First Staff Workshop in the ArtLab

Yesterday was the first staff workshop for the ArtLab, and attended by two staff members in the Dept of Art. This was a short (two hour) workshop to introduce the laser cutter, show what it's capabilities are and how to do some basic engraving and cutting. The task was to create a simple keyfob with engraved text, a simple engraved image, and a hole for the keyring. This example was chosen since it demonstrates image and text engraving, inner cut (for the hole) and an outer cut. The idea was demonstrated by Nic:

Nic showing the keyfob idea.

Showing the wooden example I made earlier.

The design on the keyfob was to be a soundwave that we recorded (of the Cube 3D printer making a lot of whirring and clunking noises), converted to a black and white 1-bit bitmap and then imported to LaserCut, plus text underneath.

Christine is importing the image file and adding text to the design to be uploaded to the laser cutter.

The design was then etched onto dark tinted acrylic, and cut out:

Christine's design etched onto tinted acrylic

The acrylic sheet on the laser cutter bed

the next workshop will be in June, and we will be showing the summer placement students (who will be working alongside us on the Creature in a Cup workshops) how to use some of the kit, including the 3D scanner, 3D printers and the laser cutter.

Driving a Stepper Motor with an ATTiny85 Microcontroller

Tim Sunerton is currently a student in the Art Dept at The University of Reading and wanted to power a number of roller blinds with motors so that they would move up and down. He had already produced one which moved the blind down into a trough of paint and then lifted this back up again and smeared the paint onto a canvas (see Tim's Blind). The blind was powered by a NEMA17 type stepper motor, a motor driver and an Arduino Uno. To attach the motor to the blind, a coupling was fabricated using the 3D printer. 

For the current project (four blinds) and as an exercise in making things smaller I suggested that the blinds could be powered by ATTiny85 microcontrollers, as we don't need all of the ports that the Uno offers. I built a test rig using some stripboard, a voltage regulator (plus a few capacitors) and an ATTiny85. The first image shows the ATTiny85 on the stripboard:

The two wires coming out of the left side of the board connect it to the power supply (in this case a bench power supply @ 12V); the wires at the right power the stepper driver and provide the pulses to drive the motor:

The ATTiny85 was programmed by piggy-backing on an Uno, which I have to say is very easy, although I eventually decided to make a programmer shield for the Uno so that you can just plug in the ATTiny85 directly into the shield and program it without needing to connect any wires. (Note: the stepper motor above was not used for Tim's blind project - just for testing. He used much larger motors for his project).

I made three of these boards and Tim used them in his project. We also had to fabricate 4 new adapters for the blinds. One of the blinds was quite big, and even though Tim used a higher torque motor, the weight of the canvas on the blind pulled the blind down against the force of the motor. This was a bit of a problem, and the solution seemed to be in gearing the motor in some way to increase the torque. After a little thought, I came up with this:

A worm gear that would increase the torque by an order of magnitude, and stop the blind from pulling down. Here's the work in progress as we tested out the motor driver (and killed it, though fortunately had a spare) and programmed the microcontroller for speed and the correct number of rotations:

We used the Uno for this particular arrangement after having blown the original driver. The motor was later attached to the frame using the bracket that we fabricated with the Cube:

Note the lack of hole in the centre of the front mount. Whoops. We later drilled a hole using a pillar drill.

Sense Scanner and Cube Printer

Sense 3D Scanner and Cube 3D Printer

We bought a Sense 3D (made by Cubify) scanner last year at the same time as the 3D printers (also made by Cubify), as it seemed like a good idea to be able to scan objects and them 3D print them. But how good is the scanner, and is it easy to use? That's what we aimed to find out ...

We first tested out the 3D scanner to see how well it performed and how easy it was to use. The sense scanner is handheld and designed so that it is capable of scanning small medium and large objects (such as a car, if you were so inclined). The idea is that you take the scanner in your hand and move around the object carefully scanning the entire object, and then the supplied software will cleverly stitch it all together. In theory. However the scanner is not cordless! Not cordless?! In practice this means that you have to hold your laptop and the scanner and move around the subject, else have a very long USB lead. Even with a reasonably long USB lead, we ended up getting the lead wrapped around the subject (Kate in this instance) making scanning a bit cumbersome to say the least. Come on Cubify, this device should be wireless; it needs to be wireless. Perhaps the next version will be, who knows.

So, we tried scanning a cup on a table as a test scan. The first attempt failed, as we ended up with three cups. The room lighting, it has to be said, does seem to make a difference to the scan. So keep the sunlight away. The next try was by placing the cup onto a box so that it is not flat on the table. This worked a bit better, but perhaps because it was just a bit easier to get around the object. The scan was still somewhat poor, with lots of holes in the final mesh. So we thought that a bigger object might be easier, so Kate volunteered to be the subject. Positioned in a chair, I positioned the scanner about 450cm from Kate and walked very slowly around her keeping the scanner pointed directly at her, as shown in the image preview given by the software. The software shows the subject being scanned, and also shows a circle on the screen to help guide your positioning. It's a bit hard to explain, without some images (which I'll take next time) and is quite difficult to get the position correct as the image moves in the opposite direction to the physical device.

After about 10 minutes of walking around Kate at a snails pace, we ended up with a mesh (I'l add the image of this next time) which didn't look too bad, aside form a few weird artefacts that were produced by the software when Kate moved the cable out of the way to stop it getting tangled (hence the need for WIRELESS!!).

The software for creating the final mesh is not exactly intuitive, and is fiddly and awkward to use. But we ended up with a reasonable model, and so imported it next to the Cubify software that came with the Cube. That is also rather awkward to use (Cubify, you seriously need to employ an HCI person(s), and sort out your crappy interfaces) but we eventually managed to convert it to the correct format and export for the Cube printer:

The image above shows the finished model, which took about 5 hours. I have removed the squiggly bits of filament that covered it. I assume they were remnants form the print process, and not errors. I was quite impressed by the quality of the print (excellent overall) and the printers ability to print overhangs without supports. Here's one more image:

A faithful rendition of kate a la Sense scanner

Close up of the Kate model

Verdict: Sense scanner needs more road testing, and shows promise. The wire is a serious shortcoming, and I am trying to figure out a way of making it wireless - perhaps via some bluetooth hack? The Cube printer is a very nice little machine and I'm really impressed with its performance. Yesterday I printed a bracket (see worm gear post) for a student in the Art Dept for some work he created, and the Cube did a splendid job.

Creature in a Cup Workshops

Creature in a Cup Workshops: the image shows one of creatures made by an undergraduate student during an Interactive Sculpture workshop in the Dept of Art at the University of Reading. This particular work was based mainly upon the littleBits synthesizer modules (designed jointly by littleBits and Korg), and includes a keyboard.

For the last month, we have been organising a series of events with local schools in the Reading area which focus on how we can bring technology to people through art-based workshops. The idea started when we held workshops for the Sensory Objects projects (see Sensory Objects) to help people with learning disabilities gain some experience in working with different senses. During those workshop sessions we explored ways of triggering sounds and movement using littleBits modules, and then build sensory devices as a result.

As part of a WP programme in 2014, we piloted the idea of using littleBits to help understand technology through creative workshops last year with Redlands school in Reading (see blog post), and it went really well with a great deal of positive feedback. After having sent out a flyer to schools around the Reading area, we will be holding the workshops at four schools in the Reading area during June and July, giving a total of 13 CIAC workshops.

Flyer that was sent out to schools for the Creature in a Cup workshops.

We have just received a new order of littleBits from the states which we selected specifically for the CIAC workshops: DC motors, servos, a variety of different input sensors and two more synth kits. This was the box of bits before they were unpacked - each was individually wrapped and had to be cut open with scissors and then distributed between the two cases:

The new set of littleBits included two cases to house all of the bits, which is a welcome addition as before we had these all of the bits were placed into four shoeboxes (belonging to Kate, who can now take them home and rehouse her dancing shoes!)

In addition to the new littleBits modules, we'll distribute all of the exiting ones between the boxes, with the exception of the synth kits. That should be sufficient for the classes of 30 we will be taking in June and July.