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Thread: Building a Gantry Crane
02-11-2006, 03:33 PM #1
I would like to build a lightweight, portable gantry crane to move new purchased HSM machines from location to a trailer.
It should be able to be setup and taken down by one person.
It should be able to lift 3500 pounds.
How would you build one that would fit these requirements?
I am leaning towards steel uprights and an aluminum I beam so one person can do the setup and teardown.
Any suggestions would be appreciated.
02-11-2006, 03:48 PM #2
Wallace sells these- they have already done the engineering. Pick the model that most closely fits your needs, and copy it.
I did this about 15 years ago, building mine for 1 ton capacity, with a steel I beam. I liked their adjustable height feature, so I built mine that way, with the verticals sliding inside a larger size of square tubing, and 2 yard sale comealongs pulling it up and down.
The casters were the biggest investment- decent ones that will carry that load cost quite a bit- I prefer plastic coated wheels, as they will go over small bumps and dont get stuck and scream like cheaper all metal wheels.
As far as one man assembly goes- I use the chainfall or a comealong to pull my I beam up to the ceiling, then bolt on the ends, and lower it down to the ground. With two people, you can lean one end against a work bench, clamp it there, and bolt on the I beam, then lift it up and bolt on the other end. Takes a ladder, though.
Here is a crummy picture of mine
02-11-2006, 04:12 PM #3
A gantry with 4000 pound capacity, 10' span (to clear the sides of a trailer or pickup) will have a total weight of 800 - 1000#. Just the I-beam on mine weighs 250#.
Google 'gantry crane' and copy an existing design, as Ries suggested. Eager to see the results
02-11-2006, 04:36 PM #4
I have been thinking of building one also, but not your weight cap, I am thinking 500-1000 lbs.
Casters will come from Enco, they have sales on their heavy duty casters all the time, they work quite well I have a set on a 3000 lb brake and it rolls reasonably easy. My suggestion on wheels would be to get the largest diameter you can, they will roll over things easier the bigger they are.
For the uprights, I saw on the other board, a suggestion for using house supports (like in the basement) they are adjustable, and reasonable, plus they hold a lot of weight.
Does any one have any thoughts on using these ?
Sounds like a good idea, but I will have to go look at them to know for sure.
02-11-2006, 04:45 PM #5
By 'House supports" I am assuming you mean a 3" pipe with a screw jack in it?
This works ok for a house, where you really dont want to move it much, and you sure dont want to move it fast, and you need fine adjustment.
But on a crane, you need totally different things- if you want to move the crane up or down, my minimum increments are 6". Mine is adjustable from about 9 feet to around 13 feet tall. Those itty bitty screw jacks only have about 6" of range, total.
If you look at the pics, the smaller square tube is attached to the I beam, and the larger square tube has the casters on it. The comealong isnt on it in this picture, but what you do is if you want to raise the frame, you hook the comealong hook on the bottom of the upper tube, where it sticks out of the bottom of the lower tube, and you can pull it up. To lower it, you just let out cable. Once you have it where you want it, you put a bolt in one or two of the holes, so you are not carrying the load with the comealong. Works great in practice- I lower it to fit inside, raise it out in the driveway to unload bigger trucks.
02-11-2006, 07:21 PM #6
I dunno. I could manhandle mine to another location but dang, what a back breaking job.
That said, the hoist is built for hell and high water. Not the kind of thing I am going to shave a safety factor on and neither should anyone else doing the design and fabrication themselves.
One possibility is to forego the casters. It is 10x as easy to assemble without the casters since the bottom won't want to roll away from you.
The other possibility is to narrow the trailer. That extra width costs you dearly in strength (and thus weight) of the overhead beam.
Last option would be to build the setup into/onto the trailer (I beam running longitudinally). Just make sure to install jack stands at the rear of the trailer, and ideally some sort of arrangement to level the top I-beam too. You definitely don't want to pick up 3500 lbs and have the I-beam off level as the load will want to roll with astounding sideways force.
02-11-2006, 11:09 PM #7
This is my gantry crane.The need to move my Woodhouse and Mitchell lathe to a new shop gave my the idea to build it. I used the house jack post idea for my uprights. I wanted the option of being able to adjust the height. This crane will go from 6'6" to around 10'. I used 6" caster wheels rated for 1900 pounds.My lathe weighs 2000 pounds and I could roll it across the floor with one hand.The 6"x10' I-Beam cost $160 and the 2 jack posts were $48 each (Cdn.). The rest of the material was left overs from other projects.I bolted the posts to the I-Beam so I could disassemble it to facilitate easier transportation should the need arise. [img] http://www.photobucket.com/albums/v6...h/IM002006.jpg [/img] [img] http://www.photobucket.com/albums/v6...h/IM002008.jpg [/img]
02-11-2006, 11:18 PM #8
02-11-2006, 11:32 PM #9
jcarter's gantry (for simplicity)
02-12-2006, 01:42 AM #10
02-12-2006, 01:48 AM #11
Back to the original post, I think if you could modify the criteria to having a helper or two that would make life a lot better.
That said, I've moved a lot of machinery with this Big Orange hoist, and it is much easier to transport and disassemble, reassemble by oneself. The things that stymied me were long trailers and long lathes, and weights above 1 ton. This isn't the cheapo "2 ton" hoist...I'm not sure if they are even sold any more.
02-12-2006, 02:07 AM #12
Oh...I should also add that you are entering a dangerous phase... ....that once your capability to easily transport and move the machines increases, you are only limited by your bank account, shop space, and willingness to drive.
02-12-2006, 10:25 AM #13One possibility is to forego the casters. It is 10x as easy to assemble without the casters since the bottom won't want to roll away from you.
L K Goodwin does have aluminum gantrys with two ton capacity, 266#, about $5000:
Beacon has a similar crane:
02-12-2006, 04:48 PM #14
I made a crane that may meet your requirements. Check out files labeled Gantry_Crane. With an aluminum beam this would be a snap to set up.
The swivel legs allow for one leg to be installed flat on the ground and then erected in stages.
I got my casters from these guys. Alum whees with polyurethane thread.
02-12-2006, 05:19 PM #15
02-12-2006, 07:44 PM #16
Thanks for the responses so far....
One issue I would like to hear advice and suggestions on is how can ONE MAN assemble and disassemble a gantry crane safely?
02-12-2006, 09:32 PM #17
Tmt, the way I assembled mine, working by myself was to lean the uprights (no casters) against the workbench. Then heft the bridge beam up while standing on the workbench (120 lbs) and set it on the top of the uprights.
Carefully install the bolts.
Then raise up one end at a time like Barry suggested and install 2 casters.
Another possibility would be to have some temporary "strapping" like 1/4 x 1-1/2 flat bar that you'd attach in an "X" pattern (2 pc) to keep the uprights, well, upright while setting the bridge beam.
Really, a gantry is best assembled on the ground, laying over sideways.
The problem is that it is hell to get it upright with something less than a forklift, and if you had that, the machine would already be loaded and gone.
Considering that you have to assemble the hoist twice and disassemble the hoist twice plus any other chicanery in moving the machine, driving time there and back, it makes for a long tiring day.
That's why I suggested building the gantry into a trailer. This way no disassembly or reassembly, just pull up, load, tie-down and go. Unloading would be easy too.
02-12-2006, 11:01 PM #18
In case you're wondering how I raised one end, here's my method. Place a floor jack next to the gantry. Measure the distance from the top of the floor jack to the best point for lifting (the projecting I-beam in my case). Subtract an inch & cut a 2x4 to that length. Raise the frame high enough to slide blocking under the end, lower the jack & install the casters.
I really wouldn't want to do this more than once
02-13-2006, 12:58 AM #19
"That's why I suggested building the gantry into a trailer. This way no disassembly or reassembly, just pull up, load, tie-down and go. Unloading would be easy too."
I would be interested in seeing how one would attach a gantry to a trailer and still have flexibility to the machine.
02-13-2006, 05:21 AM #20
Sorry. No pictures. But the idea is in my head. It is a monorail design, though.
Sometimes you will see a setup like this on a medium duty truck used for gravestones or setting concrete tanks off.
The I-beam is set longitudinally on the centerline of the trailer, underhung from cross-supports overhead, so a trolley can traverse the length of the rail. The I-beam should be mounted with bolted structural clips rather than welding as it's a high-confidence joint.
The I-beam needs to have some overhang. But keep it as short as possible while still remaining useful. 2 feet comes to mind as max cantilever of the trolley. The web needs opposed angle irons thru-bolted so the trolley does not exit the rail (end-stop).
Leveling is important, so is backing up to the centerline of the machine, as it will want to swing otherwise as it leaves the earth. Ideally some screw or bottle jacks at the rear of the trailer to counteract the strong moment that will be developed up to the maximum at the point the machine is lifted free. (Normally this would compress the suspension of the trailer and the tongue coupler would attempt to leave the hitch ball)
Two considerations really, one, you don't want a strong mis-level towards the towing vehicle because the machine will roll that way, and depending on weight, be hard to stop. Second, you don't want a strong mis-level towards the back, as you won't be able to roll it into final position either. Kind of a catch-22, but the screw or bottle jacks will help keep things leveled out.
Last thing is to have a system to tie off your chain hoist and trolley so they don't freewheel when you stop and start.