T3 Back to the Future


Remember back, way back in autopilot years probably about 20. The year 2009 and the first round of our gentlemens (ladies are allowed just none have ever entered) competition the T3 challenge.

Back then just flying way points was hard and all this gear was expensive. Ardupilots were made at Sparkfun in batches that ran out quick.


Lets try it again I suspect this time the challenge would really be flying it faster than somebody FPV racing.

Read about the first time here for hints and tips. 

As tech has moved on all aircraft types welcome lets make it not above 50m and 5 laps. All of course autonomous. Extra marks if that is from take off to landing.I will count the time from take off to landing so screaming dives to the start will not help. KMLs as evidence please!

UPDATE: Rovers (and boats) are also allowed! There will be a special rover/boat class, and you only have to beat other vehicles in that class. The course for such ground/water vehicles is 100m x 100m. 

I will accept FPV times for the sake of science and should they be much much quicker it will give the pure FPV crowd something to brag about.

An Easystar (yes before HK copied it) made one lap in less than a minute in 2009 so 5 in 5 minutes should be more than possible. 

As ever the time frame is flexible but why don't we all meet back here on August the 1st and find out who won!

Please add your entries and adventures below. Points are always awarded for silliness, just as long as its safe!


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  • Admin

    Hi Healthyfatboy,

    Here is a link to my Crusher T3 Log

    I hope to do some T3 runs tomorrow as it has quit raining here and the parking lot where I run is drying out. I would like to get some consistent runs at a CRUISE_SPEED of 15m/s and hopefully some tlogs.

    Based on Linus' parsing of the datatllash log of my last runs, the rover seems to follow a slightly concave path from each major waypoint at the end of each straightaway. I had 13 sats with an HDOP of 1.3 when I made the 48 sec run.

    I have ordered two RFD900+ telemetry radios from Event 38 to ensure good telemetry during future T3s. The 3S LiPo that powers the PM on the Crusher will be used to power the RFD900 as it can draw close to an amp at full power. The best way to use the RFD900 is to reduce the transmitter power until you lose telemetry and then bump it back up a little at a time until you get a reliable connection. You do not need full power for our rover application.

    Here is a picture of run 5:


    With some tuning, I think that I can get the runs straightened out somewhat.


    Tom C AVD
  • T3

    Tom, do you have your log you can post of the runs you did? I would be interested in seeing how straight they looked and how fast you went throughout.

    So, is today the cutoff? I haven't seen much activity lately so maybe? Still waiting on the go-kart snipe or Rob's heli snipe too.

  • Admin

    Hi All,

    Unfortunately for me it rained late Friday and most of Saturday into Sunday so any additional runs cannot be completed before Monday.

    It is supposed to dry out going into this coming week so I might be able to get in some backup runs to support my 48 sec run, once the parking lot has dried out.

    Oh well, there is always the next T3 to compete in:-)


    Tom C AVD

  • T3

    Alright, I'm finished giving it another go! I thought I would go 3S and see what I could come up with. I found I could get up to around 17 ms^-1 but I just don't have the space. It was iffy enough to find a 100m x 100m area but it's just too close to the curbs to reliably run much faster than I went on my test without risking my vehicle any more, especially since I had to borrow a Pixhawk as my APM was giving me trouble. I came within inches of the curb or light post several times so my most recent submission is going to be it unfortunately. At least that one was really good for me!

  • 100KM

    I didn't check this website way too long and just noticed now that this T3 contest is running.

    Great entries of David with the flying wing in 221s and Rob with the heli in 281s. Congratulations!

    Back in 2012 my Cougar flew autonomously in 34 seconds around the figure 8. Here is the entry in this forum. The Cougar flew between 30 and 40 m/s and was controlled by a Paparazzi autopilot. Here the Desktop Record.

    Unfortunately I will not make it for an entry until Monday. In a month or two I might find some time to try. I am still flying the Cougar and using Paparazzi, but havn't done much AP flying since 2012. I think 36s per round plus 5s for takeoff and 15s for landing summing up to approx. 200s should be doable. Flying 40 m/s below 50m AGL will be quite thrilling :-)

    Good luck you guys!

  • Admin

    Hi All,

    Could not run on my T3 parking lot course this morning as the local police use it on Thu for driving practice, but it is clouding up this afternoon and will probably rain tonight.

    I probably will not be able to use the course again until Sat or Sun to get in somemore runs as it takes a while for the puddles to dry out.


    Tom C AVD

  • Admin

    Hi All,

    I was able to get Linus' parsing of my T3 run file log downloaded and I have sent it to Gary.

    As it did not rain last night, I plan on making several more runs at a CRUISE_SPEED of 15m/s and try and increase the speed though the turns.

    I realize that I need several runs close to 48sec for credibility.


    Tom C AVD

  • Admin

    Hi All,

    Linus has parsed my datalog file and found that my best time was 48 sec over ~531m for an average speed of ~11.1 m/s. My CRUISE_SPEED is set to 15m/s for the straights and my SPEED_TURN_GAIN is around 12 at the moment.

    My slowest time was 57 sec over ~513m for an average speed of ~9 m/s. My CRUISE_SPEED was set to 10m/s for the straights and my SPEED_TURN_GAIN is around 12 at the moment.

    Linus sent me a zip file of all of his analysis, but he quite Skype before I could download it so I will have to wait until tomorrow morning.

    If it does not rain tonight, then I will try to get a number of runs at a CRUISE_SPEED of 15m/s and increase the SPEED_TURN_GAIN value towards ~30.


    Tom C AVD

  • Trying to reconstruct the scene in my head. The gps probably went wide too, X8R was almost on the goal line, solder splashed everywhere.
    The broken parts pile is growing.
  • Rover came to a dead stop. The gps and telem. went through, but one battery and front drivers side tire went wide of the goal.
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