Best/easiest material for bases, hardware, etc?

What is the best/easiest material to use to make bases for robots, project boxes/mounts and so on? Acrylic seems popular, but without a laser cutter… seems hard to work with accurately. Is there some method/cheap tools for doing very precise work with acrylic or is there some kind of universal erector set type thing that is better suited for electronic projects?

I have a lot of things in mind that I would like to make, for example, one is a base that is shaped like an upside down U, which will mount an arduino on top and two servos on the sides for wheels. I don’t have many tools, so I’m finding accuracy to be a problem. I’d like to find something that I can work with accurately, for a minimal tool cost.

i love polycarbonate plastic. i got to use some in a school robotics project and dear god i was in love with it. you can cut it with a dremel or band saw or whatever. not the most accurate, but it’s easy to do.

Polycarbonate! It’s so good, and we use it a lot on my FRC team. Polycarb is generally expensive but is high quality. Acrylic will do just the same, for cheaper, but is a bit less forgiving when cutting it. Cutting acrylic with a band saw is difficult as it will tend to melt, so i end up using a dremel tool with something akin to a mill bit. At first it was difficult to manuever, but after playing around with some scrap, I got fairly decent with it. To protect both sides of your project, all you need to do is cut out another piece, mount that with bolts above all your electronics and other stuff. If you are looking to heat form as well, acrylic is easily formed (Never tried polycarb…)

Would this work for you?

As in any engineering dilemma, the answer to what is “best” is directly related to the specific situation at hand . . . aka, there is no universal best material, only some choices that are better than others for a specific application.

For project boxes, premanufactured enclosures are available in an almost unlimited array of materials, sizes and designs; and usually offer the most professional looking results. Most projects seem to fit in enclosures costing $5-20 and in my experience, despite a well-equipped shop and good access to free or almost free acrylic, polycarbonate and ABS sheet stock I still often buy an enclosure because the materials, hardware and some kind of new milling cutter I always seem to need often outweigh the cost of the enclosure . . . plus my time, plus the improved cosmetics.

Although more expensive, polycarbonate is almost always preferable to acrylic, especially if there are any physical stresses involved such as in a robot base. Acrylic is notch sensitive and needs the right tools (drill bits, cutters and blades) to properly machine it without inducing stress cracking. It can be rough sized very easily by scoring a straight line from side to side, then snapping it over the edge of a table.

Polycarbonate is a dream to work with in comparison, although you would be wise to get a book from the library or research on the net for good machining recommendations:

In some cases, MDF (Medium Density Fiberboard) works as a good project base for a robot . . . it is relatively inexpensive and easy to work with . . . it does not however come in thin sheets.

Baltic birch, marine grade and aviation grade plywood can be easily acquired in small sizes (often 12 x 18”) from many hobby and craft stores. It is available in thicknesses 1/16 – 1” and is completely free of the voids and imperfections normally found in construction grade plywood. It is also made up of thinner plys than construction plywood. It cuts and machines very well and looks good without secondary finishing.

Aluminum sheet (1/16 - 1/4” thick) can be purchased cut to size from many steel suppliers (some operate just like lumberyards). Although more expensive by weight than plastic sheet it has great rigidity and machines well. Perhaps you might want to reserve this for when your robot moves from prototype to permanent device.

Finally do not discount thin sheet metal (approx 1/16”) which can be used to make some very light weight reasonably stiff enclosures that I have also seen used as a robot base. Although more difficult to work with, if you are a university student with access to a shop or are on good terms with your old high-school shop teacher than you can probably get access to some punch and brake equipment. NOTE: that Hammond and some other enclosure manufactures offer inexpensive, simple aluminum chassis with covers that will give you a place to mount your sensitive electronics.

Okay, so if you have read this long post this far, I’ll give you a freebee! If you are a university student, or work for a company that is involved in any kind of engineering, you might even be able to get a free enclosure that suits your needs. Many manufacturers of plastic enclosures offer a sampling program. Check out their customer service page or dig deep into their site map to find a possible link to their sampling program.