My Gantry Crane Build

[av8or1]

Then came the c-channel that will be used for the pivoting mechanism:


The supplier was even able to fabricate some custom pins for me, after my request for them to do so and sending them a drawing of what I would need. Those went into primer naturally:

[av8or1]

Unfortunately I had only one spray can's worth of the rusty metal primer business, so for the flat plate that I'll weld onto the c-channel to give it more thickness I was forced to grind a little more closely and apply self-etch primer:


Finally, I had to leave these for the night because they need to be cut to length. The supplier had them listed at 8" long but I only needed 5". I didn't notice the oversight until after they had begun preparing the order. Therefore I decided to just leave it as it was, cut them myself and then have some small scrap pieces leftover. Dunno what you could use them for, but I'll find something. Eventually. Anyway these are the radius-ed components that will be welded to the top and bottom of the gantry's legs:


And that would be as far as I could manage tonight. 'Had to get inside and help the wife with the process of getting our son into bed dontchaknow. I do that every night, without fail, so my projects require more time than they otherwise would. In my previous-to-marriage-and-children life I would have worked on this until the wee-hours of the morning and had it all but finished. No more. However no complaints. That tradeoff is a good thing actually.

Anyway thank you for reading.

[zoama]

What do you lift with this gantry crane? I ask because it's built so heavy.

[av8or1]

What do you lift with this gantry crane? I ask because it's built so heavy.

Eh, it's overkill zoama. And how. Mostly, my projects are automotive related, though I do run bigger trucks. I have an F350 and an F450. On occasion I have need to lift an awkward and/or heavy item off of the ground and into the bed or vice versa. So it comes in handy in those scenarios. And of course pulling engines and transmissions, a purpose or which I've already used the gantry in fact:


And of course it yanked that drivetrain right out like it was nothing, I mean absolutely nothing. That said, a gantry of this size is still overkill for such usage. However, that was always the plan. I am a big believer in overkill, generally speaking. And this gantry is indeed that. I chose the height based on the notion that a pending project I have will involve removing the cab off of my F350. So I measured the height of the truck (which is a 4x4 so it's taller than a 4x2), factored in the height of the trolley and hoist and came up with a number. I decided to build telescoping verticals in order to have an adjustable height. I did that because the aforementioned height that I will need for the cab removal put it rather high into the sky and if I had built the verticals as one solid, non-adjustable component, then you'd need to move it around at that towering height too. Somehow that seemed a little more unstable, if running around on un-level asphalt, than I was willing to accept. So with the adjustable variant I can place the main I-beam in its lowest position for relocation, and by an appreciable amount IIRC. Thus the extra effort required (and $$$) for adjustable, telescoping verticals was worth it. For me it was anyway.

Finally, the primary reason that I chose the (overkill) materials that I did was because they were specified on a formal gantry design plan that I loosely followed. During my research into gantry cranes the recurring theme that I encountered was to follow an established plan from well-known, reputable supplier. Folk/companies who have built these things for a while and who have a history with them. There are el-cheapo gantry cranes that can be had for less (Harbor Freight for example), but boy, I wouldn't trust those things much further than I could throw them. They just seemed so flimsy to me. So I found a company that manufactures gantry cranes professionally, got a plan and worked with it. I went with a little beefier material than the plan specified, but the 1/16" thicker material was actually an option on the plan, so I felt comfortable with that. In hindsight, the extra thickness probably was unnecessary given my use case scenarios. However I did so because the steel supplier gave me a price on the 1/4" material (tubing) that was equivalent to his quote for the 3/16" variant. So I thought to myself "why not go with the heavier duty stuff if it's the same cost?" And thus price drove that decision really. It is noteworthy that the final product I built was actually small in comparison to the cranes that the company from whom I got the plans typically builds. Hah! And yet to common, non-shipyard, non-railyard, non-etc. folk such as myself, my gantry appears gargantuan in stature.

Anyway I then ran the numbers and would feel comfortable rating it at a ton with a safety factor of 5. Or rating it at 2 tons with a safety factor of 2.5. The main beam deflection at 10,000 lbs was within the tolerance for that weight, and with room to spare. So it could likely be rated even higher, but I stopped doing the math at that point since I'll never use it for anything that even approaches those numbers.

I ordered the spindles and hubs yesterday. Those should be here mid-to-late next week. I am eager to get the wheels and tires on it, for it should move much easier around the asphalt than it does currently.

Overkill? Yes. Overkill = good? Yes. In my book at least.

Thanks,
Jerry

ps- I forgot to mention that I chose the width of the gantry solely based on the width of my F450, which is the largest truck I will likely ever own. The width of the gantry yields a good cushion on either side and that was what I was pursuing when I drafted the original design. The plans I followed specified varying length options and the one I chose was within the stated range, so I pressed ahead with that choice. It has worked out well. Easy to back the truck into, no clearance issues to contend with.

[zoama]

Did you dill a hole in the bottom of the uprights to let rainwater out ?

[av8or1]

Did you dill a hole in the bottom of the uprights to let rainwater out ?

Excellent thought. And yes I did in fact do that:

[av8or1]

Of course, the other aspect of having big toys to play with is that you are the best friend of all of the neighbors.

When they need to change the configuration of their outboard boat engine, for example, they call you. Lol

[av8or1]

Alright, so there has been a development in the lil' side project to put wheels on the gantry.

I had some concern regarding using tubing as the carrier. Tubing with one side cutoff mind you. The initial thought was that if I welded 1/4" plate to the outside of that c-channel that was made from tubing that it would have the strength and rigidity necessary to support the loads that the gantry might encounter. "Eh....dunno" I thought but decided to try it to see if it could work. Well some testing over the weekend showed that it wouldn't be the best course of action. Ergo my instinct was correct. 'Gotta trust that more often.

So I went back to the drawing board (or desk as the case was) and drafted a new design:


Better to do that than to proceed with the implementation of a previous design due to being too prideful to change, that type of thing. So on with this one I went. I have much more confidence in the strength of this design, for the channel (which is actually channel this time and not tubing) is mounted vertically and 1/2" plate is welded to both the top and bottom. I'll retain some of the components I've already sourced, to include the outer flat plate. I'll need that because the "standard channel" doesn't have web thicknesses anywhere near what I'd prefer, at least not in the "commonly used" variants it doesn't. And I don't want to have to buy a 20' stick merely for the sake of obtaining that web thickness when I can just weld plate onto the outside of the 3/16" webbing of that channel. The 1/4" plate + 3/16" channel webbing thickness = 7/16", which is quite close to the 1/2" that I wanted. So I'll call that good.

Anyway I've requested the new material from the supplier. No word on when it will be ready.

Thanks!
Jerry

[av8or1]

The update is that the supplier finished preparing the raw material on Friday. I picked them up just prior to their closing. Friggin COVID screws everything up doesn't it? lol

Anyway, the spindles and hubs also came in, so I collected all of it this evening and took it to the outbuilding to begin work:

[av8or1]

The flat plate is 1/2" as per the new design drawing. The new channel is a standard size, C6x8.2. It's web thickness is only 3/16" IIRC:


That would arguably be enough, but as always I believe in overkill and since I have these outer plates remaining from the previous design, plates that are almost the correct size (will need a tad of shortening), I plan on welding them to the outside of the channel to give it just that much extra strength and rigidity:

[av8or1]

And of course the primary element of strength with the new design lies with the increased thickness of the C6x8.2 in its corners. As can be seen in that picture, the difference in thickness and thus strength is formidable. Still, I'll augment that with the 1/4" plate leftovers.

After unloading and a quick inspection, I put the angle grinder to work, cleaning off the rust and mill scale. I then beveled all of the edges that will be welded. Doing this alone can be a time sink, but if you have a sufficient available window of opportunity, then such work can be almost therapeutic. Unfortunately I began to exhaust my available time tonight. Thus I managed only to finish the grinding work, to clean the components with acetone (quick wipedown) and then get them into rusty metal primer:


As per my normal MO. The wife has a full day of stuff to do tomorrow, so I'm not certain how far I'll get with it, or if I'll manage to find any time to even address the project. TBD. But no complaints. After many years of wanting to be a dad, I enjoy Father's Day thoroughly! So happy Father's Day to all of you dads out there!

Thanks,
Jerry

[zoama]

Thanks for the updates and happy father's day.

[av8or1]

Thank you zoama, I appreciate that. I trust that all of the fathers out there had a good day also!

Work is crazy-busy. However I was bound and determined to make at least some progress with the gantry-on-wheels project. However meager. As it would turn out, that progress would be more modest than planned, but that happens.

And this is the very reason that I'd like to bring the project to a conclusion:


I think I mentioned this, but if the gantry sits in one position for a while, and especially if it has rained, then the casters create divots in the asphalt. I'd prefer that to not continue to occur.

[av8or1]

And so I cut the support plates down to 5 3/4" and applied my usual rusty metal primer. These plates will be welded directly to the top and bottom of the gantry's legs, outboard of the casters (on the bottom) and the leg gusset plates (on the top):


Those dry as I load everything into the cart:

[av8or1]

And make my way to the gantry:


As a pilot, conforming to procedure is ingrained in my nature. Thus I began to test everything prior to using it. Unfortunately my Lincoln Electric Viking helmet's auto-darkening mechanism failed its self-test. But that was a good thing in that I caught it prior to attempting to actually weld with it. My guess is that the battery is low, since it has sat in its welding helmet bag for a few months now. However I don't know that to be the cause. So I'll have to look into it; but I didn't want that to ruin the effort, so I went back into the outbuilding and grabbed my "manual helmet" that I bought way-back-when as a backup:


It would indeed need to fulfill that role today, so that was good foresight. However, I am out of practice with this old school means of laying beads. My auto-darkener has spoiled me. I definitely need practice with this thing, as I would find out.

[av8or1]

So with the decision to proceed using the manual transmission helmet, I decided to verify that my 275p is in working order. It's been about a month since I laid power to it. While on that subject of power to the welder, I must admit to not being a fan of this:


Not certain if that was/is intentional or a "build error" of sorts, but I've never liked that since the day the welder arrived. I'd prefer to see the wiring tubing extend into the terminator's housing without any wires being visible near that point. It would be relatively easy to repair on my own, but I simply haven't done it out of concern that doing so might invalidate the warranty somehow. For that reason alone, I've left it as it was when I took delivery. Anyone know if this is a common thing or ... ? I can't see a reason why you would build it that way, but perhaps my electrical wiring biases have me blinded...

[av8or1]

Anyway it powered up, no issues:


And my pre-programmed settings/modes remained as they were saved several months ago. That is to the good. I have my 6010 mode set at 90A (leftover from the initial gantry build) with my preferred hot start and arc force values also ready to use:


Although you can't really see that in the picture due to the sun. Oh well.

[av8or1]

The first item on the agenda today is to weld the H-beam end pieces on, as per Mark's recommendation. These are merely 1/4" plate, but I think that they'll suffice for that task.

After grinding off the burnt orange paint (I am in Austin, TEXAS - home to the Longhorns dontchaknow) and the rusty metal primer that existed beneath it, I had a smooth surface on which to mount the end plate. I covered that in weld through primer, naturally:


And then fitted the first one in place and secured it with magnets. Anyone else have a love-hate relationship with magnets? lol

Time to get to business. Decided to follow the same MO as when I built the thing: 6010 for the root and 7018 for a couple of cap passes. So I'm in 6010 mode, 90A, hot start and arc force (dig) on the go. Rod in the stinger, ground on the leg. And bunk. I struggle with the manual helmet a bit. Every time I nod my head in a yes gesture so that it'll drop into position, the end of my rod moves out of position, no matter how rigid I attempt to maintain the starting position. lol I ended up welding a small drop onto the face of the plate for that reason! Bwahahahaha! I definitely need more practice with this critter. After a couple of minutes though I caught back on to a technique that can work, so that was to the good. I lay down a few tacks and then the first bead. Raised the helmet to get the second rod. Something doesn't seem right. It's darker out than when I dropped the helmet a couple of minutes ago.

Yeah. This happened:


You gotta be kidding me! Uhhhhhh...someone didn't tell the forecast, which I checked prior to launching this afternoon, that it was a-gonna rain. Well bunk.

[av8or1]

None of the wet stuff has made its way down to terra firma just yet, but I am not taking any chances. I grind off the slag, brush it down, wipe it off and coat everything near the end of the leg in rusty metal primer. I then unplug the grinder and welder, load everything back into the cart and head for home. Just as I get everything inside the outbuilding and the doors shut, the heavens open up, once again reminding us mere mortals of who is actually in charge.

So today ended up with the one bead down and that's it:


As mentioned, quite meager progress, but this one was not my doing, so I suppose one could find comfort in that if they were so inclined. It is what it is, I'll revisit it when I can work permitting. For now, she'll remain as she is:

[av8or1]

So the update. The short version is that work has been dominating my time as of late. However I can't complain about that too much, as it is what funds our existence; and no one would listen anyway, so why waste the oxygen?

I had planned on making some real headway this holiday weekend. However I ended up working a fair amount of it and we received short bits of the wet stuff, on-again-off-again type of scenario. Thus the opportunity windows would be limited in number and duration. That said, I did manage to at least weld on the end plates that Mark suggested, grind their welds (well, the ones I cared to grind anyway; the interiors I just left as-is) down, clean off the surfaces and lay on the rusty metal primer:


And wouldn't ya know it, just as I was starting in on the support plates, I heard rumblings off in the distance. So I loaded all of the gear back into the cart and called it a day. Sure enough, about 20 minutes later we received yet another sprinkling. It didn't amount to much and was done in about 3 minutes or so. However there's no way of knowing the wx's intensity nor duration, so I err on the side of caution and merely avoid it altogether.

Meager progress in comparison to what I had hoped for, but I'll take progress whenever it comes my way:


Hopefully work will return to normal soon and I can finish off the project. TBD.

I did decide to order some bushings for the king pins; found those online. Who knows when they'll arrive, we'll see. Finally, I found the outer welds on the lower side of each end cap to be challenging; especially since it's been a few months since I've laid down any beads. The reason was they were out-of-position and involved a weird rod angle. It was difficult at first for me to put down anything with decent consistency. There would be some relief found by elevating the gantry with a floor jack. However I didn't attempt that initially and found the going a bit rough with the gantry resting on its casters. Admittedly, I elevated only the one side; I found that by the time I had ran a few beads on that side, I was able to lay down some respectable stuff on the other without the need to raise that side of the crane. So in short, I was able to shake off the rust (no pun intended) and once that was done I was laying beads as per normal. Settings were a bit lower though, as the plates were only 1/4" and I used some 3/32" 7018 that I had laying around. I stuck with 1/8" for the 6010 though and the identical settings from back in the day.

I digress. Hope everyone had a good 4th!