Wednesday, December 30, 2009
Sunday, December 27, 2009
Die ou se kinders probeer sy Easystar RC plane afskiet met vuurwerke, terwyl dit met 'n kamera op die vliegtuig afgeneem word.
Saturday, December 26, 2009
Thats plane programming!
Originally uploaded by hyper7pro
I was helping to test a GPS telemetry device today in my Yak 54. It works, and the data is pretty interesting. Takeoff speed is 100Km/h, and the plane goes from 0-80Km/h in 3 seconds. Top speed was 206Km/h, highest altitude was 460m above takeoff level.
And that was with me flying fairly gently because of all the delicate electronic test/development boards on board the airplane.
Tuesday, November 24, 2009
Sunday, November 22, 2009
Monday, November 16, 2009
Friday, November 13, 2009
Hier is iets van Manfred af:
Hi daar Johann, hier is iets vir ons blog. Ek het hierdie nuwe Phantom gebou vir n vriend van my Francios de Waal. Die vliegtuig is 'n kwart skaal 2007 pylon racer. Wag net vir die weer om saam te speel dan sal ek hom maiden. Aangedryf deur n O.S 46. Soos jy sal sien op die foto's lyk hy nogal indrukwekkend. Nou ja, dis al van my kant af vir eers . Groete Manfred.
Dit lyk awesome Manfred! Sterkte met die maiden vlug!
Net ietsie interessants oor die (Full size) vliegtuig:
"One such model, the "Phantom 70," is a quarter-scale replica of the Aberle Phantom biplane. Based in Fallbrook, California USA, the full-scale Phantom was built by Aberle Custom Aircraft and sponsored by Kyosho during the 2007 Reno Air Races. The plane set a biplane-class speed record in 2004 with a top speed of more than 241 mph. A new record was established in 2006 with a speed of 251.958 mph.  "
Sunday, November 8, 2009
Friday, October 16, 2009
Sunday, October 4, 2009
Monday, September 21, 2009
Sunday, September 13, 2009
Sunday, July 26, 2009
Sunday, June 28, 2009
Sunday, June 14, 2009
Friday, June 12, 2009
Article by Kenneth Macrae:
I’m trying to get back into flying and while going through “pre-preflight” checks, I realized that my nicad batteries are not to be trusted, perhaps as a paper weight or to play dodge ball……
I recently bought a 8 amp linear BEC for my ¼ scale cub ( which I still haven’t started building……) and thought, it can’t be complicated to make my own. And it wasn’t.
I did a quick search and one gets two types of “normal” voltage regulators. The trusty 78L05 or similar which requires the supply voltage to be a least 2 volts higher than the regulated voltage i.e. you would need a 7 volt battery pack (at least) to supply a constant 5 volts. The “other” type of regulator is a LDO type, “Low Drop Out”.
The drop out voltage is the lowest permissible supply voltage for the regulator to maintain the output voltage.
You get different types of LDO’s which can have an impressive drop out of 0.3 volts at full load right up to 1.5 volts at full load for that regulator. The regulators which have a low drop out obviously cost more….
Using the 0.3 volt LDO, at full load, the supply voltage then needs to be at least 5.3 volts to ensure 5 volt output.
The BEC I built makes use of a maximum 2S lipo (7.4 volts) and can work right down to 6 volts (the lowest limit for a 2S pack without damaging any of the cells). The advantage of using LIPO’s for a receiver pack are numerous and could probably occupy a number of pages, but for me it was:
More trustworthy than my old nicads
Easy to charge (if you have the right equipment) with in about an hour
Predictable and no memory effect
I’ve added additional circuitry to give an indication of the pack via 2 LEDS (light emitting diodes).
Above 6.4 volts, the green LED is on
6.15 to 6.4 volts, the green and red LED are on
6.15 volts and below, the red LED is on
Once the red LED is on, it’s time to stop flying and charge the battery.
The specs for my homebuilt BEC are:
Constant 4.81 volts at 1 amp
Can comfortably handle up to 3 amps peaks
Has a maximum practical limit of 2S lipo (I don’t see the point in using more LIPO’s as the extra “volts” are converted to heat and it’s a real waste…..)
Below are some graphs showing the performance of the BEC:
Figure 1 Vout at 1 amp - fully charged lipo was not used
Depending on the capacity of your LIPO will dictate the length of your total flights. With the built in “battery checker”, most of the guess work would be removed.
Figure 2 Vout at various loads