Servers by jDrones

Sub 250g Micro-Drone Flying More than 25 Minutes!

(S) #9

I wonder how that GPS dipole antenna performs from the “32.4km Long range FPV…” vid, compared to the tiny patch antenna on the mro/matek gps’s?

All the copters people posted in this thread are amazing!

(hans bert) #10

2x US18650VTC6 (now you can get better ones)
pixracer fc (every plugs, connectors removed)
modded 5x3 props
DYS 1306-2300KV motors
Hobbywing XRotor 4-IN-1 Micro 20A ESC 3-4 (much to heavy today)
Beitian BN-880 gps
my frame is around 9g, motors are glued, no screws
legend 1 camera striped with modded firmware and lense

(Ricardo Maroquio) #11

Yes… I will try this mod with one of my Matek Compass+GPS. I found two mods that can be usefull for endurance improvement too. The first is to decrease the 1306 motor KV to around 1800 and the second is to remove the LVC from ESCs. I’m studying these subjects now…

(Ricardo Maroquio) #12

Okay… it is very close to the one I posted in the video above. I ordered some 1306 motors and 5” propellers to go further. There is a Kakute F7 Mini now, weighing only 4g. I found a BLHeli_32 28A 4in1 ESC with only 4g too. Everything is on the way… :crossed_fingers:

(hans bert) #13

no bec and no current sensor?

(Ricardo Maroquio) #14

Yes… Not mandatory, imo… Anyway, I ordered Airbot Ori32 too. It is a biiiit heavier, but have full telemetry. :wink:

(hans bert) #15

current/voltage is very important for me.

(Ricardo Maroquio) #16

I think the voltage sensor is really important for security reasons, but current is not so much. Considering the weight of a simple power module (2.54g) to provide the voltage measurements, maybe the Airbot Ori32 would be a better ESC option, because it have full telemetry too. Also, my hope is that, as both ESCs firmware is BLHeli_32, I can disable the LVC function. BLHeli_S does not have this option… :confused:

PS: I just figured out that Kakute F7 Mini seems to have a voltage monitor… :wink:

(S) #17

The Ori32 esc is the worst I’ve used as far as low voltage… So bad, Airbot admitted it was an issue and refunded me! It cuts out at 7v!! 3.5 per cell! It’s not suitable for 2s. It’s a hardware limitation of the mosfets they use, is the way they described it to me. Changing the LVC in BlHeli didn’t do anything.

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(hans bert) #18

there you go :wink: its not as easy as it seems to be to get to that goal.

(Ricardo Maroquio) #19

Man… it cutts-off power at 7V? Did you turned off voltage cutt-off in blheli32 configurator? I hope this other one works… . I sent an email to Holybro to check if Teko32 mini really does not support 2S. Few options below 8g. Let’s wait…

(Ricardo Maroquio) #20

Yes, that’s true. Hard work ahead…

(Ricardo Maroquio) #21

Are you using Kakute F7 too?

(S) #22

No, I’m using omnibus nano v6

(Ricardo Maroquio) #23

Okay… I just asked because I am suspicious that the Kakute F7 is having a problem with voltage below 6V, not the ESC… :thinking:

(S) #24

A few years ago, I built a 1s copter, before any 1s flight controllers were available.
I basically cut the traces around the FC’s on board power supply and connected a pololu step up/step down regulator in its place. The pololu regulators are tiny so didn’t add much weight.

(Ricardo Maroquio) #25

Okay. Thanks for the tip. I have some Pololu step-down voltage regulators to 5V and to 3.3V, but not a step-up. I will order some and test, just to try to isolate the problem. Anyway, this trick will make me loose the voltage measurement in the flight controller, right? Maybe I will have to use an external voltage sensor or use a BLHeli32 ESC with telemetry. The problem is to find a light weigh BLHeli32 4 in 1 ESC. The lighter one I found is around 10g. I have a friend that is trying to hard remove the LVC from some ESCs for me. He is expert in electronics. In the first analysis, it seems you just have to remove some resistors. In parallel, I’m studying the BLHeli_S firmware source code as well. I found a function that reads the input voltage and check it’s value. It’s Assembly, and I’ve never used it. Let’s see what we can get…

(Ricardo Maroquio) #26

Ops… I just realized that the voltage regulator in you post do the up and down in one device… Hmmm… Much better! :slight_smile:

(S) #27

I was able to get the voltage measurement to work… I figured out which pin was doing the voltage measurement and traced that back to a little voltage divider (two resistors). The voltage divider is necessary, so I cut the trace that was coming from I think the battery pad which I was no longer using, and connected a wire from the voltage divider to my battery… I don’t know where that is on the kakute, but I’m pretty sure it will have a similar setup… bat pad to voltage divider to pin on the processor.

Let me know if you have any luck w/ the LVC on the ESC’s!

(Ricardo Maroquio) #28

Hmmm… Okay!
I will try to do this.
I keep you informed about the ESC hack trying…