My 4-Day Experience w/ Ardu 3DR Kit - A Newbs Reviewby Zen [ http://diydrones.com/profile/Zen ]
April 30, 2012
I finally bit the bullet and ordered the 3DR kit. #excited
I should preface all of this with the fact that I'm not a hardware guy, software guy, r/c guy, hax0r extraordinaire, FAA commander, or anything that would make me particularly qualified -- I ordered the kit, followed the instructions, and happen to have an experienced quad flyer friend to bounce questions off of.
To start, my experience with the ordering system was lacking -- multiple kits "in-stock" but nothing could be added to my cart because one of the items in the kit was not in-stock. I could see this being an issue if it were a major component, but it was the velcro battery strap. So if you cannot delay shipment until said part arrives, and you won't let me add the kit to my cart, then you really don't have any in-stock.
Kit arrives and I spend the next two and a half days or so building the 3DR per the instructions in the wiki. It wasn't really all that difficult, just a lot of tedious work - checking, double checking, oops and fixing, etc. Issues that I had included the instructions not matching the hardware I was sent. Cables weren't the same colors, parts were off, etc.
After the main frame assembly was complete there was a very noticeable "arch" on two of the arms. If oriented in "plus" mode instead of "x" mode you would notice that the left and right arms were both angled backwards by several degrees, while the fore and aft arms formed a straight line in relation to each other. The left/right arms had to be measured and drilled out a bit to make them straight. Poor QC imho.
It was also interesting to see that 3DR was shipping bullet connectors as from my research they are notoriously sketchy. Not that it's a show stopper, but "sketchy" is not a word I want to use for any components going into a fairly expensive flying device. Replaced all the bullets with dean connectors which seem to be pretty stable. (also per the rec of my quad flyer friend)
The configuration of everything seemed to be pretty straight forward with no major or noticeable glitches. Once the beast was built it was time to see if it would fly!
Flying started slowly until I could get a feel for how this thing works. I can say that after a few minor adjustments it was picture perfect! Hovered well, responded well, and seemed to generally be a rock solid performer. I was definitely stoked to fly more. I drained one battery in testing.
Day 4: I head to the quad flyer buddy of mine's house and we head out to a HUGE field to play around and for me to learn a bit more. Drained another battery and everything seemed grand - and then...
After putting in the second battery (3rd battery that's ever been used) I start noticing a little glitch -- the controls don't seem to respond, but only for a second. The quad is hovering nicely, bank right, nothing - being a newb I'm not sure what's going on as everything else has been spotless. Bank right again and we're back. This happened a couple times in various spots, but nothing major.
We then do a vertical assent, which I've done a couple previously, but this time was different, much different. I "gas" it to probably 75% throttle and the quad shoots straight up, fast, I let off the throttle and nothing happens. The quad continues to climb and no controls will work! There was a 2-3mph cross wind and the quad climbed and was blown sideways FOR MILES. A more or less fresh 2650mah nano-tech battery carried this bitch further than I could see it until it was nothing more than a black dot across the grey sky. Nothing worked, nothing stopped it. Gone.
I have no means of locating the craft let alone troubleshooting wth happened - could it have been a bad board? bad radio? software malfunction? short? I'm not trying to lay blame on 3DR or anything, but there are a lot of assumptions made in the assembly instructions, stuff that's just plain not there, and if I didn't have an experienced pal assisting there would have been a lot of unanswered questions. Heh, at this point there still are.
So my take away from this is - WTF. I completely lost the quad I just paid 600$ for, spent 2 days building, have flown twice - barely, and have no clue as to why it decided to full throttle to the stratosphere. There appeared to be zero issues with any of the equipment, all fresh batteries, and much to the bewilderment of my experienced friend who commented that he's never seen that happen before.
So the two flights I got out of this device were awesome and I was told it was handling very well and looked spot on. Irrelevant at this point I suppose as I don't even have a handful of busted parts to scavenge from. I lost the entire craft, a brand new battery, and radio gear.
April 30, 2012
So to be clear - I bought the kit from DIY, as-is, and what came with it is what
I specifically bought this kit BECAUSE of all the safety/auto shit that's included, but didn't enable or investigate for any maiden flights.
Now that I know what's possible I would say that it's a requirement to geo fence during initial flight testing. That way if failure at least it'll be contained. I would also state that after initial testing and "burn-in" is done and everything appears to be safe, that telemetry is the next requirement. That way if fail at least you have an idea as to where to look for your shit.
I don't think anyone except the guy who was with me knows how far this thing went. It was literally almost completely out of sight, both in height and distance. Without last know coordinates we wouldn't even know where to begin looking. Someone also mentioned a liability issue, and you're spot on... It's kind of scary thinking that UAV's can just fly away on their own and drop from the sky.
RTL on signal loss, geo fencing, telemetry, gps transponders, etc all sound cool but seem 100% necessary to me. How does one know if their aircraft is 100% reliable? How much testing and air time need to be done before you're comfy knowing all is well? Sounds like you never can be 100% certain, which to me sounds like safety should be 100% required.
By Jake Stew [ http://diydrones.com/forum/topic/listForContributor?user=2egm7fj1oj7qk ]
April 30, 2012
Bummer dude. I have to say that I have read quite a few stories like that. This sport just isn't plug-n-fly yet, it really is for developers and tinkerers at the moment.
If it's any consolation, a lot of people crash and burn their first few times. Thanks for bringing up the potential 9x problem though. I've got one and should probably do a lot more testing of failure conditions.
It's too bad the autopilot didn't have more sophisticated failure handling. But I don't know how much you can really expect the autopilot to do when flying in manual mode.
Copyright 2012 http://diydrones.com/forum/topics/my-4-day-experience-w-ardu-3dr-kit-a-newbs-review