Tije de Jong made a first housing for the Tiny Cheap Fluid Bed Roaster. He also made a part that improves the movement of coffee beans inside the roast chamber. This improvement is not finished yet but it already makes a slightly larger batch size possible (310 vs 250 grams). Tije also made an addition to the chaff collector that prevents beans from escaping out of the roast chamber. Another advantage of this adjustment is that the roaster seems to need needs less fan adjustments during the roast.
Tije built a new roast chamber which allows a larger load to roast. The (free, donation supported) Artisan software reduces airflow as the beans get less heavy and the Artisan PID follows the designed background. See also https://github.com/artisan-roaster-scope/artisan
Yesterday we worked again on our Tiny Little fluid bed roaster. On the menu was to further configure the PID-settings. This should make it possible to precisely and consistently execute roast profiles.
For our test we used again Indian Cherry Robusta. This cheap coffee produced lot’s of chaff during the roast. Although the roast results looked fine we don’t recommend anyone to drink the as a single origin espresso. The bean however was perfect for testing purposes.
There were several things that we changed after our last PID-testing attempt. At first Frans brought along an active usb extension cable. This cable is supposed to make the communication between the TC4 board and the Artisan roast software more reliable. That means minimization of spikes or other reading errors. After examining all previous PID configuration attempts Frans suggested to start using the I value of the PID settings. This was a great idea because after that the PID worked magically good as you can see the graph below.
Last week we did some new tests with our DIY Tiny fluid bed roaster. There were two things to test. First we wanted to test the Chaff collector that was made by Tije. Secondly we wanted to configure the PID of the TC4/ Arduino to make it accurately execute pre defined roast profiles.
Tije’s chaff collector
During our previous tests the tiny fluid bed roaster blew lots of coffee chaff in Tije’s workplace. This made a lot of mess and we had to fix that. To solve the problem we needed a small but effective chaff collector. We were very happy that Tije made a creative solution for this. He invented a unique part for this purpose that’s smal and effective. It’s also easy to use & clean. To make the part he used a large herb infuser bowl that he sourced at a cook shop.
3D Modeling is a very powerful technology for designing and prototyping products. I recently prototyped some espresso dosing funnels. For prototyping I used CAD program Solidworks. This did unfortunately not natively run on my Mac but I was able to run it in a virtual machine. This approach however did result into many crashes and sluggishness. To end my frustration I had to use a CAD application that was meant to be used on a mac. One of those programs is Fusion 360. A few weeks ago I decided to start following a Fusion 360 3D printing course. I find that the program has a learning curve but I find it quite user friendly and effective. Read More
Yesterday we tested the “background roast” feature of the free Artisan software, with Artisan activating and regulating the heater in order to let the BT cruise along the pre-designed profile. Before our test we made a few improvements to the hard- and software configuration. Read More
Last week we updated the Arduino software of our air roaster prototype. Tije fixed the new safety switch that I brought along. In case of software failure, you want to switch off the heater and keep the blower active in order to cool the beans and prevent overheating of the blower and heating element. The switch bypasses the relays that are controlled by the Arduino control board. We also tried a new Artisan sketch that supports a “background roast” using the Artisan PID to follow a pre-designed roast profile. Read More
Recently I wrote about a 3D printable espresso dosing funnel that I designed. Yesterday the print of the design was finished. I wanted to have a fully functional prototype, therefore I chose to print it in ABS. That printing material (‘filament’) can withstand up to 100 degrees celcius. Read More
Tije de Jong, Frans Goddijn and I are thinking of a small simple affordable-for-all fluid bed home roaster for coffee. The roaster is supposed to roast 200 grams of coffee and work with the Artisan roast software. Furthermore the machine is intended to have PID control and adjustable airflow. This combination of things would make it an ideal home or laboratory machine that will let you precisely execute predefined roast curves, roast different batch sizes and give consistent results. We decided to open source the design of this machine. This enables you to build this roaster yourself, contribute and help to further develop the machine. Read More
Dosing the coffee in the espresso portafilter basket and distributing evenly can be difficult. A small funnel can help to ease this proces. Tije made a beautiful one for me and there are funnels on the market like the IDR dosing tool. I’ve recently learned how to draw in 3D and I thought it was a good exercise to made a first design. The prototype is not final and I haven’t tested it yet. You can however download and print the design yourself. Don’t forget that you will need to print it a bit larger (approx 1.5% for ABS) because filaments tend to shrink after printing. Let me know what you think about it.
Frans Goddijn and I are reviewing the La Marzocco Linea Mini this week (to be published in an upcoming issue of KTC magazine) and here we extract a first espresso, using the double basket included with the machine, the heavy double spout portafilter, the LM tamper that comes with the machine. Also using the Acaia scales and a Compak grinder. Monitoring the group temp which is very stable around 83ºC after we set the extraction temp on 93ºC using a small mechanical wheel on the top left of the machine. The roast profile shown briefly during grinding is made by the free Artisan roast control & logging software supported and developed by Marko Luther.
This post was first published on kostverlorenvaart.nl.
Tije de Jong, Frans Goddijn and I are thinking of a small simple affordable-for-all fluid bed home roaster for coffee. We use some hard- and software idea’s from the Roastuino project. Today we installed the electronics and tested several configurations. The results are promising. To be continued!