pic: Another Cheap Wood Frame Idea

Originally Posted by gorrilla

in my expeireance with it, fiberglass only becomes brittle if you dont mix the resin right, or wait to long to apply it,


they switched to epoxy resin in surfboards because, polyester resin dosent stick to the new type of foam most companies use.


you dont even have to use the fiberglass mat, you could just take a paintbrush and dip it in the resin and "paint" it around the corners and edges


we're getting off topic now.......

My experience with composites is mainly in the realm of Longboarding, and building customs out of most available types of composites. Most new users to fiberglass end up with a goopy, brittle mess, assuming they just lay the fabric and slap some resin on. You're correct about using Epoxy resin, it's much stronger (and more expensive).

Originally Posted by Rick TYler

Generally, I'd avoid Kevlar cloth (it fuzzes and is a pain to sand smooth), or carbon-fiber cloth (very hard to work with, fuzzes, and supernaturally expensive) (unless you make carbon-fiber poles as arm material, in which case I'd like you to send me pictures). Other cloths like Dynel are more for abrasion resistance than strength and will do nothing for a robot chassis than add weight.

I've had nothing but success with both Kevlar weave, as well as Carbon Fiber. Granted, these are in Longboard applications, but those tend to have a little more force involved (a 200lb rider going through a 90 degree turn at 60mph). As long as you take the time to lay out all your steps right, and then don't dawdle when working with the actual glass, you'll be fine with both these materials. If a team has the budget, there are some IMPRESSIVE things that can be done with composites. Heck, I'd LOVE to build an entire robot out of the stuff. Foam molds and vacuum bags galore!