Servers by jDrones

A 210g Micro-Quad that Flies for More Than 21 Minutes


(Ricardo Maroquio) #21

Hmm… I didn’t find a topic from him about VL53L1X. I hope he answer this comment… :+1:


(ppoirier) #22

It was in the same thread as above: HereFlow Optical Flow Sensor Testing


(Paul Atkin) #23

matek is very light but if it takes long time to lock - it means you get a lot of interference into it. it is not well shielded, and it is an ongoing issue. i have same problem as i use those matek gps pucks on all builds becouse they are the smallest ones. there is no simple solution for shielding - you need to shield both power and signal lines that feed the gps.
with no interference it locks into 8-12 sats in 20 sec time. with interference it usually locks into 4-6 sats and keeps high hdop for quite a long duration.


(Hugues) #24

Great endurance flight video.

I can confirm this based on my own tests ( https://youtu.be/yueXcnFBmpE ) and a great web site for comparing performance of various Li-Ion batteries ( https://lygte-info.dk/info/batteryIndex.html )

The reason it is the best battery is because with a level of constant drain around 10 amps, the VTC6 from Sony is the one that enables the most mAh to be used versus any other battery brand/model, even the higher capacity ones (like the Efest 3500mAh for ex).


(Ricardo Maroquio) #25

Yes… This website is classic and I bought the same battery analyzer used by them. There is another battery that is good too, but it is a bit heavier. It will make my quad weights about 240g. I will record a video using it. I think it will fly for more than 25 minutes. Maybe a world record?? :joy:


(Ricardo Maroquio) #26

The mRobotics company have a GPS+Compass with the same size/weight as this small from Matek. Check in their website. The weight is around 7g. I use both mRobotics and Matek. The mRobotics one have faster 3D fix and can “see” satellites even when the drone is inside my laboratory…


(Hugues) #27

Just checked it on mrobotics.io web site. It is a copy version of the Matek M8Q (for once americans copy chinese products): same ceramic antenna, same Ublox GPS chip, same size , same weight. The mag chip is from another supplier but this is insignificant.

I also get satellites inside with a Matek M8Q, so this is not a specificity of the mrobotics one.

An sure improvement we can diy would be to solder a bigger ground plane (must be a conductor material suc as copper) to the negative of the antenna and have this ground plane as close as possible to the negative feed plane ot the ceramic antenna. Of course we cannot get it so close as there is at least the thickness of the PCB. To put a ground plane a few centimeters away will not improve GPS reception sensitivity (and increase overall weight. If it is a few centimeters away, it is also not so useful to block EMI anyway).


(cyberpilot360) #28

Nice work! Can you share some more specs about the battery pack? How many cells are you using?
Also make sure yours telemetry module (if you have one) isn’t interfering with the GPS.


(Ricardo Maroquio) #29

Yes… the Matek and mRobotics are practically the same. Only compass is different. But I really had an impression that mRobotics get 3D fix much faster than Matek. I have drones with both. As soon as possible I will do a simple test to confirm that. About EMI, I use a plate of MuMetal 2cm below the GPS+compass. It is extremely efficient and I never had “error compass variance” as I use to have before due to the proximity of components in micro-drones. If you put the MuMetal too close to the compass, the calibration will be a nigthmare, because Earth’s magnetic field will be blocked too…


(Ricardo Maroquio) #30

It is a 2S 3000mAh battery made with two Sony VTC6 18650 cells connected in series. The main plug is a XT30 wired with 22AWG cables. The balancing wire is 28AWG. Let me know if you need a scheme of the connections. Regards!


Sub 250g Micro-Drone Flying More than 25 Minutes!
(Hari .P) #31

Can you please share the frame details.?


(Ricardo Maroquio) #32

It is a 2mm carbon fiber frame CNC machined. I can share a DXF with you if you have a CNC available…


(S) #33

The PCB is different, though… They’re not clones of each other. Things as simple as filtering, capacitors, etc, might make a difference. Both sites (MRO and Banggood, etc) have photos and you can see the different layout.


(Hari .P) #34

sorry to say, I don’t have access to a CNC.
But, can you provide me the motor to motor dimension of the frame, and post a photo of the quad.? I will make it !.


(Ricardo Maroquio) #35

Okay. I did a sketch for you. The values are in mm and the scales are not the same, so, you will have to adjust it. The main frame is 2mm thick and the battery plate is 0.5mm thick. Let me know if you need some other info. Regards.


(Hari .P) #36

Thank You very much.