Thread Tools
Mar 08, 2018, 05:13 PM
Fan of just about anything RC
SoloProFan's Avatar
Mini-Review

Diatone 2018 GT-M3 SX - Stretched X 3 inch FPV Racer (review, work in progress)


It seems that "3 inch is the new black", to loosely borrow a quote from the fashion industry.

This time it's Diatone who steps onto the plate, with their 2018 GT-M3, both in True-X and Stretched X configurations. Banggood provided me the chance to try the stretched frame version, and I'm looking forward to checking it out.



Update July 2018: Diatone has released an updated version of the GT-M3 series, fixing many of the shortcomings of the first batches. For a review of this "V2" version, please check here: https://www.rcgroups.com/forums/show...8review-wip%29



Disclaimer: I don't get paid, or in any other way make money with reviews like these. Product specifications and quality may vary at the manufacturer's discretion, and are beyond my influence. I cannot guarantee you will get a product that performs exactly the same as seen and described in this review. There is always room for a general discussion on the reviewed item, feel free to comment, but if you are planning to add a long review, instead of some summarizing remarks, it would be appreciated to put these in a new review topic or on your RCG blog page. And please, no affiliate links!

Note: When clicking a link that is posted in this review, some text or numbers might be added to the link, making it appear to be an affiliate link. However, all links I post in the review are clean, and this addition is done automatically by your browser and forum software, so sadly beyond my influence. If you don’t want this to happen, copy the link, then paste in an address line of a fresh browser window/tab.



For easy navigation, here's a list of contents:

1: Specifications (posting #1)
2: Unboxing (posting #1)
3: Preparing for 1st Flight (posting #1)
4: Flying Performance (posting #1)
5: Camera & FPV Performance (posting #1)
6: Suitable for a Beginner? (posting #1)
7: Preliminary Verdict (posting #1)
8: Additional Tuning, Modifications & Other Info (posting #2)
9: Suggestions for Improvements (posting #2)




1 - Specifications:


First, let's start with a picture and a link:



https://www.banggood.com/Diatone-201...p-1240959.html

When this review was started, the GT-M3 was priced around 154 euro.



2 - Unboxing:

The GT-M3 comes in a surprisingly small box.




Quad is zip-tied to a cardboard insert, so in theory it's secure enough. But since the box is made of rather thin cardboard, and the insert is quite loose inside the box, the previous picture shows that one of the motor shafts had already made a tear in the box. Motor seems unharmed, but still it feels a bit unnerving when you receive a box in this condition. Anyway, here are all the contents of the box:




The frame is light and compact, narrow arms and a metal upper frame:




The VTX antenna is located very close to the right rear prop. I assume that is intended to keep the quad low profile to fit inside the small box:




A receiver connection wire has been soldered to the board, with a connector fitted to it. So far I don't know of any receivers that plug right into that connector, so I'll probably end up soldering on a new wire.



3 – Preparing for 1st Flight:

The GT-M3 comes fitted with an F4 flight controller, which is identified as FuryF4OSD. Flashed with BetaFlight 3.2.1 firmware, and seems to have been tuned. A full CLI dump can be found attached to the second message in this thread, and here are screenshots of the stock PID settings and Filter settings:






Since I didn't have a receiver to plug right into the wire that is attached to the flight controller, I soldered on a different wire, which plugs into the R-XSR receiver, that I wanted to install to the GT-M3.






to be able to make a direct comparison, I will conduct the first tests with the same 3S 700mAh Turnigy 60C battery, that works so well on several other 3 inch quads I've flown. So after installing that, using a different battery strap, since the stock one didn't feel very suitable, the quad looked like this:








4 - Flying Performance:


Due to bad weather, first test hovers were done inside. The quad hovered nicely and the motors made a smooth high pitched whistle. Even on very low RPM, when testing Air Mode's idle speed setting, the motors run really smoothly. Very confidence inspiring for the first outdoor test.



5 - Camera & FPV Performance:

The installed VTX is the TBS Unify, just like the GT-R90, a very capable VTX, with different power settings, and a stable signal. There is a catch though, it comes in "locked" mode, so when you try to adjust the channel and band with the single button, it will suddenly skip certan bands, because these are not allowed in some countries, unless you have a HAM license. To unlock the VTX, you need to get to the power setting, then press and hold the button for 30 seconds. When unlocked, both leds will be lit.

I did unlock the VTX, to set to my favorite 5705 frequency, but decided to try first at the lowest power setting, to see how the FPV performance would be. Here's a video of the first flight:

Diatone 2018 GT-M3 Sretch X - First FPV Flight, stock PIDs, 3S, VTX set to 25mW (3 min 38 sec)



Apart from some noise in the image, the colors are nice, and range is decent for the 25mW setting. The quad handles really well on stock PIDs, good control, and even on 3S there is lots of power.


Update 12 march 2018:

Made a new flight with the Diatone GT-M3, this time with VTX power set to 200mW, for better range:

Diatone 2018 GT-M3 Stretched X - Second test flight, stock PIDs, 3S, VTX set to 200mW (2 min 58 sec)



Signal is more steady, though naturally it doesn't fix the constantly present noise in the image.




6 - Suitable for a beginner?


I would strongly advise against it. While very stable in self leveling mode, it's got serious power and speed, no prop guards, and no spare props. Not the best recipe for a beginning RC pilot.




7 - Preliminary Verdict:


The GT-M3 Stretched X is a very capable flyer, right out of the box, even on just 3S, it handles great. The camera offers nice image quality, and the VTX has a strong FPV signal, even on the lowest power setting. Sadly there is some noise so the FPV quality isn't as clean as it could have been. It also loses points for a rather poor battery strap, not having a buzzer, no leds, no spare props, and the box doesn't protect the contents very well. Also adjusting the camera tilt angle poses problems.

So while being a really well performing FPV quadcopter, it's not as polished as for instance the GEPRC MX-3 Sparrow, or some other currently popular 3 inch FPV quads.



Pros:

- Smooth and powerful motors
- Well tuned
- High quality TBS Unify VTX
- Good camera
- F4 flight controller
- BetaFlight OSD
- Current sensor



Cons:

- Noise in FPV image
- Camera can't be set to any angle
- No spare props
- No Buzzer
- Poor battery strap
- Box doesn't protect contents very well


(to be continued)
Last edited by SoloProFan; Jul 30, 2018 at 12:38 AM.
Sign up now
to remove ads between posts
Mar 08, 2018, 05:13 PM
Fan of just about anything RC
SoloProFan's Avatar
8 Additional Tuning, Modifications & Other Info



9 Suggestions for Improvements:

While a great flyer, the GT-M3 series is far from perfect. These things could be better:

- Cleaner FPV image
- Frame that allows to easily select different camera angles
- Buzzer
- Leds
- Better battery strap
- Bigger and stronger box, to better protect contents during shipping
Last edited by SoloProFan; Mar 11, 2018 at 07:00 PM.
Mar 10, 2018, 12:50 AM
Fan of just about anything RC
SoloProFan's Avatar
Added pictures and more info.
Mar 11, 2018, 12:24 PM
Fan of just about anything RC
SoloProFan's Avatar
Added FPV video.
Mar 12, 2018, 02:42 PM
Fan of just about anything RC
SoloProFan's Avatar
Added new FPV video, now with VTX set to 200mW, for more stable video signal.
Apr 15, 2018, 02:26 AM
Fan of just about anything RC
SoloProFan's Avatar
Diatone appears to have released a V2 version of the GT-M3 series, fixing the video noise problem, and also making some other changes here and there. I hope I'll get the opportunity to get my hands on this updated version. Meanwhile, here are a few videos of the original version, just having fun flying around:

Diatone 2018 GT-M3 Stretched - Test flight in a decent breeze (3 min 22 sec)


Diatone GT-M3SX - The first version, so not perfect, but still a lot of fun (3 min 13 sec)
Jul 29, 2018, 11:16 PM
Toycar racer
Dbz619's Avatar
not many updates since you started the review on this one. Looks great. How do you like it compared to your favorite Sparrow and xjb-145? How thick is the arms (3mm or 4mm?) Is it durable? And are the arms separate or is it one full bottom piece? thanks solo!
Jul 30, 2018, 12:48 AM
Fan of just about anything RC
SoloProFan's Avatar
Quote:
Originally Posted by Dbz619
not many updates since you started the review on this one. Looks great. How do you like it compared to your favorite Sparrow and xjb-145? How thick is the arms (3mm or 4mm?) Is it durable? And are the arms separate or is it one full bottom piece? thanks solo!

I've always felt the first batches to be more an advanced prototype, with great potential, but some rough edges compared to other offerings in the same size class.

The arms are 3mm and 4 separate parts, so if you break one, you only have to replace one.

The key performance feature of the first series was speed, but at the expense of flight time, and also the FPV image is noisy. Not something I would fully recommend, as there are quads that may be a touch slower, but do offer more tight handling and better FPV setup.

However, with the changes they incorporated on the "V2", basically fixing most, if not all shortcomings of the first batches, and even improving on some of the strong points, I think it might outperform the Sparrow and XJB-145 by a small margin. At least these would form my personal "3 inch top 3", with Geniuser 160, DT140 (if fitted with better camera) and some other quads, close behind it.

I've added a link to my V2 review to the first message, so if you haven't seen it yet, please look there.
Jul 30, 2018, 05:05 PM
Toycar racer
Dbz619's Avatar
Thanks solo. I'll check out the other thread you have for v2. Sounds like geniuser 160 would be a better deal, since it's on sale, but only a few in stock, vs the diatone high price. I'll probably hold out until some great deal, but also been flying my 4" floss and thing is super nimble. I thought my xjb-145 was my go to, but I've been flying my 4" floss more now. Both great but floss's are sweeet! Makes my xjb-145 feel a little slow now.
Jul 31, 2018, 12:18 AM
Fan of just about anything RC
SoloProFan's Avatar
If you want speed on a budget, the Dragon DT160 seems the best bet, it's almost as fast as the Diatone, if I remember well from Andy RC's speedruns, and it should now come bundled with a better camera as bonus. The Diatone V2 flies better, but it's also more expensive.

If you can convince some fellow pilots to do a group buy of the MX3 Sparrow, it can be found for something around 100 euro for the PnP, if you buy 3, which is really sweet. It's not the fastest 3 inch but certainly no slug, and there are few quads that handle as crisp as the MX3, imho.
Jul 31, 2018, 03:27 AM
Toycar racer
Dbz619's Avatar
Actually more than just speed. My floss is super nimble and smooth. Cornering, banks, flips, rolls, etc are super nice, basically everything I do with it, compared to my xjb, is 10 x better. I guess I should have been more accurate. The floss flies way better than my xjb-145, but my xjb-145 is my #2, a bit behind the floss. Maybe it's just the pids I have on it. Either way, it's my #1 now
Jul 31, 2018, 04:35 AM
Fan of just about anything RC
SoloProFan's Avatar
I know what you mean, better "connection" with the quad. That's what I have with the MX3 "V1" and GT-M3 NX V2, as well as Leader 120 for instance. Part tuning, no doubt, and part is probably frame, motors, props, etc, making it feel "just right".


Quick Reply
Message:

Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
New Product Diatone 2018 GT-M3 Normal/Stretch 130mm/143mm PNP FPV Micro D Gains Micro Multirotor Drones 118 Jul 11, 2018 12:20 PM
New Product Diatone 2018 GT-M3 Normal Plus 110mm/170mm RC Drone FPV Racing F4 OSD TBS G1 600TVL 2 scousethief Banggood.com 2 Mar 12, 2018 02:42 PM
Discussion Diatone 2018 GT-M3 Plus 110mm/170mm RC Drone FPV Racing F4 OSD TBS G1 600TVL 20A BobFromMars Banggood.com 1 Mar 06, 2018 07:16 AM
New Product Diatone 2018 GT-M3 Normal X 130mm and Stretch X 143mm smg24 Banggood.com 0 Dec 18, 2017 05:28 AM
Mini-Review RealAcc GX210 - X-type FPV Racer Quad (review, work in progress) SoloProFan Mini Multirotor Drones 7 Dec 08, 2016 04:28 PM