Overhead Mobile Gantry Crane Build (A Tool for Lifting Heavy Things)

Do you need to lift heavy things? Are you tired of all the work and the funny noises your back keeps making when you are lifting things? Are your friends tired of those calls on the weekend where you casually ask "hey, are you very busy?" and you "just need them to run over and help you lift something..it won't take 10 minutes, but they end up there for 3 hours?".....Do you need to take the bed off your truck so you can undercoat because they clearly undercoat cars at the factory with rust, and you just can't find anyone to help? YOU, MY FRIEND, NEED A GANTRY CRANE!!!

In this Instructable, I'll share how I built a mobile gantry crane to lift things around my garage, lessons learned, and share some general project approaches I used to build this tool. I built it with a combination of used components and some laser cut steel to make a useful overhead crane I can roll around my garage and use to lift large and awkward things like truck beds or such, with no help required.

Big shout-out to my friend MattJ who envisioned this build...the second he saw the shelving in my garage, he had the great idea to build one shelving system into a gantry crane...big thanks for the idea.

My approach on this Instructable is less to prescriptively tell you how to build THIS crane, and more to just give Makers like yourselves ideas about how I approached my tool build, so that you as a Maker can formulate your own ideas for your specific tool build. As such, I have not included specific dimensions/etc for reproducing this build...rather I've tried to just show how you might approach a larger scale tool build for yourself, some techniques I used as well as mistakes I made. While you may source different parts requiring differing approaches, hopefully this Instructable encourages others to get out there and build stuff. I hope this is helpful in your tool build whether your tool of choice is a gantry crane, a iron forge, or any other large-ish tool for your garage/barn/makerspace/sewing room.

SAFETY DISCLAIMER: Fabrication and subsequent operation of lifting devices such as overhead cranes, hoists, jacks, etc, are inherently dangerous. Even factory produced units can fail causing injury or death. Home-built systems should not be built or used without proper expertise, engineering principles/practice, knowledge and safe operation procedures. Cranes are serious devices, and even without any weight on the system, one even toppling over, or a component falling could definitely kill you or someone else. Please be EXTREMELY careful in any effort you make around building or operating a lifting device such as a gantry crane. I strongly urge you to consider purchase of a commercially available unit unless you have adequate expertise to ensure safety.

Availability of materials and how you source them can impact and dictate overall design...and it did for me. In my case, I was trying to keep costs down for my gantry crane build. So, my starting point and build was largely dictated by materials and tools I could source cheaply and nearby, and material/tools I had on hand. If you can afford all new materials from the steel yard, by all means go that route...but in my case...I went the "upcycle" (read: poor mans/junkyard) route and got my primary structural components from used materials. I also happen to have a steel plant a few miles from my house that's friendly to individual buyers for what new material I had to buy. It's good to be creative and explore alternatives places to get materials.

My material sources included:

Industrial Office Store Closing Auction: A local big box office supply store was going out of business. I went there during the last days of the auction/sale and bought two pallet shelving systems. I might have paid $100 for the pair, meaning I have about $50 in my main frame structure. I'm not sure what a new pallet shelving system costs, but I'm guessing it's more than the $50 I paid.

Ebay: I wanted commercially manufactured gantry crane wheels. I could have possibly made some on a lathe, but that seemed tricky. I did email a few suppliers asking for prices on wheels alone, and it was cost prohibitive. I found I could buy USED beam trolley assemblies on Ebay so cheaply that the shipping was almost more than the purchase price...so I did that and just stole the wheels out of the used trolley chassis.

Commercial Steel Plant: Lucky for me, my local steel supplier is close by, and also very friendly to individual purchasers buying small amounts...even though they normally sell material by the truckload to coal mines and other industrial scale buyers. Being able to email and ask questions, and buy new materials there is easier than you might think and you should not be intimidated about calling your local steel plant and asking for materials...they are often nice people and more than willing to help if you're polite and don't waste their time.

Metal Recyclers/Junkyards: Some junkyards sort materials and will allow you to 'come browse' for things you need. It's best to call ahead, and while I did not use this option (but I have on other projects) this is a cheap way to score raw materials for builds, and def worth checking out.

Online Industrial Suppliers: Items such as my chain fall came from an online industrial supplier. A quick google will yield any number of such suppliers. Just remember, going "cheap" isn't prob smart on something holding a ton of material in the air...so finding out your chain hoist is made of smelted peanut butter and tin, and not actual steel...well, you don't wanna find that out with something heavy hanging on that peanut butter chain above your head.

Local Farm Stores: Don't forget...some of the craftiest people anywhere are farmers. They can fix anything. As such, farm supply stores are more than just cattle feed and shotgun shells. I bought my chain and chain links at a local farm store. Make sure you pay a visit to your local farm store...they often carry heavy duty materials like chains, hooks, clevises, and other such things which are industrial grade for yanking tractors out of ponds and such...so the occasional browse of the local farm store is a good way to familiarize yourself with potential items you can re-purpose in your projects (plus, there are sometimes some cute farm girls there buying chains and clevises).

If you are sourcing material for a hoist or crane by using "upcycled" materials, its a good way to save money, but a builder should consider what sort of fatigue and abuse the re-used materials have seen in the past, and if they might be prone to failure due to reduced working load/etc. Sometimes 'cheaper isn't cheaper', so keep safety in mind when sourcing used materials.

Since I had a starting point for my main structure as a used pallet shelving system, pretty much all my design decisions revolved around that. Use of that shelving system I certain saved some money on my primary structure, but ended up still buying a number of new parts/material as well. Depending on how you source materials, you may choose to design a different structure (such as a "A-Frame" type overhead with a single beam, or some other options). Whatever tool you are building, its important you consider what you will really do with the tool and what considerations come into play as requirements.

My design was based on:

Intended Use: What I needed to lift/intended use defined many aspects of the tool build (mostly automotive bodies and engine/transmission assemblies)

Environment: The space the crane would operate in (my garage and driveway)

Mobility: I wanted my crane to roll around and be mobile.

Load: I needed to be able to lift a weight of around 800lbs

Sourced Materials: The dimensions and unique structure dictated by the used pallet shelving superstructure defined my design in many ways.

Lift Height: Maximizing my peak height for lift, but still being able to move the assembly through my garage doors (which are at 10' in height).

Flexible Use: Wanting to make the trolley system in such a way that it could be adjusted in width and wheel position, so I could use each trolley independently on other beam widths. This way, if I moved and wanted to place the trolley as and individual units on an overhead beam (such as those built into some garage ceilings), the tools would be portable in that sense.

Cost: A decent overhead trolley system can be purchased new for under $1000 in most cases (at least in the US). I wanted to come in well under that number, and was willing to give up some time to do it. Cost can get away from you easy, and little things can add up. So before you begin, it's a good idea to go through your materials list and at least put some ballpark prices beside each item. Sometimes, you can just buy it cheaper than you can build it.

Access to Tools: The fact that I had easy access to a laser cutter, a CAD Brake, CAD software, a lathe, and some excellent fabrication mentors really gave me flexible design options. The laser cutter certainly made it much more realistic for me to make the trolley bodies more complex.

As a fellow Instructables Maker speaking to other Instructables Makers, I would encourage you to make a similar list which identifies your honest requirements for whatever tools you want to make (cranes or otherwise). Consider what you are 'trying to do' and be realistic. I think I sometimes slip by trying to build a project to be 'perfect for all possible uses', when in reality, I would save a lot of time and headache if I just built the thing to meet the need 80% of the time. While it's fun to try to make something incredible and cool, "functional enough" is usually better than "never finished".

For instance I would have loved a system that lifted 4000lbs safely...or a system that had an electric trolley travel system....or a system that once out of my garage I could raise telescopically to get another 5' of lift...but if I'd done even just one of those, I would probably have never finished the project. While those things are "cool", this system covers probably 90% of the needs I have. I'd just encourage everyone to set some minimum requirements, but not to go crazy and get into a situation where you make your project so hard, it can't be finished within a reasonable amount of time, at a reasonable cost.

SAFETY WARNING: In an abundance of caution, I'd reiterate and point back to the safety warning I put in step 1. Designing any lifting system is inherently dangerous. If this is your first project, please seriously consider consulting with a knowledgeable engineer or someone with some experience. You'll probably learn something and it may help you identify safety issues that may not seem apparent. It may not seem it, but a cross member holding a small car engine might not seem like much...but if you design and build a system and it fails structurally, that small engine and the beam attached are more than enough to kill someone when they are falling.

It's a Shadoof! WHO KNEW?: So the black and white photo I pulled and placed in this step is very cool. While searching for ideas for my gantry crane, I learned about the "shadoof". Some of the earliest "makers" made this cool gadget for lifting water. Man....talk about crafty, those folks couldn't even google it...so imagine trying to come up with that thing on your own! Point is, if you're trying to do something, often some other human also had that same idea. When designing your system, don't go it alone...fall back on makers who came before you (including the folks that build the first Shadoof!) and see how THEY solved the problem. It might just save you some time (and your sanity).

No matter what tool you're making (including a gantry crane) doing a little googling and seeking guidance isn't cheating...it's learning from others (as long as the project is just for yourself...otherwise I hear they call it copyright infringement or something!) Even just looking at the Shadoof image might make you think about using counterweights to offset lifting effort, etc...so make sure you look around at previous work others have done in making tools like what you're looking to build.

NOTE: Credit to Wiki Commons for the Shadoof image, via Sir John Gardner Wilkinson / Public domain. Original File URL : https://upload.wikimedia.org/wikipedia/commons/4/4...

Now that you've decided WHAT you want the crane to do...and you have at least sorta sorted out what materials you have on hand for re-use...and what tools you have, you can start to design your crane.

I have found that doing rough pencil sketches initially, before committing to anything more firm saves me time and hassles. While tools like CAD, SOLIDWORKS, Google SketchUp, and Blender can can feel 'fancy', sometimes a pencil and an eraser are the easiest way to work out ideas in the early stages.

At the risk of harsh criticism within the New York and Milan art communities, I'm sharing a couple of my early sketches...while very far from perfect, just sitting around doodling these rough sketches got my brain thinking about the problems I might run into with various designs...don't be afraid to tinker with a pencil. It's a lot easier to make pencil drawings and find problems, than it is to start building and run into troubles there once you have a welder in your hand. ...and don't be shy if you "can't draw"....you're drawings don't have to be Picasso sketches...you just need to make enough lines on the paper so you can think about what each various design does in terms of solving your problem (in my case, lifting stuff). Also two of these photos are the final CAD DWG files I used for cutting my trolley bodies on a laser cutter. Those final CAD drawings only came after a LOT of pencil doodles, and plywood mock ups.

Once you get close to what you think your final design is on paper, then you can (if you wish) move to something on a PC like Google SketchUp or such. Personally, I use a tool called TurboCAD, which works fine for my purposes....but some of the best fabricators I've ever met never touch a computer...it's all pencils, soapstone chalk, and some supercomputer in their head fueled by MIG welder flux fumes and donuts.

Mocks ups are low cost ways to evaluate and 'see' what you've designed...the idea is that mock ups can be created easier and cheaper than the real thing. I like using mock ups of cardboard or wood for things that will eventually be 'made real' in steel. Cardboard or plywood is cheap, and easy to construct mock ups...and seeing the mock up often helps me realize problems early in the process...rather than later when it's too late and costs me money and time.

Once I had designed my trolley bodies with a pencil, and scavenged the used trolley wheels and pins from the used Ebay sourced trolleys, I was ready to build a plywood mock up to see if my idea worked like I thought it would.

I used some old 1/4" plywood I had around to cut out the trolley bodies, and drilled the plywood to receive the wheels and pins. It only took 30 minutes to cut and assemble the mock ups. Once assembled, I was able to see possible issues with my design that I had not realized when sketching up the bodies on paper. This helped me think about the value of doing things like placing 4 pins to "cage in" the trolley so it can't leave the beam, and to prevent the upper wheels from 'spreading' under load and falling. I was also able to use the mock up to validate my beam offset measurement of 1".

Sometimes parts sourced by scavenging or re-purposing on a project can introduce their own problems, and require modification to suite your purpose. On my gantry crane, this certainly ended up being the case. One unique thing that arose in my case was the pins I scavenged from my Ebay purchased trolleys were "too wide" for my beam. The mock up helped me realize this oversight on my part.

Modifying Structural Pins: Fortunately, I have access to a lathe and was able to turn down the shoulders of each of the used trolley pins so that they were narrow enough to fit my beam width.

While you may not run into this problem, keep a cool head when these sorts of issues arise on your project. While at first I was like "well this project is over"...then I realized I could just narrow the pin shoulders on a lathe, and about an hour later, I was back in business.

I think a challenge for all Makers is running into issues like this, and letting it stop a project. While a frustrating oversight on my part, after taking a deep breathe, I found an easy answer, was able to still use the pins, and it only cost me another hour to modify the old pins to work for my application.

Once I had played with the plywood mock up, I was able to see my trolley body idea in real life and come to conclusions on measurements, wheel placement, etc. In my case (and this may vary if you choose to attempt this), I used the mock up to assess and finalize measurements for several aspects of the trolley bodies. I used TurboCAD to create a file for use on a laser cutter. If you are cutting/drilling your trolley bodies using other methods, you may not need to put the final drawing in CAD. In my case, considerations I had to make in going from mock up to final drawings for the trolley bodies included:

Horizontal distance between wheels: I chose to space my wheels at a pretty wide span to distribute load. In my case, my pallet rack uses a hollow tube beam on which the wheels ride. I felt that doing a wider span might help a little with distributing the load from a 'single point' (I'm very specifically avoiding terms like "point load" here as that is not my expertise, and you should consult an engineer for any real conversation on that topic)

Offset Beam: My choice to use the pallet rack came with the hassle that the beam the trolleys ride on had a 1" offset on the inside (a lip of sorts). So I was forced to make my inner wheels on the trolley sit 1" lower than the outer wheels. This was probably the most annoying part of using the pallet rack, and honestly enough reason that I would NOT recommend using a rack that has a beam with that offset. In any event, I simply took measurements of the offset and incorporated that into my final measurements.

Pin Hole Diameters: As indicated, I did use a lathe to remove some shoulder of my threaded pins which I scavenged from the used 4-wheel trolley bodies I bought on Ebay. I did NOT however, change the diameter of the pins. I measured my pin diameters and left just under 1/16" of clearance when I set my pin hole diameters.

Wheel Axle Hole Diameters: Similar to the holes for the pins, I left a slight allowance for the wheel axles, but reduced the allowance around 1/32" larger than the actual diameter of the wheel axles.

Top Plate Beam Seat: Once I had the mock up I was able to rough out the dimensions of the top plate beam seat. While I did make a pair using my mock up dimensions, I ultimately ended up making another set later as my plywood mock up flexed and to make more precisely fitting top plates, I measured the steel trolley bodies once assembled, and then cut/broke new ones which fit with closer tolerances. Lesson learned: If you have parts to assembled, it may be best to get 'true dimensions' once assembled for making secondary parts (like the top plate)...or you're probably just better at measuring than I am in which case you may not need to do that! ;-)

To make my overall superstructure, I re-used a commercially manufactured pallet shelving structure I bought used from a major 'big box' office supply store. If you are making a tool, it may be worth considering if it there is something pre-made which you can re-use to both save money and time, like I did with this pallet shelving system.

I did have to modify the pallet shelving a bit to make it serve my purposes, and here are a few of the things I had to do:

Shortened Overall Frame Height: I wanted the gantry crane to be able to roll in/out of my garage which meant it needed to clear the garage door opening which is 10' I used a plasma cutter and shortened the four corner posts, allowing for the height increase from caster wheels I was also adding to the base of the frame. Additionally, in shortening it, that forced me to cut out and weld back in one of he angled struts on each frame. I did that with a MIG welder and an angle grinder.

Adding Caster Wheels: I wanted the crane to be able to 'roll around'. After some shopping I choose solid caster wheels (600lb load rating per wheel) which had a grease fitting and a flat top mounting plate. I welded the top plate of the caster wheels to the lower plate of the pallet rack frame. I did have to trim the feet of the rack, as the floor plates were wider than I needed.

Additional Cross Beam: Since I'd bought a couple used pallet racks, I had some extra cross beams. I placed one lower in the rack to act as a brace, to reduce tendency of frame to 'spread' under load. I just picked a decent spot about halfway down, and used the rack's pin system to drop that third cross beam into position (it is still removable). In my case I wanted to still be able to roll the frame over an automobile, so I placed the bracing beam high enough so it should clear most pickup truck beds.

Stamped load rating: It's worth noting here that on the rack cross members, there was a "per pair" (PP) load rating stamped in the steel. You can see in the photo that the pair together of cross members is rated to max load of 4950lbs when the unit shipped new.

The most fun part of this project was probably cutting the trolley bodies and top plates on the laser (and bending the top plate in the CAD brake). I had a lot of assistance from some great guys at the local manufacturing business incubator where I rented time on their laser. They helped me take my CAD file and correct mistakes, and get it ready for the laser cutter as G-Code.

I ordered raw plate material from my local steel supplier (mild cold rolled), and simply load the plate on the laser, and let it take the G-Code it generated from my CAD file, and it does the rest. Using a laser cutter makes you feel like you could honestly make anything...if you're having a bad day, I highly recommend a dose of laser cutting...it makes all your problems go away!

If you don't have access to a water jet or laser cutter, there are many alternatives including handheld plasma cutters, cutting wheel/abrasive disks, and of course...fire wrenches (aka oxy-acetylene torches). However you get your project done is up to you, but if you have a waterjet or laser nearby don't be intimidated...it's way easier to do than you think and if the shop has nice fella's like the place I use, you'll learn a lot on the way to finishing your project.

Now that I had the trolley bodies assembled on (and around) the superstructure beams, I needed to make and set my cross beam, and at the same time set the top plates that let the beam 'ride' on the trolley bodies.

Fitment Check of Top Plate: I first triple checked that my top plates fit on the trolley bodies, and that the holes aligned for affixing the trolley top plates to the trolley body plates.

Prepping the Cross Beam: I happened to have a 4" I-beam laying around so I shortened it in the band saw, and drilled two holes in each end to match the mounting holes I had cut in the trolley top plates. I had to be very careful here that the drilled I cut in the beam were spaced exactly the same distance from center to center on the trolley bodies. Once I cut the beam to length (the width of from the outer side of each trolley body) and drilled the mounting holes, I bolted on the trolley top plates onto the beam.

Place the Cross Beam: Once the top plates were bolted to the I-beam, I placed the beam onto the trolleys and installed the fasteners to secure the top plate and beam assembly to the trolley bodies.

Notes on Making the Top Plates: I need to note here that trolley top plates were made in a two step process of cutting flat plate and the holes on the laser, then secondarily bending the ends in a brake. The brake was a CAD brake which helps you by calculating how much the metal will stretch, and how much the bend radius changes your geometry and a little 'robot arm' of sorts helps you set the bend point. I have to say here, I made about 8 steel coasters for my garage in doing this. Thanks to the patience of the guys in the shop helping me, eventually I got it right, but not until I'd definitely wasted some time and plate making every possible wrong size I could in the brake.

Once the cross beam was set, I went back and checked every bolt. I found I'd left two loose somewhere in the assembly process, and I'm very glad I checked. If you are doing a build like this I'd encourage you to do small re-checks on such things.

After everything was assembled, I needed an actual way to lift things from my newly set cross beam. I ended up buying a new chain fall type hoist. I bought a 1 ton only because I may need to use it elsewhere, but I never intend to lift more than around 800lbs on this crane.

I attached the chain fall hoist to the cross beam using chain rated to 5400lbs, and used 6600lb rated links to connect the ends of the chain to each other to make a loop. I suspect this is not the preferred or advised method for making the beam to chain fall attachment (since the box the chain was in said "not for overhead lifting"). I did find devices known as 'beam clamps' which do seem to be made for affixing hoists to cross beams, so I may buy one of those later. Once I had the chain loops around the beam, I hung the chain fall hoist from it, and at that point, I had a working gantry crane.

I did a number of tests lifting small items of about 100lbs and then using a ladder to climb up and inspect the entire rig. I'm not sure what I expected to see, and I know that had there been an issue such as a crack or such, it was unlikely visual inspection would have revealed it...so I'd suggest if you do this, you come up with a better way of doing any type of testing.

Thanks: I appreciate that anyone even read/looked at this Instructable. The internet is so full of really cool projects, I'm thankful if anyone even reads this Instructable. So thanks to you for doing that! Also big thanks again to MattJ for seeing the shelves and immediately realizing their potential as a crane.

Trying Something New: I think the Instructables community is about encouraging others to try something new they might otherwise not feel capable of. Before this project, I wasn't sure I could plan and layout a set of components on a laser cutter which would fit together properly. Now, post completion, I'm far more confident in my ability to do that, and the education I got in this exercise will help me on other projects. I can't encourage enough Makers to try something, even if it seems hard. My main hope with this Instructable is it encourages at least one person to stretch past their comfort zone when it comes to being a Maker, and that you try something new that feels just beyond your current capability. I bet you'll succeed and learn a lot in the process (I did).

Bought not Built: Honestly, if I had to advise anyone or do this over again, I'd just suggest you buy a commercially produced overhead lifting system. If not that, I'd really discourage construction of a system that 'moves'. A fixed position static system for lifting is probably a better way to go. While this project was fun, I realize now I could never in good conscious sell this tool to anyone else for fear they might overload it and get injured. Further, I have no 'true' way of knowing the load rating for my gantry crane. I can guesstimate as a layman what it's max likely is, but guessing isn't a safe game when it comes to overhead lifting and safety. I will continue to use my crane, but with caution, and remaining below 800lbs (which I believe is well within it's likely max load).

Point Loads, Static Loads, Engineering Degrees and such: I learned that no amount of YouTube or Googling is a substitute for formal education in understanding point loads...and further point loads that move and their effect on structures. Loads which are moving either on trolleys (like I built here) or on casters (like on the feet of the rig here) totally change the situation vs say a system that is permanently installed in a fixed position. I earnestly believe that structural engineers earn their keep and while I suspect they mostly use software for most calculations these days, we owe some respect to those who fully understand and engineer safe products which carry loads, especially loads that move (like on trolley's). If you get a chance, hug a structural engineer today and thank them for making sure we all don't end up with heavy things coming down on our heads!

Thinking About Assembling the Tool: In all my drawing and making on this project, I had never even stopped to think about "how will I assemble this?". Only during final assembly did I realize that the only way to assemble it was on a ladder...holding two pretty heavy parts of the trolley body...trying to simultaneously align four pins in their holes...with a bunch of spacer washers loosely hanging on. That...was a bad idea. By the time I had wrestled the first trolley up and got it assembled, I really regretted not thinking about HOW the tool would be assembled once I made all the parts. While I managed to wrestle all the (sorta heavy) parts up onto the frame and get them assembled, it might be wise to think about the final assembly process in some depth, to avoid issues.

Some Oddball Notes from the project that might interest a few:

- I pulled the specs for the pallet rack from the manufacturer's website. If I'm reading it right the entire rack as a whole is rated to a max load of 28,000lbs. Obv that's prob a distributed static load, across several tiers of shelves (because as noted earlier, the max load per horizontal beam pair was 4950lbs when the units shipped new from the factory)...but wow...28,000lbs? Whew, that's a lot of boxes of paper reams!

- The pallet rack which uses holes in which the beams rest, have small retainers meant to keep someone from accidentally 'lifting' a cross beam out of the holes. These retainers are simply little steel flat springs you push into place. I could see how in a facility using forklifts, a risk of uplift of the beam could be a problem and these retainers might help prevent that. I debated if I should put at least small tack welds on where the horizontal beams where those retainers are to further prevent any upward movement, but decided not to so that I retain the option of completely disassembling the superstructure for transport if necessary.

- The main point of this project was to be able to remove and reinstall truck beds, and Jeep (CJ/TJ/JK/YJ) type bodies from their frames. The frame works delightfully well for that, as well as loading stuff out of pickup beds.

- The motor in the last photo (hanging from the hoist) is a 4.8L small block Chevy fully dressed. It's part of a Jeep FC170 build that's underway.

- The facility where I used the laser cutter is a small business incubator which specializes in helping small businesses in manufacturing to be better equipped to utilize modern CNC/manufacturing techniques. It's a Federally funded facility, but I still pay for rental time for use of the laser table. You can likely find something similar in our area if you live near a metropolitan area. Alternatively, I have found that people who work at places like steel plants, manufacturers, machine shops, etc are surprisingly open to helping the occasional hobbyist if you are respectful, you respect their time, and you have an earnest desire to learn. If you can't rent a water jet/laser near you, ask around at machine shops, and see if they would be open to letting you work in the shop on your project, or if they would cut you a deal as a hobbyist for waterjet/laser time.