Winter Flying – RCT800

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).

UFO Sighting in Uxbridge…

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.

Ansnorveldt: flying around an empty space

Recently tried to capture a sunset at a local nature conservancy: Ansnorveldt (not sure what the heck that name is about but apparently its also a hamlet in Ontario?).

Ansnorveldt,Ontario

There are about 3-4 houses nearby (whats the definition of Hamlet again?) but otherwise this area is mostly deserted! After recently crashing I am looking for deserted areas to fly around and film so the risks are minimal. I don’t want to risk an accident and I am still not certain about my craft given that it flew away without a well known cause. (I suspect parts failure and the parts has been fixed… but you never know)

Anyway, flying in a deserted area also allows you to have some comfort about flying fairly high/far… not sure if the video worked out how I saw it in my head (there was a good sunset and it was a nice night) but there is a pretty good view of the Holland Marsh at points and the farmer just across the street is irrigating his fields. Ansnorveldt is mostly fields and a few little forests here and there; a good place to hike and check out the birds. There are quite a few hiking paths and relic buildings on this property (accessible from both Dufferin and Bathurst) and a million birds!!!:

Back to making videos…

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:

A Phoenix rises…

I am not sure if you can call it a Phoenix when your bird drowns and then rises from the river to fly again? There was no fire involved but the I recently crashed my RCT800 into a river. Besides losing a few sandals, sitting in the river with the power on also seems to have wrecked 4 of my ESCs and my taken away a little of my confidence .

I’ve finally received my replacement parts and I’ve reassembled the RCT800. It’s looking pretty good with the new landing gear extensions I made from bamboo strips glued together (found black ones so they blend in pretty well). They’ll break if I land too hard but they’re fine for controlled landings and it looks more like a flying spider this way (also cheap!!). Plenty of room for cameras under there!!

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Different view (a flying spider!):

RCT800_v2_2

Power on a ready to fly!!

LightsON

Anyway, I’ve now made 3 test flights without issue and in slightly heavy winds… I think I am “back in business” although the incident has me reconsidering suitable places to fly and even considering a pre-flight checklist (never intended to get this serious about it but it might be a must with craft this big!).

RCT800 Takes a bath!

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!!

Lost:

  • 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!!

Damaged:

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!

IMAG1347

The Cause:

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!

IMAG1346

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 Parts List – actual parts used

Having recently built an RCT800 Hexacopter from parts I have a pretty good idea of what is needed to build a Multicopter and how the parts all fit together. Check out my UAV General Parts List if you are interested in a general description of the parts you’ll need.

There are literally thousands of ways to build a Multicopter now and the list of available parts and websites can be a little daunting. It’s a good idea to start out with a purpose and or goal in mind and then build your list before buying anything.  This can help you develop your desired parts list in a way to ensure success. This also lets you enter your craft specs into an online calculator tool like the XcopterCalc calculator which will point out any problems you might have and estimate your flight times.

Heli Part Purpose Pcs
Naza Flight Controller and GPS Flight Controller 1
RCT800 Airframe 1
HP4215 630KV 24N18P Multicopter Brushless Motor Motors 6
DJI Opto 30 ESC ESC 6
13×6.5″ Carbon Fiber CW CCW Propellers (6pcs) Props 1
DJT – FrSky DF 2.4Ghz Combo Pack for JR Receiver 1
ZIPPY Compact 3700mAh 3S 35C Lipo Pack Battery 1
Various LEDs Lighting and Orientation – Blue, Red, Green 1
Turnigy Receiver Switch LED switch 2
Not on board Heli
Turnigy 9XR Transmitter Mode 2 Transmitter 1
DJT – FrSky DF 2.4Ghz Combo Pack for JR Trasmitter Module 1
Turnigy 9xr Battery Transmitter Battery 1
ZIPPY Compact 3700mAh 3S 35C Lipo Pack Backup Battery 1
B6AC – IMAX B6-AC Charger/Discharger 1-6 Cells Charger 1
Wires Wires 1
Connectors Connectors 3.5 bullet 6
Connectors XT90 connectors for battery 6
Parallel Battery Wiring Harness- build or buy allows two batteries to be used at once 1

**the list above produces a Hexacopter with great flight control and performance characteristics however I am not necessarily recommending these parts. This was a relatively expensive build and some parts such as the RC Timer 630KV motors have performed a little more poorly than expected (these motors have great performance but terrible prop mounts which introduce vibration into your aircraft).

RCT800 Video – FPV Camera Mount Testing

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 Video – flying at dusk, new LED setup

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.

DJI Naza-M return to home

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).

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About 3m north of takeoff (not sure if I’ve got a config problem)… still very good!

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