Starmax L-4 Grasshopper 1400 mm – Review and construction manual amendment

I have just finished assembling my L-4 airplane. In my opinion, it is a very interesting model: Really cool plane, heavy and strong, mostly well-constructed, on the one hand. Cheap shit made in China, with missing and defective parts, and an assembly manual that is confusing and annoying, on the other hand. Here, I want to share some insights with you here – hints I wish I had had when I started assembling.

My aim is to give you a good intoduction to this model – to it’s cool and ugly sides – so that in case you are getting one, you know exactly what you are expecting. (This will cover hardware quality and the assembly only. It’s not a flight review.)

You can click on each picture to see it in full size.

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The steel and plastic parts of the landing gear need to be glued together. For me “UHU Kraft” worked perfectly.

Missing parts: In my set, the upper connector parts of the landing gear were missing. I used florist wire to substitute for the missing parts. As annoying as it is, I think my solution works nicely.

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Poor qualitiy: Steel frame of the landing gear is too wide for the under-cockpit slot it is supposed to go into.

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Solution: I am using an electric drill, 3 mm, to widen the slot on both sides. I recommend using a drill for metal, not for wood because of the tip form.

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Result: More room for the steel wire on the left hand side…

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…and also on the right hand side.

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Now, the steel frame fits in on this side…

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…and also on the other.

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To make sure the wire will never move out of the slot again, I cut pieces of wood and stick them into the slot.

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To makes sure these will not come out again, I am using two (of my own) screws…

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…and washers to hold the wood in place.

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The landing gear steel frame is now solidly connected…

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…to the plastic part right under the cockpit.

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Nota bene: When attaching the elevator control horn to the bottom side (here, plane is upside down) of the elevator unit, make sure the orientation of the horn is not parallel to the plane’s roll axis but parallel to the steel wire that is coming out of the fuselage, from the servomotor. In other words, allow for an inclination of the horn towards the fuselage.

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The plastic part in dark green is attached to the rudder; it is the basis…

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…for the control horn and holds…

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…the two thicker springs (thinner ones belong to the landing gear). I only used two screws to mount the control horn.

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Just in case you wonder: As the back wheel is connected to the rudder with springs, the rudder servo can – when taxiing – control the wheel, but the hard moves of the back wheel – when landing – can never damage the servo. ;-)

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Poor quality: When mounting these horns on the ailerons, it felt like there is a hole in the aileron body where the control horn is supposed to sit = only the wing’s covering and air below it. I was very careful when tightening the screws.

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Nota bene! The holders for these wing stabilizing bars have to be glued on to the bottom side of the wing. Make sure for every holder that the side with the bigger hole (where the screw will go in) points to the edge of the wing (for easy accessability with your screw driver).

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Should I glue that together? Although described differently in the model’s manual, the only way to attach the transparent plastic part to the wings is…

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…to glue it to the wings. Consequently you need to glue the wings together. As shown earlier, I also mounted the landing gear permanently to the fuselage. This way my Grasshopper now consisty of only two parts – fuselage with landing gear and wings with stabilizer bars. This way everything is a bit harder to transport, but the obvious benefit is improved stability.

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Each time you are getting ready for a flight, you have to attach…

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…the rear end of the landing gear and the bottom end of the stabilizer bars to the bottom side of the fuselage.

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Once the screws on the bottom are tightened, the wing bars do a good job stabilizing the wings.

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Tuning needed! The way the plane came out of the box, both servo arms were pointing in a weired direction. I unscrewed them and changed the position of both arms. They are now perfectly rectangular to the plane’s roll axis. (It allows for more rudder/elevator motion with the given servo motion.)

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Nota bene! In this model, there are two motor-related plugs (cables). One is attached to the ESC as usual, but there is a second one coming from the motor chamber (which is covered with a glued-on plastic engine hood and cannot be opened easily). I never saw that before, all models I ever had have one cable, from the ESC. However, after a while I figured out that this needs to be plugged in to the “binding” slot (!) of the receiver, it works now.

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By the way, I left out the stabilizing wires – and their holding parts on the horizontal…

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…and vertical tail.

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The model, out of the box, has little black engine covers on it, one on each side. They are attached with a screw; I took them off.

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By the way, the model comes with an XT-60 battery plug. I thought about exchanging it but decided against it for now: The cable is short so access to the plug for the soldering job seems to be tricky. (I’d need to take the engine cover off for that; don’t know how to do that or if it is possible.)

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Good quality: I like the solid, wide plastic part that forms the cockpit. Nicely integrated…

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…with the EPO fuselage. Seems to be durable, strong enough to grab and hold.

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Good quality: This “nose” holds the plastic part of the wings. This construction provides very good stability.

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Cheap design: Even when tightening the screws super carefully, they stick out on the oter side.

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Poor qualitiy: On some party the paint goes just when you look at it; some parts already come with scratches and holes

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Poor qualitiy: The back end of the left wing was already damaged when it arrived.

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Poor qualitiy: Shitty manufacture of the wings’ front side

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Good quality: Big wheels for grass (-hopping), look strong and durable to me.

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Careful motor testing in the living room: Original motor is powerful and sounds great!

 

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Thanks for reading! Feedback is welcome.

Written in August 2016 by Anatol Mika. Reach me via e-mail: bialetti1933 @ gmail.com