Spacer for SRX Magnetic encoder am-3445 FRC robotics

thingiverse

This is a custom spacer designed specifically for the SRX Magnetic Encoder (am-3445) to be properly positioned above the Toughbox Mini (am-2236). The magnetic encoder, manufactured by CTR Electronics and also sold by Andymark.com, is widely used in robotic building, including FRC First Robotics competitions. As of late 2017 or early 2018, the Toughbox gearbox included shaft now features a built-in magnet. While this eliminates the need to machine a separate magnet into the end, it creates an issue with mounting the magnetic encoder. The old method now requires additional spacer hardware like the SRX Magnetic Encoder Mounting Hardware Kit (am-3565), which is simply a grommet. This 3D printable part serves as a custom spacer that should match the precise height to ensure the LED indicator lights up properly. When printed in PLA, the recommended height of this part is approximately 8.8mm. You can adjust the Z-axis scale if you need more or less height, or sand off excess material, and even use a milk jug as a shim. For mounting, we used 12mm long 3-48 type screws, but you can experiment with 1/2" screws or create custom lengths. Be cautious not to insert the screw thread too far into the Toughbox Mini's black plastic, as this area houses a bearing and should be avoided. Only about 3 mm of thread should enter the plastic. Another approach is printing this spacer with flexible material, allowing you to adjust its height by tweaking the screw tension without compromising the bearing area within the Toughbox. Additionally, consider the proximity of the magnet to the encoder's underside housing: * Red and orange LED indicators will appear when the distance from the magnet to the detent is 2.95mm or greater. * A green LED indicator will light up if the distance falls between 0.75mm and 1.5mm.