Structurally Sound Giant Erector Set

I want to be able to erect arbitrarily shaped structures that, for example, could support the weight of a person doing pull-ups or support several adults sitting on it if formed into a box shape or whatever. But I also want to be able to put it together quickly, without need for glue, hammer, screws, or anything. And I would like to be able to take it apart and pack it flat for moving around to different locations or put it in my closet.

Is there any good materials for this? I went through Home Depot and 3/4" steel pipe seems somewhat reasonable, but there don’t seem to be any 45 degree angle fittings, which seems like it would be necessary to triangulate the faces of any shapes, for structural integrity.


There’s this -

I’ve seen it used for industrial shelving, it can hold some serious weight. It requires some nuts and bolts, but just a few standard fairly large ones (and some washers). How portable does it have to be? You could pre-build the ends as squares, and just put on the cross-pieces as required. Alternatively, parts could fold into relatively linear shapes by loosening bolts and removing angle pieces. With the plethora of holes you can make any angle braces required. Toss in a battery drill with sockets and you could erect any form in no time. I’m sure with judicious shopping you could find the right brackets to hold, for example, a pipe as a chin-up bar.

Also would be a LOT lighter than pipes that could support the same weight.

Find the scaffolding used at music concerts/theaters to hold lights.
For that matter, what do they use for the stage?

You aren’t the first to desire such stuff.

I work with industrial equipment including shelves that hold thousands of pounds and assembly lines. They are more complicated than Lego but not by much. What you ask for definitely exists in some forms. That is a fairly common requirement although some of it is much more simple to break down than others.

What are you you trying to construct specifically? I could give you links to industrial equipment catalogs with every part under the sun if you are more specific. They generally don’t even cost that much.

I don’t know if it will work in your case but you can build lots of sturdy things out of PVC pipe with appropriate fittings. You have to engineer the design well so that it will stay together but it is cheap and easy to take apart if you get it right.

standard stage scaffolding is exactly this but it might be bigger / heavier than you want. assembles using finger tight wing nuts usually.

I’ve known people who built knock-down displays for trade shows with PVC but they were for curtains and hanging posters and boards. I have trouble imagining a solid setup that will hold a 200-lb man doing chin-ups; at very least, the bar to hold that weight would be too fat.

Not sure if it will be available in your area, but Kee Klamp tubular construction sounds like a candidate - it’s used a lot for safety railings and used to be popular for constructing children’s climbing frames.


As Snarky_Kong rather enigmatically put it

80/20 is probably as close to what you want as you will get. There are similar systems as well. For instance Kanya provide what might be even more extensive possibilities.

For the REAl “Erector Set” vibe, you don’t want Unistrut or 80/20. You want “Slotted Angle Iron”:

When we used this for building stage sets, we called it “Dexion”, which must have been the name of a supplier. The stuff was ubiquitous at MIT in the 1970s, not just for Theatrical sets (all the MIT theater companies used it), but also for student projects and lots of lab construction. It’s got the holes like Erector sets, and all you need are a saw to cut it, a LOT of 1/4-20 bolts and nuts and washers, and wrenches/drivers to screw it together. A few years ago I built the framework for an easy-to-disassemble Dalek out of this stuff.

Thank you for that; the earlier post was unhelpful.

BTW, here is the Wikipedia article that describes the 75-foot long bridge that James May and others built in Liverpool out of Meccano (the UK equivalent of an Erector Set). Later, they built a working motorcycle out of Meccano.

Seconded. Tube and fitting systems will leave you constantly looking for fittings and cutting tubes. Using nuts and bolts you can build stuff just like an erector set, and easily attached sheet products for facing. And nuts and bolts will give stronger more secure connections.

While those tube and fitting systems meet the OP’s requirement to avoid screws (mostly but not entirely), I’m guessing that this is an expensive way to build stuff. Bolted together angle iron or welded assemblies are going to be cheaper.

Giving the exact name of a ready made solution to his problem is unhelpful?

Without any link or context, yes, it was unhelpful. I, for one, had no idea what you were referring to.

Without context? You mean like a post that lays out exactly what the thread will be about?

Yeah, no link. I guess highlighting and right clicking is a pretty high bar to expect of someone.

When I saw 80/20 with no further content in the post, I assumed that it meant dimensions of some product, but it wasn’t clear what product, nor what units the dimensions were in, nor any other details. I assumed that it meant something like “80 millimeter by 20 millimeter standard steel struts”, much like “2x4” means “cut lumber with a nominal cross-section of 2 inches by 4 inches (before planing)”. A link to the actual product answers all those questions.

I thought it was either an incomplete post or posted in the wrong thread. Never heard of the stuff.

I had the same reaction to “80/20” - I wanted to know just what this might be.

So I clicked on it.