Hi everyone,
just recently I came across a site of brillian nerdy geek humor by Ernest Cline (to cite him, this is “Airwolf”).
I especiallly loved “The Geek Wants Out“, either read it, or even better listen to it in mp3.
Cheers to you all,
Tim.
the vacuum worked perfectly
Hiho …
After 24hrs in the vacuum bag, the first wing just looks great! It’s really stiff and strong, I just tested it for about 4g loading without any noises or anything. (a crackling noise is a first indication for overstressing the compound material)
The chord of the wing still is larger than the final wing, as the trailing edge is excess material and will be cut to the final shape later.
Cheers,
Tim (smiling)!
exams and a new rc-plane again
Hi everyone,
Yea, I know I haven’t updated in a while, so I’m doing this right now.
Aside the work for my assignment I’m, as always, learning for some upcoming exams, if nothing fails, these are my last ones!
As my last rc-plane got damaged during the last launch I’m working on a new one. Basically the same flying-plank concept, but this time with higher wingspan and thus higher aspect ratio. Another novelty will be a small electric motor (brushless outrunner) with a folding prop, to assist the time in between thermals.
The design of the wings is different as well, this time I cut a styro-foam core (with Joern’s help 😉 ) which I’ll cover with 1mm obeche veneer. First I tried using the rest of the styro and 36kg in water bottles to press the veneer to the core, while the epoxy was curing, but this didn’t work well in the strongly curved areas around the leading edge.
For some time I thought about using a vacuum system for the pressing, so this time I decided to finally build such a system. All I need is a airtight bag, to put the wing and veneer in and a vacuum-pump to evacuate the bag.
For the bag I got me some 0.09mm PVC foil which I then sealed with a hot wire on a wooden bar, pressing it to a flat surface.
To create the vacuum, I used a cheap aquarium-air-pump, reversing the tubes on the inside, measuring the pressure-difference with a small tube, hung on the wall of my kitchen with the open bottom end in a bottle of water. The height the water rises when a vacuum is created on the other end is proportional to the pressure-difference, with 1m corresponding to roughly 0,1 athmospheres. This showed a sufficient pressure-difference of about 0,3 athmospheres while the pump was still rather quiet.
On the last two pictures you can see how nicely this works. But these were just preliminary tests, without the epoxy. The real test will be tonight!
I’ll post some further update once I see how the final test worked.
Cheers, everybody!
long due update
Hi everyone …
As I haven’t written much in a while, I’ll just give a brief overview of the last events.
As the new version of Ubuntu was released this month, I organised a small release party in Stuttgart. Though this was quite spontaneous, we ended up with a group of six Ubuntu interested people.
A few days later Kathi and I randomly got to watch a pre-worldcup soccer theatre performance in front of the new castle in Stuttgart. Especially the pyrotechnics were really impressive!
I also started working on my assignment, focussing on evolutionary optimisation of rule based designs. Ask me in person if you want a more detailed description of this. 😉
So far for this update, cheers …
Tim.
finally relaxing
After those months of exams I finally can lay back and relax!
We went bbqing at the Max Eyth See
and had a nice afternoon flying our model planes in Scharnhausen.
I even managed to get up and give my flat a spring-cleaning!
Just yesterday I went to an interesting concert in the “Laboratorium“, some modern blend of balkan/gypsy music. The band is called KAL and consists of mostly young musicians from the area around Belgrad.
After a few songs more and more people got up from their seats and started dancing around the tables … really great athmosphere in that small venue.
So far for this update, have a nice time!
Cheers, Tim.
Once more some rc-plane videos. This time it’s Martin and Jörn flying. When I got ready, it started to pour down.
– Martin Start
– Martin Flight
– Joern Start
– Joern Flight
the first flight!
The perfect day for a first flight, calm wind and blue sky!
After a bit of adrenalin the Plank2 turns out to handle quite well. The first few flights with the rubber went well, and I even managed to catch some thermals, staying up in the air for nearly 5 mins.
And some video as well: one of the first flights
Next I’ll get me a longer rubber, to get to a higher altitude from the begining, giving me more time to fearch thermals.
Cheers everyone,
Tim.