Flying the X-Ufo
Some weeks ago I bought an “X-Ufo” which is kind of a remote-controlled helicopter with 4 rotors. It’s great fun to fly but it takes a little practice to control it in the beginning, and the ufo inevitably takes some hard crashes. It’s for indoor and outdoor use, but I learned after chopping a couple of my plants that it was best to keep it outside. Unfortunately that requires next to no wind.
A couple of days ago some friends visited, and one of them got the idea to mount a mobile phone with a camera underneath the ufo. This resulted in some quite funny videos, some of which you can watch here. The phone survived, but at the end of the day, the ufo didn’t fly that well, so there’s a new one on its way. I can always use this one for spare parts.
Next thing, if money and time allows it, will be replacing the batteries with some larger capacity ones - the flight time is about 5 minutes currently - and a gyroscope replacement if possible. The gyroscope sitting on it is mechanical, and when the ufo is tilted more than around 20 degrees, it looses track of what is horizontal, and the ufo will crash. It appears it is possible to mod the ufo by replacing the gyroscope with a custom “piezo” module that has no mecanical parts and provides for better control. In fact “LiPo” (batteries) and “piezo” appear to be the buzzwords over at the X-Ufo forums. My German isn’t very good, but hopefully we’ll be able to get some hints from that source.
Click one of the pictures to the right to see some pictures and videos of the beast in action. 
August 22nd, 2006 at 12:15 am
Hi Christian, I just saw your ‘ratcheting propeller’ movie on forum.xufo.net [corrected link]; it appears to me that if you play the 2nd movie in slow motion you will see that the ratcheting sound seems to come from slippage between the pom gear and the pinion gear. It appears that the motor gear seems quite worn. The gear teeth almost seem to be ‘cupped out’ in the area where contact with the white gear is made. As you rotated the propeller, the slippage wasn’t at every tooth, but at most of them - I could see the teeth slip back sometimes, rather than rotate. In addition maybe the white gear is worn. The gap between the two gears is too big. Good luck, Mike
August 22nd, 2006 at 8:08 pm
<p>Hi Mike, I know it looks like the gears are slipping in the movie, but actually they don’t. It’s because of the bad movie quality, and that’s why I noted in my post that the gears didn’t ’skip’ - maybe that’s not the right word for it. :)</p>
<p>Anyway, tend2it posted an answer, and it appears that some motors just have this ‘ratcheting’, and in his case it didn’t make a difference in performance. Maybe I’ll try to replace them and see if I get better battery/flight performance. Thanks.</p>
<p>-Christian</p>