Saturday, December 28, 2013
Fun with the Hobbyking.com Pocket quad
I've had a lot of fun already with some of my small quads like the Ladybird and the traxsas. The fact is I kind of like them better than most of the big quadcopters since I can fly them any place any time and still have just about as much fun with them or more without breaking them or killing someone in the process. So when I saw the multiwii pocket quad at hobbyking.com selling for only $53 USD complete here http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=42844&aff=839933 it sounded perfect. Being the geek that I am, I could reprogram or just modify some of the many params and test fly it right in my room without going to the field to test it. What could be more fun than that!! So now after about 3 days of locking myself in my room, tuning and playing with this new toy, I thought I would share what I've learned so far. The first things I needed to learn was what software was needed to program and configure it. For that I found this group http://www.rcgroups.com/forums/showthread.php?t=1885026 very helpful. What I also found was I couldn't get the java gui to work in my Ubuntu linux system. I've had better luck configuring it from within windows 7 that I have running in virtual-box on my linux system. In windows 7 they also have a slightly better Gui for version 2.2 multiwii that seems a bit easier to use to change settings. But I found is I can't save the settings in a file from inside this version. So when I want to save the config file I run the java version that seems to work find to load and save configurations. Anther problem I found is that this Pocket Quad fails to have a bootloader installed that allows the multiwii to be re-programed over the provided USB interface on the board. So you can't install any new or modified versions of Multiwii into it without soldering some headers onto it and using an AVR programmer to load the needed bootloader so the USB interface could be used to program it. I was told that the multiwii version 2.2 should be good anyway and I can see from the GUI that I see V220 is what's installed already. So I'm hoping I won't have to reprogram it to have a shit load of fun. So before I bore you with any more of my ranting I should provide the most important information I can provide someone that wants to have fun with this toy. The PID settings. I'm not sure how much you will need to change these to get them to work on another Pocket quad but I would think only a small amount since they are so much the same with the same motors and same size and mass. So after 3 days of tinkering these are the value that I found that are the most fun for ME. I will later provide a link to my config file that can be loaded with the java gui. The values bellow also show what was set as default when I got the unit from Hobbyking. Also note that with the default values I couldn't get the Pocket quad to fly at all. It seemed like the RC stick input roll/pitch was delayed by about 200ms before any roll/pitch action was seen in the quad. factory defaults new values PID pitch/roll 3.3, .030, 23 1.2, .071, 20 rate 0.0 PID yaw 6.8, .045, 0 1.8, 0.14, 10 rate 0.0 PID LEVEL 9, .010, 100 20.0, 0.050, 100 throttle MID 0.50 0 EXPO 0 0.82 RATE 0.90 0.35 EXPO 0.65 0 TPA 0.0 0 I also found that if I turned the RC transmitter on after the quad that it seemed to some how lock in what the quad considered to be the center stick positions. If I had the transmitter already on first and re-programed the quad settings. It seems it would have the stick center positions off and would require me to set trim on the TX to get the quad to to fly OK. I had originally setup expo on the TX side but later put the expo settings on the Pocket quad configurations. I also have a second expo and rate on my TX that I have used to try more stable flight at times. The present values above are a bit on the wild side for a bit more expert pilot. I have yet to find a really easy flying set of PID setting for a beginner pilot on this device. Not that I haven't given up hope to be able to do so, some day. If someone does find some cool PID settings for this quad, slow or fast, Please send them to me and I will try them and share them with the world. I did find one other totally different set of PID for this device that I also tried that I found in the comments of a youtube.com video seen here . With those settings I found that I have a bit more high speed oscillation when I try to hover, but it provides some even more wild quick maneuvering that some people might like to try. And just to see what else you can do with it here's a good pilot flying acro with it . To make it slower controlled for a less talented pilot I would try play with the settings in your TX in expo and throw range. I'm using a Turnigy 9XR with the orange TX module to drive this one. I will later try one of our Spectrum DX6i on it to see how it flys and binds to that. I'm not sure how the bind works other than when I first powered it up with the TX off I started my TX in bind mode and it seemed on the next power up it was bond for good. I've seen other people that say they needed to install some program to bind it, or plug it into a full spectrum receiver but I didn't have to do that. Not sure why. I have a second Pocket quad as a spare so later I will bind that one and see what it is exactly I have to do to make it work. Ok as I learn more and people send me more info, and ask me more questions, I'll continue this article or create new ones about my now favorite toy. I'll also post some video of myself at some point if and when I get “Paul the Toy man” to video it for me. Keep having fun. I'm sure I will. P.S. If you plan to buy one of these don't forget to get the spare parts and batteries for it. Here are the links to the added parts (batt, motors, props...) I got when I purchased this one: http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=24920&aff=839933 http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=42098&aff=839933 http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=42099&aff=839933 http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=24656&aff=839933 http://www.hobbyking.com/hobbyking/store/uh_viewitem.asp?idproduct=31544&aff=839933 You will also need to make a connector adapter for the nano-tech battiers that also outperform the stock batteries that come with the pocket quad, if you plan to get them. Update: new param settings that I like so far: best flight yet with pocket quad, only works in acro mode but ok: PID 2.0, .025, 17 rc expo: 0 rc rate: .3 thr expo: .7 9XR settings channel limits: ch2 -15,100,73 ch3 -8,100,73 expo low rate: ele 50,100 ail 50,100 With these settings it flys to some degree in acro mode with just a small oscilation at about 3 per secound and responce is just a bit slow but already fun to fly at this point if the 9XR radio it fully trimed. change of pid PID 2.5, .025, 17 mades oscilation just a bit faster but still slow responce to stick movement changed of pid PID 2.0, .015, 15 still slow to respond and still osc but a bit higher freq oscilation now, can barly fly. also seems the trim is again way offset from last settings. each change of PID seems I need to adjust center trim of eli and ali. yaw trim also seems to change, now rotates clockwise from last settings. Not sure this may be a reset gyro at power up problem. I tried reboot the quad but still seems offset trim is still off. I'm also flying with 9XR in high rate 100% no expo since the rc rate .3 does the rest. PID 2.0, .015, 25 still osc at about 5 times per secound, stick responce maybe just a bit slower. no improvment PID 2.0, .04, 17 flys seems osc is a bit less, a bit faster responce? PID 1.2, .04, 17 way too slow stick responce, I can no longer fly it with these settings. PID 1.9, .05, 17 better, a bit less oscilation if any, responce time a bit better, can fly this but still want quicker responce faster rotation. PID 1.9, .1, 17 it seems slow to respond but seems more stable for unknown reason, also no noticable oscilation now. never got it fully trimed with a single battery at this setting but it seems if trimed this might be a fun setting to continue to fly in acro mode. PID 1.9, .2, 10 with this setting we now get a low freq osc like at 2 per secound like I is too high now with sample rate too slow. so bad can't really fly this setting PID 1.9, .15, 15 can now fly this but has a slow oscilation I think we still have I too high here. PID 1.9, .1, 5 very slow osc about 1 per secound like not enuf gain maybe P not big enuf with these settings, no good to fly PID 3.0, .1, 5 same but oscilation now faster at about 5 times per secound, no good to fly PID 1.5, .09, 17 one of the best yet if I could trim it this is much like the lady bird PID 1.4, .08, 17 I might try a bit smaller values for P and I but this is fun with these settings. as much or more fun than the ladybird more like the traxis. It's a handfull to fly but when you get used to this it should be a blast. responce time is now ok and maybe still just a bit of high freq osc PID 1.3, .07, 17 still not bad almost the same as above. now almost have the RX perfectly trimed but still can not get as stable as the ladybird. but remind you this is in acro mode Tried Throttle PID attenuation: was 0 now 0.2 with this setting it's like taking the big power out of lift. I can full throttle now and it's climb rate is way reduced. Also I note now that the yaw seems to intermitently drift when I throttle up hard and then just hover. yaw drift seems to move clockwise with I pulse power. will try this smaller Throttle PID attenuation: set back to zero 0 now and note no difference. so I'm no longer sure of this value. seems vertical acceleration was changed from the pid setting P to 1.3 not this change. PID 1.9, .07, 17 Didn't change like maybe the battery is dead? No lift power. will try again with another battery. even with battery change now seems PID changes are not working. like the change of throttle PID attenuation has corrupted something. Not really sure. will try a few original value sets and a few more batterys. Note: I did find when I changed fro PID 2.0, .2, 10 and back to 19.9, .08, 17 without removing the battery that flight caricteristics did change, don't have to remove battery and reset to make changes active. note2: I found I had one motor left front that seemed to have failed (spins intermitent). Not sure how long this had been failing in the data above. after replaced I set back to: one other change made I put arm on aux 1 switch due to problem with arm with ruder if I trimed too far to left. PID 1.3, .07, 18 Now with a new battery we have big throttle pulse power again. so much I'm going to try throttle P attenuator again Tried Throttle PID attenuation: was 0 now 0.2 no noticable change detected Throttle PID attenuation: was 0.2 now 0.4 Now I notice that throttle vertical acceleration is a bit reduced. still plenty of power for indoor operation but maybe outdoors we might still want more power. factory defaults new values PID pitch/roll 3.3, .030, 23 1.2, .071, 20 rate 0.0 PID yaw 6.8, .045, 0 1.8, 0.14, 10 rate 0.0 PID LEVEL 9, .010, 100 20.0, 0.050, 100 throttle MID 0.50 0 EXPO 0 0.82 RATE 0.90 0.35 EXPO 0.65 0 TPA 0.0 0 super fast yaw rate is cool if you like spinning with PID yaw 2.0, .1, 0 PID Yaw that I like but maybe will make a bit slower at some point. 2.0, .25, 0 PID Yaw that is a bit on the slow side if you like slow Yaw speeds, I flew it ok with same other settings above. I still note drift in yaw clockwise with pulse of thrust 3.0, .1, 10 PID Yaw that is even more slow but also is stable without pulses of thrust that seem to cause drift in yaw on faster settings 5, .071, 10 PID Yaw this is a good medium speed yaw that minimized yaw drift and still provides fun spin speeds 3.5, .085, 10 found these values at: http://www.youtube.com/watch?v=sakSKMbUS0c by Mega9eleven PID pitch/roll 2.6, .03, 23 rate .65 PID Yaw: 5, .077, 0 rate .55 PID Level 6, .01, 100 I can get level flight to fly for a bit but it still losses control after time. also acro has some vibration like P is too hight or ??