Increasing capactity of hoist

[TerryD]

I bought a 2 ton engine/shop host and would like to increase its capacity fully extended. I wanted to use it to set the new (short) bed on my CC as well as lifting things in the garage. The boom isn't long enough to reach the center of my bed as it sits now so I was hoping to relocate the cylinder slightly and gain some lifting capacity but also extend the boom to reach the center of the bed.

I think I can manage the rough equation to move the cylinder mounting points. I need an equation for the bending strength of the boom tubing so I can figure out if this is even possible or if I'll need to build a new boom for it all together.

 

[diesel4me]

I have a Carolina 2 ton hoist,I've used it to pull and install 8 foot beds without any modifications--maybe mine has a longer boom and legs than the one you have though?...if you extend the boom,the legs will need to be extended also,or it'll just pull a chinese wheelie ,the rear wheels will lift up instead of the load lifting up...I think if you have a 8 ton ram you wont need to move the cylinder any,it'll be harder to pump up,but still lift a good ton...

You may have to "truss" the boom up better to keep it from bending,but most cranes are underated quite a bit--if it has a 2 ton rating and looks to be made from good 1/4" thick square tube,it may flex a lot but would take a lot to make it fail...

You could hook the boom closer to the rear of the bed,and put some weight up in the front to keep it balanced when you lift it "off center" too...

I like using the homebuilt gantry crane I made from an old swingset a city playground had that was made from 3" pipe,to pull and replace a bed.....its a lot easier to lift and lower things with the winch on that...I didn't like having the bed wanting to tip and swing around with it dangling from the engine hoist...on the gantry it lifted straight up as long as you rigged the lift straps or chains in the right spot,and you can roll or drive the truck out from under the bed without it wanting to go sideways--if it tries too,you can always rope it to the crane's legs to keep it in line..

You might be better off making a crude gantry crane ,it might be easier than modifying the engine hoist ...I used a simple boat trailer hand crank winch on mine with a few pulleys so I can stand off to one side while raising and lowering things...they are a lot more usefull when loading things in the bed of a truck,no fear of a heavy engine or whatever wanting to flip an engine hoist over while your struggling to get the thing rolling and get the load in the bed..

 

[TerryD]

Gantry crane is possible, but not in the budget right now.

As for my crane, I can't find specs on the cylinder anywhere, but it appears to at least be a 7 ton cylinder (more likely 8 as that's a standard size I think) based on the math. Also, if I'm doing my torque math properly, in the fully extended position the ram should be capable of one ton rather than the marked 1/2 ton but that doesn't mean my 1/8" wall boom tubing is capable of that. I still have not found info on bending strength of the tubing.

 

[dhcomp]

I hate to say this, but for something as low risk as lifting a bed, i'd extend the legs, sleeve the boom, and go for it. I doubt it will be a catastrophic failure. Just be careful, and you'll be fine.

There is a lot more to the proper calcs than just looking up the bending strength of the tube.

 

[blazinzuk]

Depending on how much you plan on lifting consider making the beam stronger. Legs longer. All joints gusseted. You have to make everything so much stronger sometimes its not worth it. The amount of tube left in the receiver of the sliding beam is a big issue. You will have to beef up the receiver tube at the end to handle greater loads fully extended.

Just be careful I have used hoists to pick up alot of things over the years and beleive you me, it sucks when they fail

 

[TerryD]

I have some heavy wall structural pipe I was thinking about making a new boom for it with. Also making the legs telescoping so the can be stored easily and still used for long or short boom lifts. I think it will lift my short bed just fine as is our maybe with longer front legs, so I'm going to just be careful with it right now and I think it will be fine. The joints are all sleeved from the factory so I think they are plenty strong regardless of the lift up to a ton with the boom out.

 

[diesel4me]

A stock GM bed doesn't weigh much--500 lbs I'd guess,for an 8 foot fleetside..

I have pulled a few off using nothing more than a upside down "U" made of 1-1/4" pipe that was intended to be used for hanging a clothesline's ropes on,at my brothers house,the pipe "legs" slid into larger pipes cemented in the ground about 18" deep...worked slick...backed the truck under the pipe,used a come-a-long to lift the bed up,and drove it out from under it..the pipes were old and rusted and had cast elbow fitting too,no sign of any failure..

Making a gantry crane might take a few hours,but its worthwhile effort--even one made of 4x4 wooden posts with a 4x6 crossbeam would be sufficient to hoist a bed or cab off a truck...

I'd say your engine hoist should be able to pull the bed off --if you do extend the boom I bet you can get away with leaving the legs as is,just extent them as far as they can without coming out...instead of using chains or straps to lift a bed,I used 2 2x6's bolted to the bed rail in the center,I used threaded rods to bolt it to the center stake pocket holes--that way I didn't have to raise the boom so much to get the bed far enough off the frame,and it was not so "tippy"...
It's safer to move the truck than try rolling the crane with the bed hanging from it too--roll it out of the way and lower the crane down so the bed just clears the ground,then you can move it a lot easier without fear of it tipping over..

 

[TerryD]

That's a good idea using wood to lift the bed, but I this is a short bed so I don't have middle stake pockets. I was planning on making a x brace that covered all four stake holes and lift from the middle. I'm debating on what to make it from though.

 

[diesel4me]

A 6 foot bed should not be a problem for your engine crane,unless it has real short legs and boom..

You only need 3-4 feet to reach the center of the bed,the 8 foot ones I lifted with mine required the boom and legs to be "maxed out" but I was still able to do it OK.I did have to put weight up front once to level it off because I wasn't "balanced" perfectly..(the wheel wells made it rear-heavy so picking it up from the center,the rear wanted to droop)....maybe your crane is a fold up variety,mine is an old style one that you cant fold up and is made of 1/4" thick tube...

More than once I just invited some guys over for beer and had them help me lift the bed off,and walk it over to a pair of sawhorses...but the hard part was getting them to return when it was time to install the bed again...hard to fool them twice..

 

[TerryD]

but the hard part was getting them to return when it was time to install the bed again...hard to fool them twice..

This is why I bought the host. The usual guys are getting wise to me and I need to give them some time to forget....