Little Monster Coffee Roaster

prusaprinters

<p>This is a project I started at the end of ‘19 and finished about 6 months later. Since completion I have typically roasted 225g batches every 5-7 days and have done back to back 700g batches many times as well. I live in the US and didn't want to have to do major electrical work at my breaker panel, so this has been designed (fan motor and heating elements) for 120V, 30A max current.</p><p>&nbsp;I've been thinking about making a full build howto with BOM, but that’s a lot of work and don't know if there's interest. So I decided I would post info, pics and video links here to see what the response is. Leave a like and a comment if you're serious about building one of these!</p><p>The original cost breakdown is as follows:</p><pre><code class="language-plaintext">* Vacuum Motor - 20 * Vac Motor Controller - 6 * 1500W heat gun element (x2) - 50 * Heater Controller - 18 * Master Power Switch - 4 * Power Meter - 17 * Temp Meter (x2) - 22 * Temp Probe (x2) - 15 * Jam Funnel (x3) - 27 * Lantern Globe (x2) - 20 * SmoothSil 960 (molded parts) - 50 * Assorted hardware - 10 * 3D printed parts - 20 TOTAL = $280 !!!</code></pre><p>I have since added a Phidgets wireless USB hub to enable roast logging using the IOS app RoastMaster. That is certainly not required, but it is a fun and informative add-on. One could replace the manual controls with SSRs for fan and heat. SSRs could then be controlled by arduino and you'd have a fully automated roaster! I like the manual approach though.</p><p>The main housing was printed in blue PETG. The internal parts (fan motor housing and the base/air duct between the fan and heater) were originally printed in HTPLA+ (NatureWorks 3D870). The HTPLA+ parts eventually deformed and I reprinted those in HTPET - so far so good! The light blue parts are molded, high-temp, food grade silicone. The molds for these parts were also printed (vase-mode in PLA).</p><p>All of the printable parts are posted below. If you're interested in modifying the model files, that can be done from <a href="https://cad.onshape.com/documents/c6e2fdf7a8b0e8044e0b197e/w/cfe8e7739057d33162e1c74b/e/aa16effccbd8610c704c9f60">OnShape here</a>.</p>