In this post I’ll be reviewing the Eachine Micro Skyhunter. This is an EPO foam airplane with a 780mm wingspan. It comes PNP (plug-n-play), meaning that it contains the airframe, power system and FPV system (there is a variant without it as well) and requires minimal assembly. This is my first airplane, since the scratch builds I attempted before this were complete failures. A lot of people say this is not a suitable plane for beginners, as it is fast, does not have self-correcting tendencies, and doesn’t have a rudder. I still wanted to find out for myself though, and my main aim is too determine whether this is a good option for mini quad pilots who want to fly something different (and may be bored by trainer planes). This is very similar to the ReadyMadeRC Nano Skyhunter, probably coming from the same factory, though it uses a different material (EPO instead of EPP). What interested me most about this plane is the compact size and the fact that it uses common mini quad parts, meaning that if you’re a mini quad pilot who wants to fly this, you probably have the right size of LiPo, as well as better motors you can put on it.

Here is a quick disclaimer (inspired by SoloProFan on RCGroups) before we get to the review itself.

Disclaimer: This product was provided for free to review by Banggood. I will do my best to keep this review fair and unbiased. 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.

Product Specifications

Here are the product specifications as provided by Banggood:

  • Wingspan: 780mm (31″)
  • Length: 540mm (21″)
  • Weight: 230g (without battery)
  • Colour: White
  • Material: EPO
  • CG: 4cm from the wing leading edge (There is a convex point under the wing, that is the CG)
  • Camera: Eachine EF-01 AIO FPV camera
  • ESC: 20A 2-3s with XT60 connector (HobbyWing Skywalker 20A)
  • Motor: Eachine 2204 2300KV
  • Motor MAX Thrust: 440g
  • Motor Weight: 25g
  • Motor Shaft Diameter: 3mm
  • Propeller: 6×3, but works well with most 5-6″ multirotor props, even quad blade.
  • Servos: 3x 9 gram (these are actually 5g servos)
  • Recommended AUW: Under 375g

Unboxing

The plane comes packaged in typical BG style, wrapped in white foam and put in a black plastic bag. The Micro Skyhunter box itself is quite sturdy and the plane parts are well packaged inside so this is adequate.

This is what you get out of the box:

  • Wing halves reinforced with CF rods (servos preinstalled)
  • Elevator with servo and servo protector
  • Tail booms
  • Main CF spar
  • Fuselage and canopy, with removable top piece for FPV
  • EF-01 25mW micro cam + VTx
1_box_outer

The box came in unscathed

2_box_open

Well packed inside the box

 

5_wing_box

Wing halves, tail booms, and elevator

4_fuse_box

Fuselage, camera and prop

 

The Build

This was quite simple. Whatever glue you use, test it on a non-vital part of the plane to make sure it does not eat away the foam. I use UHU adhesive, but when the plane came apart after the first crash, I rebuilt it with CA (superglue). The advantage of the UHU is that it takes longer to dry allowing you align the parts easily, Make sure to lightly sand surfaces before gluing to allow the glue to bond well.

Here are the steps I followed:

  • Glue the tail booms to the wing halves. Ensure they go on the right side i.e. the right boom goes on the right wing half. You will know which is which as the cutout for the elevator should be on the inside. There are ‘nubs’ on the tail booms that align with notches on the wing halves. However, this is not enough to ensure the alignment is correct so use a straight edge to make sure the CF boom and wing are perfectly square (perpendicular).

6_boomelev

9_wingtail_assembly

  • While the glue dries, you can calibrate the ESC. Plug it into your receiver’s throttle channel. Switch on your transmitter, raise the throttle to full, and plug in the battery. Once the beeps stop, reduce throttle to minimum and allow the beeps to finish again. Ensure that the bullet connectors to the motor are solid, and secure the ESC with a zip tie and/ or double sided foam tape.

8_fusecam

  • Insert the carbon wing spar into one of the wing halves and then slide the other one down. Ensure all servo leads go downwards (are not pinched between the wings). You do not have to to glue the wing halves together, but you can.
  • Dry fit the elevator piece on the tail booms. Ensure the servo faces downwards and then glue it in. Plug the elevator servo into the extension that runs through the boom and use a small piece of tape to secure the cables.

11_without_elev

  • While this assembly dries, you can prepare the EF-01 cam+Vtx. The included cable draws power from only one of the cells of the 3S battery, which is poor design (I believe this has been fixed in newer versions). So I soldered together my own voltage regulator. I used one of these adjustable voltage regulators, set to 4.5-5V with a 1000uF 10V capacitor on the output for filtering and I cut off the included balance lead and used my own 3S balance lead (with the two middle wires removed) to power the regulator. I felt the included mount for the camera had too much downtilt so I bent it up with a set of pliers. Do this before installing it on the plane or you will rip out the plywood mount. You can then use the included screws to fix the EF-01 to the FPV canopy piece.

12_reg_cable13_reg_cable_shrink

  • Once the wing and tail assembly has finished drying, plug the aileron servos into the included Y-lead and plug that as well as the elevator servo into your receiver. You can now put the wings on and bolt them on using the  included bolts.
  • Power everything up and check your control surfaces are moving in the correct directions. The reason I have not bothered with motor direction so far is because I will be using a mini quad prop on this plane: the HQ Durable S5x4x3 and I have plenty in both CW and CCW variants. Now you can check the motor direction and put your prop on. Make sure the side of the prop with the text/ numbers (the side that goes up on quadcopters) is facing forward. I threw away the conical nut that is included for securing the prop and replaced it with a nylon locknut (nylock) for reliability.
  • Trim the control surface if required. This can be done by powering the plane up and setting all trims/ subtrims to 0. Then pop open the clevis that holds the control horn on each of the control surfaces. You can then hold the surface neutral, and rotate the clevis so it moves forward or backwards along the threaded push rod until it aligns with the control horn again. Pop it back together and you should be set.
  • Secure your battery with some velcro and check the center of gravity (CG). It should be about 38-42mm from the leading edge of the wing. You may have to push the plywood tray in the fuselage pretty far back to get it right. Plug in the EF-01 and set it to whatever frequency you use and verify that it is transmitting.
  • OPTIONAL: Put the decals on. Dipping the sheet in warm water for a short time makes it easier to peel the decals off and stick them without damage.

14_complete

 

First Flight

Here is a DVR recording of the first flight. This was done LOS by Bhavesh, a much more experienced member of our flying group. This was in order to trim the plane out. The video signal was surprisingly poor. This was despite having a diversity receiver, with the output from the cloverleaf going to the DVR and the diversity output going to my goggles.  This could be because 25mW is inadequate, or because of an issue with my power supply cable/ VRx. I will need to do some further testing on this.

Despite the small size of this plane, it handled quite well in the wind once the throttle was raised above 50-60%. It was definitely pretty quick even on the stock setup (with a 5x4x3 prop) and 3S. I will try adding a little expo and maybe aileron differential to see if it improves the performance. I may also eventually try 4S on this once I improve my skills. This plane isn’t meant to glide, another reason it is not an ideal trainer. You have to keep the throttle high while flying, something I was not used to as I have only flown quadcopters before.

On the next flight (video below) I took control once the plane was in the air and attempted to fly it FPV. However, due to the poor signal and my lack of experience with planes, my flight was all over the place and I had to give the controls back for a landing. On the last flight of the day I tried flying it LOS after a more experienced member launched it. I was able to manage a few large circles around myself, and this plane was definitely fun to fly. It was very agile and responsive, (I was flying without any expo). Unfortunately I lost orientation and smashed it into the ground. Luckily, the plane itself did not take much damage and only the glue joints came apart. Repair was pretty straightforward and I will keep this post updated as I continue flying it.

And here are a few pictures of the Micro Skyhunter in the air, taken by the chase quad:

chase1

 

chase3

chase4

chase6

 

Conclusions

It is very early to draw my conclusions as I have to fly this plane some more. Thus I will keep this post updated regularly. I think that this is a nice option for mini quad pilots who would like to try something different. However, I think some prior fixed wing experience will be very helpful as it handles very differently from a mini quadcopter and can be challenging to fly. Here are the pros and cons of this plane in my opinion.

Pros

  • Fast and agile, so fun to fly (this also makes it challenging)
  • Compact and portable.
  • Easy assembly, even if you have not built any planes before.
  • Good power even with the stock motor on 3S.
  • Easy and cheap to upgrade, simply put any mini quad motor (2205 size) and ESC and you can shed weight while having even more power.
  • Sturdy enough, since this can be glued back together after crashes. Will test this further
  • Excellent value for money as this plane is only about 70$ PNP and 90$ with the camera.

Cons

  • 25mW seems inadequate, though I will have to do further testing. A better option may be to buy the version that comes without a camera (here) and something like the Eachine TX02 200mW or a separate camera and VTx. The EF-01 also comes with a very stiff antenna, so there is a risk of it breaking off the PCB tab where it is soldered.
  • Not meant to fly at low throttle, so it doesn’t glide very well/ tends to stall at low throttle. This plane is meant to be flown fast 😉
  • Can be a little tricky to mount the battery and get the CG right. Velcro on the bottom of the fuselage helps and you will have to slide the plywood tray back.
  • No instruction manual, though this isn’t a big deal since the build is straightforward and there are many build logs available online.

Resources

Here are some more resources that might be helpful.