Chris Bott - Moderator Posted June 2, 2015 Share Posted June 2, 2015 Haha that would mean me being able to fly in a straight line! I predict that you'll have some of these soon, after all you'll need the old motors as spares for your students Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted June 2, 2015 Author Share Posted June 2, 2015 Are you watching over my shoulder as I press the "buy now" button?...... BEB Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 2, 2015 Share Posted June 2, 2015 Yippeee - I have a flying quad! I'm trying it in far too small an indoor space so won't be tweaking too much. But I think I'm gonna need a little help, or some time spent outdoors on a calm day. This is how I see it just now. It's quite wobbly in ground effect, this settles just as the ground noise goes quiet once its a couple of feet up. I need to constantly nudge forward on the ele stick to keep it in one place. It was very light on it's feet at the default minthrottle, and if it fell over I was very slow disarming it. So for the time being I've set mithrottle to 1000 (motors off) I have the roll and pitch P values at 2.0 now in an attempt to reduce the wobble. Was this the right thing to do? Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted June 2, 2015 Author Share Posted June 2, 2015 Well done Chris! Congratulations. You will always get some wobble in the ground effect - you really need to judge the quads response in clean air at least 3-4 feet off the ground. What mode do you have it in? If manual, changing P will not have much effect. If "Level" or "Horizon" effects of changing P will be more noticeable. You also might want to tinker with the "rate" setting. Default is 0.9 - which I find too sensitive. I'm currently using 0.6 and find that much better. Regarding not tipping over on take-off - particularly in manual - arm the quad, spool up the props to a little below take-off point. Then pause there for a second to let all the props synchronise. Then make a positive "lift-off" increase in throttle and get out of the ground effect. In the end you'll find that easier than loitering around very close to the ground. BEB PS HK sell some very nice after-market prop-guards that will fit on these quads Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 2, 2015 Share Posted June 2, 2015 Thanks BEB. Yep, I've certainly been in too small a space and close to the ground. 4 1300 batteries through it now. The last one outside in the gusty wind. It handles that quite well, doing about 3 wobbles when a gust upsets it, while it settles back into stable level flight. Definitley better flying around at head height. So far I've stayed in Angle mode. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted June 2, 2015 Author Share Posted June 2, 2015 Angle or Level Mode is a good place to start. But make a point of switching to manual once you feel a bit more comfortable - and have some space! Too long spent in modes like Angle and GPS-Lock at an earlier stage can make the eventual transition to manual more difficult rather than easier because you get too used to "holding the control in" to make it move. Its a bit like dihedral on a fixed wing trainer - to keep a trainer banked over in a turn you actually have to hold the aileron in. But once you go to an aircraft with no dihedral you find that you only have to roll it to the bank angle then you can centralise the stick and it will stay banked. Its the similar with manual, a nudge forward will tilt it, you can then centralise the stick and it will stay tilted accelerating forwards. Then to stop it you have to nudge back (to apply the brakes) then nudge forward to level once stopped. Based on experience teaching people to fly quads this seems to be harder to learn the longer you fly ANGLE or similar - because there the quad levels for you if you don't hold the stick in - so to go forward there you need to push and hold. Doing that in manual will have the quad on its back quicker than you can say "OMG"! BEB Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 2, 2015 Share Posted June 2, 2015 OK thanks for that, it sounds important. I think dropping rates to 0.6 will help there too. I tried manual mode very briefly, indoors in very little space, near the ground at 0.9. No wonder I didn't like it! Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted June 2, 2015 Author Share Posted June 2, 2015 One more thought Chris. You say your quad is drifting back towards you and you have to keep nudging it forward. The most likely explanation of this is that the accelerometers are not correctly calibrated - this means that what the accelerometers think is level is actually very slightly tilted in reality - result the quad moves. This is easy to fix. Connect the FC up to the GUI then take a bit of effort to get the quad really level - a small spirit level is not overkill here! Once you are satisfied it is truly level then press the "CALIB_ACC" button in the GUI. Disconnect and test fly - it should be better. BEB Edited By Biggles' Elder Brother - Moderator on 02/06/2015 23:27:34 Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 3, 2015 Share Posted June 3, 2015 It's clear that we have to make daft mistakes to learn, and this learning is proving great fun. You're right again BEB. In manual mode it doesn't drift backwards, I assume that this is because it's not using the accelerometers. On a nice level surface outside, I hit "calibrate acc" on the PC. When the blue light had stopped flashing I also hit "calibrate mag" to make sure that was done again, and did the ritual turning of 360deg in pitch and roll and yaw, well away from any buildings etc. Flying again, guess what - it tended not to drift. So on to the mistake. Hovering nicely, I thought "I know, I haven't tried altitude hold yet." So I hit the switch. Immediately the quad shot 10 feet in the air, I panicked and lowered the throttle stick. Of course nothing happened because "alt hold" was in charge so I quickly switched that off again. At this point, the throttle stick is now low, so before I could react again the quad is bouncing across the garden. One broken prop and a good laugh later. I find I just have one more of those props left. I'd better get ordering even more, at this rate. Quote Link to comment Share on other sites More sharing options...
Geoff Hoolahan Posted June 3, 2015 Share Posted June 3, 2015 Brilliant story Chris, and so easy to do Quote Link to comment Share on other sites More sharing options...
Nev Posted June 3, 2015 Share Posted June 3, 2015 Sounds like you're having fun Chris. I think I've done that one as well, although didn't realise that is what had happened, just thought I was being ham fisted. My mistake tonight was realising confirming that the back garden is not big enough to fly in. Nev. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 3, 2015 Share Posted June 3, 2015 Haha Nev, I now have visions of you knocking on a neighbours front door and asking "Please mister, can I have my quad back?" Quote Link to comment Share on other sites More sharing options...
Nev Posted June 3, 2015 Share Posted June 3, 2015 I had that thought too when I went out but it was trying to get back down on the trampoline that took the prop off Quote Link to comment Share on other sites More sharing options...
Nev Posted June 3, 2015 Share Posted June 3, 2015 But tonight mostly I have been computering ! I'm not "into computers" but I considered myself reasonable computer literate but I was struggling to change the baud rate on the GPS. Go into GNSS configuration, select the text file, select GNSS to File and off it goes, only to fail every time due to a "fail to respond - time out error" so last night I uninstalled all the files and Ublox and started again, had another go tonight checked all the connections etc. same thing. Did a bit of searching around earlier And found a bit if help One thing I hadn't done before was tick the box Store Configuration to BBR/Flash, ok so I did that. The other thing it said was configuration was likely to fail half way through when it gets to the point where it changes the speed ! This certainly looked like what was happening, so First run the configuration at baud rate 9600, it fails half way through, So next up the rate to 115200 and run configuration again, this time it gets to the end -success! Never heard of having to do anything like that before but it seamed to work Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted June 3, 2015 Author Share Posted June 3, 2015 Ah, that's interesting. Because that's the way I did it - but unintentionally! I hit the reconfigure without remembering to change the baud rate so it was still at the default 9,600 - and incidentally it did fail. Thought "Silly boy", changed the baud rate to 115,200 then configured again. All was well, so I promptly forgot about the failure at 9,600 and in writing it down didn't include the "mistaken" and apparently irrelevant 9,600 step. Only obviously it isn't irrelevant! I'm living proof that it's better to be born lucky than smart! BEB Edited By Biggles' Elder Brother - Moderator on 03/06/2015 22:53:27 Quote Link to comment Share on other sites More sharing options...
Nev Posted June 3, 2015 Share Posted June 3, 2015 It has definitely changed the speed, if I change back to 9600, nothing, back up to 115200 and it connects automatically. Longitude, latitude, time and an almost instant 3D fix. The only thing I don't get is reassuring green blocks for the satellites, I used to get 8 or 9, now nothing no greed, blue or white,just blank. Not quite the experience BEB described but it seems to be doing its thing Ah now is see, you type quicker than I do. Edited By Nev on 03/06/2015 23:04:40 Quote Link to comment Share on other sites More sharing options...
Geoff Hoolahan Posted June 4, 2015 Share Posted June 4, 2015 Unfortunately it's 2 steps back at my end. Hovering quite nicely with only a slight wobble, wind dropped so take it up to about 8 feet (still below the neighbours fence ) and suddenly one or more motors stop, the thing flips over and hits the grass. Since the weight is in the base (battery), It couldn't flip over if all motors had stopped at the same time, so one or more must have stopped first, but the experience was that all motors had stopped. Maybe the Controller shut down the others. Faulty motors? my soldering? faulty Controller? Going to have to take the props off and mock up a simulator for this (i.e. me jumping in the air and throwing the thing around). I'll let you know if I make any progress. Geoff Quote Link to comment Share on other sites More sharing options...
Martin Rogers Posted June 5, 2015 Share Posted June 5, 2015 Hi I just stumbled across your very interesting forum and I am at about the same stage as you. My quad is flying well but will not hold GPS position I have GPS fix on 10 satellites but the quad just hovers for a couple of seconds before darting off randomly at which point I have to take control. I have set the magnetic declination and tried adjusting the pos P setting from 0.11 up to 0.5 and reducing the slew to 10 but with no luck. my hardware is a CRIUS MWC MultiWii SE V2.5 Control Board W/GPS NAV Module Combo as in the link below **LINK** I have seen a post online stating that the GPS module itself needs to face the front which I'm not sure is correct (as I thought it just supplied position information) but can't see any arrow on the module anyway. The magnetometer is correctly calibrated having checked the heading shown in the GUI with a compass. The compass does move 2 degrees with full throttle applied but I wouldn't have though that this is the problem. Any suggestions would be greatly appreciated as I'm running out of things to try . Quote Link to comment Share on other sites More sharing options...
Pete B Posted June 5, 2015 Share Posted June 5, 2015 Posted by Nev on 03/06/2015 22:40:01: I had that thought too when I went out but it was trying to get back down on the trampoline that took the prop off Isn't flying it challenge enough without trampolining at the same time? Pete Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 5, 2015 Share Posted June 5, 2015 Hi Martin and welcome aboard. The only think I know to ask about the GPS would be: Does it shows a locked and working, as expected in the Multiwii GUI? I've gone and bitten the bullet and fitted prop guards to mine. While I feel a bit like a 6 year old with stabiliser wheels on my first bike, I hope it's going to save me money in props. Quote Link to comment Share on other sites More sharing options...
Nev Posted June 5, 2015 Share Posted June 5, 2015 Posted by Pete B - Moderator on 05/06/2015 17:53:43: Isn't flying it challenge enough without trampolining at the same time? Pete It's the only way I could see the quad over the fence Pete Nev Just had another delivery of props from China but I'm liking the guards Chris, may have too invest. Quote Link to comment Share on other sites More sharing options...
Martin Rogers Posted June 5, 2015 Share Posted June 5, 2015 Hi Chris, The GUI shows the GPS as locked with up to 12 satellites. I have also used the EZ-GUI app and activated the RTH function whilst carrying the armed quad, the GUI correctly shows the distance back to the place it was armed so I think the GPS position must be okay. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 5, 2015 Share Posted June 5, 2015 Posted by Martin Rogers on 05/06/2015 20:38:33: Hi Chris, The GUI shows the GPS as locked with up to 12 satellites. I have also used the EZ-GUI app and activated the RTH function whilst carrying the armed quad, the GUI correctly shows the distance back to the place it was armed so I think the GPS position must be okay. OK, well you're well ahead of me. Mine Multiwii falls over as soon as I un-comment the function. That causes lots of I2C errors - all the time. So I'm just going to wait for a "step by step" to see where I'm going wrong. Meanwhile I'm having fun getting some time in with the new guards on. Has anyone worked out a sensible duration to fly to, using a 1300mAh LiPo? Quote Link to comment Share on other sites More sharing options...
Nev Posted June 5, 2015 Share Posted June 5, 2015 Don't look at me, I was happy when the GPS managed to find my house, I haven't connected it to anything that flys yet. We are all still on a bit of a learning curve Martin but stick with us, we will get there. Nev. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted June 6, 2015 Share Posted June 6, 2015 When a slightly off angle, slightly heavy landing pushes the prop guard up into the prop, breaking two blades off it, you wonder why you bothered - DOH! Quote Link to comment Share on other sites More sharing options...
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