Diatone 2019 GT-R349 "Rabbit" - Ultimate 3 inch PnP? (review, work in progress) (2024)

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Mini-Review

End of 2017, Diatone introduced a new 3 inch FPV Racer, with the 2018 GT-M3 "Marauder" series. While offering very solid performance in speed and handling, there were also quite a few flaws, like lots of video noise, being one of the most obvious ones. However, Diatone improved this design, fixed the noise issue, and the "M3" became even more interesting. For a review, please check this thread: https://www.rcgroups.com/forums/show...ersion-(review)

Now the GT-R "Rabbit" series has come to take it's place, with the R349. Will it really be an improvement over the updated version of the "Marauder" series, or maybe introduce some new issues?

Warning!!!: There are reports of R349 owners having fried their motors upon first motor test. It is believed the Yaw D-term being set to 18 in default PID settings, is mostly to blame for this. While in some older BetaFlight versions, Yaw D term was apparently used as trick to prevent Yaw Jump issues, as of 3.5.x this value is actually working as D-term for Yaw, and BetaFlight 3.5.x tuning notes strongly advise to have this set to 0 on normal quadcopters.

Note: As Diatone is constantly improving (or at least trying to improve) their products, it could be that pictures and info in this thread differ from the R349 that you have. I will try to cover all the differences that have been found, and keep things as clear as possible.

1) Newer batches of the R349 ship with GemFan 3028, instead of GemFan 3052. Diatone states this was done to reduce the speed and make the quad more beginner friendly. It is well possible that your R349 will come with the PID settings intended for 3052 props, and thus feel very sloppy on the lower pitch props. If you want to fly with the 3028, there are some updated PID settings available from the Diatone website, which basically boil down to raising P-term for all three axis by 10 points. A "Diff" file of the updated PID settings can be found attached to the second message in this thread.

2) Newer batches of the R349 will likely only be produced with the transparant ("lucency") color canopy, and even if you order a black or white version, it will arrive in transparant color. The other color canopies are included inside the box, and you are expected to replace it yourself, if you don't like the transparant one.

Update 2 june 2019:

Apart from changes to the the canopy now using metal threaded inserts, instead of the plastic nuts that can strip easily, some more changes have been made recently. After initially coming with GemFan 3052 props, then switching to GemFan 3028 (which was said to make the quad more beginner friendly) now it comes with both props, so the new owner can choose which ones to install. Also, the Flight Controller has been updated to MK2 version, with some changes to the board layout, and maybe some yet unknow improvements. Info on the F405 MK2 can be found attached to the second message in this thread.

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 written review, instead of some summarizing remarks or a single video, 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 this 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:

2 - Unboxing:

Apparently someone had already attempted to unbox the quad, as both tie wraps, that are supposed to hold the quad strapped to the cardboard insert, were already severed. Maybe Diatone should have used 4 tie wraps instead, to spread the load over 4 points, instead of just 2. On the lighter 2 inch models that might be enough, but apparently the 3 inch version is too heavy to be held down securely during shipping.

Interestingly enough, while the page at the website where I purchased this, just like other webshops, allows you to select a color, and I opted for the black version, the quad I received, had the transparent canopy installed, so was in fact the "lucency" version. But both a white and black canopy had been included as well. Since the box was still factory sealed, this could not have been done by the seller, but must have occured in the factory.

So does this mean that Diatone no longer makes 3 different versions, but only produces the "lucency" version, but just adds the other color canopies, to let webshops list the quad in all color options? If so, that means that even if you order a specific version, you still have to take things apart to let it become that version you wanted. On the bonus side, you now get 2 spare canopies with the quad, and apparently for Diatone it's cheaper still to make just one version during assembly, and include some extra parts, then to make 3 different versions. Anyway, here are all the contents of the box:

The frame is single piece, with nicely chamfered edges. Where the motors are mounted, there is no center hole drilled in the frame, to allow access to the bottom motor bearing. The idea behind this is probably to prevent dirt from entering the opening and affect the motor bearing, and the arm might also be a bit stronger too. The drawback is that if you would wish to lubricate the bearings from time to time, the motor will have to be removed, and it adds a fraction more weight.

The metal "cage" of the Marauder series, has been replaced with a single piece plastic canopy, that holds the camera. Sadly, it's not available seperately, and the R349 frame kit is pretty expensive. But since this canopy is used on a series of quads, you can also get the R239 Frame Kit, which contains the same canopy, and is much cheaper: https://www.banggood.com/Diatone-201...p-1390986.html

However, for a part that is likely to take most of the impact in a crash, it would have been nicer if you could just buy the canopy seperately, instead of a frame kit, even when it's a cheap one.

The quad does appear to be very neatly built, solderings are shiny, and motor wires are secured to the frame with tie wraps. The battery wire with XT30 connector, doesn't have any strain relief, so if the battery is ejected in a crash, and doesn't get unplugged, there is a risk that the wires are pulled off, taking the ESC solder pads with them. If you want to prevent this, it would be smart to zip tie the battery wire to the frame somewhere.

A small bracket covers the capacitator that has been added to the stack, and apparently should also function as mounting spot for the receiver. Here we get to one of the changes that has been made since the first reviews of this quad appeared. The VTX is no longer mounted to the back of the RunCam Micro Swift, but instead is screwed down, in skewed orientation, onto the top plate covering the stack.

This means there is very little room left inside the frame to mount the receiver, and instead Diatone recommends to strap it to the rear bracket that covers the capacitator. In order to fit, the receiver does need to be very small, especially short, to prevent interfering with the battery wires. On the positive side, the receiver wire is fitted with a plug, that should allow to connect an R-XSR without any soldering. The bad news is that if you don't have an R-XSR lying around, but the longer XM+, like me, this won't work well. Not to mention other brand receivers, with different shapes and sizes. The older setup, with VTX at the back of the camera, was more flexible in this aspect.

With all this attention to detail, whether improvement or not, one thing was overlooked. There is no strain relief for the battery wires. So if in a crash the battery gets ejected, it's possible the wires will be ripped off, along with the solder pads. While nobody intends to crash, in general, the risk is always there, it's a shame Diatone didn't take this into account. The battery strap has also been routed in an interesting way, and here we see another design change. The earlier versions of the frame had openings in the bottom, now these are recessed parts, but not fully open:

One of the quad's highlights seem to be the motors, the Mamba MB1408 4000kv type. A quick test, using motor control in BetaFlight, showed these sound and run really smooth. A minor vibration peak around a certain RPM, but only noticable because on any other throttle setting, these just whir around with minimal noise.

Without props, or receiver, but with battery strap, the quad weighs just a fraction over 126 gram.

Speaking of the props, this is another change that has been cut into production, along with the re-locating of the VTX, and dropping making different color versions. First batches of the R349 shipped with the popular GemFan 3052 tri-blade props. A prop with great handling, very efficient, and providing plenty of performance. Also usually rather silent, with just one drawback, the current draw near full throttle tends to jump up quite a bit. So some manufacturers lately fitted the DalProp 3056, which despite the higher pitch, actually draws less amps than the 3052, while, if well tuned, having similar handling.

Now Diatone went in a very different direction, and included some new props, GemFan, but 3028. And even more peculiar, these props have a different shape center hole, that allows to fit a special insert, to be able to mount the props on motors with T-style mounting. Here's a picture, which also shows the inserts:

I'm in doubt whether to use these props. They might surprise me, but the extra cut-outs in the center of the hub, to allow fitting the inserts, also could weaken the hub, compared to a regular prop, with just a round hole in the middle...

Update 27 april 2019:

Not totally happy with the video noise on my RunCam VTX version R349, and ending up getting a refund for a quad that was ordered 1st of january, it was decided to spend the refund on another R349, the TBS Unify version. Since that was reported to have much cleaner video, just like on my GT-M3 V2. And apart from the different VTX, this one had a few more surprises. One thing wasn't a surprise though, again the quad had been ripped off the cardboard insert, despite the box being in great condition, and factory sealed.

Just for the record, the zip tie wasn't cut by me, it came like this, and while the other zip tie survived, it only did because it ripped out part of the cardboard insert, instead of breaking. Two zip ties just aren't enough to hold it securely in place inside the box. Hopefully Diatone will take note...

A nice surprise however, was the changed canopy design. Instead of using plastic nuts, that would strip threads easily, the lower part of the canopy now has metal threaded inserts, so that should be an improvement:

Because the canopy consists of two parts, Diatone didn't have to fully engineer a new canopy, only the part that clicks on at the bottom front. Very clever design.

But that isn't the reason for the price difference between the TBS and RunCam VTX version, as these changes are constantly cut in during production, just like the switch to 3028 props. Here is what it is about, the TBS Unify being part of the stack:

For receiver install, this time I decided to go for the solder-free option, with the R-XSR. But instead of attaching it to the rear, as Diatone suggests for receiver install, I went for putting it against the bottom of the canopy. There is very little "wiggle room" but eventually I found a setup that seems pretty good:

And here's how the quad looked before installing battery and props:

Here's one of the first flights with the TBS version:

3 – Preparing for 1st Flight:

Hooking the board up to BetaFlight, it was identified as using the FURYF4OSD (FY4O) target, and it comes with 3.5.1 versoin firmware. As usual, a full CLI dump of the stock settings, can be found attached to the second message in this thread.

Some reported the quad being well tuned, while others mention it needs a lot of re-tuning. Sometimes, perception changes how a tuned is judged, some may say a quad is nicely agile, while another pilot considers it way too loose and sloppy. But in this case there may be a different factor at play as well. The first batches of this quad shipped with GemFan 3052 props. These props are great generally, but also can draw quite a bit of amps on full throttle. Maybe that is why Diatone decided to ship later batches of the R349 with much lower pitch props, to reduce the current draw. However, it might be the PID settings haven't been adjusted accordingly, and that this is causing the massive difference in how the tuning on this quad is perceived. Some more info is needed to see what it going on here.

As mentioned earlier, mounting the intended XM+ receiver, proved a bit of a challenge. Another RCG member had managed to squeeze it between the VTX and the canopy. With that in mind, I wanted to try a similar receiver install. With some wiggling, and creating a bit of extra clearance by moving the video and Tramp control wire to between the VTX and the white plastic mounting plate, the XM+ could just about fit in there, while not stressing the antenna wires too much, and keeping the bind button free.

After some checks, like fail safe working, the props and battery were installed:

I know the receiver antenna doesn't look very safe yet, only being held by the tubes in the clear part that clips on at the rear standoffs. I'm still in doubt whether to run the antennas from the rear arms, and keep low profile, or at the top, so airflow below the props is less obstructed, and making it easier to connect the battery.

4 - Flying Performance:

Naturally, when having a new quad to try out, it's raining outside. So once again, the first test hover was done inside. So options to punch the throttle were pretty limited, but even in short bursts, and with the lower pitch props, it's clear this one was made for performance. The motors rev up instantly on the slightest throttle increase. Meanwhile the motors ran smoothly and relatively silently. Initially there was a slight drift in Angle Mode, but then I realized I had forgotten to calibrate the accelerometer during the pre-flight checks. So that was performed, and after that the hover was nice and stable.

5 - Camera & FPV Performance:

For the camera, Diatone once again selected the trusted Runcam Micro Swift, though this time with lime green color housing. The main version of the R349 uses the RunCam TX200U as VTX, which has the option to change settings using the Tramp protocol, and can be set to 25 or 200mW. The manual for the VTX, with channel map, and more info, can be found attached to the second message in this thread.

Many have been very positive over the image qualify of this setup, as can also be seen in review videos, and since the GT-M3 (second edition) has one of the cleanest FPOV video I've ever seen, I was having high expectations of this combination. However, either the relocation of the VTX to the top of the stack makes it pick up more noise from the flight controller, or I just got a lesser quality VTX, as there was clearly some noise visible, and the older GT-M3 is much cleaner. Here are a few short clips, recorded in the same circ*mstances:

Colors are still great, the image overall is sharp and detailed, so when flying, the noise will probably be much less obvious, but still it's just not as clean and life-like as it would have been, if the noise had been as low as on the M3 and the review videos that have been posted for the R349 before this thread was started.

Here's the first FPV flight:

VTX set to 25mW, but still very good range with minimal breakup. The quad felt agile, but maybe a bit "loose" so I might have to change some PIDs, or fit higher pitch props, for more "traction". Though overal it was a lot of fun to fly, and I couldn't really spot any bad flying traits, like oscillations.

Here's another flight, in a very strong breeze:

Again enough power and good flight times, but control wasn't as tight as it probably can be.

Update 26 april 2019:

After some experiments with different props, HQ 3x4x3 and DalProp T3056C. The 3x4x3 gave good speed and punch, but also lots of shaking on full throttle, like around 2:32 minute mark:

Next, the DalProp was used, here's an example of how it flew with those:

Better, still not fully stable on full throttle, but quite acceptable. However, the quest for better handling continued, and this led to trying to go back the original setup that the R349 shipped with when it was first released. I didn't have any clear GemFan 3052 on hand at the moment, but the LDARC 3050 are basically the same prop, even side by side these are almost impossible to tell apart, if not looking at the print on the blades.

Here are a few flights with these props installed:

With these props, the quad feels more responsive. Also the quad is more solid at full throttle. Drawback is that flight times become a little shorter, but can still go up to 4 minutes on a 3S 750mAh.

6 - Suitable for a beginner?

The R349 isn't the most obvious beginner choice. There are no spare props included, and the canopy doesn't offer much protection for the electronics. Also, it's very lively and fast, which would probably make it harder to control for a beginner. Personally, I think this is more for intermediate pilots, ready for a new challenge, with some more "punch"

7 - Preliminary Verdict:

The R349 is a lively flyer, which looks really sleek as well. The motors provide lots of speed and power, yet are also very smooth. The TX200U VTX provides a good signal with very little breakup, even on the lowest power setting.

On the negative side, the electronics are not that well protected by the canopy, and the FPV signal isn't as clean as on the older GT-M3, though this could be bad luck.

More or less neutral are the switch to lower pitch props, which reduces performance, but reduces stress on the battery, and increases fligh times. And the choice of a certain color version basically meaning nothing, as only a single version is shipped, with the other colors of canopy included. So you get the benefit of geting 2 extra canopies, but if you want a different color than transparant, you will have to replace the canopy yourself, and this involves unplugging the tiny and fragile micro UFL connector from the VTX.

In the end, the performance of the quad does push these drawbacks to the background, but at the same time it feels it could have been a bit more polished. So the "Rabbit" does jump ahead of it's predecessor, but maybe not as far as it could have.

Pros:

- Neat soldering and wiring
- Very smooth motors
- Good FPV range, even on 25mW
- Looks sleek and fast
- Good flight times
- Nice finish on the frame
- Comes with all 3 colors of canopies
- Now comes with both 3028 and 3052 props (since may 2019)

Cons:

- Rather weak packaging, thin cardboard offers little protection, and the quad can break loose inside the box.
- Plastic nuts holding the canopy at the front, easily get stripped threads (fixed with re-design, canopy now has metal threaded inserts)
- Not much space for receiver inside frame
- No spare props (later batches include 2 full sets of props, 3028 and 3052)
- Some constant noise in FPV signal (only on RunCam VTX version, TBS VTX version has cleaner video)
- Switching to 3028 instead of the original 3052 might not appeal to everyone (fixed by including both props in the package now)
- Some PID tuning errors, like Yaw D-term being set to 18, can cause motors to fry on some units

(to be continued)