Don't be to discouraged, all my model (boats) are wood!!! i guess wood on a combat robot will only serve so far, budget & ability's all come into play when taking on any project regardless of what it happens to be, one thing i know... no matter what you do in any hobby, if your having fun then nothing else matters!!

Fyi...you can laminate ply wood with Carbon fiber cloth or kevlar it will make your 'wood' last a lot longer & tougher, weight addition is subject to testing, as epoxy add's weight ( and it can be a lot if your not careful), but if you get a good laminate going, possibly using a vacuum lamination technique or a decent application method in using rollers to squeeze out as much excess as possible the weight addition compared to strength it no doubt worth the effort, which was actually my first though going into this project, making up a mold and making new shells out of GRP & CF would cost me nothing but time.

I am half tempted to pull out my foundry and cast parts with recycled soda cans, free aluminum, casting is the 'poor mans' CNC machine in today's world!, just youtube casting, you can use your ''''wood''''' as former's if your going to sand cast, or if you got some left over foam board, u can make up parts can cast using the loss wax technique.

Other options if your like me and can recycle things effectively, youtube again... look up recycling HDPE, something you will have access to freely, milk cartons, bottle tops, just slice em up put on grease proof paper on a baking tray then in the oven for an hour at 175C, till is pliable ( like gum), you can make patterns if you keep turning the plastic, then form into blocks buy compressing the very hot gum like consistently into a mold, do it fast mind ( more use for your wood again) and let it cool, break out the mold and then just use it as you would a sheet, hand tools, power tools w/e.

Recycled robots... cheap but still effective!