[pras870]

I agree, if you absolutely must use a plastic, use lexan. It is more durable, and while it does splinter and shatter, it is less likely to do besides plexiglass. If you use this, you have to support it, using plexiglass or lexan will no support is a sure way to have a base be totally demolished. Supporting the base with aluminum extursion at stress points (if you can, ask an engineer to evaluate your design and offer advice on where to support it) is a very good idea.

Now Ken is also right. There is absolutely nothing wrong with using plywood as a base. In fact, one team that comes to mind that uses a wood base every year and is one of the well known teams in FIRST is Team 173 Rage. Every year they use a wood frame (which I'm not mistaken is supported by aluminum brackets). It may splinter, but with the brackets, it's an easy fix. Just put a sheet of aluminum or steel over it, bolt it on, and you're ready to go. I bring up Rage, because they are one of the well known teams that uses a wood base, and have so for years.

And yes, if you turn up at your regional with your robot unfinished, it's guarenteed other teams will come over to help you. No team is going to look down upon you, in fact most teams will do everything in their power to make sure your robot works and is able to compete. That's the great thing about FIRST, everyone is willing to help each other to make sure the competition is as good as it can be and everyone has a fighting chance.