Here’s the project outcome.., 8 x 8 LED grids connected up as a 2 down 2 across. All LEDs are illumined with the full brightness test pattern from the Fadecandy server web page. You’ll notice that there is a slight impurity in the ‘white’ because of the different performance of the red green and blue LEDs within the WS2812B. In practice multicoloured patterns are shown so this is not noticeable. Frosted Perspex is used to diffuse the light. A future design may secure the Perspex in a channel within the MDF as no amount of hot glue secured these well enough.
This is the rear view showing the LEDs zig zagging across the LED mount panel. The MDF panel is on the shoulders of a narrow piece of MDF around the inside of the frame. LEDs in strips of 50 were purchased so an extra strip had groups of 14 unsoldered to make these up. The 64 were then rolled without twists onto an old ribbon cable spool so that is was easy to unroll flat onto the LED panel. Heavier hook up wire was taken to every 16th LED to cure any dimming of the LEDs at the end of the strip.
To make the cubes in to which the LEDs shine 3mm MDF was laser cut into narrow slotted strips, 7 horizontal and 7 vertical. The cube size is about 52mm. MDF ‘staples’ were also cut and within the mount panel you can see 10mm diameter holes for the LED and the staple arms to be accepted. Each LED and staple were hot glued.
A custom loom was made with heavier gauge (16AWG) hook up wire for the ground and +5V – 64 LEDs take about 2 Amps at full brightness. When soldered onto the pins and the crimp folded over this just fits the JST connector. For mobile use power was taken from a 12V car battery with a 5 Amp DC to DC step down buck converter module adjusted for 5V output. One per 8 x 8 grid and again part of a loom – à la spaghetti junction – manageable with only 4.
Using the Fadecandy module and the Processing.org IDE the project was quite code light.
Code to write patterns to the LEDs was just a few lines
Libraries for images, video and audio are easily available
Processing code and Fadecandy’s fcserver could be a computer that we could leave at an installation (e.g. Raspberry Pi)
Sample Processing.org code for this project is available on Github…
One of our long running projects was to design and build large form factor RGB LED grids for a Processing day involving algorithmic soundscapes with reactive displays.
Unforteuntaly due to lockdown that didn’t happen, but the development and construction of the grids continued and during a break in lockdown, we did a guerilla art installation displaying ‘8 bit’ style fireworks and fire displays between Halloween and Bonfire night.
A while back hackaday posted about Trammel Husdons Charliewatch (An analog watch that uses 72 tiny ‘charlieplexed‘ leds.
We liked the project so thought we’d have a go at building some, plus it was a good excuse to try our hand at small component (0603) SMT solder paste assembly and pizza oven reflow.
With a few cosmetic tweaks to the PCB (the original used numbers but Roman Numerals seemed a bit more appropriate for an analog watch) and a bunch of PCBs ordered from JLCPCB, we assembled a couple to test and to design a new case around.
Future updates will include updates on final case designs and materials.
This is what happens when your .SVG export is set with incorrect settings. I left it running for a bit – I thought it looked interesting – also, no pen lift (the horn fell off the servo).
I was playing around with some simple ‘tween’ curves in Rhino / Grasshopper – hoping to increase my proficiency in GH to create some interesting vectors.
The same drawing, with a slightly different home / start position. The red is a STABILO point 88, the magenta is a Pilot V5 Hi-Tecpoint Rollerball Pen Extra-Fine, and the blue is a Eye Micro Rollerball UB-150 (didn’t know that till I just hit up their website!) I knew there was a reason as to why I horde stationary.
The green is a STABILO pointball, the nib is a little large and barely fit through the gondola nib guide thingy, so could have done with a larger hole for it to fit through.
I ended up slowing the speed of the motor accel to a whopping 5 (seconds to max speed) and then I changed the max speed to 25 (half original value). A notable difference in both speed (slower) and resolution (straighter lines (but still not perfect)).
Through our meetup group, Rob organised a Green Woodworking workshop with Toby from the Green Wood Work Shop! After a bunch of emails, we finally found ourselves wandering through the Purbeck woods trying to find the place, only 40 mins late we could hear the banter and see the smoke rising from the charcoal burners. We were greeted by Toby and his dog, and a couple of the guys that made it, some as far away as South Africa! (I jest, he lived nearer London!)
Fortunately being late wasn’t that much a problem, I quickly followed what the other guys had started and found myself introduced to wooden mallets, lumps of wood (turns out it was Ash) and hand axes, some heavier than others! We had a few options of what we could make, from rounders bats, garden dibbers, to spatulas.
Some images from the day:
The rather rudimental work holder / lathe
The axes had flat faces on one side, and chamfers on the other, this helped them bite into the wood. Some had both sides sharpened, some had short handles, some had long.
Some rolling pins, a dibber and spatula, some having aged better than others.
Forget what this is called – but it makes the stock as smooth / round as possible before heading to the lathe.
Using a gouge to make a mark for the poppet to be located. I thought the poppet (work holder screw thing’ was a funny name, but we still say, ‘pop it in’ – don’t we?
Guide on using the roughing gouge
Tools of the trade
The beginnings of a rounders bat
venting the hardships of motherhood into this bat
This was a tricky tool to get to grips with, it gave a smooth flat finish, but any lapse in concentration and you’d put a lovely gash in it!
Lots of these on the ground – how many dibbers have been made here?
Rushed this – took about 1.5 hours start to finish – broke a sweat!
Unfortunately I didn’t get a snap of everyone’s finished work! Maybe ill update if I can get copies.
Thanks to Rob for organising the day and Toby for hosting (also, to his mum for the food and cake!)
Was a great day out – I think the potters wheel will be next on the list!
I fancied making my own VPIP based V plotter – and made some very minor alterations to the cad data (plastic parts) in the process.
Just some of the parts required to build the thing – dog optional.
The plastic parts for the build. Printed on my Mini Kossel in el cheapo blue via amazon @0.2mm layer height.
The first job was to deburr the parts that required it – note the colour change depending on light conditions! The below image is a truer representation of the actual parts.
Bashing the pulley thingies onto the motor shafts
Followed by mounting the motors.
And what is potentially the coolest part of the project (IMHO) is a swappable thing that allows for the pen nib to be stabilised. I have a couple of these with different diameter holes for the different sized pen nibs, eg a sharpie. This should keep the pen at 90 degrees to the paper and not move around inside the gondola. It just needs a deburr in the below image.
And as usual, I got carried away building the thing to carry on taking photos…
Firstly I extended the mounting brackets for the motors – this will allow me to position the endstop encoders later down the line.
These are v1 of the endstop thingies – they will protrude fromt eh front of the machine, but its really the only way I could get it to work ATM. It has Z adjustment with the M3 screw and two captive nuts, and Y adjustment of up to 10mm – having not used these before – hopefully this will give plenty of adjustment to the ball string on the machines.
I reduced the diameter of the gondola so it would print on my mini Kossel (160mm). I also added another screw mounting to hold all the components together.
I added a spacing for the bearing housing – allowing the shaft to move freely as it was being constrained by the enclosed design, as you can see from the lovely image below – grey bits are the recess!
The weights now have their own printed mounting – V1 worked with a little filing, so V2 I’ll try and fix that!
I finally got around to building the new Hat for the Pi, but that has a few teething problems at the mo – so currently its not moving.
This also has its own electronics mount – but I forgot about the SD reader at the bottom of the Pi, so I had to hack away at it a bit! I aim to make a cover for the electronics at a later date.
I added cable sleeve and that makes it look that little bit better – but the cheap DuPont connectors are utter crap and just pull apart without any prompting >:(.
So, hopefully the config for the UART will get sorted reasonably soon, so I can start drawing with this damn thing! Its been a fun build though, I hope the work on the plastic parts can result in some high res / fast drawings to be created – speaking of which, better get cracking with that!
Last Wednesday I ran a small ‘Messy Workshop’, where I introduced several students to the processes of moulding and casting. I only had a short amount of time – around 3 hours. Within this I had to squeeze quite a bit in, so I put on my best motor mouth for the occasion!
I brainstormed what I could include, and got some guidance from the tech in the casting room – I’ll create some basic moulds using the vac former, a silicone mould of the same shape in order to do a comparison of the two processes, and a couple of different resin types; polyester (clear cast in this case) and Polyurethane (Fast cast).
After half an hour of me waffling on about the contents of each canister, types of facilities available, and associated H&S we created some basic alginate moulds and created a plaster cast of our hands / fingers.
This was pretty decent and took us to around 11am, when we took a short break – this allowed for us to give the plaster some time to cure. We were all rather hasty in our de-moulding, and lost a few fingers, most people thought this was the most distressing thing they had ever seen, whilst others found the whole thing rather hilarious!
Typical art college fayre!
After all that, we continued on to the resin room where we created the reproductions using the vac form moulds. I prepared several, but gave the option for students to create their own if they wanted to make more than one. I also showed the silicone mould off and we poured that one as well. Over the remaining hour, resin was mixed and moulds were poured.
Well, onto one of the real reason I made this a forum post, was to show off some nifty mould making processes I had a go at. Not only is the nature of these mid week workshops a way to get some cool stuff (mostly hard skills) introduced to students, but is also a way for me to indulge my nerd and try and create / explore new ways of doing the stuff we do already, which can all be summed up as making.
Tuesday was spent mostly drafting in Rhino 3D some nifty tile pieces, the kind of thing we might look at 3D printing one offs, and then going off to reproduces using a variety of casting mediums. (or maybe in the future, we will simply 3d print the lot?), anyway – I made a bunch of tiles.
a typical process would be to create a plastic / wooden / Lego box to place them in to enable us to pour silicone over.
Well, now we’re in CAD and can 3D print the form, why not add a mould box into the mix, print it all out, and pour strait away.
The next thing I went on to illustrate was the process of creating a shape from a two part mould.
The parts for a two piece mould
All the components we went on to make on the Wednesday were simple one piece moulds, with an open back – this enabled us to quickly make some shapes. I created both side A and side B, in Rhino, as if they were made from silicone. The components also included the pour hole and the bleed lines already in place. This is something that you would usually create by submerging the parts 50% on clay and sculpting out the pour and bleed lines.
The next cool thing you add are the ball bearings / marbles, as these create locator pins for both side A and B, ensuring that you don’t miss align the mould and create a miss cast.
In the real world, that’s a days work (sort of ) and is also rather messy, you have to take precautions that you don’t get clay all over your original work. Once you have one side in silicone, you dismantle everything, take it all out – and then re construct the box; this time with the silicone and the part in the bottom, and now you can pour a new batch of silicone on the top (silicone wont stick to silicone) and your on your way to having a two piece mould. Sounds tricky? It is until you do it yourself!
Well – that will all take 2 days what with the cure time, if I’m lucky – and I only have 3 hours. I do have the benefit at this point to a couple of hours to prep for the session however. I think to myself, what if I were to take the workflow of creating the walls for my simple shape and turning it into its own mould box, and creating the mould box for side A and side B of a two piece mould?! Well – here goes. Mouldception.
This is what the mould will look like, rendered blue to represent the silicone material! note the pour holes, bleeder lines and the positive and negative locators.
Everything went as planned! I created the mould boxes for side A and side B, poured in the silicone, and 12 hrs later, had the silicone in my hands.
The silicone parts visualised next to their respective mould boxes.
A quick pour of the parts and we can see how things turned out. the pour hole could have done with being a little larger – perhaps we can use a syringe to force in the material as the working time is around 1 or 2 minuets.
The two parts of the mould taped up and ready to pour
The bleed holes worked really well…. except for perhaps my positioning of them , I was still left with a hole in the first reproduction.
I was able to position the two together, make the pour, and 15 / 20 mins later I got the parts out. The striking thing here was how much they resembled the 3d printed parts!
The parts that I printed were done so on the ‘fast print’ setting so contain all the features of a fast 3d print – its really amazing how much detail is carried through the mould / casting process – and how many comments we got thinking the resin part was made by a 3d printer, as it had a similar weight, finish, and surface quality.
I’ll return back with some HQ images of the printed + resin parts later, so into the process I guess I forgot to document the later (more interesting?) steps!
Collection of moulds, in both PLA and silicone.
Plaster cast finger mountain
The two part moulds.
The principle is that you cannot cast material that goes hard (plaster / resin) into a rigid mould. So here you can see we played around and injected silicone into the PLA moulds.
In the silicone moulds of the same shape, you can see we have poured / cast the resin. the reproduction (minus the air bubble) is great! All details captured.
The two types of mould for the larger tile piece. The ‘Vacform’ moulds and the silicone mould. The silicone moulds (condition cure) are only good for the Polyurethane resins (fast casts) and the vac forms for the polyester resin (clear cast).
Clear cast with pigments – and loosely mixed inside the vac form!