well, to sum it up, the second day wasn’t as productive as i wished in terms of crafty handworks, besides the cooking of course. i was mostly trying different approaches to generate thrust with mixing and interfering with mostly “household chemicals”. but since the civil versions of these (backing soda aka nitron and white vinegar) were not very effective in what they should do i decided to consult a chemist for some better “solutions”.
basically if you add backing soda (nitron) to white vinegar a chemical reaction should begin which generates a lot of co2. if you do that in a closed plastic bottle you generate a lot of pressure which you then can use as a partial thrust if you poke a hole or 2 into the right places.
the main issue with this method is that the thrust is created very rapidly and strong and dissipates just as fast again. this makes is not a very effective method to generate constant thrust.
so anyway i got some higher concentrated nitron at the pharmacy (hope dies last) and kept on trying to find any good solution to propel my fishtorpedo. unfortunately nothing worked as hoped and in my time of desperation i unfortunately also forgot to take any pictures of this day. both things that should change the following day, which was the last one of our workshop experience. read on in the next chapter!
After all my tries tiding and untiding the copper around for two days, last one was dedicated more to make a playful device in which a lot of expectations were involved. There was a vague idea of what could be a coordination game in which tehoretically two persons could make levitate a neodymium magnet ball and be astonished by this effect. This could have theoretically happen if all coils could work at the same time or at least work continuosly. I had several problems to make things work with the coils, first of all because I didnt know how much sensitive was the isolation around and in that sense I didnt take care to drag them agains the floor, I didnt know it could happen so easy and were so sensitive to have some sections exposed due to be recycled material, and also most of the problems became when in this third day I had to fix the coils to an structure to make the distribution to play with them.
But problems aside, I had a very funny time learning about electromagnets, and I guess still was playing a lot the device even if it was only with the expectatives, was kind of “magic” to move things without touching.
I guess still there is a lot more work on the way, but was a great expeience.
Figured out I could use a higher and more sturdy hinge, welded it on top and used the bar I found on Wednesday to make the thin rod go through. Since there were small angles when I welded both times, they added up and I ended up with a slightly off mechanism. But this did not affect throwing since you could fix it as you were aiming.
I decided that the piece that stopped the bar -that was also fixed to the ground- didn’t have to be a fixed single piece. I screwed the bottom piece onto the wood platform and fixed it 2 clamps. And with a small cap (that was spray painted later on) from the kitchen the catapult was ready for testing.
I was glad to see that my colleagues were more than happy to try it and play around with it before people even started to show up. We played around with pretzels and a game to see who would be the first to get a rock inside a plastic cup later in the evening.
And the final bonus cat photo:
For the final class I decided to assemble the final part of the worm to the rollers. In order to let the whole structure move forward, i located the two motors inside of a wooden cube.
With the help of Michael, we changed the hitters from the motors and we simplified them. After this, I had to connect the backside with the motors to the rest, and Tim suggested to use some thread, in order to avoid that some parts might remain still and fixed.
In the end, the worm looked like this, and it was able to move the rolls (more or less) after being hit and move forward (if it did not get stuck before). It was actually very challenging for me finishing it in 3 days, and getting to know the materials and all the possibilities. Sometimes it was not so easy to decide which one was the better solution for some of the issues, because I didn’t have much experience with making robots (or pseudo-robots) before.
After building the structure, the next step was moving all the wheels forward just by rotating and pushing the last one. First of all, we add an aluminium piece to the motor, so that it would be possible to kick on the last wheel. In order to check the different movements produced by it, I added some anti sliding material, but no big differences were observed.
The wheels didn’t move (of course) as they were expected, and Tim suggested to locate the worm between two pieces of wood. Therefore, it would be possible to rotate the hitter from the motor and (maybe) getting a bigger displacement, but then displacement of the object would be very different to the one I had in mind. Let’s see.
It took some time learning how to make a thread in the aluminium piece to fix it to the motor, cutting it and also recutting the last cogwheel in a (slightly) more precise way.
For the next & last class I planned some more changes:
-adding a second motor.
-locating the motors inside of a wooden cube, so that the two hitters help the structure to move forward after hitting the cogwheel(working as crutches)
-changing the first wheel depending on the necessary weight.
Let’s hope it works.
Tim suggested we work on a 2nd mechanism on top of the 1st layer so that we can launch stuff with more momentum and control. I started off with a small hinge that would balance the long bar on top. Had some trouble with the drill and broke off the first piece, then struggled aligning the holes on each side.
After the 3rd try I had a small hinge that works with a proper piece that has aligned holes and is loose enough to move.
At this point I had a basic mechanism that works, but I doubted that the small hinge would be enough, so before leaving I found 2 small parts and a thin rod to mimic the first level I already developed that was working.
My plan is to make a hole through the bar and let it rotate on the thin rod and create the hinge out of a larger piece. The last part would be to find a solution for the stopping mechanism that is connected to the ground.
Last but not least, second day bonus cat photo:
First attempt to work with electromagnets
After bad weather(no sun for sun powered devices) one of my two options to develop took the leading develop and I started to collect and manipulate copper to create coils for electromagnetic purposes… The idea is to create a levitating device with handmade everything. After first naive introduction into electromagnetic fields, the development before TIME IS UP point to make more a funny pinball controled by electromagnets than any complex weird and magic stuff.
I like to plug things and see sparks so that is how I spent my first day testing that magnetic fields are real and no so hard to create. Other thing is to control them, after trying to solve any of the maths from faradays law the test and error is going much more happily in this experiment, hopefully without any big damage to any borrowed device or hurting myself.
Thanks to all the bloggers of experimenters and fake videos I am on the row to get my first interactive electromagnet piece, is not that accuracy will be its main virtue but thats the funny thing to break the ice to experiment with electricity and get curious about interesting new technologies.
Thanks for the moral support and comprehensiveness from my crazy approach, something is getting done! Here some pictures few but shiny!