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ideas on how to turn a small crane (think engine crane mounted from the center)

dave_dj1

dave_dj1

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I am putting this crane on the tongue of the dump trailer I am building. I will have hydraulics that will
a) lift the main boom
b) telescope two sections out
c) rotate the crane from the base

I would really like 360 deg of rotation, not sure how to get there.
I can do two cylinders and get like 190 ish deg of rotation (not out of the question)
Any thoughts on how to make it rotate 360 without breaking the bank?
I've thought about using a winch motor with the cable doubly wrapped around the shaft to get both directions
Any ideas on a worm gear set up I could find in a junkyard?
Speed can't be too fast as it will be super fast 10' out.
At extended length I am hoping to lift around 200# (big chunks of firewood)
It will also have a winch mounted on it to drag stuff in close or to lift with.
Thanks
 
Did you mean 2000#? Because 200 really doesn't seem like it would need all that. Even 2,000....I'd skip the power rotate. Even the power telescope seems excessive.

I'd look for someone scrapping an old service truck and try to score an autocrane for a grand or so. You'll come out way ahead.
 
Buy a crane off a service truck or even better buy a service truck and use the crane on it. To make it swivel 360 you’ll need a minimum of a 6 port hydraulic swivel. This is super spendy part unless you can salvage one off a excavator. Even then those are typically only four port.
 
dave_dj1 said:
I would really like 360 deg of rotation, not sure how to get there.
I can do two cylinders and get like 190 ish deg of rotation (not out of the question)
Any thoughts on how to make it rotate 360 without breaking the bank?
I've thought about using a winch motor with the cable doubly wrapped around the shaft to get both directions
Any ideas on a worm gear set up I could find in a junkyard?
Speed can't be too fast as it will be super fast 10' out.
At extended length I am hoping to lift around 200# (big chunks of firewood)
It will also have a winch mounted on it to drag stuff in close or to lift with.
Thanks
Click to expand...

double acting cylinder
wrap cable around pipe, think like an old bow-drill like you'd use to start a fire with a stick
tension it enough that it grips the pipe
will get you 360 degree or more rotation
 
bgaidan said:
Did you mean 2000#? Because 200 really doesn't seem like it would need all that. Even 2,000....I'd skip the power rotate. Even the power telescope seems excessive.

I'd look for someone scrapping an old service truck and try to score an autocrane for a grand or so. You'll come out way ahead.
Click to expand...

No I mean 200# It's more of a novelty thing for me.
 
ThePanzerFuhrer said:
Buy a crane off a service truck or even better buy a service truck and use the crane on it. To make it swivel 360 you’ll need a minimum of a 6 port hydraulic swivel. This is super spendy part unless you can salvage one off a excavator. Even then those are typically only four port.
Click to expand...

Can't really get a service truck where I can pull my dump trailer (log roads) I think the crane off a service truck would be too heavy and too long also.
 
[486 said:
;n215113]

double acting cylinder
wrap cable around pipe, think like an old bow-drill like you'd use to start a fire with a stick
tension it enough that it grips the pipe
will get you 360 degree or more rotation
Click to expand...

I'll look into that idea, kind of what i was getting at with the winch idea. I figure a couple of wraps at minimum.
 
drew you a picture
red is cable, got a threaded end for tensioning, or maybe just an eye-bolt would work I guess
cylinder pushes and pulls, blue pipe spins either way

photo34777.jpg
 
[486 said:
;n215127]drew you a picture
red is cable, got a threaded end for tensioning, or maybe just an eye-bolt would work I guess
cylinder pushes and pulls, blue pipe spins either way
Click to expand...

That is the way the snowblower chute rotates on my JD snowblower
 
I would think for the weights you are talking about actuators / electric winch would be much easier to make work than hydraulics imo.

200 lbs is nothing, you could do that with a thrust bearing and a small lever.

486 has a decent idea could also use rack and pinion, should be able to get them at McMaster or cobble something together from scraps. I would think straight cut rack attacked to the actuator then matched to a straight cut gear mounted on the column.
 
or maybe stick sprocket on crane tube
then weld roller chain to a bar or square tube, makes for a rack without the expense of buying a gear rack
 
You dont want to make a potentially dangerous situation should whatever rotation device give way under a load. You gotta think you might not always be lifting while on a flat surface. If it is flat ground, no big deal. But If you are parked on a hill and have the boom 10ft out with a couple hundred pounds on it, that is a lot of force trying to rotate the crane. If a cheap worm drive doo hickey snaps at a bad time you can have a lot of force giving a brutal pinch or worse. Maybe some kind of spring loaded anti rotation pin just as a safety backup.

Sounds like a cool project. I am kicking around the idea of a truck mounted deer hoist made from an old cherry picker, either that or just drag it up in the bed with an ATV winch
 
I have one with a hand crank worm gear to sprocket drive, it would move couple hundred pound logs pretty easily. What about using 1/2 a drive axle with the welded diff at the base, put the crane on the rotor or drum, drive the pinion with a reversible motor and sprockets and chain drive? Just spitballin.
 
Last edited:
A crane that little doesn't need powered rotation, IMO, and lots of older 1 ton service trucks running around with powered boom and winch, but manual rotate


if you're set on doing it, worm gear and hyd motor is the way to go

I could see a worm gear and a crank handle with some sort of brake

I have a 3200lb auto crane on a truck, it's bitchin, but it weighs 700lbs, and is fixing to come off

I'll buy one, or more of those little harbor freight ones that tuck under the bed rail of a pickup for the little loads, probably put a removable gin pole setup on a pickup, and drag anything else out to where I keep my forklift:laughing:
 
Dethmachinefab said:
Big sprocket on crane and small sprocket on a proper sized hyd motor will work and be cheap/simple.
Click to expand...

That is an option but the best I can do as far as I know is a 4-1 ratio, not sure that is low enough. I've never messed with a hydraulic motor, can they be operated slowly and still have power? Any idea on what to look for, high torque, low rpm I would think?
 
Years ago I built one using a flexplate off a small car and a starter motor wired to a house style dimmer switch. Worked surprisingly well for what it was

the turret was the spindle off a Dana 60 and an old Dana 60 dually hub with the crane welded to that. Spun around really easily and actually held up to quite a bit of abuse. It's still out back in the barn somewhere and I use it every now and again
 
Does it have to be powered?

How about a worm gear hand cranked winch mounted vertically with the gear around the crane`s vertical shaft. You could even extend the hand crank out to the edge of the trailer. Nice thing about worm gears is they usually are self braking. (If the gear ratio is steep enough, you cannot turn the worm gear by forcing the big gear).

hand winch.jpg
 
1981K20 said:
Years ago I built one using a flexplate off a small car and a starter motor wired to a house style dimmer switch. Worked surprisingly well for what it was

the turret was the spindle off a Dana 60 and an old Dana 60 dually hub with the crane welded to that. Spun around really easily and actually held up to quite a bit of abuse. It's still out back in the barn somewhere and I use it every now and again
Click to expand...

^^^This^^^

200lb load 10ft out, the crane will only ever see 2000lbs. D60 spindle/hub wouldn't flinch at that.
 
Ive got a handful of big sprockets in the 14” diameter range. I could send one very near the price of shipping.
 
Run a single acting cylinder plumbed through the center of whatever your hub is for the power up/down.

Cut threads on a thick wall pipe and weld in a threaded insert to make a two stage screw. Mount it inside your boom with a crank on the back for your telescoping action. Stick a drill on it if you want power.

Skip the powered line and just use chain and grab hooks or stick a hand crank winch on it.

Powered rotation can be easily solved in several ways that have already been covered.
 
dave_dj1 said:
That is an option but the best I can do as far as I know is a 4-1 ratio, not sure that is low enough. I've never messed with a hydraulic motor, can they be operated slowly and still have power? Any idea on what to look for, high torque, low rpm I would think?
Click to expand...

Hydraulic motors are the definition of high torque low speed power. Torque is a function of pressure and motor displacement, so with a fixed max pressure if you need more torque can just use a larger displacement motor. Downside is that larger displacement means slower speed for the same flowrate. Bottom line, you can easily get a motor that will be sufficient.
 
Note that a rack and pinion system requires a precisely machined guide to hold the rack in the right position - too much clearance or flex in the guide means excessive backlash and potentially stripping out the rack or it coming unengaged under load. Too little means it binds. Same thing with a worm gear.
 
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