My first build - Tarot 650 Sport

Ok, I’ll start this off with the typical newbie introduction. After studying this for some time now, and using the recommended learning approach of learning to fly a small quad, I think I’m ready to take the next steps. My ultimate goal is to be able fly over 20 minutes while carrying various camera and other mapping related equipment. But for the first step, I want to focus on the main components while continuing to learn.

My first build is planned as follows:

Frame - Tarot 650 Sport
FC - Raspberry PI 2 Model B
Motors - T-Motor MN5208
Props - APC 16 x 5.5
ESC’s - HW XRotor 40A
PDB/BEC - Pixnor PDB with Dual 5V and 12V Adjustable BEC’s (not sure about this, recommendations?)
LiPo - Dinogy 6S 11000 mAh
PM - Navio Power Module (question below)
AttoPilot 180A module
Manual TX - FrSky Taranis X9D Plus
RX - FrSky X8R

I’ve settled on using the PI / Navio+, the Tarot airframe, and the FrSky TX/RX for manual control. Using eCalc, along with my best other estimates toward AUW, the above config gives very good flight times.

Now the questions:

I want to explore converting this to an X8 as one of my next steps. Can anyone recommend vendors or sources of quality 16 and 17 inch props with a variety of pitches?

I am starting to realize that getting telemetry data to a ground control station / Mission Planner is not feasible without using a second TX/RX (separate from the X9D / X8R combo). I can’t fully get my mind wrapped around why two TX/RX systems are needed, but can someone explain this and recommend a second system? WiFi and cellular systems are interesting, but will probably not work for me due to range and coverage issues. Along these lines, can FPV TX/RX systems provide FPV goodies along with telemetry data to Mission Planner, or would FPV require a third TX/RX system?

I am also very interested in the GPS aspects of Navio+. I use precision GPS (L1/L2) equipment in my work daily, and already have everything I need to handle the base station aspects of an RTK system. Does anyone have experience with acquiring and using L1/L2 capable receivers and antennas that are suitable for quadcopter use?

I’ve seen here that there a wiring work-around to correctly get current and voltage info fed to Navio by eliminating the current and voltage wiring from the Navio PM, and feeding C and V data from the AttoPilot module like, LiPo -> BEC -> AttoPilot -> Navio, I think. However I am uncomfortable with the diagrams I’ve seen. Can someone clarify how the wiring should work?

Alright, fire away, it can’t hurt too bad.

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I am also interested in doing a similar project! keep me posted on how it is getting on !

Lets start with the props. Best I’ve found (and I’ve tried all of them) would be Foxtech Supreme series. They’re so much lighter and stiffer you’ll see a huge difference in flight performance. A little pricey though. As for radio link, the easiest solution is still 3dr radios or clones. I personally use a mix of RFD900, RFD900u and 3dr’s depending on the application and range required. A RFD900 at the base station and a 3dr on the air side will still give you a huge range beyond you control radio link. Here’s a link to the RFD modems

As for using attopilots, are you running more than 4s packs? If not, I’d stick with the standard power module. If you are, have you looked here: I use this on most of my units that are 6s to 8s. Note you will have to calibrate you current multiplier. Not too difficult, but it will usually be off a bit.

Ian, I am planning to document the build and post pictures and results as I move along. Thanks for looking.

Shaun, I am planning to use this build as a stepping stone, so some of the components are geared toward the future. For my first steps I will be using the props I referenced in my first post, but eventually, would like to convert (with extended arms) or build a separate X8 configuration. As I move forward I will look into the Foxtech Supreme series. Do you know if they make 16 and 17 inch props with varying pitches? I did not see any in a quick search. My studies up to this point lead me to believe that a coax system where the same diameter props, with a lower pitch on top, yields a good combination of efficiency and response. Of course there is no shortage of opinions out there, so I plan to test. Here is a link to a reasonable study (?).

Yes, I am starting with 6S, as that is where I believe I need to end up. In a post I saw yesterday (after mine), CodeChief, suggested a power module that I had not seen and I believe will suit my needs and eliminate the need for the AttoPilot. Thanks CodeChief!

I have been communicating with pneves (Paulo - Airborne) regarding their MavLink to FrSky SmartPort Converter, and Paulo helped me understand some of the difficulties associated with manual control radios and their relationship to telemetry radios. I will definitely look into the RDF radios suggested by you and Paulo.

Thanks Shaun, and Texas size thanks to Paulo!

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The coax efficiency problem was a big question I was asking myself a while back. We’re running everything from 15" X8’s the 28" heavy lift systems for lidar. After a lengthy research project with the University of British Columbia we found similar results to you referenced article. The real world outcome was two well designed propellers of the same pitch and diameter performed better than an optimized combination of lower quality props… And the sad truth is the efficient high end propellers are far and few. No chance of finding a good quality (efficient) 28-6 and 28-8 for example. I hope some manufactures come out with some varying pitch versions…

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Which LiDAR system are you carrying? I’ve been looking at the Velodyne products.

Thanks for the prop input, it looks like I’m on the right track.

Regarding RC systems, how are you connecting your radios? I am planning to use the FrSky X8R, and realize that I will need some way to convert to PPM from SBUS. Initially I was planning to use Airborne’s SmartPort converter, and still hope to do that, but in talking with them, the UUART version is the only one that is stable right now. It looks like the RFD900 you referred to requires the UUART port. So unless I’ve got something mixed up, it looks like I’ll have to get FrSky’s SBUS to CPPM converter. Does this sound right, or is there another way that I’m missing?


I’m running an x8 configuration with 1555 cf props, mn4014 370kv, xrotor escs , and 20k mah 24v. It’s an excellent setup. I tried longer props, different voltage, etc. This is the winner. Don’t run simonk escs :slight_smile:

it’s over powered for mapping which is what I use it for. It runs at 50% throttle with a sx260 on 2 axis gimbal and 2x 10k mah 24v 10c lipos. Flight time is between 25-30mins.

Despite the excessive power and inefficiencies of the coaxial setup, where this setup shines is in inclement weather. Wind? What wind? :slight_smile:

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Aquila, Are you using OPTO XRotors? I’m looking to use BLHeli on my XRotor OPTO’s, but delivery is sloooooooow!

What frame? and gimbal? I’ll have a look at the SX260.

Thanks for the input!

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I wouldn’t even mess with bheli, honestly. Unless your after something very specific. The stock xrotors are fantastic. A little secret to getting flawless performance out of any x8! I found it a while back and can confirm its the best. I have zero sync issues.

The gimbal is a cf diy 2 axis “card camera” kit with 2212 gimbal motors. You need to do some modding to fit an sx260 but it fits. The sx260 or sx280 is fast enough to shoot from a fixed wing so this gives some flexibility in your collection from a multirotor.

The frame is a heavily modded tarot 650…

In this picture, it’s running a pixhawk, but in currently in the process of switching it to a navio. Not much changes but some antenna placements and I can git rid of the static tube and use the external ms5611 I have hooked up to my navio. Both the static tube and external ms5611 work like a charm to eliminate the inevitable low pressure pocket that is very pronounce on x8’s.

Side note - you can get a Cirus 24v+ 90a power module on ebay for $10ish. Easy as it gets, no problems in mission planner with lipo monitoring. Just connect it like a normal power module.

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Aquila, that sounds like good advice on BLHeli. I’m glad to hear you are having good success with the XRotor.

The gimbal / camera setup will probably happen later, but it’s not too early to start planning, thanks!

With your mods and all, what is your AUW?

You’ve certainly given me more to research regarding the MS5611 setup. Navio+ has the MS5611 on board. Are you saying you will also use an external MS5611 in conjunction with this?

As I mentioned earlier, CodeChief suggested a power module similar to the Crius, and I have a similar one on order.

Thanks Aquila, it looks like you have a lot of hands on experience with this!

AUW is about 5000g , ecalc gives me mixed 20min, hover 26min. But I have found my average flight time to be 27min at a slow boring mapping pace and 30mins at hover :blush:

As for the ms5611, i disabled the onboard ms5611 and enabled an external unit and mounted it up above the low pressure “bubble” that causes the loss in altitude during movement. This thread explains the issue and the concept on how to fix it with a static tube:

My tests showed both methods seem to work just about the same. The external ms5611 is just less hassle, cleaner, and less risk of failure, thank you Emlid! :smile:

I found the static tube to be a exercise in patience. And no matter how you make your seal over the baro, the risk of failure is just greater than the external baro.

Tıp - the ic2 lead going from the external ms5611 to the auto pilot needs to be as short as possible, so move your auto pilot up to help mitigate the length of the lead.

This is good stuff Aquila! In general, how high above the upper props are you placing the external MS5611?

That is dependent on the build and its characteristics. But I think 150mm - 200mm above the tops of the props will be where I end up mounting it on my frame.

And always always, regardless of where your baro is, onboard or external make sure you isolate it with the proper foam! This is crucial. But I won’t go into that as there are lots of threads and references to this this practice on the interwebs.

Thanks Aquila, I’ll be looking more into this as I move further along. From what I can see, you are correct…lots of opinions out there.

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Do you have a full parts list?

Ian, The list I gave in the initial post is very close to what I have in hand, or on order. The exceptions are: the power module and I have now decided to go with the RFD900+ radios for GCS telemetry. With regard to the power module, CodeChief (in a separate post) recommended using a more robust power module for power systems greater than 4S. It may be a few weeks, but I plan to document and post results of the build as I go.

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any updates on your project?? especial for what power module should be chosen when a multicoper is powered by 6s lipo battery pack or higher?

@aquila are you gonna have a try on 3 axis gimbal with storm32 controller [1] on your tarot 650 sport

[1] SToRM32 gimbal controller with Navio+

Samuel, nothing new yet, still gathering components. The power module I ordered is:
Andoer APM2.5.2 APM2.6 Flight Control Board Pixhawk Power Module V1.0 Output BEC 3A XT60 Plug
It supports up to 7S.

John, looks like you have already ordered a Storm32 BGC (Brushless Gimbal Controller) for taking control of 3 axis gimbal ( or 2 ). But, what gimbal are you gonna employ in order to mount what camera you are gonna pick up from the market?