NEED: carbon fiber/kevlar/composite I-beam

I found a great website last year that sold carbon fiber and kevlar I-beams, angle beams, all kinds of shapes you would normally probably buy in aluminum extrusion (also sheets, panels, grates…). I cannot find that site nor any others like it. So does anyone know a supplier of this kind of material?

I was hoping also there might have been a material resource section of this site, but canʻt find anything like that. Would be nice to start something like that perhaps, unless Iʻm missing something.ʻ


Not much help with the I-beams, but this is a great site for supplies to make your own parts (not too hard):
They’ve also got resins, brushes, gloves, mold material (rubber, though you can use anything as a mold, including wood and metal), mold release (carnauba wax), gelcoat (big thing… adds a hard, smooth finish to the material), etc. is another great place to get stuff. They have pre-made parts, though I’m not sure if they’re in the sizes you need.

It seems that, at the moment, it may be easier to use fibreglass and/or Kevlar, because there is an industry-wide carbon fiber shortage. There is (as I recall from a year or so ago) only one factory in the world making it, and the US government is taking up quite a lot of it for new combat aircraft (F-22, F-35). There are/were plans to build a second plant, or convert another to carbon fiber manufacturing, but I haven’t heard about it since I stopped doing model rocketry as much.

As far as using fiberglass goes, you want to use the matte material (unwoven) for most everything, and woven stuff for reinforcement. Also, use true epoxy resin (Aeropoxy, West System), not polyester. And try to vacuum bag if you can, as it removes air bubbles. If you can put it on a sheet of balsa (a couple of layers per side on a sheet of 1/16" balsa, for example - you may need/want more fiberglass or wood), you can get incredibly strong sheets, far stronger than wood, but just a bit heavier than a balsa sheet.

A note about using pure composite: Resin is heavy. It makes up most of the weight of a material, because there needs to be a lot of it. Make sure you have the weight before you use composite parts.

-Jake Alexander

McMaster has FG I-beams as well as some other shapes too.

Also, talk to squirrel from 1726. They have used FG I-beams on some of their robots I believe.