There are many classifications that brackets could fall into but in the REV 15mm Build System there are two major groupings of brackets: motion and construction. The major distinguishing feature of motion brackets is a 9mm bearing seat to support Hex Shafts and Bearings. Construction brackets are essentially any bracket in the 15mm Build System that does not have a bearing seat. Because the term construction bracket encompasses a broad range of REV products it can be further subdivided as structural brackets and actuator brackets.
Structural brackets act as connectors between structural components. For example, these are the type of brackets you will want to use when connecting Extrusion to Channel elements. Actuator brackets on the other hand are intended to mount and support motors and servos.
Another key point of bracket distinction in the 15mm Build System is that there are both metal and plastic brackets available. Many of the brackets, like the 15mm 90 Degree Bracket (REV-41-1480)(REV-41-1305), come in a metal and a plastic version. Though there is some overlap between the metal and plastic brackets, there are also key differences between the two type of brackets.
Follow through the rest of this section to learn more about brackets.
Alignment Ribs: Protrusions on one side of the bracket seat into the extrusion channel to help align the bracket to the extrusion and add strength and rigidity to joints.
Extrusion Mounting Holes: M3 Mounting holes on an 8mm pitch.
Bearing Seat: Brackets with a 9mm hole can be used to mate with any of the plastic bearings to support a shaft.
Motion Interface Mounting Pattern: Circular M3 hole pattern on a 16mm diameter is used to mount to REV Robotics shaft accessories.
The image and definitions in the introduction above use the 15mm Motion Bracket (REV-41-1303), which is a plastic bracket, as an example. The table below outlines the basic differences between the plastic and metal brackets.
The actuator brackets all have an 8mm pitch for mounting to Extrusion or Channel. The interface pattern changes depending on the specific use case bracket. For instance, the Metal Bent HD Hex Motor Bracket (REV-41-1487) has a different interface than the Metal Bent Planetary Motor Bracket (REV-41-1563).
Most of the actuator mounting brackets are metal brackets, with no plastic alternative. In the REV 15mm Build System there is a Plastic Servo Bracket (REV-41-1319) in addition to the metal servo brackets.
It is also important to note that the Core Hex Motor (REV-41-1300) has the Motion Interface Pattern and can be mounted to any bracket with the Motion Pattern.
The Variable Angle Bracket (REV-41-1318) is a special kind of construction bracket which allows 2 pieces of extrusion to be mounted together at any angle from 0-180°. For additional strength, after the ideal angle has been set, miter the end of the extrusion with that angle. Attached the extrusion to the bracket through to arc and center hole. Then drill a hole along the alignment mark arc so that it lines up with the extrusion slot and add another bolt to fix the angle.
The Indexable Motion Bracket (REV-41-1313) is a specialized version of the Motion Bracket. This bracket is made up of two pieces: the smaller piece has alignment ribs and fits onto the extrusion, while the larger piece has a motion interface pattern and a bearing seat. On the inside face, where these brackets meet is a fine sawtooth pattern which mesh when they are bolted together to hold the shaft offset. To adjust the offset, loosen the screws and adjust as needed. Tighten the screws to fully engage the teeth to secure the bracket.