulled to hard the crane slipped on the slime on the ramp even with the legs out and was partly in the water
they had three full sized semi tow trucks hooked up all with the front wheels a foot or two in the air one with a duel rear axle had the forward set of rears a bit off the ground also but that crane was not moving
later they hooked up a 4th truck and dragged the rig up the ramp finally
[This message has been edited by ray b (edited 05-01-2015).]
I looked around the net at other kinds of hitch mounted accessory's and the only thing I found that was even close to holding heavy weights was the motorcycle carriers and those were only rated for 600 lbs at best unless they are mounted on a motor home. Even those are only rated for 1,000 lbs.
