I've been thinking recently about using my 3D printer to build small structures and

I’ve been thinking recently about using my 3D printer to build small structures and stuff, using a system of printing joints for pipes or tubing. Doesn’t need to be hollow. My question is where can I buy some form of tubing/piping in large quantities for a cheep price? Something that is structurally firm? I can think of so many applications, the idea came from some toys (Knex, Tinker Toys) and from looking at tower cranes and other structures. At this point I think anything in small diameter would be fine, 1/8", 3/16", 1/4" and the like. I can cut it down to any lenght I need.

I would start with pvc pipes.
But probably end up using those metallic pipes people are using to make “industrial” furniture (but I don’t know what is actually for and can’t find in my country)

You can use fairly large PVC pipes to get the rigidity you’ll want, or you can use smaller metal pipes. Do you have a preference? Both PVC pipe and steel EMT conduit are readily available and low cost in most of the world. I would suggest going to your local big-box hardware store (like Home Depot or Lowes in the US) and handling the various options in the plumbing aisles to see what feels right.

How long and how rigid does this tubing/piping have to be? Given the narrow dimensions you are asking about, the stuff used for drip irrigation comes to mind… probably fairly cheap, especially if purchased in bulk.

I did that very thing using carbon fiber tubing pieces bought off amazon. If you do not need massive pieces, Carbon fiber is actually pretty cheap. used in making big drones mostly

@Tobias_Obermeit is right, carbon fiber tubing is probably your best bet. You can also usually purchase it at rc hobby shops or composite material specific vendors.

@Richard_Turnier it probably wouldn’t need to be longer than like 12"-18" a piece. I’ll look through that, Thanks!

@Neal_Grieb @Tobias_Obermeit thanks, I’ll look into that!

@Ryan_Carlyle I would just be a little worried how PVC flexes a little, my expirience with PVC is from sprinkler pipelines… Are the smaller dimension PVC pipes a little more firm?

@Aaron_Roth no, small PVC is very flexible. I was thinking you wanted bigger/longer pieces. 1/2” nominal schedule 40 PVC is plenty stiff at 12-18” but CF is way better if you want something thin.

@Ryan_Carlyle I found some EMT conduit here that is priced well, but I couldn’t find anything under 1/2"…
https://www.homedepot.com/p/1-2-in-x-10-ft-Electric-Metallic-Tube-EMT-Conduit-853428/100400405

At those sizes, I think you need to look at rods if you’re looking to keep the cost down and have a rigid structure.

@Jeff_DeMaagd Actually that might work a lot better! It doesn’t need to be hollow, I just didn’t know what to look for. And the rods look a lot les expensive! Thank you

@Jeff_DeMaagd I was able to find some ABS rods for not too much money, about 25$ for 200 50cm lengths of 4mm rod. It should be more rigid than the PVC, correct?

I suppose, I haven’t thought about it. I don’t know what you have in mind, it might help to make a test assembly.

@Jeff_DeMaagd I’ll see once it gets delivered. Put together some small tests with it and see what I can make. I’m also waiting for my new heated bed, it should arrive some time this week too. Thanks for the help. Will post pictures once I’ve got something assembled