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Saturday, May 31, 2014

Teardown of a laser printer



In this age of mass consumption  and programmed obsolescence, it is not surprising that a few years after you shell out money for a printer, the availability of its consumables starts to decrease, followed by an increase of the associated price.

Thursday, May 29, 2014

Gimbal finally onboard

After a long wait and a hassle with a chinese seller, finally I could but together the gimbal, flash the board with Brugi (Martinez) and do some tuning and testing.

While a first flight have not yet been done, manual handling with rough attitude change movements shows that the gimbal seems to respond pretty well and no vibration could be perceived in the video at 1080p.


Wednesday, April 2, 2014

Custom made BEC

BEC's, which is short for Battery Eliminator Circuit is a fancy RC hobby term for a DC-DC converter that steps down the voltage to a given value used for example by servos and control electronics such as radio gear and flight controllers.

In the market there are two main types, most of which convert from a higher voltage to 5-6 Volts DC. These can either be of the linear type, or switching mode. The first is the simplest, where a simple linear regulator is used to drop the voltage to a constant value at the output. These tend to be very low noise steady sources of voltage, but have the disadvantage of being quite inefficient, getting worse the higher the input-output voltage differential. A considerable amount of energy is wasted in the form of heat.

Sunday, March 30, 2014

2nd quadcopter practically RTF...

Other than having the recently ordered flight control board (Multiwii SE) mounted and configured, everything else was completed today with the addition of the custom made landing gear:


Tuesday, March 25, 2014

Brushless gimbal almost complete



With the arrival of the Mobius action camera, which is a Full HD (1920x1080 @ 30 Hz) little animal (very nice video quality for the price), my aerial filming addition to my #1 quadcopter is almost complete. The only missing element is the gimbal controller board, which I have ordered through ebay, but my mistake (or not) the seller have sent the MPU6050 instead (which I had at the same time ordered from a different seller). Result: I have two MPU6050 gimbal sensors and no gimbal controller. As such a dispute is being solved, and the seller decided to (supposedly) ship me the controller board. Otherwise I will escalate to ebay, get refunded, and the seller downgraded (or banned, who knows..).

Tuesday, March 18, 2014

Improved quadcopter - more "avionics" and increased run time

In the several weeks that followed a crash caused by an ESC failure, plenty of work have taken place (some of which documented here). Several things have been done since:
  • Replacement of the ESCs with a 30 Amp quad ESC;
  • Upgrade of the flight controller firmware;
  • Building and programming the PPM Sum encoder;
  • Building a BEC/filter with 12 V and 5 V outputs;
  • Adding landing gear;
  • Adding voltage and current sensor;
  • OSD firmware upgrade;
  • Change of LiPO battery from 11.1 V (3S) to 14.8 V (4S);

Monday, March 17, 2014

Induction Stove

Some days ago my father asked me to check if I could repair this single element induction stove. I disassembled the device to inspect its inner workings. I was a bit curious because I have never taken apart this kind of apparatus.