DIY Moxon antenna for TBS Crossfire and FrSky R9M

Moxon antenna in layman terms, it's probably a simplest linearly polarized directional antenna. It's like a bent halfwave dipole with a bent reflector in a back. Think about it as a very simplified Yagi antenna. It does not have much gain but has very good backward rejection. And thank's to a simplicity, Moxon is super easy to build at home. And I'm proud of radio carrying handle snap mount. I think I did a good job over here.

I've built mine with some 3D printed parts, 0.8mm copper welding wire, 22cm of RG174 coax and RP-SMA plug. And some glue of course! Result? It's definitely directional 🙂 I'm not using it very often, but it's small enough to be taken everywhere where I take my X10S.

3D printed racing drone, part 3

It is done. It is alive. My 3D printed FPV racing drone works. A few weeks ago I finally flight tested my design and it works! Even better than expected, since I survived the experience without a scratch. OK, I did not crash it yet, but give me some time for that too….

3d printed fpv racing drone

And I have a cool name for it: Isando which means hammer in Zulu. Kind of fits, right?

Ah, STL files are available on Thingiverse of course.

3D printed racing drone, part 2

My 3D printed racing drone is done. More or less. I was able to finish it a few weeks ago and even perform a maiden flight. It survived the experience, but I also discovered few problems I will have to solve before officially calling this project a success.

3D Printed Racing FPV Drone

3D Printed Racing FPV Drone

First of all, the decision about hard mounting a flight controller and not installing a capacitor on mains was a bad one. Not only motors are "twitching" from time to time, a video is very noisy. I hope big low ESR capacitor will solve that, since there is no way for soft mounting for this frame.

3D Printed Racing FPV Drone

Besides that, it worked just fine. I will try to prepare a video from the maiden flight in a few day, for now only a few pictures and final specification:

  • Frame: PLA 3D Printed, 220mm motor-to-motor diagonal
  • Motors: EMAX RS2205S 2300KV
  • ESC: Racestar RS30A BLHeli_S
  • Flight controller: FrSky XSRF3O running Betaflight 3.2
  • VTX: TS5823 200mW
  • Camera: RunCam Swift
  • Total weight, no battery: 380g

Total build is, of course, heavy, but not that heavy as I feared. I was expecting something way above 400g. The frame is also quite stiff. I wonder how much beating it will be able to take….

3D Printed Racing FPV Drone

3D printed racing drone, part 1

I've been pretty busy last 2 weeks. Among other things, I've started to design 3D printed racing drone frame. I'm fully aware there are plenty designs available on Thingiverse, but almost all of them forgets that plastic filament is not carbon fiber laminate and what works well with carbon, will fail with filament. So, I came up with this:

3D Printed Racing Drone

3D Printed Racing Drone

  • suitable to 220x and 230x motors with 19x16mm hole spacing
  • fits PCB and 36x36mm flight controller (30.5mm hole spacing)
  • size: 220mm motor to motor (diagonal)
  • fits "standard size" FPV camera

It is heavy for sure. It has thick arms and a lot of M3 nuts and bolts connecting all the parts together. I hope it will be enough to survive at least some beating… First flight in a few weeks since I'm still waiting for motors.

Project Dualcopter – worklog #3

It's been exactly one year since my last update on Project Dualcopter. On 20th of October 2016 I've posted that there was a progress. Now, 12 months later, I once gain report, that there was a progress…. That was slow….

3d printed dualcopter aka flying bucket

servos for 3d printed dualcopter

  • I've finally installed control surfaces and servos
  • I've finally decided where LiPo will go: to the top of the whole stack. I want CoG as far from control surfaces as possible. They will not generate much force, so I need as much torque as possible. So, long lever FTW
  • My daughter called it Flying Bucket. Makes sense, right?
  • Plans for next week: battery mount

Very custom FPV quadcopter for my daughter

When few months ago my older daughter (10 years old) started to express interest in FPV quadcopters, I was both happy and concerned. Happy, since I would have someone to fly with. Concerned, since she has no idea how to fly, I do not have a quadcopter for her and there is a big chance she will get bored fast. So, instead of getting her a brand new, cheap, standard off-the-shelf drone, I checked my repository of “spare” parts and drones, purchased this and that and week later “Omlette du fromage” came to life…

Scarab Knife 200 cartoon sticker bomb

Continue reading Very custom FPV quadcopter for my daughter

GPS Racer: worklog #9 – double rangefinder setup

My GPS Racer is less and less fun project. For last few weeks it acts as sensor platform for my attempts to bring rangefinders and terrain following modes back to INAV. This time in a way that will work.

Two weeks ago it was carrying HC-SR04 sonar (crappy device). Week ago it was carrying US-100 (much better device). This week it is carrying both US-100 sonar and VL53L0X lidar!

INAV with US-100 Sonar and VL53L0X Lidar

DigitalEntity apparently had too much spare time and he finally wrote (ported) a driver for VL53L0X and starting from version 1.8 (probably) INAV will be able to use this cheap lidar.

INAV with VL53L0X Lidar

Yes, VL53L0X is cheap and that means it's not state-of-the art device. First of all, it has limited range. 2m is all it can do in a room. No idea how it will behave in sunlight. Hard to guess, but I'm afraid that 1m will be all it will able to do in real life conditions… But we will see in a next few days.

Depron Airboat Worklog #2

Next week passed and Depron Airboat is almost ready. Almost, since it still needs some finishing and I'm missing a BEC. Turned out that total power usage of one 9g servo and FrSky X4R receiver is slightly too high to just use single LM7805. 350mA during servo movement means more that 2W of heat ((12-5) * 0.35) over single LM7805. Too much, so I will have to scavenge old models for still functional step-down converter.

airboat depron hull parts

Hull made from 6mm Depron is now glued together using Uhu Por and polyurethane wood glue. It measures 18x8x2 inches. I've put my 3D Printed propulsion and steering system on it and did first static test.

It works. First water tests next week.

Depron Airboat Worklog #1

One of my first DIY RC projects was a Depron Airboat I've build almost exactly 2 years ago. 12x6x2 inch hull, motor, servo, rudder and ESC. And honestly, I loved it. It was a great fun playing with it. Too bad, it did not survived very long. It broke in a middle of a lake and I decided my live is worth more. All I have left is a video

This season I started to build another Depron airboat. Slightly bigger, heavier and with more power. And partially 3D printed. Hull will be made from Depron, but propulsion and steering system will be (is) printable.

Depron RC Airboat Propulsion system

After few hours of printing time, propulsion and steering is done. What is left is to make a hull. 18x8x2 inches made from 6mm Depron. I might cover bottom with glass fiber and impregnate with polyurethane wood glue diluted with alcohol.

New thing will be a reversible ESC. I've already configured and tested FVT Littlebee 20A to act as reversible ESC and it seem to be working like expected. I only wonder how effective rudder will be when on reverse. Not much I effective probably…

Depron RC Airboat 3D printed Propulsion system

And yes, STL files will be available when this is proven to be working. Everything for the community 🙂