DIY- Mini Quad Fiberglass Frame

Last year this time, a five-man team including me were working on a mini tricopter for a competition which later got replaced by the mini quadcopter for unexpected reasons. In the span of less than two months (Dec 2013-Jan 2014), a bunch of guys who had never before been around a multirotor and watched months of partial failure with the tricopter which barely lifted a foot off the ground and turned into a three bladed weapon of mass destruction, actually pulled off a working quadcopter that complied with the competition rules.
Honestly, trying to build a mini FPV multirotor with a flight time of 15 minutes is quite a challenge for any beginner. To build a mini quad that weighs in close to a kilogram to do 15 minute flights is out of question. But, we did manage to build a 330mm FPV quad that flew 10 minutes+ on a 3S 1Ah LiPo which is not really bad.
How we did it is not complicated as it is, but it took a lot of prototyping and design optimizations before we saw any real exciting number like 400g AUW and 10 minute flight times. I’m sure there are better contraptions than what we managed, but I’m going to share one crucial thing about our quadcopter, its frame, just in case someone out there is trying to build something quick & dirty similar.
The quadcopter’s frame was the centerpiece of this puzzle, it needed to be very light and very strong — classic engineering paradox — and the final product was a light 28g and about 50 crashes strong fiberglass frame. We improvised on most parts of the glassing process, but you don’t necessarily have to.

Continue reading “DIY- Mini Quad Fiberglass Frame”

G3 “Sinister Saint” — The RC Car From My Dreams [UPDATE]

Its about 6 years now since I fell in love with contraptions rolling on three wheeled under the influence of instantaneous torque from an electric motor working its magnetic magic inside a metal can held against sintered magnets.

Continue reading “G3 “Sinister Saint” — The RC Car From My Dreams [UPDATE]”

DIY- gForce meter 1.0 [UPDATE]



So this time around, it’s another fun and functional microcontroller based DIY, a g-force measurement system with data logging to SD card.


1) Arduino UNO w/ATmega328P
2) 3-axis accelerometer breakout
3) SD card
4) SD card breakout w/level shifting circuit
5) LED Continue reading “DIY- gForce meter 1.0 [UPDATE]”

DIY- xESC Adapter [Ver1.0 w/ATmega8]

This Arduino based DIY is for everyone who would wants to run aeroplane ESCs with a surface radios. It goes in between the ESC and Rx. Although, there is already an adapter called Pistix available in the market for the same purpose, I couldn’t find any schematics or instructions about it to build one myself. With some help, I came up with something similar. How the adapter works: An aeroplane ESC needs 0% throttle indication at startup, but since a surface radio throttle is set at about 25% by default, it makes the ESC beep as a warning to set the throttle to 0%. For the aeroplane ESC to work, you can either mechanically modify the Tx by setting the default position of the throttle to 0% or if that is not possible, you can do it the software way; the adapter takes the 25% signal coming from the Rx and remaps it to 0%, as an indication of ‘no throttle’ to the ESC. Materials required: 1) ATmega8 or equivalent microcontroller- 1 nos 2) 16MHz crystal- 1 nos 3) 22pF ceramic capacitors- 2 nos 4) Servo extender- 1 nos 5) PCB Additionally, you’ll need a programmer to burn the code on to the ATmega8. I used an Arduino UNO board for the same. The Arduino code and the schematic can be downloaded from here– Tested the adapter on my air boat, works flawlessly! I used an ATmega8-16PU microcontroller for this project, couldn’t get the code to run on an surface-mount ATtiny45-20PU, if some electronics genius on here can do that, it can physically reduce the size of the adapter to less than half. I couldn’t have done this project without help from Trishit Ghatak and PeterH (Arduino forum)