Flying around in the fresh winter air!! I am getting good performance from this setup in the winter however on a recent flight I came down pretty hard and broke some landing gear on my rct800. I am sure this would have been fine in the summer but in the cold they snapped… extreme cold definitely will affect your battery performance! I came down early when I broke my landing gear after draining my battery at least 3-4 minutes early (it was -7).
Recently found a great place to fly around in Uxbridge, Ontario; a big empty field on the outskirts of town! From the right perspective and distance this would have been a UFO sighting for sure. Anyway, if you look around on the internet for this kind of thing I am sure you will find quite a few supposed UFO sightings where the video looks something like this:
I think that in *most* cases its probably not aliens flying around… just someone like me having a bit of fun!!
**I’ve actually been thinking about adding more LEDs (orange) to the rear of the craft because its still ((surprisingly!)) possible to lose orientation.
The RCT800 is back up and flying after crashing into a river a few weeks ago. After rebuilding almost the entire aircraft it was finally time to strap on a camera and go make a video of a nearby nature conservancy.
It was a nice day and the area was completely deserted but I was taking it nice and easy too! I lost a little confidence after the crash and I am slowly working back to feeling like the aircraft is an extension of my arm again.
Looks like I am on track since the video shows almost no vibration:
It was a beautiful day and a perfect time to make some aerial videos on a sweet marshy part of the Holland River. I wish I had taken some pictures to document the crash but at the time I couldn’t manage it because I was frantically running in a panic! The only real pictures I had of this event are in the Holland River somewhere.
About 2 minutes into a controlled flight my RCT800 became completely uncontrollable (stable mode) and stopped responding properly… while drifting away!! In a panic I threw the RTH (return to home) switch hoping that this function might be able to control the craft when I could not. This caused the RCT800 to start dive bombing the ground before flying up again (like giant Us in the sky). I stood there watching with a feeling of helplessness (and a little horror) for about a minute or 2 until the crash. Anyway, the Holland River really isn’t that big or wide in this area but this was (of course) exactly where my RCT800 ended it’s crazy flight… in the river with a giant splash! You can’t see the river from where I was standing but I saw the splash well enough and started running!! The RCT800 was in the River on the opposite bank from me and 100s of meters away! When I got to the craft some of the props were actually still spinning (slowly) underwater!!
- My Cannon Digital Elf – somewhere in the Holland River by Rogers Reservoir Newmarket. This isn’t a scary river at all but on the day in question it had a good current going and there is a nearby waterfall. Decided not to push my luck too much in the River and couldn’t find the camera from shore when it became detached from its mount.
- My flip-flops!! There is a mud flat leading up to the River and as I ran for my craft I literally sank up to my thighs in some spots… alas my flippy floppies were claimed by the river bank!!
So far my tests indicate that I’ve got 4 blown ESCs. I bought the DJI 30amp Opto ESCs so this was an expensive crash (around $80) but given what else might have failed I am pretty lucky. I have yet to receive my replacement parts (ordered) but I should be back up and running with this craft soon. I had also made landing gear extensions from wood; these were completely smashed by the crash but they were cheap and home made so not a big deal!
It’s a little difficult to know exactly what went wrong when you retrieve your partially smashed helicopter from a river but I did notice one important point; the GPS mount is made from a fibrous material and the pole seemed a little compromised and bent at one end. It’s not clear if this was from the crash in the river or a prior incident but I think this could have caused the antennae to bend mid flight. This would have caused problems for ALL the flight modes I used while trying to recover the RCT800. Ironically, I did not try full manual mode because I thought it would make things worse and this mode may not have been affected by a bent GPS. You can see the frayed material in this shot. The next version will NOT use an antenna and the GPS sensor will be mounted flat on the airframe to prevent a recurrence. Also, if something like this happens in the future I will definitely be going for a controlled crash if the auto pilot modes don’t work. In hindsight, I let the craft hang in the air for too long when I still had throttle control and could have put it down (crashed) more quickly. The results may have been the same but hitting the river was a complete fluke!
It’s really not much consolation but at some point everyone crashes. This makes safety and aircraft maintenance a paramount concern. If my little crash had happened in a busy area it would have been terrifying and dangerous! Anyway, as it turns out no one has more experience crashing UAVs than NASA (they’ve been doing it since the 60s). A little while back they released an e-book about it… It’s called Crash Course and dissects quite a few of their UAV crashes. Cool toys and expensive crashes these guys have!
RCT800 FVP Camera Mount Testing (Also known as the last few videos and pictures I took with my Canon Digital Elf before it went swimming and never came back).
The brushless motors I bought from RCTimer (630KV) seem to have one fatal flaw; the motors are great in terms of performance but the prop mounts are poorly milled and or cast. They make it almost impossible to mount your props without causing an imbalance and vibration. This turns your sweet flying rig into a vibrating machine and makes good videography pretty tough (make that impossible… see the last clip) even if your props are balanced.
I’ve been testing various materials to deaden the vibrations and sponges from the dollar store seem to make great (cheap!!) vibration absorption material. In total, I tried rubber bands, paper, duct tape, string, a homemade shock, and two different sponges before coming to a solution. The homemade shock had some promise but it was outclassed by a simple cheap ($1) sponge so I didn’t take it further than a few quick tests.
As you can see from these two test videos the results for regular dollar store sponges were decent (compare these videos to the last one). I found that all I needed was a little bit of sponge between the camera and the aircraft’s hard surfaces. This almost completely eliminated the vibration from the props.
Got pretty high in this video… You can clearly see the river that I later had to wade into in order retrieve my Hexacopter after it went haywire and crashed.
These results are especially good if you consider the movies I was able to make earlier (before adding the sponge).
Here is a sample of those vibrations, as you can see the movie is unusable and a little sponge will absorb quite a lot of shake (the only real difference between the movies above and below is the camera mount sponge padding)
RCT800 – flying at dusk in a local parking lot. Recently modified the LED configuration in order to see them better. Was using the IOC (intelligent orientation control) in Head Free Mode at certain points during the flight. With this mode enabled it doesn’t matter which way the nose of your aircraft is pointing; the direction of the craft is controlled by the right stick (in Mode 2) and the aircraft moves in relation to it’s takeoff point.
One of the great features of the DJI Naza-M with GPS is the “Return to home” failsafe. With this feature enabled, its possible to setup a TX so that you flip a switch and your aircraft comes home. In practice this works really well and the RCT800 always lands within ~3m of its takeoff point. It seems to reliably land ~3m North of takeoff. Its also possible to setup the RX (certain receivers) so that the failsafe triggers this function. I’m scared to test it (turn of my transmitter while flying) but the RCT800 has this feature enabled too.
What “Return to home” does:
- Craft stops moving
- Craft climbs to 20m (above most obstacles and trees)
- Craft turns towards “home” and flies there (scared the hell out of me the first time!)
- After a brief pause 20m above “home” the Craft slowly lands and disarms
I took the following pictures while using the “return to home” switch on my TX (obviously no hands on the controls).
About 3m north of takeoff (not sure if I’ve got a config problem)… still very good!
Every aircraft needs lights!! Added Red (left) and Green (right) LEDs to the RCT800. Also added some Red, Blue, and Green to the interior of the craft for “bling”. The LEDs are wired up on a Turnigy receiver switch and can be turned on and off from the TX!
In General, Proper lighting for an aircraft is:
- Red on the Left – check, I did that ;.)
- Green on the Right – check, I did that ;.)
- White as far aft as possible – Nope, didn’t like that scheme and it’s only an RC UAV…
Finally the RCT800 Frame has arrived and I can do a little mock up while I wait for the last little bits and pieces. This is a pretty robust frame when assembled and it also seems relatively stiff. There are lots of screws needed for this frame design and they’ve got a tendency to come loose (a little locktite can go a long way here). **Now that I’ve had the frame for a few months, I’ve had a few crashes (minor) without damaging anything so I know this is a strong frame.