The Diatone GT-M3 is a 3″ Micro Quad in a stretch X frame. It’s a PNP model which means it comes pre-built pretty much with everything you need but a radio receiver. In this review we will take a close look and I will show you how to set it up and how it performs in the air.
Buy the Diatone GT-M3 PNP Racing Drone from:
The Stretch X is designed for racing while the Normal X is designed for freestyle as discussed in our mini quad frame buyer’s guide. But I don’t see why you should be restricted by these configurations :)
- Frame Size: 143mm, fits 3″ propellers maximum
- F4 Flight Controller
- MPU6000, allows 8K/8K Looptime
- Betaflight OSD
- 16M Flash Memory for Blackbox
- 5V BEC
- Current Sensor
- Camera: Runcam Micro Swift 1
- VTX: TBS Unify Pro
- ESC: BLHeli_S 25A ESC Dshot600
- Motor: Edge racing 1408 4000KV
- Supports 3S and 4S LiPo
Really good spec and all top notch brand name components :)
I like how the GT-M3 is shipped with prop nuts of all different colours. The build quality is just excellent and the design is very well thought out.
Diatone’s recent pre-built models are all shipped with TBS Unify Pro video transmitters. They could probably have saved $20-$30 by using a generic VTX just like they’ve done with the FPV camera, but I appreciate having a brand name VTX on the model. Having all the latest and greatest components onboard makes it one of the most premium micro models on the market.
They designed a PCB board to house the VTX which contains what seems to be a power filtering system for clean video. All the capacitors are well protected by the frame and nothing is sticking out.
The arms are 3mm thick and replaceable, sandwiched by two 1mm plates. This makes a super stiff frame. Carbon fibre looks to be of good quality.
The countersunk screws on the bottom plate are such great touch in the design. This prevents batteries getting puncture from screw head when landing or crashing.
I really like the frame design, if you wish to build one with your own electronics, you can get the frame separately here:
- Stretch X (143mm): http://bit.ly/2xLnT8I
- Normal X (130mm): http://bit.ly/2syGFeg
Diatone decided to use 20AWG wires for the X30 pigtail, which I would consider small for the 1344W rated power, with a peak power of 1548W. For 4S that’s roughly 80A to 90A!
I guess they are trying to make this quad as light weight as possible, by using the smallest possible wires for this build in the cost of higher resistance and power loss. That shouldn’t bee too big of a problem if we don’t draw that kind of power constantly.
In my testing with 4S batteries, the quad draw no more than 30A in high speed cruising, and no more than 60A in punch outs. Not quite close to the rated power, but at least we know it should be a problem for the thin wires.
Installing the Radio Receiver (RX)
I like the Diatone GT frame design, you only need to remove 2 screws to access the FC stack by lifting the cage up.
Here is the connection between FC and R-XSR. I am using TX6 (UART6) for SmartPort. Because it’s an F4 flight controller without built-in inverter, I am using the “uninverted” Smartport signal. Or you can use soft serial to handle the original “inverted signal” if you want.
I installed the receiver on top of the VTX with some foam tape. The antennas are fixed to the rear arms with zip ties and heatshrink.
A bit Heavy?
The GT-M3 weighs 142g without battery which is pretty heavy for a 3″ quad. The frame might look a bit “bulky” but it’s actually pretty light weight at only 21g.
The main weight contributor is the 1408 motors which weigh 19g each. Most 2.5″ or 3″ builds these days run 1106 or 1108 motors that are around the 8 to 10 grams mark, which makes a 40g weight difference between these builds.
For this reason you really have to use 4S to bring out the power in these motors. 3S is fine too if you just want to cruise.
I am using 4S 1000mAh LiPo with it, 800mAh would also do nicely. Make sure the batteries come with XT30 connector though.
Setting up in Betaflight
The quad ships with Betaflight V3.2.2, so I decided to update Betaflight firmware first to the latest V3.3. If you are not familiar with Betaflight you can skip the update and just set it up to fly. Here are the settings I used in Betaflight.
- 8K/8K (Gyro Sampling, Looptime)
- Setpoint Weight: 0.95, Transition: 0.2
- I just left PID at default for now, will come back when I have come up with a better tune
Testing, Flying and Final Thoughts
Quite a few people complained about the motor bearing wearing out quickly on 4S. I’ve only flown the quad for a few batteries so it’s still too early for me to comment on durability. But I will come back and update if i have any issues with it.
To be honest, the design of the GT-M3 is close to impeccable. Diatone has gone through at least 3 iterations of the GT series to find a recipe that works. The parts are solid and have excellent quality, you do get what you pay for.
The GT-M3 flies very much like a 5″, perhaps not as fast, but it’s very snappy and has great acceleration. Perfect for indoor racing, and outdoor acro flying. It’s quieter and less intimidating than a 5″ mini quad to fly in a busy park :)
And yes, so far I am very happy with the GT-M3 and I do recommend it.
I know this is years later, but just received the GTM3 from my dad. After updating firmware no pid tune is in place and curious if you could share what numbers you were using or what you found to be a great balance?
I no longer have this quad so I don’t have the numbers for the latest version, the old numbers are unlikely to work as expected in the new firmware, but Betaflight Default should work pretty well. If you want the most out of it you probably want to tune it yourself. I have a tutorial here.
I installed a Crossfire Nano receiver, keeping the 5V and Ground connections where they were ON THE FC and TX6, RX6. Now, the issue was sometimes the receiver wouldn’t connect to the transmitter. 4 times out of 5 it didn’t work. I did the binding process over and over, and sometimes it worked and many more it didn’t. I resoldered everything and no luck. I resoldered again, this time changing the 5V and Ground from other points on the FC. The problem persisted. Now, suddenly the quad only beeps 3 times (not 5) at start up, the receiver won’t connect and Betaflight won’t recognize it. I would really appreciate your advice. Thanks!
I would sort out the binding issue first, which is unrelated to your flight controller.
Try to contact TBS for support, you paid premium price for it. If it’s a hardware issue you should be able to get replacement.
Once binding issue is sorted, than you can look at the connection issue to flight controller.
How durable is diatone ? Are the eletronics good?
The electronics are superior, I have 5 builds using the same Diatone Power Stack and it is bullet proof.
Escs have tons of capacitors for clean video signal. Mated with the F405M FC this is simply the best stack for the money.
I love the Diatone GT M3 and fly it lots. The only complaint I have are the inferior bearings Sunnysky has used in their motors, because the motors are simply what makes this little powerhouse, and that it is. I have ordered replacement ceramic type bearings as replacements. Once done I will have a bullet proof 3″ build that can be flown day in and day out without any issues whatsoever.
I got a lot of trouble with the M3, strong drift to a side in Acro or Auto Mode. Updated BF with BF tune from Diatone but its not getting better. Any solution?
Maybe Can you try swapping the left motors to the right just in case it’s faulty motors.
Best to join our forum if you want more prompt response on troubleshooting help: intoFPV.com
Does anyone know if I can use a 2S battery with this gt m3?
Yes but it’s will feel very much under powered :)
Well I start with first min of flight hit branch, ripped all the wires video and rx. My problem is the pad for sbus is ripped off was still on the rx wire, as well as the power pad. I have my power from another place for the 5 volt. What to do for sbus I’m totally confused. Should i use the rx6 and the un invented pad on the rxsr. Am I close ?
Thanks in advance
The arms on my M3 stretch X shift/wiggle if a pull on them slightly. Do yours move at all if you pull them? I think it’s causing my motors to sound rough/vibrate when I throttle up. Any feedback would huge. Thanks – Carlo
They come with flat head Phillips screws which easily cam out when trying to tighten.
Replace them with a socket type head or equivalent, and your problem will go away. They have to be super tight or the arms will move.
Especially the front arms.
What’s faster the GT-M3 or Babyhawk R 3inch?
I need a replacement arm, since they are “replaceable”, can u point me in the right direction? I can’t seem to find them since I started looking a couple weeks ago.
Same problem here. Cant find those replacement arms anywhere. So… i bought a 2e frame, just for the arms…
it’s available on their website: diatone.hk
Do you think the micro eagle would fit this frame without exposing the lens?
it will fit, but the lens will definitely stick out.
It will fit yes, but the lens will be slightly exposed.
What’s faster the GT-M3 or the GT R-90?
probably M3, the R90 is a smaller 2″ quad.
You mean true X for racing and streched X for freestyle ?
You’re saying it’s an unibody design, but it looks like that’s actually 4 independant arms sandwiched between two plates. Is there two versions around? BTW any idea on how to source the spare arms? Also the esc FC sfot mounting cage?
Frame looks great :D
Yes you are right the arms are replaceable, i got mixed up with another frame I am reviewing at the moment LOL :D thanks for pointing that out! As far as i know spare arms aren’t available separately, but I hope they do become available soon as I’ve asked Diatone about it.
Have you tried the 2.5″ version? I’ve got one on the way in the hope it will perform similarly.
I really want to try that also, but as far as I can tell the main difference is the motors :)
So they should be both brilliant little park flyers.