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.
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
I recently got some Indonesian Mandeling coffee. This green coffee looks like a mess, some are large, lots are small, many are broken and a large number of them have defects. More than 12% of this coffee should not land in your cup of joe. But after proper sorting, this bean can really shine. The problem however is that this sorting is a tedious proces. It takes more than an hour to sort 750 grams of this coffee. Frans Goddijn uses a his own fan and a pan technique for sorting the beans. This is presumably a good and effective method. But because I was looking for my first Laser Cutting project I thought of something else. Read More
Here is another espresso funnel that I made. The bottom of the funnel is slightly curved, this creates a tight fit with an espresso basket. Want to try it? Just download the model from Sketchfab. The models doesn’t need to be scaled when printed in PLA. For the best results you need to print it upside down.
Our little kitchen is crammed with cooking equipment and giant roaster, a huge EK43 grinder and a big espresso machine. A few months ago I bought a Londinium R lever machine. The machine is still unpacked but it will be installed in the coming days. The machine has a huge lever that makes the machine a bit taller than my previous La Marzocco GS3. I’m sure that my girlfriend will not be pleased because our tiny kitchen will look more crammed than ever before. The best thing to do would be a complete kitchen makeover or just move to another house. This, however isn’t very practical because we can’t afford any of those at the moment. I, however thought of a different solution that was much more practical. The idea was to make our EK43 grinder look a little smaller. How could we do that? Well, I recently bought a tiny lovely 3D printer. Read More
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
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.
I know that this coffee thing has got out of control. It has taken over our house. Our kitchen has become something of a laboratory. This 5 square meter space is crammed with cutlery, cooking equipment, kitchen appliances, dishwasher, washing machine, fridge, deep freeze, a vegetable stall and all of my coffee things: a giant roaster, a huge grinder, a big espresso machine and lots and lots of other coffee related stuff.
I have tried to convince my girlfriend that our kitchen situation was quite normal. This was everybody’s kitchen situation, I could hear myself say. However my words weren’t compelling and after some time I had to admit that she was right. Entering our kitchen gave me bad vibes. It was absolutely no relaxing feng shui environment. It was certainly the worst room in our house. Also, the space was not very practical. All the kitchen counters were filled with stuff. There was no more room left for cooking. That’s why I could regularly find my girlfriend on the kitchen floor, the only ‘open space’ left in the room. While cutting vegetables on the cold floor I ofter heard her mumbling ‘I hate this kitchen’. Read More