Bicycle speedometer magnet fixture

prusaprinters

<h4>The problem</h4><p>The magnet of the electric bike of my father-in-law used to rotate on the spoke it was attached to by the default single-screw mechanism (see picture below) causing the speed controler of the motor to malfunction (for anyone interested: Bosch error code 503).</p><figure class="image image-style-align-center image_resized" style="width:51.74%;"><img src="https://media.printables.com/media/prints/298823/rich_content/94b2cb7d-e530-4a58-85da-3e9ba7b54724/without_clamp.jpg#%7B%22uuid%22%3A%22cd0311b3-53b3-4f28-9623-978f25894c90%22%2C%22w%22%3A1024%2C%22h%22%3A673%7D"></figure><p>&nbsp;</p><h4>The solution</h4><p>To prevent the rotation of the magnet and its securing mechanism, I designed a fixture whith which the magnet is fixated on two spokes instead of one, preventing rotation. The fixture was designed for a magnet with 10mm diameter.</p><p>I printed the fixture in Prusa PETG Orange at 0,2mm layer hight, 100% infill without supports. The bottom radius got a little distorted, but still worked fine.</p><figure class="image image_resized" style="width:60.62%;"><img src="https://media.printables.com/media/prints/298823/rich_content/da3d450f-2e82-432c-aa46-10b69812eef5/clamp01.jpg#%7B%22uuid%22%3A%22ca375555-0cf1-4ab0-8c45-7196a88baa07%22%2C%22w%22%3A1859%2C%22h%22%3A1394%7D"></figure><p>&nbsp;</p><h4>Disclaimer</h4><p>This design was not tested over an extensive period of time. Weather and influences from biking might affect the mechanical properties of the fixture. <strong>Use at own risk!</strong></p>