4 <title>USB desk fan modification</title>
5 <!-- 2020-08-10 Mon 07:18 -->
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198 <div class="row"><div class="col-md-9"><h1 class="title">USB desk fan modification</h1>
200 <div id="outline-container-sec-1" class="outline-2">
201 <h2 id="sec-1"><span class="section-number-2">1</span> General</h2>
202 <div class="outline-text-2" id="text-1">
204 <li>DISCLAIMER: I DO ELECTRONICS AND 3D DESIGN SOLELY AS A HOBBY. THERE
205 COULD BE ERRORS THAT CAN RESULT IN ALL KINDS OF DAMAGE. USE THESE
206 DESIGNS AT YOUR OWN RISK.
209 <li>This design is released under Creative Commons Zero (CC0) license.
214 <li>Svjatoslav Agejenko
216 <li>Homepage: <a href="https://svjatoslav.eu">https://svjatoslav.eu</a>
218 <li>Email: <a href="mailto://svjatoslav@svjatoslav.eu">svjatoslav@svjatoslav.eu</a>
230 <li><a href="../../index.html">Other physical projects in this repository</a>
232 <li><a href="https://www.svjatoslav.eu/projects/">Other projects hosted at svjatoslav.eu</a>
240 <div id="outline-container-sec-2" class="outline-2">
241 <h2 id="sec-2"><span class="section-number-2">2</span> Project description</h2>
242 <div class="outline-text-2" id="text-2">
244 End-result looks like this:
249 <p><img src="make.png" class="img-responsive" alt="make.png">
254 It all started with couple of cheap USB desk fans that were a bit too
260 <p><img src="mini%20fan.png" class="img-responsive" alt="mini%20fan.png">
265 Idea is to add DC-DC step-down converter to reduce motor voltage to
266 make it quieter (<a href="https://www.amazon.de/gp/product/B07K3W78SQ/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1">Purchased form here</a>). And since I already have this
267 USB powered thing on my desk, why not to share this power to allow
268 charging of various other USB powered devices.
272 I ended up with this schematic:
273 <img src="schematic.png" class="img-responsive" alt="schematic.png">
277 USB power of 5 volts that enters the system via DC jack is distributed
278 to two USB-A connectors on the front panel. Note: USB data is not
279 connected. Therefore this hub is for power sharing only.
283 DC-DC fly-back converter could introduce voltage ripple in the
284 system. To smooth it out, there is capacitor (C1) and inductor (L1).
288 Step-down voltage converter has adjustable output voltage. So after
289 assembling, it can be tuned with screw-driver to reach desired
290 noise/airflow tradeoff.
294 From original fan I kept:
308 Engine is attached with screws to following back-plate:
313 <p><img src="fan%20housing%20-%20fan%20mount.png" class="img-responsive" alt="fan%20housing%20-%20fan%20mount.png">
318 And result is encased into pipelike case:
323 <p><img src="fan%20housing%20-%20cover%20assembly.png" class="img-responsive" alt="fan%20housing%20-%20cover%20assembly.png">
332 <li>STL: <a href="fan%20housing%20-%20fan%20mount.stl">fan mount back plate</a>
334 <li>STL: <a href="fan%20housing%20-%20cover.stl">pipe-like case</a>
336 <li><a href="fan%20housing.FCStd">FreeCAD project</a>
341 Fan enclosure attaches to the rectangular body below using following
342 connector (glued to the fan housing):
347 <p><img src="fan%20housing%20connector.png" class="img-responsive" alt="fan%20housing%20connector.png">
355 <li><a href="fan%20housing%20connector.stl">STL file</a>
357 <li><a href="fan%20housing%20connector.FCStd">FreeCAD project</a>
362 Bottom part to house 2 PCBs, on/off button and DC connector:
363 <img src="bottom%20stand%20body.png" class="img-responsive" alt="bottom%20stand%20body.png">
367 Component attachment:
368 <img src="make,%202.png" class="img-responsive" alt="make,%202.png">
372 And is closed by cover:
373 <img src="bottom%20stand%20cover%20assembly.png" class="img-responsive" alt="bottom%20stand%20cover%20assembly.png">
380 <li>STL: <a href="bottom%20stand%20body.stl">bottom stand body</a>
382 <li>STL: <a href="bottom%20stand%20cover.stl">bottom%20stand%20cover.stl</a>
384 <li><a href="bottom%20stand.FCStd">FreeCAD project</a>
389 After assembly, it looks like this from the back:
390 <img src="make,%203.png" class="img-responsive" alt="make,%203.png">
394 Note, part of the body is deformed during printing. I have heated bed
395 and I even printed raft support in Cura and it did not help. In my
396 experience black PLA filament is awful in comparison to transparent
397 one. Has inferior flow (results in slower print speed) and tends to
398 deform easily. Will never buy it again.
402 Fan top and bottom halves are attached using <a href="https://www.amazon.de/gp/product/B00OOLKD2G/ref=ppx_yo_dt_b_asin_image_o00_s00?ie=UTF8&psc=1">camera tripod quick
407 </div><div class="col-md-3"><nav id="table-of-contents">
408 <div id="text-table-of-contents" class="bs-docs-sidebar">
410 <li><a href="#sec-1">1. General</a></li>
411 <li><a href="#sec-2">2. Project description</a></li>
416 <footer id="postamble" class="">
417 <div><p class="author">Author: Svjatoslav Agejenko</p>
418 <p class="date">Created: 2020-08-10 Mon 07:18</p>
419 <p class="creator"><a href="http://www.gnu.org/software/emacs/">Emacs</a> 26.1 (<a href="http://orgmode.org">Org-mode</a> 9.1.9)</p>