All posts filed under experiment

Vixen – Nikon DIY Telescope adapter

My girlfriend recently got a present from a friend who is also a wonderful dressmaker. It’s a beautiful Vixen Japanese telescope. Using this vintage telescope and watching the sky is truly a magical experience. It reminds us that we are very small and that we are all part of this giant cosmos.

It’s kind of mind blowing when you think about it. Things we are made of were once made in stars.

This is not meant to be a philosophical post, so let’s get back to the telescope. After looking through the telescope I thought it would be great to make some pictures of the moon. I have no experience whatsoever with telescopes but I though a simple way to do this, would be by using my smartphone. After a few tries this seemed to be a rather difficult task. First, it’s difficult to aim the telescope in the right direction, secondly it is very hard to manoeuvre the phone and get the view focused on the camera sensor. You need to precisely get the focus right, that’s almost impossible in case you have ordinary human hands.

I thought: Is there an easier way? Would it be possible to use our old Nikon DSLR Camera for this? I would need some kind of adapter between the telescope and the camera. The camera has to be aligned with the optics and should be firmly fixed to the telescope. After a bit of searching in open source 3d libraries like thingiverse I saw that other people have made designs for attaching a camera to a telescope. I however could not find the right adapter for my setup.

Then I thought: Why not design and print my own? That’s exactly what I did.

By using the excellent Fusion 360 software I designed the adapter. This design was printed on my tiny 3d printer. After a few trial prints the adapter was ready and fitted perfectly. I think this is rather amazing. A cheap 3d printer is capable of making parts that fit a high precision device like a DSRL camera.

Below is the 3d model (you can download the model on sketchfab)

A picture of the adapter

The telescope with the mounted camera

Another picture of the moon that was made with the setup

3D printed Compak hopper adapter for Mahlkonig K30 grinder

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.

k30 adapter screw
k30 adapter top
k30 adapter base
Hint: To attach the top and base part, you need to put some filament in the small holes and use glue.

TC4 board by Viliam

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!

Another nice movie by Frans.

Fluid Bed Roaster, new edition 2

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.
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Tiny Fluid Bed Roaster, new edition

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

Measuring the effect of the Londinium Distribution Tool

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

Tiny Cheap Fluid Bed Roaster update 8 Feb 2017

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.

Movie by Frans Goddijn.

Tiny cheap fluid bed: chaff collector and more testing

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.

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Tiny Fluid Bed Roaster update

(movie by Frans Goddijn)

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

Affordable fluid bed roaster

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!