Comments

• 3D Robotics

  Chris Anderson July 10, 2015 at 8:18pm

  Joe, do you mean how to export logs *from* an Android device running Tower? If you have a Droneshare account set up, it's automatic. If not, you can find the logs using an Android file browser. Here's the location you'll find it in (ignore the ad in my stupid file browser, and the reason I have no logs is that they're automatically deleted when they're uploaded to Droneshare):

  
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  Joseph July 10, 2015 at 7:11pm

  Can anyone tell me how to export the log from Tower o an Android device. I'm trying to it currently has me stumped.

  Thanks Felipe I ended up ordering APC props direct from APC.
• Felipe Rabat July 6, 2015 at 11:50am

  @Joe, I bought 3 sets of these props (which gives you 2 sets of 6), and I am happy with the results.  You do need to balance them, but they are very close to balanced from the factory (I have flown with them as they come from the factory, and vibrations are within parameters, but I prefer to balance them none-the-less...).  
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  Joseph July 6, 2015 at 10:17am

  New Y6 Owner, I am having trouble sourcing frame parts, where can I find them? I also need to find a good source for ordering the APC props for a decent price.
• wendell austria June 23, 2015 at 8:50pm

  Iv'e had my right top motor go out on y6b without any issues during a long flight .... the bottom motor took over so smoothly i didn't even notice it went out until it got close enough to notice ... even didn't notice anything on my fpv monitor during the whole flight and video was smooth as silk...now i have 2 builds with the pixhawk and picked up a Iris+ for my kids to start off with.
• Felipe Rabat June 18, 2015 at 7:14am

  A couple of things: 

  (1) I have found out that for take off, it is better to gun it (not FULL throttle, but enough to get it into the air quickly) than to slowly creep the throttle up.  When you slowly creep up the throttle, there is a good chance it will roll in one direction or the other.

  (2) I had a 3DR ESC that was bad from day 1.  3DR replaced it with no cost to me, so service was good, but my point is do not assume that just because things are new they are not bad.

  (3) Check that everything is connected the way it should be.  I had 4 motors wired wrong, and since they cancelled each other, the only symptom was poor yaw, but during take off, it would tilt.

  (4) During my last flight (before I crashed - well, let's rephrase that; before I landed it at about twice the permitted descend rate), I did have a pulsating sound in my ship.  It flew just fine, and the telemetry was perfect, so I just thought it was an out of balance prop (it could have been).  Once I finished upgrading my Y6, I will have to check my motors and ESC to make sure they are all up to spec (I have a spare motor and a spare ESC, so if anything is suspect, it is coming out).
• James A June 18, 2015 at 2:28am

  Craig it could be one of the motors or even multiple, I had the same issue although it was normally in one direction. Turned out to be two bad motors, the only way I new was a pulsing sound when going beyond about 40% throttle followed by running up all motors individually with props on (take care) and finding two would just stop going any faster and start making the pulsing sound after about 40% throttle. If you had one bad motor then you can easily fly once it's off the ground so you may not notice it. Of course if it is this then it may be an esc rather than a motor. This issue had me foxed for ages but once I replaced the motors it fixed the issue.

  Here's my original thread. 
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  Doug Walmsley May 25, 2015 at 2:29pm

  Well as you know DG, I've spent a lot of time configuring my modified Y6B to use 690Kv pancake motors for performance and cooling and 1247 on top and 1347 on bottom and have found at the moment the best configuration for me.  It really boils down to cost vs benefit.  Since there is no out of the box design that is optimal, you really do spend time and money experimenting on the best configuration.  

  I feel 3DR's Y6B as it is works fine with their motor and propeller configuration, but adding additional accessories/weight to it changes the delicate balance of their design thus requiring you to develop alternatives which I did to mitigate the overheating issue on the lower motors.  This also could explain why 3DR stopped developing and supporting their Y6 design for the most part.

  Unfortunately there is no other sites in the internet that helps people to develop their designs other than Ecalc which hasn't perfected their coaxial data but is a good tool for evaluating many frame/power plant configurations.
• DG May 25, 2015 at 8:40am

  So the question of the day for DIY coaxials is.....

  How much time and money are you willing to spend to get the perfect combination?
• DG May 25, 2015 at 8:37am

  I did some reading, then had a discussion with the guys at Ecalc about this:

  http://www.ecalc.ch/calcinclude/help/xcoptercalchelp.htm#hints  and started a discussion at RCG http://www.rcgroups.com/forums/showthread.php?t=2365475

  There many variables here.  Leonard Hall did testing for 3DR before the Y6B was released and explains why the 10x4.7 top/bottom combination was chosen. http://is.gd/eW0JV1

  One of the variables that has a large effect on coaxial performance, at least from my observations, is the axial distance between the top/bottom props. 

  The current configuration on my Spy 750 is 15x5 top 14x7 bottom. A month or so ago I bought some 15x6 for the bottom, did a AT but didn't test much, and unfortunately chipped one of the 15x6 and put the 14x7 back on.

  During all this, I made changes in the parameters based on statements by Leonard and didn't keep good track of them so decided yesterday to go with a fresh install of 3.3 rc5 and start from scratch.

  The latest Auto Tune improvements really shined, and the pwm results are this

  

  One of the biggest advantages I've observed with the current configuration is it is more difficult to produce the Vortex Ring State on faster descent. A concern is if the copter will fly with 5 motors should one fail. I haven't tested that.

  However to be totally candid, I think the ultimate solution is a combination of things to test, which I don't really care to do, that being:

  1) testing different axial distances between the props. Using the prop adapters to accommodate the Xoar props increased the distance which appeared to help.

  2) using different kv motors top/bottom

  3) combining 1 & 2 with trying multiple props sizes and pitches.

  So many degrees of freedom here. So for now my Y6 flies well, the motors are cool as cucumbers top/bottom, but is not as efficient as I'd like.

  At some point I may try some good CF props (TM or Foxtech Supreme), but the cost would be more than what I paid for the motors as using the same size/pitch on top/bottom on this Y6 makes for poor performance!

  As I stated in the RCG discussion, Marco Robustini probably had it right:

     Interesting discussion, I follow with interest.
  Personally I abandoned coaxial configurations because they have only an advantage in my opinion, good thrust considering the small size compared to a flat, all the rest are only disadvantages.