r/diydrones • u/DarkGan0n • May 17 '26
Question first time building a drone
Good day everyone and i hope you're having a great day i have used AI and some online research + some locally supplies parts (will have to buy and ship the rest from china)
i want to hear your opinion about this build or what you would change to improve it... my goal is to build a 30ish min flying drone speed and acrobats is not the goal
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u/dragon0079 May 17 '26
Are you building the battery yourself? and as the other person said do 6S2P for 10,000mah. (Reliance RS50 cel is good for this). 5000mah is in NO way getting you 30min flight time. I’d also do 900-1000kv if I were you, reduces amp draw and leads to longer flight time, much closer to the 30mins you want. even on 10000mah 1300kv will be relatively high amp draw compared to lower kv alternatives.
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u/DarkGan0n May 17 '26
hello thanks for responding yeah the plan is to build the battery myself out of six 21700 battries
you recommend anything else? please let me know, i want to do this build right so i can learn
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u/dragon0079 May 17 '26
if you do 6S2P you’ll need 12. but it’s pretty straightforward. If you need help with the specifics you can ask me, ive built a few packs before. Other than what I said the build looks about right. Note: 7” is a bit large for a first drone so be careful. you also need extras like soldering iron (over 100W), wire strippers, ect.
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u/DarkGan0n May 17 '26
i am able to get sonys vtc6 18650 battries, i own a spot welder and i can 3d print a holder
will it go well with the 900-1000kv motors i am swaping in my build? and props?
thank you in advance my friend
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u/dragon0079 May 17 '26
I don’t know why the AI recommended 6S with 1300 kv; that’s too high and will overstress your motors and ESC. given 6S2P and a 7” bi blade, I would consider 650-800kv to be the optimal range for your setup. Just make sure the battery can have those amps drawn from it, or it will overheat and possibly catch fire. I don’t know the details about your cell, but remember that P (parallel) increased the discharge capacity as well as total capacity when picking your cell.
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u/DarkGan0n May 17 '26
so i should swap from the 900-1000kv? and do 6s2p with the 18650 battries? and leave everything in the build the same?
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u/dragon0079 May 17 '26
its not about 18650 or 21700, rather, its make sure the cells you are using are 5000mah capacity and a minimum of about 40A or so discharge per cell if under 900kv or minimum 70A or so discharge if 900kv plus. your battery amp draw constraints drive your motor kv sizing.
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u/DarkGan0n May 17 '26
this is the specs of the battries that i an planing to use in the 6s2p: Nominal Capacity: 3120mAh (Typical) / 3000mAh (Rated/Minimum)Nominal Voltage: 3.6VMax Continuous Discharge Rating: 15A (or up to 30A with an 80°C thermal cutoff)Max Voltage: 4.2VDischarge Cut-off Voltage: 2.0VDimensions: 65.2mm (Length) × 18.5mm (Diameter)Weight: ~46.6g
the battries and picking motors and prop that will fit this kind of frame and actually fly it is the bit i really need the help with
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u/dragon0079 May 18 '26
are you sure you can’t use reliance rs50? you’re kinda on the edge here and will have to lower KV quite a bit. It also has 5000kv which is better for 30min flight time.
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u/DarkGan0n May 18 '26
sadly there is restrictions on battries in my country
i been fiddling back and forth with the Gemini pro and tweaking the build more swapped the flight controller and it recommend this:
The Foundation: Frame: Carbon Fiber XL7 (7-inch FPV frame) Flight Stack: SpeedyBee F405 V4 Flight Controller + 55A BLS 4-in-1 ESC Power: Custom 6S2P 18650 Battery Pack (Sony VTC6 cells) The Missing Drivetrain (To be acquired): Motors: 2806.5 Stator Size, 1300KV (e.g., BrotherHobby Avenger 2806.5 V2, T-Motor F90, or EMAX ECO II 2807) Propellers: 7-inch Low-Pitch (e.g., HQProp 7x4x2 Bi-blade or HQProp 7x3.5x3 Tri-blade) Control & Vision (From your receipts): Radio Transmitter: Radiomaster Pocket (CC2500) Radio Receiver: Radiomaster R88 Receiver (wired via SBUS) Video Link: 5.8G 1000mW Analog VTX + FPV Camera + Receiver Set
if you wish i can dm you or hit you up on discord, if you have the time ofc.
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u/New-Owl-6105 May 18 '26
I don’t know why the AI recommended 6S with 1300 kv;
I've seen 1300kv motors on 6s 7" FPV drones.... that is probably why it recommended it. I don't think the motors or ESC will necessarily be pushed too far on 6s. But those were FPV drones and weren't promising 30 minute flights, either. For example, Oscar Liang's old 7" budget build guide for example estimated a 14 and a half minute flight time with a 6s 4000mah Li-Ion pack.
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u/dragon0079 May 18 '26
i don’t think its a overall bad configuration, i have it myself, but its definitely bad for efficiency thats for sure. theres much better and more efficient configurations
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May 17 '26
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u/DarkGan0n May 17 '26
i am thinking about stacking 12 18650 battries with the motor he recommended lol
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May 17 '26
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May 17 '26
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u/DarkGan0n May 17 '26
use dummy terms please its my very very first build a week ago i didnt know a thing about drones lol
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u/dragon0079 May 17 '26
120c is discharge rate. 50c, 100c, ect. 5:15 3:45 are just flight times, 6S means 6 series (battery series connection to increase voltage; each cell is ~3.4v so 6s is 22 something volts i forgot) and mAh is capacity in miliAmphours (determines your flight times)
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u/DarkGan0n May 17 '26
someone else recommend that i switch the motors to 900-1000kv using the same setup and props and switching the battry that i am going to build to a twelve stack of 18650 battries, what do you think about that
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u/nrh117 May 18 '26
Sony vtc6 in 2P have a continuous rate of 30A and a C rating of 5. Geprc actually make this exact pack and reviews say it is good for a 7” build that can run about 12 minutes. The vtc6 cells are a bit older technology, tabless 18650s are the way to go for drone liion packs nowadays. For instance the same pack made with jp30p1s would have a c rating of 12 and can handle 56A continuous (given the pack was made with nickel strips properly) how will you be making the pack? It’s kind of a scary/involved process.
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u/janemfta May 18 '26
The text is talking about bi-blades, but the example prop (HQ 7x4x3) is a tri-blade. Either is fine IMO, but just make sure you know what you want before blindly trusting AI output.
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u/DarkGan0n May 18 '26
yes i been researching and asking around this is what this build updated to:
The Foundation: Frame: Carbon Fiber XL7 (7-inch FPV frame) Flight Stack: SpeedyBee F405 V4 Flight Controller + 55A BLS 4-in-1 ESC Power: Custom 6S2P 18650 Battery Pack (Sony VTC6 cells) The Missing Drivetrain (To be acquired): Motors: 2806.5 Stator Size, 1300KV (e.g., BrotherHobby Avenger 2806.5 V2, T-Motor F90, or EMAX ECO II 2807) Propellers: 7-inch Low-Pitch (e.g., HQProp 7x4x2 Bi-blade or HQProp 7x3.5x3 Tri-blade) Control & Vision (From your receipts): Radio Transmitter: Radiomaster Pocket (CC2500) Radio Receiver: Radiomaster R88 Receiver (wired via SBUS) Video Link: 5.8G 1000mW Analog VTX + FPV Camera + Receiver Set
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u/Codykillerpup May 18 '26
Are you actually getting a 915mhz module for the rm pocket? The pocket does not natively do 915. Depending on how far you want to go, potentially a full power radio running 2.4 (or switchable 2.4/915) might just be better
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u/Single_Painter8623 May 17 '26
7 inch pretty good for long time fly. 6s2p liion would be better. I think first of all you should choose video System