Tefifon custom (preamp) PCB mount

prusaprinters

<p>When restoring some Tefifons, I wanted to install a preamplifier in the original case. There is more than enough space, but no obvious mounting options. Of course, I didn't want to drill any additional holes in the unit. So I came up with this design, which uses the two screws on the back of the Tefifon. Normally, the screws hold the strain relief clips for the audio output cable and the power cord:</p><figure class="image image_resized" style="width:62.21%;"><img src="https://media.prusaprinters.org/media/prints/68215/rich_content/d357e4dc-8740-4a71-b451-ddca06438d62/original.jpg#%7B%22uuid%22%3A%221da0f017-0371-4fde-8b55-5c1d3823310f%22%2C%22w%22%3A1149%2C%22h%22%3A843%7D"></figure><p>So I decided to put the mount there, around the connector for the remote control. My design has two strain relief clips that replace the original ones:</p><figure class="image image_resized" style="width:71.22%;"><img src="https://media.prusaprinters.org/media/prints/68215/rich_content/25205ea1-9360-4153-8602-2bd66aec2bf0/mount_b.jpg#%7B%22uuid%22%3A%2256655eef-104f-4a17-aa81-88adedfd1b43%22%2C%22w%22%3A1282%2C%22h%22%3A560%7D"></figure><p>The holder fits very well in the case:</p><figure class="image image_resized" style="width:67.37%;"><img src="https://media.prusaprinters.org/media/prints/68215/rich_content/4e269288-6ced-4f27-b251-ee36a03dd581/mount2.jpg#%7B%22uuid%22%3A%22b15f1091-dd72-4a5d-beff-685bccd5b7d1%22%2C%22w%22%3A1215%2C%22h%22%3A886%7D"></figure><p>And here you can see my PCB mounted:</p><figure class="image image_resized" style="width:60.94%;"><img src="https://media.prusaprinters.org/media/prints/68215/rich_content/8a19c41c-07c8-4507-95b1-253e56096eaf/mount3.jpg#%7B%22uuid%22%3A%22d3953a2c-0566-4900-807b-963156d945db%22%2C%22w%22%3A972%2C%22h%22%3A692%7D"></figure><h3><strong>Printing</strong></h3><p>I have printed the pcb mount using PETG in variable layer height (0.12…0.3mm). The design is optimized for the given print orientation - no need to rotate the STL model.</p><p>You will also need two of the strain relief clips, which I have provided as a <a href="https://www.prusaprinters.org/prints/68192-universal-strain-relief-clip-m3-12mm">separate project</a>.</p><h3>Assembly</h3><p>6 pieces of M3 nuts have to be pressed into the plastic. Also there are two ruthex M3 threaded inserts for the PCB mount. Any M3 heat set inserts should fit.</p><p>Unfortunately the original M3 screws from the Tefifon are not long enough to mount this part. You will need M3 x 8mm flat head screws instead. The original scews can then be used to mount the PCB, so you can keep the original parts on the device.</p><p>For mounting the strain relief clips you will need M3 x 16mm flat head screws or similar.</p><h3><strong>Design and Source Code</strong></h3><p>The mount has been designed using OpenSCAD. I have provided the source code for download, so you can adjust the design to your needs.</p><h3><strong>PCB</strong></h3><p>The PCB mount holes are 60mm apart. So that's what you have to adjust your PCB design to. I have designed my own preamp in Kicad. Unfortunately I can not upload those files here - but it is not design for easy reproduction by others anyway… Here is my schematic - just for reference:</p><p>&nbsp;</p><figure class="image"><img src="https://media.prusaprinters.org/media/prints/68215/rich_content/fd5974ec-3be1-46f9-aba6-c7d7dc8351cb/schematics.png#%7B%22uuid%22%3A%227b9d7992-b556-4832-8704-a44f4ecce086%22%2C%22w%22%3A1190%2C%22h%22%3A909%7D"></figure><h3><strong>Happy printing!</strong></h3><p>If you like this design, then <strong>please leave a like</strong> and also <strong>post a photo in the comments</strong>.</p><p>Looking for more Tefifon related stuff? Have a look at my <a href="https://www.prusaprinters.org/social/52356-mageb/collections/64615"><strong>Tefifion collection</strong></a>.&nbsp;</p><p>You might also want to check out my <a href="https://www.prusaprinters.org/social/52356-mageb/prints"><strong>other designs</strong></a>.</p>