This page is an archive of iMAL's wiki that operated between 2012 and 2022. It documented projects, residencies and workshops mostly taking place at iMAL's Fablab.

Older & newer Fablab projects are now found at

Rhizome (\ ʁi.zom \)

Rhizome (\ ʁi.zom \) is an interactive installation exploring the theme of "Memory".

An 8mm Eumig projector from 1932, projects a holiday film captured in the sixties, on a visible surface of approximately 1.5m by 1m high.

The projector is equipped with a "Looping" device to continuously broadcast the 18 minutes film.

The projector is equipped with a contemporary mechanism (stepper motor) and a micro computer (Raspberry Pi).
A detector (sensor) quantifies the number of people present in front of the installation.
When more than 6 people are detected by the sensor, an abrasion device is automatically engaged, the film passes through a chemical solution that dilutes the image printed on the support.

The information present on the film gradually disappears from the original medium, but is now transferred to the memory, or onto the viewer’s recording tools (phone, camera), which in turn can be used for the narration, or the sharing on social networks in order to make this memory survive. If worth it ...

When less than 6 people are in front of the installation, the film continues the projection without abrasion, there are not enough narrators to transmit the memories.

It is above all a discreet and intimate installation, which addresses the theme of transmission, memory, forgetting, the time that passes, and the contemporary ways to transmit and engrave a moment.


Residency has started @IMAL - 15.04.19

It's 10 O'Clock, Xavier just welcomed us and instantly made us feel at home.
Today we will be preparing the different materials needed to go further.
Martin Pirson will be working with on the software part that will activate the various mechanisms.
I will take care of the design/concept and mechanical/electrical Steps

Day One@Imal
Disassembly of the 8mm projector to modify the motors & light.

We bought a few RPi 3B+ thanks to the Grant from Imal, we think we can eventually run the software on it.
Day one consist of installing the software on the rpi and disassembling the projector.


Day Two @Imal

Update 1:
So today's plan is to create a software based on Machine learning, that will (if everything goes as planned):
_Detect if someone is around the installation,
_Detect if this "someone" is using a smartphone pointed to the installation,

Update 2: Sometimes things don't go as planned...

Problems emerged....
_It's pretty tough to detect a smartphone without invading people's privacy (We decided not to...)
_We need more speed & torque for the projector:
So I've disassembled the projector and inserted a Nema 17 stepper motor to drive the round belt that initiates the whole projector. The old DC motor from 1930, was well ... old & lacked some torque and I wanted somehow a better control on the drive mechanism. Having a Stepper motor could give me more control, I could eventually slowdown the movement, maybe the image created would be kind of interesting speeded or slowed.
The problem with stepper motors, is that they usually loose all their torque when speeding up, we usually go over this problem using a reducing gear mechanism, but it's mainly used to slow down and get more torque. We need SPEED & TORQUE.
So I decided to use a DC motor from an old drilling machine.

Update3: DC motors from drilling machines have almost no torque. We need TORQUE.

Update4: The Rpi can't handle Martin's program...

We need beers, many.


Day Three @Imal

RPI > No!

We need a stronger computer than the RPI's, we're not going to make it.

Update1: We bought a computer... BMP5 PRO Mini PC 4 Go DDR3 + 64 Go eMMC ....Pffff Windows....Brrrrrr

Martin is getting some good results on his super powerful computer.
Instead of capturing a Smartphone (which is quite complicated and "privacy invasive") I tried to find a particular gesture linked to the act of taking a picture.

Update2: The program will detect if one or both hands are located in a "zone" comprised between the shoulders and the top of the eyebrows.
Yes basically, most of the times when you're taking a picture your phone is in front of your eyes. Well it's a start, but the program is giving some good results.

Update3: I'm back to the good old stepper motor, never giving up, just going bigger. I'm now wiring a Nema23 linked to a TB6600 driver & built a bigger pulley on Julien Maire's metal lathe. Merci Julien.

Update4: I bought Led lights used in car headlights, the old light from the projector was a 220v 250W lightbulb. They are expensive, hard to find, and difficult to control. It's not an option for an installation. We need spares and reliability.
The old light was around 2500 Lumen, car headlights are around 4000Lumen, I hope it won't burn the movie... No dude, it's LED and I also bought a 12V fan to cool this stuff.

> Beer time.


Day Four @Home

We stay home depressed & hungover,
We need to think where we're actually heading.

Update1: Postman just delivered the new PC (pffff windows....)

Update2: We like Katsudon lunch from Izakaya! I meet with Martin for some food and drop him the computer so he can spend the whole bloody afternoon installing the M****ing windows.

Update3: I bought a square 20W LED from a garden projector with the grant from Imal, it's a 3500 Lumen, I like the shape it should work and it has a big PCB which is pretty good to dissipate the heat. I'll brake the case and instal it on the projector today. Whoop!

Update4: 11.54am I can finally drive the Nema23 fast and with torque, one problem solved!


Day Five @Imal:

Back on Track!

The new computer responds pretty well to Martin's program, but we now have a problem with the camera's we used.
They're old Playstation camera's we buy for 2€ at Cash Converter's, they're pretty powerful but unfortunately they only work on 32bits OS browsers. We're now on 64bits.

Update1: We need other Usb Webcam...

Update2: The Stepper is mounted on the projector, we got Speed and Torque! Hoooray!

Update3: The light rocks! We got Light!

Update4: I'm not confident with my former design for the 8mm Looping, when it's not clear in my mind it means that something is still missing...
I need to take a few days to redesign the installation anticipate how people will interact with it.

It's Friday, Friday means > Beers!


Day Six @Home

Martin needs a break from me, he did a good job on the software I'm confident for the next steps.
I spent the day on blender redesigning the whole project.

Initially I wanted to build a metal structure that will support the projector and the projection screen. I would have welded here at home and then spray painted.
I think I want to experiment something more contemporary in terms of aesthetics.
An old projector with a clumsily welded frame doesn't sound right to me anymore.
Show must go on. I spend the day thinking, I might try some T-Slot Profiles this time.

Let's Roll, I'm lucky to benefit a grant from Fédération Wallonie Bruxelles for this project, let's make this happen, I'm buying the profiles online, it will take about a week to arrive, project is on hold, it gives me time for the design.
I haven't had much opportunities to use the machines from the Fablab, I like to experiment but hate to waste material, so design has to come first.
I will come back to use the laser and cut some of this beautiful orange acrylic > Ideas emerge...


Day Seven @Home

It's Easter! Happy Easter!
I'm using the excuse of the residency to skip my grandma's Easter Lunch.
It's getting clearer, still some stuff to design but basically, we're going T slot with a visible orange acrylic casing that will contain all the electronics. so yes everything will be visible, nothing to hide here.

Update1: So we need something to deteriorate the 8mm film, the first idea was to use a small stepper that will turn and drive a small metallic sponge that will work as an abrasive on the film, the content on the film will slowly fade out. Well it's the idea.
It's cool but it lacked something... Maybe too technical, too subtle, lack of contrast... And I have this tattoo gun lying on my table.
I like the noise.
Let it be a tattoo machine!
I will posting some pictures from the design evolution on the Wikimal's Gallery


Day Eight @Home

'Been working on the screen design and on the film path for the looping, I think we are getting there but I'm still not totally happy with it.
I usually leave things behind for a few days, anyway I can't really start the build for now, 'waiting for the postman to arrive with the Tslot profiles.


Day Thirty four @Capture from Kikk Festival

We are Alive!!! The installation is up and running! (pretty okay actually)

We've encountered quite a bunch of difficulties, bunch of them were solved, many will remain a mystery to you.
(You can always contact me via email if you want more details, but remember a little mystery is important)

I am working on a small vidéo that will show the project in working estate.

Again a Big thank you to ImalFablab for their valuable help, Thank you Xavier and Stephan for your warm welcome and help.






FabLab residency

Date: April 2019

Last updated: June 2019