I fancy building a 13" heavy-lift drone for a bit of a fun (and some heavy-lift challenges).
I’ve ordered an 8S1P battery, 1309 Gemfan propellers, 350kv motors, an 8S 80W ESC and F722 FC stack. For the frame, I’ve gone for this: Mark4 13 Inch V2 Version Carbon Fiber Rc Racing Fpv Crossing Drone Frame Fpv Crossing Captain Endurance Heavy Load Frame - AliExpress 26
In this LDO podcast Chris Rosser has got me worried that the frame will not be very good. But he doesn’t make a 13" frame.
Has anyone got any experience with 13" frames?
He also says in that Podcast that an ESC for a 13" drone will cost £300. The one I have ordered did not cost anything like that, which is also a worry?!
@jpmreece and @GVG_Air - do either of you have any wisdom to share with me on this?
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I’d be happy to support any questions.
What is the current draw of the motors at 8S? That will help you spec an ESC properly and allow headroom.
With respect to frames, I’ve had a very positive experience with the Mark 5 frame but very bad experience with the darkstar 20. I was looking very seriously sat the pulsar 10 as an alternative to the Mario 8 I just built.
There is less information about larger frames, are there any other viable alternatives?
Excellent questions! I’m not sure. These are the motors I ordered:
4pcs Flashhobby A4320 4320 350KV 6-12S High Speed Brushless Motor Long Range X-Class RC FPV Drone Model - AliExpress 44
The listing says:
Idle Current: 1.09A/16V
Max Power: 4650W
Max Pull: 9560g
Internal Resistance: 0.05Ω
Configuration: 12N/14P
Rated Voltage (Lipo): 6-12S
Peak Current: 93A
And there is this table:
so at 25V, 100% throttle, they will draw 53.5 Amps.
The ESCs I ordered are these: SoloGood F722 80A Stack 8S Flight Control Suitable for 13 inch FPV Freestyle Drone - AliExpress 26 they say they support up to 80A. So will that be OK? Enough headroom?
On frames, this could be an alternative: GK-V3 10 13 15 Inch Carbon Fiber FPV Drone Frame KIT 7MM Arms For RC FPV Freestyle Long Range Racing Drone Quadcopter - AliExpress it doesn’t have any bracing between the arms though, like the one I ordered, so maybe not as good. Hard to know!
Thanks so much for taking the time to discuss this with me.
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Always interested in this stuff but I don’t really know about frames.
You say it’s for fun and occasional lifting - that says it all really - you’re not building it for industrial applications so you don’t need to max out all your components.
Even a high end esc for this build shouldn’t cost much over £100.
I would stick with that frame and upgade it if you need to.
Looks like enough headroom. It sounds like an interesting build. What is the target lift capacity? At full throttle there is a decent amount of force put through each arm. Rigitity is going to be the key!
I would recommend anti spark xt90 connectors!
@SimonDale I viewed this with interest as I’m currently building an 11" very similar to the one you’re doing. Like you it’s for fun and the challenge of it. But I’ll be flying it LOS! Just to make it more interesting!
I’m having issues jetting the drone to ‘Arm’/Activate ready for lift-off.
Any suggestions?
TIA
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If you are considering LOS it might be worth looking into iNav rather than Betaflight. I’m experimenting on my 8", autonomous flight and recovery feel superior to Betaflight.
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I haven’t got that far, my stuff is still on its way from China.
Is there a CSC that you must do? (Combination Stick Command).
Do you have GPS lock? If you have a GPS it is required for arming.
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Morning @SimonDale I’ve tried most of the usual one - both down/centre, both down/out etc. haven’t tried one up/one down combos yet, but will
I think I remember there’s an option to enable one of the buttons on the TX device, but can’t find it!
Search continuing…
If I find it, I’ll report back…
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No GPS yet, awaiting delivery of the module…
I’ll remember the tip for when I install it though.
Thanks
Silly question:
Have you mapped the arm channel on the transmitter to the arm function in firmware?
No, I don’t remember mapping that one. I’m out ATM I’ll have a look upon my return
Thanks
Let me know how you get on
Well, not very well! To say the least…
RC = RadioMaster TX15 MAX
FC Software = BetaFlight
First I googled and ascertained CH5 is mostly used for Arm function. Set CH5 for arm, assigned to switch SE (2 pos toggle) values 1000 & 2000 as recommended as per ELRS setup
Before First Flight - ExpressLRS
Problems started when I looked for CH5 settings in the BetaFlight S/W. the additional switches are labelled as AUX 1-AUX y so I tried several other configs, all to no avail!
suggestions would be much appreciated…
Do you know the CLI code/syntax to set the thr to zero?
I can’t find an option to set to zero
Aux1 is channel 5. Use the receiver tab with the transmitter connected to validate which channel moves when you click the switches.
Thanks JP, got that far today, the Arm switch now triggers the channel on the Receiver tab, so that’s working.
Just need to reset the throttle to zero as it just will not Arm without it being Zero as it states throttle not zero!
Any ideas please?
I’ve reset gimbals and recalibrated everything I can find and somethings I couldn’t find again if I tried…lol
Zero throttle is the stick fully down, not centered.
There is also a limit somewhere for 0 which I think is 1050 by default, you could increase this.
You should be able to see the arming flags on the config page. With usb connected there should be 1 error.
Make sure you test inside with the props off ( sorry if I’m teaching you to suck eggs with this statement )
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Done it! It now arms on command!
The fix was to set the Throttle channel as low as possible, then recalibrate the pots. Faking that it is below the default minimum of 1000, this seems like a bodge to me, but it works for now. I’ll be looking for a better solution after the build is finished.
Many thanks for all your assistance and suggestions…
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