eric's model flying blog

As I wrote before, so far i've ordered everything I used from Chinese web vendors. The argument initially being the price, of course. I did not want to invest too much in a project with an unsure outcome, if that's not necessary. And in my case, there were many possible negative scenarios, making this a sort of high risk project. I did not know if I could pull it off, software-wise. I had some confidence in me getting the mechanical part sorted out. But then, if those two would come together, I did not even know if i could fly at all, or if I would like to fly such an apparatus. Or if I would continue to like it, once the challenge of getting things to work would wear off. But since my experiences with those Chinese vendors was positive all around, I continued to order from there to this very date. I have only once not received an order (out of some 200 orders), and that was settled with a refund after only two messages. Also, I received something different than I thought I

After connecting up the motors, and the battery (props still removed!), the moment of truth was there... No smoke! So no electrical shorts yet. Then for the first time ever spanning up the motors! I had attached a piece of sticky-tape to the motor shafts, so that I could see the turning direction (the tape bends due to the forces of the air, and stays deformed after stopping the motors). Of course, two out of 4 turned in the wrong direction, so I had to swap two wires per motor to get that corrected. I had deliberately connected the motors with bullet connectors, both for modularity, and for being able to quickly correct this. After swapping the wires, and one last check of the spinning directions, it was time to mount the props. Again, observing the turning directions. Then, outside, with the quad in my hand - looking out for the diameter of the props to be well clear of anything, especially my arms - a first spin-up. With about 1/3 throttle, I tested out if the corrections

OK. What!?! Vortex Ring State! It's the helicopter variant of a stalled wing. I had not heard of it yet, when I fist encountered the effect. It comes down to this: if you descend vertically, and you do that relatively fast, you get into the downwash of you own propellers. That will cause your props to loose lift, and you descend even faster. Your natural reaction would be to throttle up, because you are now descending more rapidly than you planned, but that makes the downwash - and therewith your predicament - only worse! The only thing you can do is pitch or roll to move out of that vertical column of air, not necessarily with more throttle. Only: you have to think of that, and act on that, before you hit the ground... I didn't. It caused my quad to "land" on one arm, and that was a touch too much... So now I had to go shopping for a new frame arm. I decided that buying a new frame would be a better option, because it is not that much more expensive, and I could imme

After first flight, comes first mods 😉 One of those things you know in advance about this hobby: once you have a flying system, you recognize opportunities for improvement, which leads to modifications. That's just as sure a bet as saying you will crash at some time.  In this design, I initially had the battery placed between the top and the bottom plate. But there was no good way to secure it such, that it would not slide forward or backward between the plates. And a slidings battery is disastrous for the Centre of Gravity being as good as possible in the middle, as the battery is by far the heaviest component. There was not enough room for friction material. Hook-and-loop would be even thicker, and require the battery to be peeled off, for which there was no room either of course. So the battery had to go under the bottom plate, with hook-and-loop, and a battery strap for added security. But landing on the battery is not the brightest idea, so I ordered some of those l

As a Mechanical Engineer, working in the machine-building industry, I got interested in the possibilities of IoT applications. So I started reading up on the subject of sensors, and data processing. I soon stumbled upon the Arduino environment. It's a relatively easy programming environment (C++) which can be used to program relatively cheap I/O boards of that same brand (or even cheaper Chinese clones thereof). After some simpler projects with data collection from sensors, data manipulation, and outputting a response (like reading an RFID chip, checking against known chips, outputting an LED color dependent on the ID) I more or less accidentally found a website of a guy that had made a quadcopter flight controller out of an Arduino. Since I am interested in anything that flies, I sort of wanted to be able to do the same. But then again, I did not want to spend much money on a project with a high risk of failure, so I "chopped it up" in smaller pieces. First of all,

Besides my blog on personal flying, I hereby also start a blog on my unmanned flying experiences. See  https://ericjesppl.blogspot.com/  for my "real life" flying blog(s) This is to separate the two somewhat, since there are people that prefer to follow my "real life" flying adventures, but are not so much interested in building and flying quadcopters and model airplanes. And I have shared so many stories about my model flying on so many channels (forums, Facebook, YouTube), that I decided to put it all inone place so I can refer to posts in this blog instead of type it all over again on a different channel. So this blog is all about unmanned flying in all it's aspects. I'll report on the building process of my self-built multicopters. Self-built quadcopter Also, I fly a regular, commecially available drone, GDU Byrd Standard and a model airplane Hobby King Durafly Tundra And there will be more as time progresses :) This blog will be on