FT Guardian Gremlin v.2

The Flite Test Guardian Gremlin v.2 is an excellent first step into the world of FPV Quadcopters.  The Guardian Gremlin v.2 kit provides a great build experience, striking a great balance between being easy to build, but technical enough to get your feet wet.  Great for the beginner, a school STEM program, or for anyone that wants a durable, easy build to get into the air quickly and confidently.  

What’s in the Kit?

The Guardian Gremlin v.2 kit comes with everything you need to get started.  The top and bottom frame plates are made from Delrin, laser cut in true Flite Test fashion.  It provides a stiff, lightweight, and durable frame that can take a decent amount of abuse.  The fasteners and standoffs are all nylon, keeping the quadcopter lightweight.  The Guardian Gremlin v.2 is a sub-250g aircraft, meaning no requirement for FAA Registration.  

It also comes with a capable yet beginner friendly all-in-one flight controller, the JHEMCU GHF411AIO-BMI.  It’s a 25.5mm x 25.5mm F4 based toothpick flight controller with 40 Amp BLHeli_S based ESC.  The flight controller comes with connectors for the motors making them an easy plug and go solution.  That’s not to say that soldering skills aren’t needed, the RadioMaster R81 receiver and the Caddx Ant AIO FPV camera will need to be soldered, as well as the battery lead.

Versatility and Value

The Guardian Gremlin v.2 kit itself provides a value beyond just the initial build and flight.  It has the airworthiness to fly both indoors and outdoors.  The cinewhoop styling offers a significant degree of protection, safeguarding the props from damaging objects (and people).  It also has enough power to hold its own out among the grass and trees though it can get knocked around by the wind a bit.  While the recommended battery is a 2s battery, the Guardian Gremlin v.2 can be flown on 3S for a little extra power once flying confidence allows.  

The neat part about the flight controller that comes in the Guardian Gremlin v.2 kit is the versatility.  This is a 2s – 6s capable board, meaning its life isn’t restricted to just living in the Guardian.  It can be moved to many different levels of aircraft providing value beyond just this kit as long as it can fit the 25.5mm x 25.5mm mounting pattern.   

Building the Guardian Gremlin v.2

The ease of building the Guardian Gremlin v.2 makes it a great first level kit for beginners, STEM programs, and even those that want a new, easy build to get into the air.  Starting with the Delrin bottom frame, getting the motors installed is the first priority.  While the motor wires can be routed many ways, find a solution that works best for you.  Go ahead and mount the Caddx Ant AIO into the included 3D printed camera mount.  Next, break out the JHEMCU GHF411AIO flight controller.  Note that there is an arrow on the top of the board that notes it’s orientation and ensure that’s pointing toward the front of the Guardian.  Utilize the included stack hardware to mount the board (don’t forget to add the gummies for vibration dampening!) which will give you some idea as to how you want to route the motor wires, where you’re going to put your receiver (we recommend using the RadioMaster R81), and how long your FPV camera and receiver wires will need to be.  Remember, measure twice, cut once!  Also, don’t forget to check the length of your battery lead.  Once you determine that, you can solder up those components.  Add the remainder of your nylon hardware if you haven’t already, check that all your wires are out of the way of your props then add your top plate!   Make sure you don’t go crazy tightening the nylon screws into the nylon standoffs.  While lightweight, they are a softer material and will deform or strip easily.  I screwed them all in by hand to get them most of the way, then add maybe a quarter to a half turn with a screwdriver to seat them just enough.

It’s really that simple to get the Guardian Gremlin v.2 built!  The JHEMCU GHF411AIO really bring down the complexity, as does the Caddx Ant AIO.  By combining components, it all cuts down on the amount of time building, reduces weight and gives you that time back for flying.  For detailed build directions, I encourage you to watch the Guardian Gremlin v.2 Build Video on Flite Test Tech channel.

Flying the Guardian Gremlin v.2

The Guardian Gremlin v.2 flies really well.  For a sub-250g aircraft, it feels and flies similarly to a 5-inch.  It can roll and flip with the best of them, but its focus really shines in its versatility of being able to fly either indoors or outdoors.  Having the propellers guarded by the frame of the aircraft gives the Guardian a safety factor not often found in some of its bigger counterparts.  It lends itself well to the classroom, where safety, fun and learning are all of utmost importance.  It also does great outdoors as well.  It’s very durable, and the lightweight nature of the Guardian means that if you do crash or bump into something, the chances of damage are very low.  It also lends itself well to practicing for cinewhoop style flight.  While mounting a GoPro or something similar is out of the question (unless extremely lightweight), practicing for those types of shots is definitely something the Guardian is capable of.  Just be careful when flying around people!

Thoughts and Suggestions

While spending a lot of time with Guardian Gremlin v.2, it’s a great little quadcopter.  The value it brings, especially combined with the RadioMaster T8 Lite and FPV box goggles is amazing, especially in something that you get the build yourself.  A lot of the beginner friendly bundles out there now, while good, are mostly pre-packaged and ready-to-fly.  There’s a level of accomplishment that comes from building and flying your first quadcopter.

With that said, here’s a few things that I’ve discovered that may help you:

1. Update the Betaflight firmware before flying it.  

2. Make sure you check that your motors are spinning in the right direction before flying.  This is easy to do and fix within Betaflight.  Make sure your props are off first.

3. If your FPV Camera mount is a little loose, shoot some hot glue on the underside of the frame to help keep it in place.

4. If you eventually want to step up to 3S you’ll need a bigger o-ring.  You can pick one up at your local hardware store.  Take your Guardian and your battery with you to make sure you get the right size.

5. If you don’t know how to properly tune a Quad, that’s alright!  The default Betaflight tune is decent to get you going, though the motors will be a little hot.  FliteTest has a dump file of a more ideal tune that you can load directly onto your flight controller if you want to use that.

6. While the Guardians props are protected, always use caution when flying around people.  Make sure they know what you are doing and are okay being around a quadcopter in flight.

Final Thoughts

I am extremely impressed with the Guardian Gremlin v.2.  While not the most technologically advanced quadcopter out there, the aspects that FliteTest has focused in on, being ease of build, ease of flight, focus on introducing flight to beginners, STEM, and versatility, are done extremely well.  It’s a simple aircraft, but it accomplishes a lot in that little package, and I think from both a hobby aspect and a STEM aspect, it’s a great addition to the FliteTest lineup!