Not off to a good start in the new year...
- Thread starter RTRyder
- Start date
I flipped the switch to failsafe for RTH but all it did was rise to 20 meters and start circling. I flipped to manual to get TX control back, went to ATTI mode and flew it back manually, just as I was coming down about 10 feet out from the takeoff point this is what happened. Not a low power problem, batteries had 31% remaining immediately after...
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Sorry to see all this Ken. Hope you can retrieve some crash investigation info to set your mind at rest. Nothing is worse than not knowing what happened. I think you have to start working backwards. Motors on test stand with same esc and prop size and run some hard testing runs. I did have a similar crash when the motors stopped phasing due to the wrong timing. It took some finding as it would only occur when the pwm signal was rapidly changing. i.e. in the descent.
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I have a suspicion I know what happened but I doubt that I will ever be able to confirm it one way or another. I haven't yet powered it up again since the crash and I don't want to speculate about anything until I at least do that. This AV has already been straightened once from a not quite so severe bashing, I have disassembled and taken a close look, one of the arches for the roll cradle is stretched so that it's no longer a continuous curve, probably really need to replace both arches and the rack gear at a minimum.
From the ground I saw it twitch like it was going to flip then it recovered for a second, then it just went over towards the right rear corner, it hit on its side then did a bounce/roll back to almost upright using the AV and Nex as a pogo stick in the process. I've done RTH with this WKM sucessfully before, not sure what the problem might have been with that. Since the last time I did an RTH I have installed the datalink and Click and Go waypoint (which I was not able to get to work that day also), and the night before I upgraded to the 4.26 firmware. I had two normal flights prior to this one so none of it makes any sense. I don't think the firmware upgrade to the WKM had anything to do with it and as I said I need to power it up and see if everything is working before I can even begin to come to any conclusions on what may or maynot have happened.
Thing that sucks the most is the damage to the 5N, certainly won't get covered by warranty so I eat whatever the cost may be to fix it. Still does video and stills, won't replay the video and the LCD doesn't close tight against the body anymore so not something I can just live with and hope it won't get any worse. If repair cost is too high I'll just try and find the basic body for sale at the best price possible and use lenses I already have.
One thing for certain, the CS will not fly again until I have a handle on what happened. Fortunately the frame came through undamaged, but I'd almost rather have to reapir a broken frame than potentially write off an AV130 and Nex 5N.
Ken
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DucktileMedia
Drone Enthusiast
Ken, this is the stuff our nightmares are made of. I always wondered if Phto Higher sold replacement parts. I would imagine not as they want to sell overpriced parts as a unit.
I have the programs on my CNC for my carbon hex, which is very similar in dimensions to what you have. If you need some parts machined or a whole new kit, I can help you out. The cost for me to make one full kit in carbon is about $350, less labor.
I have the programs on my CNC for my carbon hex, which is very similar in dimensions to what you have. If you need some parts machined or a whole new kit, I can help you out. The cost for me to make one full kit in carbon is about $350, less labor.
They do sell parts, I've bought some from them for my older AV 130. Worst case I'll take the Savox servos from the bent mount and put them in the older 130, there are differences but I have a mill and lathe in the garage if I need to make them fit in the older frame. What I may do is just take the roll cradle from the old one and use the servo and drive setup from the new one along with the top frame until I can get the parts I need from P/H. That will leave me with only the one operational AV 130 but since its now winter that probably won't be too much of a hardship until I can either fix or replace the bent mount. First priority is to get the Nex 5N fixed, that will undoubtedly be the most expensive consequence of the crash unless I wind up buying an entirely new camera mount, and that won't happen for some time with the Christmas season just behind and available cash at a low point.
Ken
Droider
Drone Enthusiast
@ Ken be aware that the servo drive wheel is smaller on the older AV130's than your newer one.
@IrisAerial. PH do a very quick spares service BUT the shipping is very expensive.. I think ALL regional PH dealers should be required to keep basic replacement parts as I am in my dealership
Dave
Dave
@IrisAerial. PH do a very quick spares service BUT the shipping is very expensive.. I think ALL regional PH dealers should be required to keep basic replacement parts as I am in my dealership
Dave
Dave
Yes. well aware of the gear size difference, I have one of each type on hand. I have yet to put the roll cradles side by side, there may be differences there as well.
I managed to get the bent cradle as straight as possible and back into the top framework, not even close to as smooth as it was and should be, which isn't surprising considering how badly bent it was. I just sent a parts request to Sue @ P/H for pricing on the two halves of the roll cradle along with a new roll pinion and some misc bits, I should know by this time tomorrow what it's going to cost for the parts to fix it right. I could use it in a pinch as is but but it's definitely not right and it would most likely show up in the end result.
Ken
seattle_helo
Member
Ken, so sorry to see this. Hope you can isolate the exact cause.
nick
nick
I've already got the quote from Photohigher for the parts to repair the AV 130, I wasn't expecting to see anything until tomorrow morning my time at the earliest due to the day/time difference, great service!
As someone else noted the shipping is the killer ordering parts from N.Z., about 2/3 the total of the parts cost in this case, but to have them in my hand in a couple days is worth it IMO. Now I just have to put the CS on the bench, plug a battery in, and start looking for a reason why it decided to fall out of the sky...
Ken
Payment made, parts on the way, gotta love Paypal and the internet!
As someone else noted the shipping is the killer ordering parts from N.Z., about 2/3 the total of the parts cost in this case, but to have them in my hand in a couple days is worth it IMO. Now I just have to put the CS on the bench, plug a battery in, and start looking for a reason why it decided to fall out of the sky...
Ken
Payment made, parts on the way, gotta love Paypal and the internet!
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jeffscholl
Member
We have a few spare 130 gimbal gimbal arches.
I don't think we have the gear wheel though.
Best,
Jeff Scholl
btw...tried to PM you but it said your mail box was full.
I don't think we have the gear wheel though.
Best,
Jeff Scholl
btw...tried to PM you but it said your mail box was full.
And the answer is...
I just got the CS on the bench for a little diagnostic session and for once there's a concrete, indisputable cause for Sundays aerobatic attempt by a non aerobatic hex. Took the props off, connected a battery, gave the motor start command, 5 motors spin... Hmmmm....
Took the top deck off and checked wiring, all good, wiggle any and all connections, this time the motor gives a couple of back and forth twitches that I've seen before, lost a phase on the ESC. Disconnect the ESC, pull it off the frame, remove shrink wrap, immediate stench of burnt electronics.... AH-HA!
Closer look under a good light and sure enough burnt output FET on the ESC, so we have a cause, ESC failure while in flight. As much as it sucks to have it happen, I'm happy to be able to say I found the reason why. Now I can fix it and move on, a new set of Maytech ESCs on the way to replace the entire set of DYS currently in place.
If anyone thinks a large hex can still fly on 5 motors, I have conclusive proof that it ain't happening...
Ken
I just got the CS on the bench for a little diagnostic session and for once there's a concrete, indisputable cause for Sundays aerobatic attempt by a non aerobatic hex. Took the props off, connected a battery, gave the motor start command, 5 motors spin... Hmmmm....
Took the top deck off and checked wiring, all good, wiggle any and all connections, this time the motor gives a couple of back and forth twitches that I've seen before, lost a phase on the ESC. Disconnect the ESC, pull it off the frame, remove shrink wrap, immediate stench of burnt electronics.... AH-HA!
Closer look under a good light and sure enough burnt output FET on the ESC, so we have a cause, ESC failure while in flight. As much as it sucks to have it happen, I'm happy to be able to say I found the reason why. Now I can fix it and move on, a new set of Maytech ESCs on the way to replace the entire set of DYS currently in place.
If anyone thinks a large hex can still fly on 5 motors, I have conclusive proof that it ain't happening...
Ken
Jeff, thanks very much for the offer, had I seen it a bit earlier I would have been on it. As is, I just received the tracking number for the parts shipment from Photohigher, I'll have parts in hand Thursday morning. If only I could get the NEX 5N repaired that quickly...
Now to go clean out some of those PM's clogging my inbox.
Ken