Tetrix Build System

Structural Elements


Channels are the main building structure of the Tetrix build system. Think of a Channels like the bones in our bodies- they provide the strength and rigidity for the frame of the chassis. Channels are long extruded pieces that are in the shape of a "U." This "U" shape allows for two functions:

The Channels come in five sizes: 416mm (16.378 inches), 288mm (11.34 inches), 160mm (6.3 inches), 96mm (3.78 inches), and 32mm (1.25 inches). For the purpose of consistency, MakerLessons will refer to any section of Tetrix Build System that is 32mm (1.25 inches) as: One Tetrix Unit. In other words, the Channels come in one, three, five, seven, and nine tetrix units. 

Mounting Brackets

Mounting Brackets within the Tetrix Build System come in four basic styles, all of which have 90° bends. From top left to bottom right we have the Inside Corner Bracket, L Bracket, Inside C Connector, and the Adjustable Angle Corner Bracket.


Flats are secondary building structure of the Tetrix build system. They are slender flat lengths that are 2mm thick. Flats are lighter than channels because they are one one dimension compared to the channels. The thinness also leads to bending where the channels wont. Flats can offer a good compromise of strength and lightness when combined with stand offs.

Flats come in four sizes: 288mm (11.34 inches), 160mm (6.3 inches), 96mm (3.78 inches), and 64mm (2.5 inches). The smallest of the flats come in two different styles as well- one with the traditional hole and mounting system and the other with adjustable angle slots. 

Bars and Angles

Bars and Angles are even lighter and thinner than both flats and channels. They are more narrow than flats and channels and have a thickness of 3mm. This makes them slightly more rigid than the flats but still more flexible than the channels. Unlike the rest of the Tetrix Build System, bars and angles do not have the pattern of holes that channels, brackets, flats, plates, and the rest of the tetrix structural parts do. This limits how and when they can be used. 

Bars only come in one length of 288mm (11.34 inches). The Angles come in two lengths, 288mm (11.34 inches) and 144mm (5.67 inches). 


Plates are a six by two tetrix unit flat structure of the Tetrix build system. They are 192mm ( 7.56 inches) by 64mm (2.5 inches). They are 2mm thick which makes them bendable like the flats but are more rigid because of having twice the width. Plates make great floors and foundations of a chassis when combined with channels. This allows for large grids of the tetrix hole pattern to be build off from. 


Tetrix Tubes are an extruded hollow cylinder that has an inside diameter of 14.3 mm and an outside diameter of 15.7 mm. This leaves the actual metal to be about .6mm thick and despite that is fairly rigid and strong because of the shape of the tube. Tubes have the benefit of being sturdy because of the dimensions they innately have but light because they are hollow. When combines with the Tetrix tube mounts, tubes can assemble extremely sturdy but light structures. However, not having as many mounting points, tubes are less modular for expanded creativity and options when making assemblies. 


6-32 Bolts

These 6-32 Bolts are Zinc plated steel and are perfect to use to secure Tetrix elements in place. The bolts come in a variety of different lengths and driver heads.

6-32 Kep Nut

These 6-32 Bolts are Zinc plated steel and are perfect to use to secure Tetrix elements in place when paired with the corresponding bolts. All the bolts in the Tetrix Build System will match with the 6-32 Kep Nut. A Kep nut is a special nut that has a hex head that is pre-assembled to a washer. The washer is a spinning external tooth lock washer that also makes assemblies more convenient. When tightened, the kep nut has a locking action whereas the washer acts like a spring applying an outward force from the surface preventing it from spinning. 

Stand Off Posts

Stand Off posts are hexagon shaped female to female tubes that are tapped completely through with a 6-32 screw thread. Stand Off Posts allow for the connection of any two structural elements for the purpose of added strength or spacing. Tetrix Stand Off Posts come in five different sizes, 2 inch, 1 inch, 32mm (1.26 inches), 28 mm (1.1 inches), and 16 mm (.63 inches.) The outside hexagon shape fits a 9/32 inch wrench. 

Round Spacer

The Round Spacer is ideal for maintaining proper distance between two Tetrix elements attached on either side of a structural part. The flat round spacer is 2 mm thick – the same wall thickness as TETRIX structural elements- this makes it perfect to act as a washer to add space where needed to line up to other tetrix parts. The inside diameter is 8mm (.31 inches) and the outside diameter is 27mm (1.06 inches) The patterns of the holes are identical to the other hole patterns on Tetrix's structural elements. 

Simple Assemblies

Channel Right Angle

The Inside Corner Bracket is designed to mount two channels, flats, bars, or plates at a 90° angle on the outside of the elements. This orientation aligns the elements so that the spacing of the holes continue to line up during larger assemblies. 

Stand Off Structure

Stand Off Posts can be used for spacing or or create structural assemblies like shown to the left. A stand off assembly like this one using flats and stand offs combines the benefits of a flat such as its light weight and the strength of a channel because this structure creates strength and rigidity that comes from having dimensions in both height and width