Home built gantry cranes

[Dabbler]

I thought people would like to discuss gantry cranes and how they might be built, used, etc.There seems to be some interest in me describing the build of mine, so here goes:

I needed it to be versatile, from 7' tall overall, to doing an 11 foot lift. I knew that I'd be lifting stuff up to 2 tonnes, so I built it to carry at least twice that - this is common practice for rating lifting equipment.

My first design choice was to make the tubing size all 4". Right away I screwed up and bought steel for the legs with .250 wall. Way too heavy, after all I wasn't building a 50 ton crane! I re-purchased .166 wall which is still stronger than I needed...

Here's a photo in Bert's basement, with a 7' ceiling. Note it is using the short main beam for maneuverability and lower height. It is made from the 4" X.250 wall tubing discussed above.



The castors are 2800lb Casterland casters with rotational locks.
The legs are 6 foot long 4X4 .166 wall tubing.
The diagonal braces are 2X2X.125 angle iron
The risers the move up and down, and hold the main beam are 6 foot long 4X4X.188 wall tubing
Those trapezoidal plates are high tensile steel, waterjet cut .250 thick
This main beam is 6' long 4X4 .250 wall
The long main beam shown below is 4" X8" X.288 wall structural tubing X 10 feet 4 inches long
All fasteners are 3/4" diameter national coarse, except:
The plates connecting the main beam to the risers are 3/8 plate, with tow 5/8 fasteners per plate, 4 plates
Here's it is in use at my shop:



A few design notes: With the large beam it will safely lift 5 tonnes, so I overbuilt by a bit. With the small beam it will lift closer to 7 tonnes, because of the short span and thick main beam walls.

The build was mostly "drill holes", get plates from water jet, assemble. The only welding was for the plates the casters sit on, the casters will fail before the compression welds give out.

A quick word on the weight. It isn't light. the main beam measured 225 lbs. Each end assembled is over 225 lbs, but one guy can lift it up to vertical with out too much grunt.

Feel free to ask any questions,...

 

[Tom Kitta]

I assume the top bar is also 4" steel just b/c you were buying a lot of it - have you considered using a T beam or two C beams so that you can have a trolley move side to side?

 

[Dabbler]

The trolley will run on top of either main beam. Custom built, of course - because, my-way.

 

[Dabbler]

Oh, and because I was broke and had the 4X4X.250 in the back yard.

 

[Hacker]

Nice looking gantry. I like that you can adjust the height adds some versatility to how you can use it.

 

[Dabbler]

Part of the reason for not documenting it earlier is that the build is still ongoing. I have some improvements in mind for next time I need it. Little tweaks, but things that will make it nicer to use.

 

[Chicken lights]

Part of the reason for not documenting it earlier is that the build is still ongoing. I have some improvements in mind for next time I need it. Little tweaks, but things that will make it nicer to use.

That’s the part that makes it fun. I can do “this” but I need to change “that”

There’s no perfect it’s always an evolution

 

[Janger]

As impressive as the pictures are it is way more impressive in real life.

 

[Canadium]

Totally awesome! Something I really need to see and think about. Thank you so much Dabbler for posting this!!!

 

[Hacker]

How do you raise and lower the gantry?

 

[Dabbler]

How do you raise and lower the gantry?

Ahh, a great question...

The very first time it took 7 hours of messing about with various lifting devices. It also had the heavy legs at the time, making each A frame a 2 man lift. --It was horrible!

The second time I built a wooden crane deck at the top of my garage roof, and it took a couple hours and a little butt-puckering....

Nowadays it is a simple 1/2 hour job. the A frames are built and spaced at the lends of the beams, pointing outward. I then use a Genie lift like this to raise the main beam:



Then each A frame is raised and a pin inserted. then the diagonal member is installed. Gantry is ready...
After seeing the process once, @RobinHood did it on his own quite easily.

 

[Dabbler]

And the elephant in the room: price. All in, it cost about 1200 dollars. The Princess Auto, fixed height '2 ton' gantry was 1100$ at the time. So even though it is extravagant, it was about the same as the PA one.

 

[Canadium]

How do you store it?

 

[Dabbler]

I break it down completely and store it in the backyard. For a while the A frames remained fully assembled, but they are pretty heavy to lug around with one guy. Disassembled it is very easy.

 

[Canadium]

The trolley will run on top of either main beam. Custom built, of course - because, my-way.

I'm wondering if a trolley is really desirable. If the crane was slightly off level wouldn't gravity pull a loaded trolley crashing to one side?

 

[Hacker]

And the elephant in the room: price. All in, it cost about 1200 dollars. The Princess Auto, fixed height '2 ton' gantry was 1100$ at the time. So even though it is extravagant, it was about the same as the PA one.

I would say that is very good value for the money and time invested. A gantry is something that I have been contemplating building for a while. Thanks for sharing this.

 

[Hacker]

I would think that if would not be a very good practice to do any lifting with any equipment that is not level. Too many variables are introduced when things are not square and level when doing heavy lifts.

 

[Canadium]

I would think that if would not be a very good practice to do any lifting with any equipment that is not level. Too many variables are introduced when things are not square and level when doing heavy lifts.

The devil is in the detail. Just exactly how level is good enough. Do we just eye ball it or do we use a machinists level? Is shimming it to level acceptable? Would shims add an element of instability? Personally my guess would be that eye balling might be good enough if a trolley is not used. But greater precision in level might be required if a trolley is used.

 

[Hacker]

The ones that I have used with a trolley if the chain is hanging straight down it is usually good enough to use. Always put a bit of load to test if the trolley is going to walk on you. You really shouldn't use a gantry to move around heavy loads on an uneven surface.

 

[Canadium]

The ones that I have used with a trolley if the chain is hanging straight down it is usually good enough to use. Always put a bit of load to test if the trolley is going to walk on you. You really shouldn't use a gantry to move around heavy loads on an uneven surface.

Suppose as in my case the object is merely to get a heavy object off the trailer and onto the ground. The ground just outside my shop is a gravel driveway that might not be perfectly level. I have no intention of moving the gantry any where with the load. Merely to raise the load a few inches off the trailer and then down to the ground after the trailer is driven away. My guess is I would be best off without a trolley. An approximate level might be good enough.