Journey to FPV – Blade 350 QX
I have been involved in RC in one shape or form since the late 80’s when I got my Tamiya Frog. I started racing in the early part of the 2000’s and ran everything from 8th scale, monster truck all the way up to 5th scale which I now spend almost all of my time doing now. I’ve mostly been a ground pounder but have puttered with flying along the way. FPV (First Person View) has been the holy grail for many enthusiasts and with tech becoming cheaper all the time reliable FPV gear has come within easy reach.
Enter the Quadcopter! DJI and their Phantom were something I started looking closely at about 2 years ago. The whole idea fascinated me and I began to look closer at the technology and began to save my pennies. There was lots of information on the web but the price point of the Phantom kept me at bay as I was unsure about making that kind of investment. I began to hear rumblings about a product from Eflite that caught my attention and it’s price point peaked my interest. The following blog is my journey into the world of FPV flying, the choices I made along the way and maybe some insight on what I may have done differently.
When I first went to ‘ol Fuceye with my vision of FPV he was one step ahead of me and in truest Fuceye form had thrown himself headlong into the fire not even wasting time with the frying pan. The run down he gave me was largely in another language and I only really grasped about 30% of what he was talking about. The truth is, even for the hardened RC guy there is a massive amount of information and an even bigger pile of gear you need to learn about to even get started. I began to look to forums like FPV Labs which is a wonderful resource with a ton of knowledgeable people on board. The great part about this particular site is that many of the manufacturers are members so you can get information right from the horses mouth on many topics. Dare I admit it, I even turned to Facebook and joined a Blade 350QX owners group to ask questions from a group of like minded people.
As I stated my jump off point into FPV was buying the Blade 350QX. This “quadcopter” was a balance in budget for me and had many of features that the Phantom did with the exception of the camera gear that comes standard on the Phantom. In Episode 35 of TDS I spoke with Steve Pettroto from Horizon Hobby and heard about the likelihood that accessories for the Blade would be forth coming. The main reason I went with the Blade, as said earlier, was largely price. Flying has always interested me but it seems when I have laid down money, in the past, on things like my Eflite Blade 400 or my plane they keep me interested for a bit and then it was back to beating on my 5th scale gear. I didn’t want to dump $1000 into a Phantom to have it gather dust on the shelf beside some of my other “experiments”. I wasn’t prepared for what happened next.
Without getting ahead of myself lets talk about the Blade 350QX a bit with my 20/20 hindsight clearly focused on the past.
One word of caution before we get to far. This is my journey and the research I have done is biased by limitations I have placed on myself in getting into this area of the hobby. One of my biggest constraints, for now, is budget. I’m trying to find gear that will give me the biggest bang for my buck. Granted there are some areas you just can’t skimp on but I believe there are corners that can be safely cut. For every site I found with equipment there were two more with even more goodies to look at it. The following is not the end all when it comes to FPV, I encourage you to look around and see what tweaks your imagination. I offer this as only a guide to how I got started and some of my observations along the way. Enjoy.
Blade 350QX (First Generation)
By the time this thing hit the market I was pretty much chomping at the bit. The good people from TGN Distributing were able to get one very early and sent it up to me with my brand spanking new Spektrum DX7s radio. I picked the Bind and Fly version because usually the radios they give you in the Ready to Fly kits are such a let down. The stock radio is a Spektrum 6Xi and I already have one that came with my Blade 400, it was time for something better.
The kit came out of the box and set up with the radio with no issues. The quick start manual was pretty typical and the full manual was available on line. Flying the 350QX was stupid easy, in “Safe” mode I was able to get up and flying around in no time at all. Safe mode creates a 30’ circle around you and once in the air the heli won’t come inside that circle. You also have stick relativity which means no matter which way the heli is pointing it moves in the direction you move the stick. The other two modes presented further challenges and I found myself alternating between “Safe” and “Stability” mode. The big novelty for me was the return home feature, before you take off the GPS on board locks its “Home Position” and if you get into trouble you flick the switch and the 350QX will take over and fly over to it’s home position and land on its own. This was awesome! Finally a bird that would let me fly and mess around without hours of hovering to get used to stirring the sticks.
The 350QX came with a camera mount that was setup for a GoPro. It was basically a mount equipped with 4 rubber pillows that assist with reducing vibration. I was pretty disappointed in this system because it had an annoying tendency to come apart on a rough landing and to put it back on meant removing the whole mount from the body of the heli. I finally addressed this issue by running zip ties through the rubber mounts so they can’t over extend.
As I sat back and tinkered with my new toy I began to look towards the phantom and its video downlink capabilities and its gimbal and started to get anxious for the upgrades to come out for the 350QX and I waited, and I waited. The next thing we began to hear about what a new version of the Blade being released, the Blade 350QX2 AP Combo. This was a new version of the Blade that included new firmware and improvements to address some of the shortcomings of the 350QX as a camera platform. One of the problems that they addressed was the landing gear. The gear on the 350QX were far too short to be of any use with a gimbal slung underneath, even with the GoPro it sat close to the ground and the new landing gear were much taller and much beefier. This was to accommodate the new gimbal they were releasing as part of the kit and a new camera with a wifi downlink, NOW we were getting somewhere.
For us early adopters there was a cable to buy that would allow you to flash the firmware and upgrade to 2.0. The new firmware gave you a new flight mode, “AP Mode” and eliminated agility mode which was fine with me because I never used agility mode anyway. You can bring back agility mode it just requires some tweaking of the settings. The AP mode was supposed to be smoother transitions and not as jerky to allow for smoother video. This mode scared the crap out of me. In order to maneuver you have to really ram the input into the sticks and I found I would have to start in Safe Mode and switch in mid flight as the bird seemed so lazy in AP mode. My first high altitude flight with AP Mode was about 400 feet, and I didn’t think it was going to come down. Apparently in Safe Mode the descent rate is about 2’ per second and in Stability Mode the descent rate is about 3’ per second. In AP Mode I grew a little older waiting for the heli to descend.I’m not a big fan of this mode and rarely use it. I mainly switch between Safe and Stability when I fly.
The main part about the upgrade I didn’t like was the $18 cable I had to buy to plug into the board. I think this was short sighted on the part of Eflite and I think the built in USB port on the Phantom is a far more elegant means of allowing upgrades.
The gimbal they released was a 2 axis brushless gimbal, the GB200. Initially the price for this hit at $229.99 which I thought was a little steep. A very short time later the price dropped to $199.99 (I’d be pissed if I was one of the early adopters). I began to look at other options and found that there was a virtual plethora of options when it came to gimbals that went from the cheap to the crazy expensive. My one question was one that no one could give me a good answer. What was the difference between the $60 ebay Chinesium gimbal and the $400 DJI gimbal for the phantom? I put this question to the owner of a hobby shop and his answer with a giggle; “nothing”. Granted the GB200 has some extra features like being able to plug your $18 upgrade cable into the gimbal as opposed the main board and it does allow for minor functionality with mid air adjustment of the horizontal access, allowing you to angle the camera down, but nothing that really held it apart from its Chinesium cousin. I did a lot of research on the web and watched numerous videos using both gimbals and I don’t see much difference. I read extensive reviews and watched endless You Tube videos and the vast majority had good things to say about it. I decided to go ahead with the Chinesium version as a $60 experiment. It’s on its way here, I will no doubt write about it a little later. On the topic of the gimbal I did upgrade to the taller landing gear which was stupid easy and a great upgrade, they are much more sturdy and give you tons more ground clearance. Even if you aren’t thinking about going with a gimbal I would still recommend upgrading the landing gear.
When I went on vacation to PEI my goal was to fly everyday and really get proficient with this kit. It was during this rash of flight time that I learned another shortcoming of the version 1 of the 350QX, the blades. I had heard stories about the blades in the version 1 being brittle and breaking without warning. I had recently broken a rotor in an “incident” involving my neighbours tire, a story for another day. I purchased a full set of the “B” blades that had been released by Horizon to replace the original blades. I had the 350QX in a low hover about 2 feet off the ground and was playing with the radio when TWANG one of the blades came flying off for no apparent reason and the heli dropped like a rock, bounced and landed on its back. I punched at the throttle cut and starred in disbelief as I walked over to assess the damage listening to the “HELP ME” tone coming from my downed bird. I could see no flaws in the other blades and had no explanation for the failure as I had no crashes and had inspected the blades prior to this flight finding no issue. With a broken rotor and a cracked body I called Horizon looking for an explanation. What I got was an explanation, two full sets of “B” rotors and a new body shipped to me free of charge! I’m not gonna lie, I was a little shocked. This was definitely a customer service with with me! Put down whatever you’re reading this on and go over to your 350QX…… look at your rotors, if they don’t have a “B” on the crown (see photo) take them off call Horizon and throw those in the garbage! I’m just thankful my camera wasn’t on board and even more thankful I wasn’t at 400 feet when the blade let go!
The one thing that really impressed me was the ability to fly this heli in the wind. I had this up in 30 km winds and it had to work for it but it wasn’t impossible to manage and when in “Safe” mode it was still able to maintain its position which was impressive when you consider its size and weight.
I Got The Power!
One of the nuts I needed to crack before getting too far into buying FPV gear for the 350QX was how I was going to power it. Many guys are utilizing the balancing plug for additional power and one trick some are using which I am going to utilize is adding a second small LiPo behind the gimbal to power my down link. You have to be cautious with power usage. I have read that adding a gimbal alone to your power drain with cost you up to 40% of your battery. I think this why Eflite started looking at mods for allowing 2700MaH and 3000MaH batteries for use to get the flight times back up.
I did some experimentation to get a handle on flight time. My goal was to max out my flight time but leave enough in the tank to get me home should I be down range a bit when the timer goes off. I started with 11 min but found that my battery voltage was still over 11.1v when I pulled it out of the chassis I upped it to 12min and that seems to be the happy medium with it coming out of the heli at 11v. The low battery light sequence kicked off around the 11 minute mark but I figure there was some wiggle room worked in. What I need to try is flying it until the “Go Home” kicks in from lo battery voltage.
Poking around the inside of the body I found a set of two three prong plugs off to the side of the main board to the left of the battery, if looking inside the battery port. I immediately became excited as these looked suspiciously like servo plugs! My dream was that I could plug into these and assign them as a controllable channel on my radio, my hope was that they allowed for sufficient power output to run, at least, my gimbal.
Once again I waded into the internet but couldn’t find anything but people with the same questions and no firm answers! I broke down and called Horizon and they were able to determine, after no small amount of looking, that these were simply dumb connectors that outputted 4.8v each. They had no additional function beyond that, for now. As a footnote, according to Horizon, the negative pin is the one on the outside edge of the board. I haven’t tested that so make sure you meter it first. I haven’t given up on the functionality of these two pins and am hoping a future firmware upgrade will march them into use but for now I am going to fall back on my initial plan of using a small LiPo for the downlink and the balance plug for the gimbal.
The whole point of this exercise is to shoot killer video or take stunning photos. My go to for this type of mission was my GoPro. Now I have the original hero but it was more than enough to at least get me started with shooting some video. The included mount that allows you to shed the armoured case only works with the newer generations of the camera but with the stock case you still mount it, however it only gives you a very limited downward angle. I’m sure I could have tinkered by adding some of the accessories to give me more room but the angle it does give is sufficient. The issue is that I still don’t have downlink capability and this brings me to the new camera that was released by Horizon Hobby (We’ll come back to GoPro in a minute).
The C-G01 was Horizons entry to the FPV camera market. It started out at $299.99 but, like the gimbal, dropped to $199.99. Still cheaper than a GoPro but very light on features. Only capable of 1080p video at 30FPS, its still photos were only 2 megapixels?! This blew me away, I haven’t seen a 2 megapixel camera come out in years! This camera, though, did allow for a 5.8ghz wifi downlink to an app on your smartphone. It was also equipped with an external antenna, presumably to increase the range of the wifi connection. I haven’t looked very closely at the app but I am told that GoPro did have a hand in its development. I was all set to pull the trigger on this camera until I saw the specs. Curiously it isn’t until just recently that they published the actual specs on what the camera was capable of, even when I called Horizon they were sketchy on what they would tell me. When the reviews started to come in there was not much good to be said about the camera image quality but apparently the wifi downlink worked well.
So my natural fall back was to look at GoPro as they also touted a wifi downlink that according to their website was good out to 600’. I bought a Hero 3 White Edition and headed out to the Canadian 5th Scale Nationals to try it out. Very easy to set up and at first the downlink worked perfectly. Now onto the dangerous assumption phase of the story. I never looked to see what the frequency was that the GoPro transmitted its wifi on, I “assumed” it was 5.8GHz when in actuality it was 2.4GHz which is the same frequency as my radio. I had all kinds of problems with my GPS but was able to get it to fly but the “go home” feature would not work at all. Even if I turned the wifi off in the camera it still caused problems throwing enough interference to mess with my GPS lock. On the Blade Helis website there is a template to wrap your GoPro in copper tape to eliminate this issue, not the ideal ending to the story. There is also a warning buried on the 350QX page about the evils of GoPro interference. In the words of Jules from Pulp Fiction; “Thats some need to know shit”.To top it all off the wifi downlink on the GoPro SUCKS! At best I was able to get about 50’ of altitude before the system crapped out and at best there was at least a 4 second delay. I was hugely disappointed and returned it on the Monday. I have had no issues with my first generation Hero. Despite the issues I still want to use the GoPro as I still believe it is the best action camera on the market right now. As a footnote I did send an inquiry to GoPro, never heard anything back
When My Interest Really Caught Fire
On the topic of the Canadian 5th Scale Nationals, lets talk about Luke and his hexacopter. Looking at his setup and how he was running FPV really got me fired up. This hex was something else and his FPV setup was simple and inexpensive. He was flying on 2.4GHz with his camera running on 1.2GHz. He was running with a GoPro Hero 3 hardwired to an external transmitter but wasn’t having any issues with it throwing interference which lead me to believe maybe my GoPro was defective or my 350QX was overly sensitive to it. The ability to fly first person was very cool and I have included one of the videos produced by KPOP featuring some of the footage captured by Luke and his hex.
KPOP Video To Follow……When He GETS AROUND TO POSTING THEM!
Even with the problems I had with the GoPro I still got some impressive results and I was hooked. I spent a lot of time hassling Luke about his setup and looking at components on the internet. The more I looked the more I found and that lead to the next chapter in my journey to FPV.
Picking My Downlink
I think, of all the areas I researched, this choice was the biggest one I made. I’ve had a little experience with wireless video transmission and not all of it good. I’ve experimented with Chinesium equipment before without a great deal of success. We fiddled with FPV on 8th scale buggies but ran into all kinds of issues with having a stable link. Without the stable link getting a recording is next to impossible. This is where using something like a GoPro is useful because it allows you to record your video on board and then downlink a lower resolution video for you to control your movement.
Earlier I talked about my 2.4GHz radio and how I had interference when I fired up the GoPro. When looking at frequency for video transmission bigger is not necessarily better. Many people are using frequencies ranging from 900MHz to 1.3GHz with output power below 1000 mW. I looked at transmitters that were in the right frequency range but were 1500 mW and up to as high as 2500 mW. You would think with more power you would have a better signal and greater range? Not necessarily, it turns out that with that much power you create a lot more noise which can lead to a less reliable signal. Lower frequency means greater penetration but it seems that transmitting power in the 400 mW to 800 mW range seems to be the sweet spot. Again, I looked to Luke and his hexacopter and he is using a 12 channel Chinesium transmitter and receiver that can range from a little over 900MHz to 1.3GHz. He is flying with a 2.4GHz radio and has run out of radio range and still had a stable video link. Having said all this I began to see many sites that seem to be preaching the benefits of using a 2.4GHz for your video link. The obvious problem being interference with your radio. The part that confused me was that why does the video downlink interfere but someone standing next to me with another 2.4GHz radio causes no issue. I posed this question on FPV Labs hoping for insight and got just that, obviously from someone smarter than me. Here is the answer I got;
Credit goes to “Airborne” on FPV Labs for this;
DSSS and FHSS RC systems use Spread Spectrum transmission techniques to mitigate frequency conflicts. They are designed to coexist peacefully with other spread spectrum devices, even systems using other technologies to accomplish spreading.
Even if two systems land on the same channel, or onto a channel occupied by another spread spectrum device such as wifi, they will either hop past it (FHSS) or “spread around it” (DSSS) and enough of the data packets get through that link is maintained.
Analog video is not spread spectrum. It blankets a large chunk of the band with old fashioned analog modulation, making that portion of the band useless to spread spectrum devices. There is a reason you need a license to transmit more than 10mW of analog video, but don’t need one for a wifi router with 20x more power. The wifi router isn’t likely to interfere with anyone.
Your average FPV video signal is, as Hans notes, many times more powerful than your 2.4 control signal, and wide / dense enough that any hops landing on it are lost (FHSS), or that spreading around it is ineffective (DSSS).
Hopping systems (FHSS or DSM-X) are slightly more immune to 2.4 video conflicts, as they are apt to hop onto a channel not occupied by the video signal, and some packets will still get through.
As I said, there are some people on that site who really know their shit! With the Blade 350QX I don’t have the ability to upgrade to another operation frequency like UHF so I am left to pick from technology that allows me to work around having to use 2.4GHz on my radio. In the end I went with what I knew was working; I bought the same system Luke was using, it was a balance between function and budget. I paid about $60 for this 1.2ghz 12 channel system with a transmitter operating at 400MHz that came with all of the cables and bits and pieces to get me going. I am going to have to make some changes to the cables but we will talk about that later.
Lets Talk UHF
One of the solutions to the video downlink issue that people are turning to is UHF for your control system. Ultra High Frequency equipment operates between 300MHz to 3GHz frequency range. These systems utilize some manner of ground station and it gives you fantastic range and penetration and frees up frequencies in the 2.4GHz range for your downlink. The best part about this type of system is its ease of use. When you buy a UHF system it comes with the transmit module and a receiver. The receiver is much the same type of tech you would find in any kit you would normally but for 2.4GHz.
The transmitter though is the genius, it takes advantage of the trainer plug on the back of most air radios. When the trainer is active it diverts all commands from the 2.4GHz antennae and sends them out the trainer plug into the UHF transmitter and off to the aircraft. A simple solution using tech that most of us already have!
I looked closely at the Dragon Link and Luke introduced me to DTF which uses OpenLRS. This is just one of several UHF systems but has some highly interesting features, for example it has a lost model beacon which emits a series of tones from a downed aircraft that allow you to hone in on it. The other major draw, for me, is the price. This system is very affordable and ships from companies that are inside Canada which is another draw for me as I don’t have to deal with customs!
It’s In The Mail, Now What
So my gimbal is enroute, my video downlink gear is in the mail not all I can do is reflect on my choices and wait for the mailman to show up. The whole goal I set out to achieve was to get this 350QX FPV capable without spending an arm and a leg. I had entertained the idea of simply selling the Blade and buying a Phantom but I didn’t believe I would get a sufficient return on my initial investment to make it worthwhile. I have learned ALOT in the last month or so and I have to say I am looking forward to getting this gear hooked up on my heli but my research (Thanks Fuceye) lead me down a road I wasn’t expecting. When I sat with Dave talking about my desire to do a custom build multi rotor and my concerns about it spiraling out of control financially he put me onto Team Blacksheep and WHAM I’m starting have thoughts about a fixed wing winter project. Watching some of their videos I start to think THIS is the FPV I want to get into!
Here is a Video from the Team Blacksheep Library
I think, at this point, I would warmly recommend that if you are looking at FPV; DO YOUR RESEARCH! Do not simply jump into the first gear you look at, this is the error I made in making what I feel was a bad choice with the first gen 350QX. I think my excitement to get into the field and my assertion that I wanted to save money forced me down a road that cost me more time and money that would have had I taken more time to do my homework.
Do I regret going with the Blade 350QX at this point? Yes and No. I think the blade is a great little flier but I think it was rushed to market as Eflite saw that DJI was eating their lunch. I have no hands on experience with their gimbal and am highly unimpressed with their camera but I still am way under the dollar amount I would have had to spend on the Phantom. I know spending the extra money on the DJI would have given me an out of the box AP ready heli, but where is the fun in that. I have had a lot of fun researching this project and I am looking forward to tinkering with this system to get it squared away. I think time will tell if it was worthwhile, I am hoping once I get home and my gear starts to arrive things will really come together and we can really get some great stuff.
Let’s Do Some Ghetto FPV
There is no law to say you MUST have a downlink to rock some aerial photography. You can get some great results by simply strapping the GoPro onto the mount and heading into the great blue yonder! Set you camera to shoot time lapse, I set it for one photo every 2 seconds. On and average battery you then have to wade through about 300 photos which doesn’t take long. As you can see from below you can still get some great results without going to all the effort of gimbals and downlinks.
Granted there are some obvious drawbacks. The higher you go with the heli the harder it is to see the thing and orient where you are shooting. In the above photo I’m not sure what my altitude was but I was high enough that I could really see the heli and hence couldn’t see it’s orientation. The beauty of the quadcopter is that you just need to be able to tell which way to steer it. I was in AP mode for that shot and it took a lot of input into the sticks to get where I wanted to go but even though I was way up, it still felt very stable in the air.
So, finally the gimbal has arrived and I began the process of mounting it to the body. The replacement parts from Horizon Hobby arrived in an impressive amount of time. The original mount is basic but effective and I wanted to replicate the position as I wanted to make sure the camera was far enough forward that the blades and skids would not get in the picture when I was banking.
The gimbal was more or less plug and play. I read alot of stuff on the internet about these gimbals and people seem to love ‘em or hate ‘em. It seems you are at the mercy of the people way over seas as to whether or not you get a good unit or not. The main problem you have to tackle is that the top plate of the gimbal is not set up for the Blade, the holes are drilled, I believe, for the Phantom. I sat and thought about how to do the mounting and of course looked to You Tube. There are a couple of improvised quick mounts that i really liked, including one that utilizes a GoPro quick mount so that the gimbal can be quickly removed. In the long run I only intend to use this rig for AP so I decided to mount the gimbal in a permanent position. I looked about for some hardware to use and ended up diving into my Baja parts bin.
I backed the bolts with nylon lock nuts to avoid any chance the mount loosening due to vibration. I got some feedback on the web saying y mount was too far back and would cause the heli to fly nose heavy. I didn’t find this to be the case and it actually held level flight and the forward engines didn’t seem any hotter than the tail engines. I figured it wouldn’t be an issue as this was more less the same mounting location for the eFlite gimbal. Once I add in my transmitter for the down link to the rear of the heli that will hopefully balance it out more. We will talk about my “adventure” with the video down link in a moment.
Lets talk a little more about the guts of the gimbal. When I pulled it out of the box the gimbal was all assembled and there was a startling lack of any instructions. The one thing I was really hoping for with this specific board was the ability to line in a remote receiver to give me pitch control on my 7th channel. The one way to do this manually is to push that little white button on the board and move the camera, when the board resets it will stabilize with the camera in its new position. This gives you the ability to aim it down slightly for the purpose of AP.
I haven’t done a ton of research on this board but the same gimbal from Good Luck Buy has a specific set up on the additional pins that allow for pitch control. I will update this section once I do a little more research. When I went out for the test flight I had a hard time getting the GPS to lock. I think the problem was that I was running the power cable over the top of the body was causing interference with the GPS antenna. When I moved the cable under the belly of the bird the GPS locked but the RTH didn’t work right. I assume I am getting noise from the gimbal but am not sure, I need to do some more testing and work towards isolating the problem.
The Down Link
The video down link was something that I did much research on. There is a wide array of choices and frequencies not to mention antennas. My God! antennas are a whole other blog. In the name of saving some cash I elected to go with a 1.3 GHz 12 channel receiver with an 8 channel transmitter. Now with this system there is a wide array of power levels to go with. The problem is that if you go with too much power you end up throwing a lot of RF noise which will mess up your video. Now I am by far no where even close to an expert in RF tech and I looked to what some of the guys I have know are using an elected to go with a transmitter that was 400 Mw.