I do a lot of smaller copter tuning and I know it’s hard. In fact many of the features I have developed have been primarily targeted at making smaller copters work better - why should BetaFlight have all the fun.
I therefore proposed to the investment committee that I do a series of standard builds so that people could basically copy the setup and quickly and easily get a really great ArduCopter experience. This is the second in the series
The meat of the content is contained in a series of youtube videos that I will describe here. This series is shorter than my ArduCopter 7" Long-Range Standard Build which contains a lot more detail. This series just highlights some of the build and tuning difficulties that you might encounter.
Note that although the proposal was for a 4.1 tune, since I ended up having to use the Kakute H7 Mini, this will only work on 4.2.
1. Frame Assembly, ESC and Motor Mounting
The first video at the top is frame assembly of the Rekon 5. Mounting the T-Motor F2004 3000kV motors. Installing and soldering the Tekko32 F4 4in1 mini 45A ESC. Mounting the RunCam Phoenix 2 Joshua edition.
3. Kakute H7 Mini Installation
Installing, soldering and configuring the Kakute H7 Mini flight controller.
4. Flight Controller Configuration
A walk-though of all of the changed settings. See parameters attached above for details.
5. Tuning and Flying
Running autotune to get a good initial tune. Tuning yaw through D. Flying.
6. Fit and Finish
Re-tuning to get higher ANGLE_P and better stability. Changing the Triumph LR Pro for a regular Triumph Pro u.fl to get better VTX performance and better GPS performance. Some notes about flying with LiIon VT6 packs.
Hi Andy, I built a 5" with slightly different components, but I’m looking forward to compare your tuning settings to what I got, I could definitely use a better tune!
Chris Rosser (AOS) is going to produce an ultra light 5" frame (probably less than 50g versus this frame which is quite heavy at about 75gr). That might be interesting.
And there are lighter motors too at the same 2004 size. Also I believe a 2300-2400Kv 2004 would be much more efficient than these 3000Kv motors, for long range/max autonomy.
The 4S LiIon VT6 packs that I have for this are 208g. I think you need something substantially smaller all round to get under 250g. Under 250g was not the goal
To 46gr you have to add the wiring, solder, packaging, balancing wires, so you get closer to 50gr/cell.
Li Ion is what is required indeed for max autonomy.
If the objective is max autonomy, you do not fly a 5" which is overkill in size and weight. You can fly a 4k camera or even a Gopro on a 3" or a 3.5" on a 2S LiIon.
In fact there is an optimal design for each specific objectives you require from your build : do you need a camera ? do you need a gopro ? do you need autonomous missions ? (which require a GPS, a magnetometer which adds weight, etc)
Hi @Hugues ,
we were talking here about a sub 250, but it seems that everything is at a standstill.
Meanwhile, with a friend we are testing a 3" build made with the material indicated in my list (including lidar and optical flow) and at 2s Liion we are at 249 grams. However, I think that the choice of 3 "is the best way. I remember your 28 minutes 2s Liion
Nice thread on the sub 250g project.
We (as a community around Ardupilot) have not yet a viable 3" solution that is sub-250, can use all of Ardupilot’s features (mostly autonomous waypoints), carry a digital fpv camera and possibly also an HD camera such as a 360go, SMO 4k or Gopro without jello/vibrations.
Ardupilot is on the 3" size copters not as good or not as easy as betaflight. I do not know why. it should not be the case. I assume it has to do with a design and internal algorithms differences between Arducopter and betaflight ?
My sub 250 (219 gr exactly) has been flying for two years and has all the basic functions of arducopter: RTL / smartRTL, waypoint (also in the field), loiter, GPS poshold, FPV, pos hold optical flow, 15 min flytime ( without modification esc for the moment), Yappu telemetry on the radio (thanks Andy).
On the next there will be DJI digital FPV (which can record quality DVRs), esc modified to work at 2.5V, front lidar for obstacle avoidance. With the plugin for the initial parameters, notch filters, autotune for the PIDs, I don’t see great difficulties more than betaflight, on the contrary it seems more flexible to adapt to any configuration, unlike the Inav presets.
Some information can be found in the thread sub 250 already posted, also in my youtube channel you will find some tests. However, going into the details takes time, I had intended to do it but the ardupilot funding committee at the moment does not find it useful, I don’t know. However even my 5 "has been flying for almost two years (2 inav + 2 arducopter you can see it in the sub250 thread) and it was relatively easy with the sequence: initial parameter plugin, notch, autotune.
The issue is the frame. The intent of this series is to reach as many potential users as possible with standard well made components that give them a good experience. We are not targeting power users who will be more comfortable with esoteric parts, builds, complications etc. I think this build is at the limits of what complexity is worth it - obviously you guys will be able to go further but you are not the target market here
TBS have some new superlight frames, it might be worth exploring in that context.
Andy,
i think the frame is not really a problem. In the thread of the sub 250 I have proposed three, at low cost, and two of these already fly with arducopter.
It can also be viewed here and there are also wonderful open source files (with DXF files). Look here for example … 3 “to 5” by changing arms
In the spirit of reaching as many people as possible with this build. It might make sense to do the exact same thing but with digital. Just switch out the sixty9 vtx/rx and cam. I know that difference sounds trivial but it could be an addon video. Therefore building off all of the videos you’ve already done so you can reach many more people for a small amount of cost and energy.
I think this concept in general though is a great idea. I know that my first ardupilot project felt much more difficult compared to betaflight. In reality it ended up not being any more complicated but that appearance of difficulty can cause more apprehension than actual difficulty every could.
Are the new lightweight TBS frames you mentioned already out or something coming out soon?
