Home Chapter 15 Glass, Plexiglass, aluminum, sheet metal and fasteners
Glass, Plexiglass, aluminum, sheet metal and fasteners


Glass and Plexiglas are popular with artist working with electronics as the translucency allows you to enjoy the beauty of the electronic parts and these parts become texture in robotic art, installation and invention. Glass is excellent as it is a dielectric and will not conduct. The drawbacks are glass is fragile and you must either have access to a hot shop or find a commercial glass blowing facility. Few schools have access to glass blowing facilities. Borosilicate glass is another option otherwise known as lamp-working glass and it is stronger and can be continually worked before the final annealing process. 

An exotic and increasingly less expensive material that can be finished with a completely clear finish like glass is rapid prototyping and we are seeing many artists adopting rapid prototyping materials and integrating these with electronic form.

John Marshall and Cezanne Charles have created a sound work where they uses SLS to create a form and designed it to house the electronics which were custom designed for the electronics to fit.


BA B & L by John Marshall and Cezanne Charles (Root of Two), 2001. Dayton, Ohio. 


Aluminum is the natural material for electronic and robotic installation as it is soft and relatively inexpensive and readily available. The low weight of aluminum relative to its strength is very high and it is easy to drill and tap.There are also a large variety of extruded aluminum parts available from most hobby shops as well as online. Generally you can choose a 6061 aluminum which is strong and better for structural works and where finish is more important than strength a 6063 aluminum would be a good choice. 

Aluminum can also be easily laser cut with an industrial laser cutter in your town though you will have to check with your local shop to see what thickness they can cut. Water jets are also a possibility for cutting aluminum and can cut massivly wide or very thin pieces of aluminum. 

Aluminum can also be easily powder coated to protect the metal from oxidation over time or to add custom colors.  Powder coating is a process of dipping your aluminum or other parts in a bath of dry powder and then the powder is baked on to create a smooth hard surface. 

A good source for aluminum stock is : Onlinemetals.com

For projects like the Augmented Fish Reality I have been able to cut .25 inch aluminum with a Bystronic laser cooled with a cloud of nitrogen. Since Aluminum so soft and will go molten after it is cut it needs to be cooled quickly. 

Carbon Fiber is another option for building lightweight and strong structures and it also has a high tensile strength and low thermal expansion so may be appropriate where heat and cold converge. A good source for these materials is Midwest Products Inc. Carbon fiber works well with epoxy's and seems to also glue well with Cyano Acyrlates. They are difficult to cut with any but the sharpest saws. I have been using a steel cutting hand saw to carefully saw through rods. 

Sheet metal is easily cut with shears and can also be bent though this material can really cut your hands unless you wear gloves and use files to sand down rough edges.

Robotics can be constructed with a variety of fasteners, however, reusable fasteners such as nuts, bolts, and screws may be a better choice than glues and adhesives, which are difficult to disassemble for repair and upkeep.

Another good way is to use rivets, but it is not easily reversible. The artist Michael Hyatt created a work constructed with flat stock aluminum that was 1/8 thick by 3/4 inch wide and fastened it with rivets. He used a vise to bend this standard aluminum stock and then drilled out the appropriate sized holes before using a rivet gun to fasten it all together. Before committing to the method and materials Michael Hiatt modeled the work in 3D.


Viral Toxoid by Michael Hyatt. 3D model. 2005.


In this work, Hyatt used an ultrasonic sensor (center top of image, refer to sensor chapter) to sense people, which triggered a bubble blower to blow bubbles onto the viewer.


Viral Toxoid by Michael Hyatt. 2005.




The most common fastener for robot construction is the machine screw, which is like a regular household screw without the tapered end. Machine screws are meant to be secured with a nut and can differ by size and number of threads per inch, head type, and driver type.

The head type refers to the shape of the head of the screw, such as pan, flat head, round, oval, Fillister, and truss. The driver type refers to the tool that needs to be used to drive the screw. Phillips and slotted are the most common types, and hex, Torx, and Pozidrive are other options.

The well-outfitted shop should have a good supply of 6/32, 8/32, and 10/32 stainless steel nuts and screws.

Machine screws are held in place with nuts. Six-sided hex nuts and wing nuts are some of the most common, but there are also nuts that dig into soft material called blind nuts, self-locking nuts with nylon inserts, and many other varieties.


Array of screws


Five-Sided and Six-sided hex nuts


Washers are also used with screws and nuts to help spread the tension of the screw and nut across a larger surface area. Lock washers are flat washers with teeth and prevent the nut from loosening itself from the screw.




Standard fasteners are zinc-plated steel, but screws, nuts, and washers are also made from a variety of other materials. Steel fasteners can also be found with a black-oxide finish or hot-dipped galvanized finish for use where water corrosion might occur.

Stainless steels’ resistance to rusting and corrosion makes it a good choice for any work that might be exposed to the elements.

Brass is an attractive choice used mainly for its looks. Another attractive option is colored zinc-coated fasteners that can be found in green, yellow, and other colors.

If weight is a concern, nylon is much lighter than brass or steel, and aluminum is a great choice when weight is a concern but metal is desired. It is also the choice material if working with an aluminum structure, as steel will eventually corrode aluminum framing.