63” Nexa L4 Grasshopper - RC Groups (2024)

Sep 25, 2023, 12:57 PM

• #1

ChinoDiablo

Thread OP

Discussion

MotionRC delivered my Nexa 63” L4 Grasshopper this weekend and I’ve finished putting her together 3 days later.
I had never heard of Nexa models but a flying buddy has one their J3 cubs and I really liked the way his flies so I had to get one but not exactly a J3.
The L4 Grasshopper is a J3 Cub but in drab olive green and extra windows for observation. The Nexa L4 is nicely detailed with a self-sticking vinyl printed covering that I’ve never seen before. The invasion stripes, checker board and number markings are all printed on. Only the pretty lady and some miscellaneous numbers and the usual scale text markings are applicable by the builder. Quite frankly, the results would have been better if everything was printed on.
Anyways, I’m getting ahead of myself.
It comes reasonably boxed with a good instruction manual.
Quality of the parts and built up wing and fuselage are quite good although I did have to do some enlarging here and there to get the horizontal stab in. Apart from that, the usual enlargement of servo holes was needed to get everything to fit.

My setup:
SunnySky2820 800kv motor, good for about 750 watts on 4s.
65amp Gecko ESC
Promodeler DS160CLHV mini servos in the wing
King Max 5514hv standard size servos for rudder and elevator.
Lemon 10 channel Rx with stabilizer and telemetry

The landing gear assembly is decently robust with a functional spring torsional setup instead of a hard stiff wires.
All the windows are installed which is a huge plus in my book.
The firewall requires drilling to mount the standoffs for the motor.
No parts were missing, misaligned or non-fitting (apart from aforementioned H stab).
The wing struts are strong with perfectly located hard points in the wing.
A 3mm hex bolt holds the struts to the fuselage so field assembly requires you bring a 2.5mm hex driver.
But the intermediate struts are cleverly designed and are easy to mount and dismount and fold back for storage.
You do have to cut out the dummy engine which I hot glued on and used a silver paint pen to give it some bling.
Battery access is through the scale-like cabin door and window which flips up. I used a strip of Velcro on the wing and on the window pane to hold the window up when the plane is on the bench.
Cabin Accessibility is sufficient and better than taking off the wing or flipping the plane upside down to change out batteries.
There are 2 cabin seats, the rear one is fixed and the front one is held in place with a magnet. You need to pull the front seat out to put in the battery which sits up against the firewall.
My one and only complaint is about the wheel axels being a threaded bolt and nuts. The threads on the bolt invariably eat up the inside of the wheel axel hole. I used a set of smooth axels I had laying around but the axe length was a little short which didn’t allow me to use the OEM wheels so I supplied my own. The OEM wheel covers fit perfectly.

Flying impressions:
The L4 Grasshopper flies exactly like the J3 Cub that she is.
With A 3600mah 4s battery up against the firewall she balance at 75mm, a tiny bit tail heavy by the manual’s spec.
With a 4000mah, it balances perfectly.
My motor setup at 750 watts and the plane being about 6+lbs give a very scale flying experience.
Coordinated turns are a must and full power is required for loops.
I didn’t try knife edge or other aerobatic shenanigans, mostly slow flying just at around stall speed across the runway with tail-up touch and goes with long roll outs.
The invasion stripes give great visibility in the air even on gray days.
Overall, She flies as I had hoped she would.

At $269 delivered, this plane is a bargain!
https://youtube.com/shorts/TAMaUCHOD...jM5YIDjgZ2axOd

Oct 04, 2023, 07:09 AM

• #2

ChinoDiablo

Thread OP

This guy hated some aspects of the Nexa TriPacer.
He's not entirely wrong.

https://youtu.be/_g0?si=9KTSJx4kZj2dDi8p

Oct 05, 2023, 08:52 PM

• #3

Sam Ehab

The video is not available any more!!!!

Oct 06, 2023, 12:11 AM

• #4

ChinoDiablo

Thread OP

Weird. I just watched it the other day.

Oct 07, 2023, 08:38 AM

• #5

MNFinn7300

I was just looking at this plane. I was looking for my first ARF and First balsa. I was thinking because it's a Cub, it might be ok for a first go at a balsa ARF build, since I have experience flying that type.

How difficult would the build be for someone who's just breaking into ARF assembly?

Oct 07, 2023, 08:48 AM

• #6

RC Man

That's a beautiful airplane at a very reasonable price. https://www.motionrc.com/products/ne...rf-nxa1005-001

I see that they have spare parts - nice.

.

Oct 07, 2023, 09:53 AM

• #7

ChinoDiablo

Thread OP

As a first ARF, it will be a good learning experience because not all the pieces are exact fits and you'll need to do a little bit of easy problem solving.

Things that need to happen:

• You may or may not need to enlarge the end of the opening to accept the horizonal stab. Mine was about 2-3mm short. I just carved it a bit more open so I could get a good fit of the H stab. I used thin CA on the tail assembly. If this is your first foray into Thin CA, make sure you get/use the special applicator tips cuz this stuff gets everywhere fast. Generally, just a drop or two will do along most joint lines cuz the stuff really seeps in.
• You need to drill the holes for the motor stand offs which requires a relatively exact measurement on the firewall.
• You need to plan out the interior layout for Rx for easy access. Short aileron Servo Extensions that reside in the Rx are a must if you're planning to take the wings off for transport/storage.
• You may or may not need to enlarge the servo hole openings in the fuselage and wing to accept the the servos that you have. 2 standard size servos for the fuselage, 2 mini size servos for the wings. An Xacto knife is the tool for this. and then you should use a pin vise to pre-drill the holes for the servo hold down screws. In a perfect world, you'd also put a drop of thin CA in each hole to harden it for the long term. In that same world, you'd would do that for every hole you pre-drill.
• You'll need to mount the cowl properly with the proper distance to prop and using the pin vise, drill those holes and hope your prop shaft is centered.
• You'll need to carefully cut out the LG fairings and the dummy engine. This is kinda fiddley and requires patience and a sharp pair of scissors and eXacto knife blades.
• You'll need to round out the dowels that are the anti-rotation "pins" that line up the wings to fuselage so that the wings can easily slide on and off during mounting. I used just enough friction on those dowels and the tension in the wing bracing so that I wouldn't have to screw the wing from above into the aluminum wing tube (which I think is an awful way to mount a wing). For me, there is plenty of friction in the wing tube, the dowels and plenty of tension in the wing bracing to keep the wings secure enough without doing that since I'm just doing some lazy, easy flying and not extreme aerobatics.
• You may want to file down the bolts that are the wheel axels so that they don't shave the insides of the plastic wheel hubs.

As a bonus, the front windscreen and all the windows are already installed. This in itself is a huge plus because many ARFs require that you cut out the windows from a larger sheet of vac formed plastic and then adhere them to the fuselage with canopy glue. A very tedious procedure with the number of windows in an L4GH.

If you do plan to get one, please post your progress here and we'll help along the way!

Last edited by ChinoDiablo; Oct 07, 2023 at 11:32 AM.

Oct 07, 2023, 12:04 PM

• #8

MNFinn7300

Thank you for all that information! I'm a little on the fence about getting one, just because it's a totally new experience compared to PNP foamies and putting together profile foamies, but with potentially being shut down from most flying for up to six months due to winter, a project would be good.

Seeing as how it would be a project plane, having to do some fiddling with it is not a negative for me, as it's something to keep my hands and mind occupied. From what I read, it looks like I'll have to get a couple tools, namely the pin vise and applicators for thin CA, since I've mostly used medium. Boy do I know how CA can get all over!

Oct 09, 2023, 06:23 PM

• #9

MNFinn7300

Oct 11, 2023, 11:07 AM

• #10

ChinoDiablo

Thread OP

Oct 11, 2023, 04:46 PM

• #11

MNFinn7300

Thank you for that info. learning power systems is a new thing for me. I was looking at 80amp ESCs but I'm getting hung up on what motor to get.

Last edited by MNFinn7300; Oct 11, 2023 at 04:53 PM.

Oct 11, 2023, 06:22 PM

• #12

ChinoDiablo

Thread OP

Matching a motor to a plane can be a little tricky but knowing what size the plane is and what you want to do with it are the main factors.
I think that 125 watts/lb is a scale power setup. I would consider 200 watts/lb to be overpowered for a Cub.
For a 4s system, a motor with a kV of 700-850 will be good for slowflyer at the low end to a sport/3D at the high end. 1200kv will spin a smaller prop very fast and is good for a speed plane.
The simple math:
With a 4s battery each cell is 3.7 nominal voltage to 4.2 volts fully charged, multiplied by the 4 cells = 14.4-16.8 volts.
kV = Revs per volt so a 1000kV motor will spin 14,400 - 16,800 rpms but there is 20% efficiency loss so actual rpms is 11,520 - 13,440 with no load on it.
Then when you throw a load on it (propeller in this case), the amp draw goes up, the RPMs go down and the watts go up. Thus: Volts X Amps = Watts.
If battery voltage is constant, and your motor has a given kV, then the load will determine what size ESC is required.
The bigger the prop, the higher the amp draw at WOT (wide open throttle) so a balanced system that works within the ratings is important.
If you use too small an ESC or too big a prop, you'll either burn out the ESC, the motor or both.

Clear as mud, right?

Oct 11, 2023, 10:26 PM

• #13

MNFinn7300

totally clear as mud. Thank you for trying to help this newbe to ARF figure things out. I'll be purchasing the plane, servos, a servo tester, and watt meter in the next few days. I'm went with a E-Flight Power 52 motor, and a Spektrum Avian 80amp ESC
, since I know them a bit. Everything is ordered except Servos, cine I need to read a bit more on those. Motor and ESC were a little simpler to figure out. Watt meter will tell me how things are.

Last edited by MNFinn7300; Oct 12, 2023 at 06:12 PM.

Nov 03, 2023, 08:02 AM

• #14

MNFinn7300

For my grasshopper and got my parts and I'm getting ready to put it together. Trying to figure out motor mounting. I have an e-flite power 52. And it seems like, when I have tht motor mount centered on the mounting plate, the motor mount goes over the top of the mounting plate, so figuring out drilling is tripping me up.

Also, looking at the firewall, I am uncertain on how to figure out where to drill tht holes for mounting everything.

Nov 03, 2023, 10:28 AM

• #15

walter3rd