Greetings from Thailand! Live long and prosper!
And what did you do today?
Happy NEW YEAR!!!!!
January 1st, 2012CNC me pt. 3 – creating realities
December 3rd, 2011Having at least a plan for the cross table I started working on the parts. I struggled for a while trying to find a place with the means of doing precise cuts and drills into aluminum. In the end I did the cutting in a former workplace of mine and had to do the drilling at [c-base] of which I am a member for about a year now. There I had to cope with a cheap drilling stand. I built me an improvised guide to at least have some precision in one axis. Some holes I had to turn into long holes to be able to adjust to tolerances. Those don’t look so good but I hope it will do.
I found some basic flaws in my design already. I made the mistake of not taking sideway pressure from the drill itself into account. The telescope slides have a sideway tolerance of about 1mm. I will continue anyway, maybe I find a way to correct this by adding guides or the machine will at least give me the means of drilling exact holes and help me build the next one ;)
the drilling guide
a long hole. a crater, rather
21st of december: all parts drilled
CNC me pt. 2 – Electronics I
November 19th, 2011Searching for a control solution for my CNC mill I found a whole bunch of possibilities. My requirements were these:
- cheap (why, of course!)
- USB solution
- ready PCBs
- open source if possible
Most CNC configurations still rely on a computers LPT port. This is due to the fact that a program can access this port in realtime as opposed to the USB port, which is buffered. There are several solutions on the web using microcontrollers to execute the code given through the USB port. I went for the one done by [planet cnc] in combination with classic l297/298 motor drivers by [PMinMO]. Both provide ready to use parts, kits and schematics to do your own board designs. I went for the kit solution instead of designing my own boards because I wanted to spend more time on mechanical design. PMinMO provides a truly great documentation with his boards, by the way! I got a PCB and a preconfigured chip from planet cnc. He provides a software with drivers for windows (costs though) that should also work under Parallels and such.
I soldered one driver and the controller board together but haven’t gotten around to do any tests yet…
soldering the smd parts to the driver board
the controller (w/o chip) and one driver, waiting to be tested
CNC me pt.1
November 18th, 2011I started making plans for a CNC mill some weeks ago and totally got sucked into it. Here are some pictures of the plans i made with sketchup. More soon…
the bottom axis
the second axis
Update 11/11
November 12th, 2011It’s been a while since my last post, so i think you deserve a little update on my where- and whatabouts.
After spending most of the summer doing technical coordination for the [Festival Über Lebenskunst] I went directly to helping the team of Tomas Saraceno set up his exhibition at [Hamburger Bahnhof], Berlin. I really enjoyed that, Tomas having a nice team and his works keep impressing and inspiring me.
Right now, badly in need of a job to earn as much as I can before going to Thailand in January, I started a soldering job at [Koma Elektronik], helping them to assemble their circuit boards .
Of course, I kept working on the [Diskokugel], trying to improve the circuit. Read more about that [here]. I also contemplated some on my actual intentions with this object. I will share that with you soon.
And, to make things worse, I got inspired by an [instructable] to build my own CNC-mill. That is just another example of how I constantly underestimate the time and effort (and money) of the tasks I keep imposing on me. I’ve already invested 3 weeks into it without any visible result and I keep going… Il post some pictures soon, however.
On other news: Halloween came and after laughing my ass off watching this [cookie monster video] repeatedly, I had to refer to it with my costume for the annual party in Frankfurt.
God's away on bizniz...
...
Trying to make Diskokugel louder
November 1st, 2011After my first experiences with the [Diskokugel] circuit building [Audioweb] and [AudioSphere] I tried to optimize the circuit for further use. That means I tried to look for a way to get some head room with the volume, since the current design didn’t quite satisfy me volumewise. I discussed the problem with Christian and we did some experiments using a [TDA7053a]. Not only would the TDA make a higher amplification available. Working on 5V instead of +/- 5v, as the transistor circuit works right now, it would have rid us of one power line that has to be transferred into the turning ball via a sliding contact. Also, soldering two chips on the board would have been much faster than soldering those 16 transistors.
The TDA7053 has a DC volume control input, which made us hope that we would simply connect it directly to the 4094 register to switch it on and off, making the 4066 switch obsolete. Unfortunately that didn’t work. The 7053′s offset voltage rises with the applied control voltage, thus producing a crack at the output when raised rapidly. Ultimately we got the thing working by keeping the control voltage at ~0.7V and switching the audio signal on and off with the 4066. However, since in this version all amps are constantly active, I am afraid the whole system would be prone to interferences and the power consumption would be very high. I had a very hard time testing the whole setup. I don’t know if it was my breadboard or whatever, but something started oscillating regularly and there was never a setup tat was save from that or other interferences. Christian told me however that he got something working.
I am not sure how to proceed yet. I think I will stay with the old circuit for now and see how far it takes me. After all, one result of the experiments with the TDA was that a higher volume makes it harder to locate the source of the signal. That would be sort of counter productive. It also shows that there are possibly limits to the use of this whole technique…
Audioweb 0.1
September 5th, 2011As a special gimmick for my birthday party i used the elements of [Audiosphere] to build a web o 6×6 speakers on a wall in my room. The sensation is, of course, a different one and since its now totally at hand, I will do some more experimenting in the next weeks.
the cable length of the sphere didn't fit, so it doesn't look perfect yet. I still like it :)
AudioSphere for PDCON
August 14th, 2011Having introduced the [Diskokugel] project at Berlins biweekly [puredata] [user group], I was asked to build an installation for the finalizing event in Berlins [LEAP] gallery. Being busy doing technical coordination for the [Über Lebenskunst Festival] this was quite a task.
I used the five prototype circuits to build a walk-in sphere of 40 speakers. The speakers were attached to nylon strings stretched from the ceiling to the ground, so you could bend them aside to step in. In an effort I provided a crude interface in PD that provided a joypad for people inside the sphere to select different programs, such a random, sound going in circles, etc.
Contentwise, we had placed a call for content, which resulted in one piece that was handed to me and which worked quite well. I have yet to get the adress of the composer to thank him again ;)
The result was quite to my liking and so was the feedback (apart from nobody understanding the interface, but in the end that didn’t matter much). The sphere was fun to use. I personally found it pretty dizzying standing inside the speakers while the sound came from a different direction every 25 milliseconds. Unfortunately, as of now there are no pictures to show. The installation stood at LEAP only for two days, in which I had forgotten to bring my camera. Hopefully I will find someone of the PDCON who made good ones.
[UPDATE: pictures of the building process and a picture from a mobile phone (thanks ckp and astring!)]
a picture by astring
in action. the nylon-strings could be bent apart to step inside. (pic by ckp)
arrangement of the circuits
some notes
more notes
Diskokugel
July 8th, 2011Diskokugel is a work in progress, hopefully soon to be finished. For the whole story and latest updates check [here]
0.2beta
I started the project “Diskokugel” in autumn 2009. The vision was to build a ball made of speakers that can be turned on and off individually. This ball would turn while sound would be “reflected” in one constant direction, just like light from a mirrorball. So I went to the [sublab], a hacker space I am co-founder of, and asked for help. I got it galore from Christian, who volunteered to design a circuit that would both be cheap and easy to build.
A new Gadget 2.0
July 6th, 2011YEAH!!!!
Behold! I finally upgraded my [bike sound system], adding extra power, a subwoofer and a battery charger for everlasting supply. It doesn’t look as decent as the last one did but it totally rocks. The first test run was a trip to the [Fusion Festival], around 120 kilometers. The dynamo provides enough power to reload the batteries while the system is playing.
I started of with the [TDA7052] 1W amplifier I had already used with the old sound system, only this time I used two, one for bass and one for mid/high frequencies. But the TDA is made for 8Ohm speakers and my bass speaker had 4Ohms and so had the two high/mids in parallel. So I decided to get something bigger. Now I have an [AN7148] delivering 2×2,5W at 12V 4Ohm which is totally sufficient to predominate the occurring head wind and most traffic noise :)
The battery charger was built according to the circuit provided by [forumslader.de] . Documentation is in German only but it’s extraordinary! It’s housing has still to be completed. To be done in time for the Fusion Festival I was a bit in a hurry.
The AN7148 in its housing. Batteries (9xNiMH) sit at the right.
The battery charger