DemonRC NOX5 racing quadcopter is done

It took my time with this build, that is sure… Somehow there were always more important things to build. Anyhow, DemonRC NOX5 FPV racing quadcopter is finally up and running. DemonRC NOX5 quadcopter

What is inside? Nothing special:

  • Frame: DemonRC NOX5
  • Flight controller: Airbot Omnibus F4 v4 running Betaflight 3.1.7
  • ESC: DYS XSD30A BLHeli_S
  • Motors: EMAX RS2205S 2300KV
  • Camera: RunCam Swift2 2.1mm lens
  • Video transmitter: TBS Unify Pro v2
  • RX: FrSky X4R-SB
  • Propellers: DAL T5045C Cyclone

DemonRC NOX5 quadcopter

DemonRC NOX5 quadcopter

As a bonus, 3D printed TPU GoPro Session mount. But the bottom line is, it flies!

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Hands on: DemonRC NOX5 FPV 5″ Frame

So many things to do, so little time… I’ve purchased DemonRC NOX5 quadcopter frame more than a month ago, but had some time to take a look at it only today. This is not a cheap stuff. More than a $100 for a 5″ frame is few times more than I’ve used to pay. But I just had enough of cheap chinese frames. Don’t get me wrong, they usually fly alright, but both quality and user friendliness lacks a lot. With “premium” frame at least I’m sure that I’m getting a good quality carbon fiber and someone actually thought for a moment about “tiny” details a place for VTX transmitter or battery strap…

So, please welcome DemonRC NOX5:

DemonRC NOX5 FPV quadcopter frame Continue reading “Hands on: DemonRC NOX5 FPV 5″ Frame” »

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3D Printed 35deg camera stand for Runcam HD / Mobius

I have no idea how I was able to build drones before I've bought my 3D printer… I before I've learned basics of 3D design. So, today I present you upgraded version of my Runcam HD / Mobius camera mount I've designed few months ago.

Changes:

  • tilt angle increased from 25 to 35 degrees
  • allows to use wider zip tie for mounting

3D printed camera stand for RuncamHD Mobius 2

3D printed camera stand for RuncamHD Mobius 3

3D printed camera stand for RuncamHD Mobius

STL file can be downloaded from Thingieverse

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3D Printed RunCam HD / Mobius camera mount for Reptile X4R 220

After I finished my new Reptile X4R 220 racing mini-quad, I've realized, that there is no way I will be able to mount my RunCam HD on it. Comparing to ZMR250, 220 frame is just small. On a top plate there is enough room to fit battery, RC and FPV antennas and all what is left is around 35mm in the front. Plus, with angled FPV camera, there just no place for RunCam HD/Mobius form factor cameras. So, some time with 123D Design and few hours of printing, and here we are: 25 degrees mount for RunCam HD and Mobius camera specially designed for Reptile X4R 220 frame

25deg Runcam HC and Mobius Camera mount for Reptile X4R 220

This mount has 25 degrees inclination, will fit both RunCam HD and Mobius (not sure about RunCam HD2…) and its base is only 42x32mm. So it can be installed on small frames like 220. But, it will also fit bigger. No problems here.

25deg Runcam HC and Mobius Camera mount for Reptile X4R 220

The best way to install it on a frame is to use either zip ties or double sided velcro straps. There is a slot for 20mm wide velcro straps. To make it better, use 3M Dual Lock between.

To securely install camera also use 3M Dual Lock and use a velcro strap too. That should keep everything in place just fine.

3D Printed 25deg Runcam HC and Mobius Camera mount for Reptile X4R 220

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Hands on: Reptile X4R 220 quadcopter frame

Last week, first parts for my new racing quadcopter started to arrive. One of them, was carbon fiber frame: Reptile X4R 220. Why this one? Like I stated many times: I'm cheap. Plus, I did not wanted to go with another ZMR250 build. This frame was easily available, within budget and good looking. So, few weeks later, here we are…

Reptile X4R 220 frame - parts

Specification:

  • 220mm motor-to-motor
  • Weight: 120g
  • 4mm carbon fiber arms
  • 2mm carbon fiber bottom plate
  • 1.5mm top plate
  • 35mm aluminium standoffs
  • adjustable camera mount (fits HS1117 and RunCam Swift)
  • integrated power distribution board (PDB) with 5V BEC

Reptile X4R 220 frame - arms and bottom plate

After 2 evenings with this frame, I'm almost finished with a build.

Pros:

  • overall quality is good
  • everything fits, no need to ream holes, sand or cut anything
  • more nuts and bolts than required

Reptile X4R 220 frame - arms

Cons:

  • top plate are rather thin. I would prefer 2mm top plate or maybe 2.5mm bottom plate too
  • power distribution board is an structural element of whole frame. If you want to use different PDB (I wanted to use Matek PDB-XT60) you might have a problem. Some improvisation will be required
  • In theory, each arm is kept in place by 3 M3 bolts. In theory… In practice, one of those bolts enters nylon standoff. Not metal nut, but nylon. So, instead of 3 bolts per arm, it is only 2.5 bolts or even less… too bad… Still, whole build is rigid enough…

Reptile X4R 220 frame - all things in place

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Flight controller 30.5mm to 45mm mount adapter

Almost all “racing” MultiWii derivatives flight controllers like Naze32, SPRacingF3, CC3D or Sparky, besides the same CPU family (STM32) and ability to run Cleanflight, share the same form factor: 36x36mm size and 30.5mm hole spacing.

That creates a small problem when mounting them to some bigger frames designed to fit APM, Pixhawk or MultiWii. They do not fit and require additional adapters.

Facing problem like this, I’ve designed simple 3D Printed 30.5mm to 45mm flight controller adapter.

Naze32 SPRacingF3 45mm adapter

To use, 4 hexagonal nylon M3 standoffs have to be glued into place. M3 thread is rather too small to print on most 3D printers. It’s just faster and simpler to glue standoffs than try to print threaded holes. I used epoxy glue, but hot glue also can be used if needed.

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PID values for Reptile 500 frame

I know, I know… posting PID values for one multirotor is not very useful after all. The same frame with different motors, props and battery might require totally different PID values. But.. At least they can be used as starting point for customized tuning. So, here is my configuration for Reptile 500 and frame and following configuration:

  • Battery: 5000mAh Turnigy 3S,
  • FC: Flip32 running Cleanflight 1.10,
  • Motors: Turnigy Multistar MT2213 935KV
  • Props: APC 10×4.5 MR
  • ESC: AfroESC 20A running OneShot125 and BLHeli 14
  • Weight: 1300g with battery

So, if you have somehow similar configuration, you might try my values. And they are:

  • PID Controller: LuxFloat (BTW, as far as I can read C code (last time I was programming with C about 20 years ago) and know smth about PIDs, this is the only controller implemented into Cleanflight that actually is written in a proper way. The way I see it, all the other works only by mistake, specially on D part. Who thought that substracting D term is actually a good idea?)
  • Roll (P / I / D): 2.5 / 0.06 / 70
  • Pitch (P / I / D): 2.5 / 0.06 / 70
  • Yaw (P / I / D): 2.5 / 0.1 / 0
  • Other controllers on default values
  • Custom mixer from this post
  • PID and gyro filtering enabled via CLI with following commands (BTW again, those filters are he best thing that came in Cleanflight 1.10. Everything is much smoother with them. Good job on those):
    • set dterm_cut_hz = 16
    • set pterm_cut_hz = 32
    • set gyro_cut_hz = 64

Important note for 2015-11-22

PID values from above has been determined as main source of extensive high frequency vibrations causing jello effect. Specially high D, even with LP filter, was causing jello effect. Read this post for improved PID settings for Reptile 500 frame and Cleanflight.

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Cleanflight custom mixing for Reptile 500 frame

Asymmetrical frames like Dead Cat or Spider type have many advantages. Big central plate to put all the electronics, front view not obscured by arms and motors. And they look cool. Way cooler than traditional X frames. But there is a price. Because they are asymmetrical, flight controller has to put much more effort into stabilizing them. Motors are not in equal distance from center of weight, and because of this require different force applied when performing stabilization. Quad will fly even when standard X configuration is programmed into flight controller, but will not archive best performance. For example, when FC wants to roll, different motor distance from COG might induce also pitch rotation. Of curse FC will compensate in next cycle for that unwanted pitch movement, but what if it would have to do that? Less corrections, lower power usage, higher stability, better control.

Reptile 500 frame quadcopter in flight

This is why most flight controller software allows to program almost any motor configuration and tell it how far any motor from rotation axis is to match applied force for each motor separately. General rule: motors closer to rotation axis require more force than those further away (torque and stuff). This is called custom mixing. Continue reading “Cleanflight custom mixing for Reptile 500 frame” »

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Let’s build class 250 quadcopter: frame assembly

Yesterday I finaly had some time to work on my 250 class quadcopter based on ZMR250 carbon fiber frame. There was a plan to finish it before weekend, but looks like plan will have to be changed. I’m missing motor screws. They were not with frame nor motors. Too bad…

ZMR250 quadcopter frame assembly

ZMR250 with Flip32

dav

After one evening of work I’ve been able to assemble bottom plate with motor arms and attach Flip32+ flight controller to it. As you can see, Flip32 is rotated 90 degrees clockwise. USB port points left, not back. This allows much simpler access to USB port. On the other hand, it requires additional configuration entry that allows fllight controller software to compensate for that. But all in time.

One last remark: the frame, even without top plate is super stiff. Very good since it will take serious beating in next weeks. I’m finally learning to fly in Rate mode without auto-leveling. Boy, it’s hard. After two 20 minutes sessions I’m able to make a turn…

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Let’s build class 250 quadcopter: frame

Many say that small 250 class quadcopter are super fun. Small, fast, agile, tough and crash resistant. I’ve decided to check it out and build 250 quadcopter drone by myself. And next few posts will be tightly connected with this topic. Let’s call it a build log.

The most important part of every multirotor is a frame. It decides about everything. For my quad I’ve decided to use ZMR250 clone frame made from carbon fiber.

ZMR250 quadcopter frameThere is also glass-fiber version of this frame, and it’s half a price (below $20 while carbon is around $35). So, what do we get for additional $15? We get 2 good things, and one bad. But let’s begin with good things:

  1. carbon fiber is lighter than glass fiber. My frame weights 145g while glass-fiber equivalent weights 181g. 36g might not seem much, but it is a difference after all. In my oppinion a difference worth $15,
  2. carbon fiber is more durable than glass fiber. At least in theory. So, in theory carbon fiber quadcopter frame should be harder to break during crashes. We will see.

An the bad thing? Well, carbon conducts electricity and can block radio waves. This means, that you have to be extra careful with all the cables and antenna placement. Insulate everything, never leave any cables touching the frame and antennas has to be placed as far from frame as possible. Some kind of mast would be recommended.

 

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