I told you I'd tell you how I made a deff rolla

Unfortunately I didn't get any 'before' pics of the deff rolla because my wife had her camera (the nerve). But here's a pic of it finished and attached.

And I'll explain how that was made. You can use any cylinder of the appropriate size (I used two empty citade wash pots glued together). I wrapped some plasticard (in my case harvested from a hard card protector) around the cylinder after scoring and folding it so it would have those hard corners. The spikes are made by cutting a chunk of empty sprue into a squat pyramid. I cut a ton of said pyramids, glued them onto the rolla, and then glued a bit of sand around each one. The mounting for the rolla was made by cutting some more plasticard into the appropriate shape. I also glued some ancient rhino hatches on the sides to give it some depth. Overall, pretty easy.

I used a lot of plasticard in making this piece, but I'm too poor to afford plasticard at the moment and I improvised a lot. Here's a list of places from which to harvest plasticard:

Used gift cards/membership cards/credit card offers

Hard card protectors

Empty milk cartons

Medicine containers

Over-packaged toys

Also, cardboard will work for a lot of the same things as plasticard. The core of my battlewagon is thin corrugated cardboard. Here's some more pics of my mostly finished battlewagon cuz that's how I roll.