Sunday was the ‘Make My Day’ festival located on Morecambe Promenade, set up by The Exchange, a maker group operating out of Morecambe. LAMM had been given a stall at the show to display our own set of interests and skills, consisting of 3D printed objects, a set of computers to dismantle and the incredibly popular slime production.
Shaded under a gazebo Elly, Bill, Dave and Andrew welcomed visitors to the stall to educate them on the wonders of making things. On one side was the computer area, offering a mix between ‘how its made’ and ‘scrap heap challenge’. Dave supervised all age ranges to take apart the many defunct laptops that had been donated to us. It was really great to see the excitement that taking things apart inspires, stimulating the curiousity that is the foundation of all makers. Asking that always important question ‘how does it work?’
The main attraction of the day was undoutedly the slime factory. Where Elly and Bill aided the crowd in turning PVA glue, poster paint, bi carb and shaving foam into a gloopy, slimey mess. The audible astonishment when the activating contact solution was added to the mixture was really something to behold. A special mentinon to both of them for the hard work they put into doing this as they rarely had a moment to themselves.
The festival was excellently run, with a great assortment of stalls and attractions offering so many different activities for participants to enjoy. A lovely lunch helped the volunteers to keep going and the weather made it a really ideal day.
A great thanks to everyone who volunteered and the organizers of the event. These attractions are so important to keep the spirit of creating and community alive. Knowing the drive to create is what got us as a society to where we are today, events like this ensure the next generation will keep the tradition alive.
This Saturday 17th March 2018 is our usual Open Day and it is also World Create Day along with Hackaday.io.
There are over 100 spaces participating this year! Here is everything you need to know to make #WorldCreateDay the most amazing world wide event makers have ever seen!
Here is the link to our event on Hackaday.io, so maybe sign up if you are coming along: https://hackaday.io/event/78299-wcd-shadowcat-systems
Use the hashtag #WorldCreateDay and Tweet about our event!
Take pictures & tweet them with the hashtag #WorldCreateDay, and encourage people to do the same. Make sure to ask for permission to use them in images shared online! The more you post the more likely you will be featured on Hackaday.com!
Follow the Tweet wall linked below to see all the creation happening world wide! Everyone at our event can follow along (and join the buzz themselves) if we put it on a screen somewhere.
In the third post of the month/night after a cabinet and a Google hat I wanted to quickly talk about Prusa Control. Prusa Control, for the uninitiated, is a cut down version of the, very useful and powerful, Slic3r software for the Prusa printers.
Prusa love Slic3r and there is no reason to doubt it. They build a custom profile for the software and make sure it is shipped and linked across their brand. however they note that it can be over-whelming for beginners. That’s where Prusa Control comes in.
Prusa Control is aimed at ease and speed and with just settings for the Prusa 3D printers and there is something lovely about that. I have installed the beta and used it for a first print in my new cabinet.
It worked really well.
In fact I would say close to perfect. I printed with a brim and with loose settings (.2 at 15% infil for speed and ease) and I got a near perfect print with good bridging and detail and a wonderful layer height that is regular with no breaks or interrupts. The brim was light and they clearly had taken care to make sure it was a well printed but easy to remove printing support.
So for new users and for experienced users wanting to cut out the interface and get straight to the printing then it is worthwhile having Prusa Control next to Slic3r in your toolkit.
I also liked how smooth the layer height display worked after generating which is very quick and efficient.
The second blog post of September, and actually the second of this evening, concerns a recent build of an electronic item I did with my son (#1Son, Ben).
I managed to pick up the Google AIY Hat for the Raspberry Pi with MagPi for a very affordable £5 and Ben and I decided to build it together and to video it for our YouTube channel.
The build was complemented by printing a box from a design on Thingiverse instead of using the cardboard one. Rather than say too much more I have copied the video link* (and you can also play the video below) so you can view it without leaving this page.
If you like the video please give us a thumbs up, and if you have constructive criticism then please feel free to comment.**
As always I wouldn’t be doing this if I didn’t have so much support and encouragement from my LAMM peeps, thanks guys, and especially, as always, to TBSliver who is always there with advice and support. He gets a big shout out and lots of free dinners at my house ;P.
** A part of me says that if you have negative or destructive personal criticism then I should probably know what it is or alternatively you can write it on a piece of paper and place it under a rock on Mars for me to find when I decide to be a Spaceman in some alternate reality :). I really would like to hear any good criticism, positive or negative that helps me in the future.***
*** Obviously, and I shouldn’t need to say this but a small part of me realises this goes to YT and Twitter as well so has to add this caveat, if you have any criticism of Ben then do the decent thing and keep it to yourself, children have far more impressionable egos :P.
For a while now, I have been trying to make a dry box for storing 3D printer filament, having had problems with a reel of ASA filament becoming damp and the prints made from it coming out pitted and fragile. The first idea I tried was to use silica crystal cat litter as a dessicant in a sealed box. I bought a transparent storage box with a rubber seal and a packet of silica cat litter, as well as a cheap digital hygrometer / thermometer. Then I burned some holes in the lid of a plastic fast food tray with a heated skewer, and put the cat litter in the tray. Finally I put the tray, the hygrometer and the filament into the storage box and sealed the lid.
I left the cat litter in the box for a full day, and the humidity reading actually increased slightly from 55% Relative Humidity (RH) to 59% RH. This was at a nearly constant temperature varying from 24 °C to 23.7°C. The increase was within the error range of the meter but not the significant drop I had been hoping for.
The next thing I tried was to crush the crystals using the somewhat crude method of wrapping them in a strong piece of cloth and bashing them with the end of a brick, to see if this would increase the surface area of the crystals and make them absorb water better. This didn’t work so well as silica crystals are quite hard, and it also didn’t make them any better at drying the air in the box.
I suspect that the reason the cat litter didn’t work is that even though silica does absorb water, the granules you get in the sachets that come with electronic devices are prepared in a way that makes them highly porous and able to absorb atmospheric moisture, whereas the silica that is used as cat litter is designed to absorb liquid water so they make it out of solid crystals.
At this point I did a bit of research online and found this web page about drying mushrooms. It has a pretty good summary of the three main substances used as dessicants, how effective they are, and how to use them. In order of increasing effectiveness, they are silica gel, which will bring the humidity down to about 40% RH, calcium chloride, which is what is found in home dehumidifiers and can bring the humidity down to below 25% RH, and calcium sulphate, which is the strongest of the three and according to that page can lower the humidity to a few percent RH.
As it says on that page, calcium sulphate is the same chemical substance as plaster of Paris. This is a substance which attracts water strongly into its crystal structure, and can come in several forms depending on how much water it has absorbed: hydrated (fully saturated with water), hemi-hydrated (partly saturated), and anhydrated (no water at all). Plaster of Paris is the hemi-hydrated form and can be bought quite cheaply from craft shops.
The simplest way to make powdered plaster of Paris into a dessicant would be just to heat it in an oven to drive the water out of it, let it cool in a sealed heatproof container, and then put it into the dry box. This would probably work okay, but it would have the problem that air wouldn’t be able to percolate through the powder easily so it might take a long time to dry the air in the box.
I decided instead to try to make it into granules, thinking that they might absorb the water vapour better. The rest of this post describes how I did this.
The photo above shows some of the equipment I used to make the granules – two non stick baking trays, a bag of plaster of Paris, a mixing bowl and metal spoon, and a kitchen weighing scale. I also ended up using a couple of large glass jars, some rubber gloves, two plastic bags, a piece of heavy cloth about 40 cm square, some string, a pint glass of water, and a brick.
The first thing to do was to measure out enough plaster to fill the baking trays in a thin layer. You may want to wear rubber gloves for this as plaster is slightly irritant. I did this by just spreading it out in the trays to what looked like a reasonable depth to be able to break it easily once it had set.
Then I put the mixing bowl on the scales, zeroed them, poured the plaster into the bowl and wrote down the weight – 442 g.
You make up plaster by mixing it with water in a ratio of 100 : 69 by weight. This makes 305 g of water, which makes a total of 747 g in the bowl. I then made a bit of a hole in the middle of the plaster and poured water in until the weight was (about) 747 g. Then I mixed it with the spoon until it was smooth, and poured it into the two trays in roughly equal amounts.
I then allowed this to dry for a while (the instructions on the plaster say 6 – 10 minutes). The next thing was to take the plaster out of the trays and break it into granules.
To do this, I first put the trays inside a large plastic bag and turned out the sheets of plaster. These came out quite easily.
Having done that, I then put the bag inside another bag, broke up the plaster sheets a little bit by hand and then wrapped the bags inside the cloth square with a piece of string.
The next thing was to bash the bag with the end of a brick until it seemed like the plaster sheets were all broken up. Then I took the newly broken granules out of the bag, laid them out in the baking trays, and baked them in the oven at 230°C for two hours.
I left the trays on the hob for a couple of minutes to cool down a little, then poured the granules into the large glass jars to cool properly.
Once they were cool, I put them into the plastic tray with the holes in the lid and sealed this in the storage box with the hygrometer reading visible through the plastic sides.
Finally it was time to see if the granules were going to work. I wrote down the time and relative humidity for the next few hours, and watched the humidity fall from 62 % RH at 16:42 to 27 % RH at 23:04. It fell quite fast at first, going down to 38% by 18:03, and then slower after that. Whether it will get all the way down to the level of a few percent that the web page I referred to above says you can acheive using calcium sulphate, I’m not sure yet, but I’m pretty pleased with this result, as it is below the level that is supposed to be acheivable using silica gel.
One test I would like to do is to open the box again in a day or two, let the air mix, and then see if the humidity drops as fast the second time, to get an idea of how much drying capacity this amount of dessicant has. If I get around to this I’ll post an update in a comment.
On the 17th of June from 12pm to 5pm we are organising a day of demos and talks on the subject of ‘3D design for 3D printing’. There will be several talks and demonstrations on the subject of how to use 3D design software to produce physical objects for manufacture, whether on a 3D printer, laser cutter, or CNC milling machine. If you are curious about 3D printing and other computer based manufacture techniques but don’t know where to start, or if you have experience but would like to share skills and ideas with others, this could be the event for you. All ages welcome but under 16s must be accompanied by an adult.
The talks / demos will be:
Tom Bloor – Introduction to Fusion360.
Ian Norton – Modelling in OpenSCAD.
Andrew Baxter – 3 ways to model a real object in FreeCAD.
— break —
Dave Leack – 3D Printing with Blender: Common errors and how to fix them.
Ian Jackson – Modelling in Vectric Aspire.
The talks will last between 30 to 40 minutes, with a 20 minute break in the middle.
If you would like to help publicise this event, please download and print out this poster, and put it up wherever you think people might be interested.
The AGM for Lancaster and Morecambe Makers will take place on Monday 27th February 2017 at 19:00 GMT at the Space
Please could all Members make the effort to attend this meeting, if you cannot attend we will require proxy votes beforehand
If you would like to raise anything please let one of the directors know by the 19th February, so that we can add it to the agenda. The agenda will be circulated before the meeting to allow time for Proxy votes
In accordance with our Articles of association two of the directors will stand down at the AGM to allow others to become directors.
If anybody wishes to nominate or be nominated to the board please let us know before the 13th February 19:00 GMT.
Please submit in writing a statement with the intention to propose the appointment of a person as a director; contains the details that, if the person were to be appointed, the association would have to file at Companies House; and is signed by the person who is to be proposed to show his or her willingness to be appointed.
Please submit any point, proxy votes or nominations to firstname.lastname@example.org
The two directors who will be standing down this time will be:
Fear not, for I have hacked the new one this evening and it’s pretty straight forward 🙂
Well that mostly looks similar…
Still looks similar…
Well that’s different. The two boards are fixed together and the front board has to come away from the plastic shafts for altering the time and lux level
Those are really annoying to get back in but I’ll come back to that.
Different AC supply board this time around. Let’s take a look see what’s going on..
So capacative dropper is driving an actual bridge rectifier this time rather than four discrete diodes. Seems like there’s a lot here we don’t need….
I always end up with spare bits when I take things apart….
Right, so now we look like:
So having removed all but the diodes for protection and the capacitor for smoothing the supply, we’re left with +24v going in and a working automation PIR! I put the front board in place without screwing it in and put the spacers on the back board as it came but without the screws. We’re no longer dealing with mains voltage and the spacers keep everything sensibly… well… spaced… Best update the labelling…
That’s a bit neater than the previous scribblings with a sharpie… 🙂
I’m hoping that step by step pictures and the diagram will make it clear how this change works. The PIR module is 24v all along, all we did was remove the AC components and drive it directly.
There doesn’t seem to be an LED on this model. The relay is triggered by dropping the signal line from the front board to 0v. It floats at +24 otherwise so technically we could lose the relay completely and drive that back to an input. I’ve not tested that so your mileage may vary.