I recently bought a second hand Mahlkonig K30 Vario grinder. This grinder did not work at all but I got it for only 150 euro. After a thorough inspection I found that one of the essential wires for starting the grinding was loose. Just a little bit of soldering was enough to make this grinder work again. This made me happy but the grinder was still not usable because it lacked a hopper. I searched on the Internet for a replacement but these replacements seemed to be quite expensive. Luckily a friend of mine, Frans Goddijn, still had beautiful spare Compak – Londinium hopper stored in this attic. Frans was generous as ever and gave me the hopper for free. There was however still one problem to be solved.
The Compak hopper did not fit my Mahlkonig K30 at all. How could this be fixed?
I decided to 3D draw and print the adapter. I made the design with 3D CAD software Fusion 360 and printed it on my small but excellent 3D printer (prima creator). The hopper was printed in several parts, because there was an overhang in the design and that might have given bad printing results. The design also includes a printed screw to fix the hopper to the adapter.
Download the 3d files if you want to print the adapter yourself.
A few months ago we wanted to order some extra TC4 boards for our roaster. This board is an arduino shield that can handle 4 thermocouples and takes care of precise temperature measurement. During the order process we had a problem. We could not order them anymore from the mlpg-website. All the “order buttons” seemed to be disappeared and mailing them gave no response. But somehow the universe came with a solution. A few weeks ago we got in contact with Viliam from Slovakia. He also needed TC4 boards for his projects and he told us he had decided to produce the TC4 by himself. In case he was succesful we could order from him. A few weeks ago he told us that he had succeeded and he would send us one of his first production TC4 v6.01 board and his Zero Cross Detector (ZCD). The ZCD is a device that detects the sine waveform transition which is needed to control the airflow of our AC Blower. Today we tested his boards and it all worked perfectly. Many thanks for Viliam to keep this valuable arduino shield alive!
Last weekend we tested the Fluid Bed Roaster again. There were several improvements made to the machine. Tije has improved the thermal insulation and housing. Also he improved the internal airflow, this prevents beans from unintentionally ending into the chaff collector. Also some software changes were made. To prevent burn through of the heating coils, the fan now has to get a minimal of 60 percent power. Otherwise the heating element will get no power. To improve roasting performance it would be helpful to use different PID-settings during a roast. Tije tried to implement this, unfortunately this didn’t work. Frans Goddijn contacted Marko Luther, the maker of the more then excellent Artisan roast software. Marko is again very helpful and tries to fix this. Many thanks again for his outstanding help. Read More
Last week we tested the next version of The Fluid Bed Roaster prototype. Tije designed and constructed this new roaster. In the picture above, you can see him charging green coffee beans on the prototype. The roaster has a build in cooling, chaff collector, LCD screen and it uses a more powerful and less noisy blower. Also the roaster has a higher capacity (batch size) than the previous model. I worked on the Arduino TC4 control board and electronics. In this first test we encountered a technical problem. I got a much cheaper relay to drive the blower of the roaster. This relay blew immediately after powering up the device. We will switch back soon to Crydom 2425-10 relay that has proven to work solid in the previous prototype. For speed control we reverted back to manual Variac operation of the blower. The PID settings to control heater intensity also needed some work and Tije has already worked on a heat isolation of the roast chamber. The purpose of this insulation is to make the roaster more energy efficient and make it easier for the roaster to reach a desired finish temperature. Read More
The recently launched Londinium Espresso Distribution Tool promises to reward you with a very high level of consistency to your espresso extractions. What is the effect of using the LDT? Does an espresso made with this tool taste better? Frans is doing a series of experiments of the tool in combination with different Compak Grinders. Blind tasting is a great way to measure the effect of the LDT but a downside of this method is that it’s very time consuming. One would need many samples tasted and compared. Also this method is not completely objective. The selection of the espresso tasters would influence the result of the experiment. Read More
I recently disconnected my Everpure Claris water filter because of a my house renovation. This left me with a problem. Where could I find filtered and softened water for my espresso machine? Luckily my friend Frans Goddijn helped me out. He supplied me with bottled water that was filtered with his BWT Bestmax premium water filter. Read More
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.
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.
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
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!
Many coffee roasters use roast color meters to monitor the quality and consistency of their roasts. Furthermore, calibrated roast color can be used for productive communication between roasters and coffee traders. For instance, a trader could provide a target roast color for a specific coffee. Also, coffee roasters around the world could share information about the roast color they find best for certain beans. Read More