Precision Coffee Roasting Gets Even More Precise With Help From the Makerspace


In an effort to improve the precision of coffee roasting at Swift & Finch, Mark McLucas upgraded the Victory 10 roaster by replacing the analog environment thermometer with a SOLO 4824LR PID controller and T-type thermocouple, which are capable of providing real-time temperatures within 1/10 of a degree.  The bean pile temperature is monitored by a near identical setup from the manufacturer.  He used the laser to cut an acrylic face plate and etch labels for both PID controllers, enabling him to differentiate between displays at a glance.

Precise monitoring and control of both bean pile and environment temperatures is
critical to producing clear flavors and a clean cup quality.  The temperature curves of both BT and ET move somewhat independently throughout the roast, and are manipulated through adjustments to airflow and gas charge.  Ideally, the two curves, though being 100-150 degrees apart at certain points, can be manipulated to move in tandem, the bean temperature gradually climbing to meet the environment temperature at the end of a roast.


To help with process control, he used the laser cutter to create a dial face for the gas control knob, making it easier to track and repeat exact set points procedures and train others in the fine art of bean browning.

To some, roasting coffee is considered to be a sensory operation: something conducted purely by watching bean color change, smelling for the development of compounds, and listening for first and second cracks.  However, the last few decades have brought about a more scientific approach to growing, processing, roasting, and preparing coffee, with roasting being one of the most crucial.  At the risk of sounding melodramatic (as is the inclination of some coffee professionals or people that fancy themselves as one), a coffee that has the perfect biological parentage, the ideal environment, and the best of care in growing, harvesting, processing, packaging, and transport can be blunted and even completely botched by roasting it without the same level of care and control.

All in all the project took approximately 6 hours, with approximately 3 hours spent designing the pieces and testing various laser settings to get the dimensions right, the edges clean, and the engraving deep enough.  The remaining three were spent on reassembly and testing.

What laser settings worked well? I found for the acrylic I used, a quicker speed (70), a lower power (35), and more passes (19) worked best for the vector cut.  I left the piece in place, added my engraving to the design, and ran the raster engraving back over the vector cuts as well to help clean up the edges.  Any pointers to other folks based on your experience?  Experiment a lot and be patient.

A well done laser cut is a beautiful thing.


$6 Upcycled Dog Bed

We needed a new dog bed. OK actually, the dog needed a new bed. Here is the sad “before” state.


Dog beds cost like $25-40. That’s just silly. It’s some fabric and stuffing. So, we got some supplies. A throw blanket from Wal Mart ($2.87). Iron-on seam tape ($3.97). And the best part – we had a couple of old study-buddy pillows that were ready for donation to the thrift store, where they would no-doubt sit endlessly waiting for one of the tens of people in the world who buy used pillows to stumble on them. Since everyone has some old pillows of some type lying around for stuffing, total cost for the dog bed: $6.00.

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Phone Engraving

One of the first things I thought when I saw the laser cutter was “I wonder if I can etch my phone with it?” Naturally, I placed my phone in it without a second thought, found a picture, and tried to engrave it. The only problem is that the pictures DPI (Dots per inch)was too low and it looked like a giant blob, so my dream was delayed. I eventually got some lessons on how to use it from various members (thank you, by the way) and with a little practice, I cut out my name on some scrap acrylic. I made that light up and change colors, and with that success I threw my phone in there and had some great results, so good in fact I did it to another phone. Both were such a success, I engraved a phone case, and the front glass on the second phone. Soon I am going to engrave an Ipad case and maybe other phones too! Hopefully I am going to upload a video of the ipad case getting engraved soon and some more pics.

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