Longing Innovation LY-250 (Red Bee Edition) FPV RTF Review

Review by Nicholas Turner, Staff Contributor

Equipment Used:

All stock equipment

Pros:

- FPV RTF Package

- Cool colors

- 2 and 3 blade props included

- Fairly durable

- 7" monitor

- Monitor works with other VTXes

- Monitor easy to see outside

- Adjustable camera angle

- Modular design

- Box doubles as carrying case

- Helicopter style landing gear

Cons:

- Battery buzzer is weak

- Can't manually change FPV channel

- Monitor mount screw doesn't hold well

- Li-Ion batteries by default

- Must get the (+) and (-) terminals of the batteries right to prevent damage

- Charger only charges 2 Li-Ion batteries at a time

- No OSD, at minimum battery voltage would be nice

- Lipo conversion kit available separately

- Monitor is hard to impossible to see in direct sun light

Summary:

Note: The LY-250 from Longing Innovation comes in a few different names (Red Bee and Dark Knight I know of at the time of the review). The only difference I can tell between the two is the color of the canopy.

 

When I first learned of the LY-250 I was curious. The stock Li-Ion battery setup, RTF package, and modular design to allow for conversion to lipo batteries really intrigued me to the quadcopter being unique in allowing a user to start flying FPV a bit more tamely and then move up to more aggressive flying.

 

Unboxing:

I was fully impressed with the packaging the LY-250 and all parts. Each part is packaged in its own location in the foam and was super snug. This type of packaging really protected everything from damage. The TX did have the thumb sticks removed from the gimbals and packaged separately. As seen in the unboxing portion of the video, everything was there as expected. The screwdrivers and two bladed props lay on the foam under the quadcopter. Props are removed for storage in the box. I did find what looked like an action camera Velcro strap, which HobbyWow indicated to me was the lipo conversion kit. At the time of the unboxing HobbyWow was unfamiliar with the lipo conversion kit. I do have one on the way as of the time of writing this mini-review.

 

Assembly:

Assembly is as easy as selecting between the two and three bladed props, then installing them. I found some disconnect in labeling. The props are labeled with a circular arrow to indicate the direction they are to turn. The arms are also labeled the same way. Prior to maiden flight I matched the circular arrows from the props to the arms and put the props on with the numbers facing up (numbers on props point in the direction of travel, up for quads and front facing for planes). This caused the thrust to be pushed up above the quadcopter, thus pushing the quadcopter down and keeping it grounded. I swapped the props around and was in business. I recommend having a jeweler's screwdriver or small hex to push through the hole in the prop nuts to help tighten them properly.

 

The monitor mount is placed over the TX antenna and a screw is tighten to keep pressure so it doesn't fall off. I found the supplied screwdriver to be on the small side for this screw and used a larger screwdriver from my set of tools. The monitor is attached to the mount via a silver thumbscrew through the specified hole on the mount and bottom of the monitor. The monitor mount has a screw to keep tension for keeping the angle of the monitor in place. I found the supplied screwdriver handle was too small to get enough torque to tighten it down properly, thus the monitor would flop around on me. Once tightened, the angle holds until bumping/jostling the TX and monitor. The monitor's antenna is screwed in place to the connector on top. I found the monitor washes out easily in direct sunlight. Thus one needs to be in the shade or make your own sunshade.

 

Flying with Stock Li-Ion Cells:

Maiden flight in flight mode 0 (auto leveling) was calm and unexciting. With the two bladed props on I felt the LY-250 slid around a little more than I was expecting. The TX felt nice in my hands, surprisingly the weight of the monitor does not make it top heavy and hard to hold. On maiden flight I flipped to flight mode 2 for increased throws. Incidentally I held full left aileron expected the quad to zoom sideways to the left, instead it flipped. I wasn't expecting this and the quad hit the ground as I was not high enough to flip completely. On this crash the weakest part of the landing gear broke at one location. This location being where the screw goes through the landing gear to the frame for mounting. Some JB Weld helped epoxying it back for a while, but another hit broke the same location. My first three flights were LOS (line of sight) just getting used to the quad. Flights 4-6 I started to use the monitor more, as a joint of LOS and FPV flying. Using the monitor is super easy and I really like the quality and field of view of the camera's signal. I found doing easy circuits around the yard fun and enjoyable. Flights 5 and 6 I switched to the three bladed props and found I prefer these over the two blades. I found them to be quieter and more dialed in than the two bladed props. The quadcopter just felt more stable and tighter on the responses. I also ended up cartwheeling the LY-250 on the ground, one blade on a prop got a little bent. I was able to bend it back and keep flying, no other damage than the JB Weld joint on the landing gear was noted. I also incidentally landed the quadcopter in a lower level branch on a pine tree, again no damage and I continued flying.

 

Lipo Conversion Kit:

The lipo conversion kit consists of a hook 'n loop (aka Velcro) strap and an XT-60 connector. Fortunately the LY-250 quadcopter is a very modular design making the conversion easy. Longing Innovation has a video on their YouTube page. But their video connects the wrong terminals, which provides no power to the quadcopter. To convert from stock Li-Ion packs to Lipo perform the following:

  1.  Remove canopy
  2.  Locate the two screws in the middle of the flight board that are above the battery bay terminals
  3.  Remove said screws
  4.  Using the two removed screws, screw the eyelet sides of the battery lead to the appropriate screw holes
  5.  Flip the quadcopter over and unhinge the battery bay door
  6.  Using a screw driver pry off the battery bay cover with the power switch
  7.  Pull out the metal underneath the cover just removed
  8.  Trim the side of the frame at the bottom of the flight control board around the middle of the battery bay on both sides of the frame (this allows the hook 'n loop strap to slide between the battery bay and flight control board). Refer to the video on YouTube by Longing Innovation, but check the positive and negative leads to attach them correctly.

 

Flying on 3S 2700mAh Lipo:

There is no mention as to the size 3s/4s lipo supported/recommended by Longing in the manual and all the text online doesn't call a size battery pack out. Most 250 quadcopters on the market use 1300-1800mAh 3S or 4S packs. At the time of this review I didn't have this sized pack, only 2200mAh and 2700mAh 3S packs. My Tenergy 3S 2700mAh packs came with XT-60 connectors, so I chose to use these. I will stress these are larger than expected and I had to modify the landing gear by temporarily mounting wood blocks on the bottom of the landing gear to create the required ground clearance as not to puncture the battery. The 2700mAh packs are also considerably longer than the battery bay, so the center of gravity of the quadcopter was negatively impacted (towards the rear as a put more battery towards the rear). I will say on lipo the battery voltage screen appeared to be brighter, it's not large enough to report the full voltage. I could tell on the first flight the lipo gave the quadcopter a lot more punch and was more responsive to my inputs. I found myself lying around in self-leveling flight mode a lot, trying to get used to the changed flight characteristics. I did not fly long enough to find out if the low voltage buzzer works with lipos. But I was having a blast flying on lipo power. I firmly believe once used to the flying characteristics of the LY-250 under Li-Ion power, upgrading to lipos will greatly enhance your flying experience. I'm not going to switch back to Li-Ion, but if I do need to it's easy to do. I found myself flying about 10-20 feet off the ground, if not higher, under lipo powered flights whereas under Li-Ion powered flights I was staying closer to 10 feet in altitude. This difference is due to the responsiveness of the quadcopter when powered by lipo.

 

Conclusion:

Being my first 250 class quadcopter I enjoyed it a lot on the stock 8C Li-Ion packs. But since it takes 4+ hours to charge for about 15 minutes of flying, it's not something I can fly at a moment's notice. The stock 8C Li-Ion packs are good for easy cruising, but don't expect to win any races with it. I'm looking forward to the Lipo conversion and switching exclusively to 3S 2200/2700 25/30C packs to see how it performs. I don't like how the VTX appears to be hard coded to a frequency in the spectrum. I would prefer to have the ability to switch when needed so I don't interfere with someone else who is already flying. The LVC buzzer is lacking on the loudness side. If you're flying under goggles and are a good distance away, you may not hear it all. I did notice the buzzer will momentarily beep before it stays on consistently. Given the two crashes I've had with the unit, it's fairly durable. The Li-Ion packs are fair. They don't have a physical difference on their positive and negative terminals, so pay attention to the labels of the batteries and battery trays when inserting. The do get very hot in the quad. So if you're going to swap them between the TX and quad, per the manual for extra flying, let the packs cool down to prevent damage. Aerobatics are easy to perform in the advanced flight modes, when quick enough in pulling back throttle, flips can appear to be stationary in altitude.

 

The lipo conversion kit is a must have in my opinion to enhance your flying experience (and to get more flights quicker) with the LY-250. After doing the conversion I could tell the additional power is what the quadcopter had been begging for. Being able to get the quick punch outs and quick bursts of power allows the quadcopter to really enter into local racing fun. As expected he Li-Ion stock packs are good for getting you into flying quadcopters for the first time and then upgrading to lipo for additional power and quickness.

I will give a negative comment in that the yaw rate appears to be fastest under auto leveling flight mode. Personally I would like to see no difference between auto, aerobatic, and full manual flight modes. Perhaps a little research I may be able to figure out PID tuning on the quadcopter, but for now I'll leave as is.

For fun I did turn the monitor on and used my FX797T camera to find the frequency the monitor is tuned to. This worked beautifully and I was able to FPV a surface vehicle this way (not using the LY-250's TX for control). Since this worked, I may look into making a conversion cable to power the monitor externally with a lipo so I don't have to turn the TX on all the time.

A big negative to the LY-250 is lack of ability to manually configure the 5.8GHz frequency and channel. It's unclear if it is a hardcoded frequency and channel or the VTX/VRX auto selects on start. I'm going to assume it is hardcoded as I can turn on the monitor first or the VTX first and receive the signal. Meaning you can't get more than one in the air simultaneously, which negates the point of racing similar/same quadcopters with your friends.

 

Is it for beginners? I'm torn. I think someone with experience like me flying r/c and especially smaller quadcopters will be ok. But someone picking this up as their very first r/c aircraft may be disappointed when the plastic parts break.

 

Is it a racer? No, stock it's just a cruise around lazy flyer. The manual indicates this type of flying on the stock batteries will give flight times of 10-15 minutes but aggressive flying will be closer to 5-7 minutes. I've not timed myself and I don't fly to LVC buzzer just because I don't want to run to LVC and get away from a safe storage charge. With a lipo setup you may be able to race your local friends, but I would not recommend this for something like the Drone Nationals as it just won't be as quick or responsive.

 

Do I recommend the LY-250? I'm on the fence here. It's certainly not going to disappoint if you keep its limitations in mind (stock Li-Ion setup, fixed FPV 5.8GHz frequency and channel). But if you want a hardcore racer, you'll probably be disappointed. I also expect the plastic to eventually wear and break sooner than a carbon fiber or composite frame would. There are more durable frames in the same price range that may prove to be better than the LY-250.

 

For now it's my only 250 FPV quadcopter and I'm just going to have fun flying casually with it and getting into FPV flying. But I suspect if I move up in quality and performance of quadcopter frames, this one may just become a lazy Sunday flyer/basher to try new things on in order not to risk my better frames.

 

I'd like to thank HobbyWow for the contest on RC Groups and randomly picking me as one of the winners.

 

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