[chuckknigh]

There is a construction site about a mile from me, which is building a very large steel building. They have some short "offcuts" of some very large (1' across, 4-6' long) steel I-Beams.

Has anyone built a machine from I-beams? It seems like it'd be a very stiff way to build a machine, and if aligned like an "H" it would provide 2 heavy duty rails that, presumably, would be reasonably parallel to each other.

Seems like a good starting point to me!

Just looking for ideas -- some brainstorming. Post away...I want to see it, no matter how off-the-wall your idea really is!

-- Chuck Knight

[Klox]

CK, I am in the planning stages of building a drilling machine. The client wants a machine that can drill dia 20mm holes in a dia 50mm stainless steel pipe. Some of the pipes are a couple of meters long. I'm thinking in the same line as you to make a frame from I-beam (about 4" x 2") and then make a bridge where i can mount the pillar of the drill.
The only big obstacle is to get the two rails (beams) 100% parrallel.....

Klox

[balsaman]

I beams are designed to be ridgid for bearing a load horizontally or vertically, but not good for applications where they would be subject to twist. They would be great for a base.

Eric

[chuckknigh]

Well, at a certain scale, the i-beams are capable of withstanding quite a bit of force in any direction. The ones being thrown out by the construction site are HUGE...a foot across, the good part of a foot "tall", and 4 or 5 feet long. Pretty stout stuff. Looking at it a different way, they're extrusions, but appear to be made from 1/4" - 1/2" thick material. Just a guess, as I haven't gone and taken a look, yet...they may very well be even heavier!

You can imagine why I got so suddenly interested...

I wonder if it'd be practical to lap (is that the right term?) the two rails, till they were flat relative to one another? I wonder how flat they are to start with?

So much potential, and so many details to be worked out... MORE POSTS! Let's get brainstorming, guys! This could be a cheap and very effective way to build these things, if my guess is right...but as always, the devil is in the details.

-- Chuck Knight

[TRC1]

A piece of 12" I beam is probably at least 3/4" thick and probably a couple hundred pounds at 6' in length. Unless it is formed, (1/8" sheet)but I have never seen the stamped and formed sheets ending up in an "H" shape. Keep us posted though, as I have been wrong before!
JD

[Klox]

I think I-beams are relatively straight. How straight do you want to lap the i-beams? You'll find someone with the right equipment to machine or even surface grind it 100% straight, but it would cost money (lots!).
The other thing i have experienced in the past is that when you order material (especially long pieces) and the supplier manhandles it a bit rough it ends up bent at your doorstep.....
When i get to the project i'm planning i would rather bolt the frame together than weld it....

Klox