[Gdeaver]

We have use FRP pultrusuions for our arm before. Worked out very well. As mentioned attachment points require different techniques than metal. Clamp thing onto a tube. We used carbon cloth to reinforce birch plywood. A coupler for a motor was made out of chopped carbon fiber and epoxy. You may have a problem with cost. The market price for carbon cloth is way up their. Also beware that certain prepeg resins are toxic and I wouldn't want to use them around students. Amine allergies are enough to worry about. Putting some fiber in your robot can be a good thing.