Jim Aero Neutrino 4M F5J (Strong) Build Log

This is the build log for the Jim Aero Neutrino F5J electric sailplane.

The Neutrino is built and ready to catch some thermals

Neutrino Build Log

This will be the build log in photo form. I'll have some descriptions in the captions for reference and maybe more text along the way. The full review with my thoughts and video is available here

Neutrino Parts

Here are the base weights of the main parts. I did hear from the manufacturer that they used heavier core materials on this plane, making it the strong/windy version. Standard and lite layup production versions will be about 10oz lighter all up.

  • Left wing tip 138g
  • Right wing tip 138g
  • Right Center panel 203g
  • Left center panel 209g
  • Horizontal 26g
  • Vertical 38g
  • Main spar 53g
  • Tips spars 10g each
  • Front fuse 84g
  • Rear fuse 40g
  • Total Airframe Weight: 949g (33.5 oz)

Neutrino Gear

I purchased the majority of the gear from Soaring USA and also wanted to send a huge shoutout to MKS Servos for providing the servos and to Castle Creations for providing the ESC. Thanks for helping with the review!!

Neutrino Build


On the wings I used some high quality wire that I had to make a custom harness. I realized later that the wire was a lot heavier than what was included in the kit, so I went back in and switched it all out. The wire included was all the correct length and will work perfectly. I did choose to use Deans 4 pin plugs all around though for convenience.

Rear Fuse and Tail Feathers

Front Fuse and Final Steps

Assembly at the Field

I LOVE how small the Neutrino breaks down. The four-piece wing and two-piece fuselage allow you to pack it down to a small box or bag if you want for transport and storage.

Once you get to the field, setup is a breeze. There are 3 joiner rods for the wing. I start by joining the two center panels, then connect the deans servo leads to the panels at the root and attach the wing to the fuselage with 4 screws.

I then take the rear fuselage and slide the vertical stab down into place ensuring the pushrod is inserted into the control horn properly. The horizontal stab first slides onto the elevator pushrod and is then secured with two screws. Next I take the two fuselage halves and connect the tail servo lead. Then slide the rear fuselage into the front fuselage ensuring the tail is properly aligned. Once fully seated I use a piece of electrical tape on the joint.

Next I insert the tip joiners and slide the wings on, connecting the tip panel servo leads and using electrical tape to secure tip panels in place. It takes just a minute or two to get it together or break it down. It's super simple and easy to do.

Ready to Fly!

That's it for the build. I have around 35 hours or so into the build, taking my time and documenting. It was a joy with no hangups. The assembly manual was not available at the time, but it was pretty easy to figure out where everything goes. The only thing I didn't install was the ballast attachment. There is a balsa and fiberglass mount included that you can glue to the fuselage. You would then make your own ballast and use a screw to attach it. I plan to install that at a later time should I decide I want ballast. The final weight ended up at 1494g or 52.7oz including 2oz of lead in the nose for balance. That weight is fine by me as you'll see in the flight video on the review page. I'm told full production models of the standard and lite layups will be 41-43oz all up which is awesome! Now that the build is done, you'll want to see how it flys so click here visit the full review article.

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Apr 15, 2019, 08:02 PM
Registered User
cloudsplitter's Avatar
Hi Jason,

I was wondering why use the R9 and R3 receivers. Were there not enough channels for all of the controls? Or was it perhaps redundancy? Thanks!
Apr 15, 2019, 08:37 PM
RCG Admin
Jason Cole's Avatar
Thread OP
The R3 is setup as a satellite receiver. General consensus on these big all carbon planes is to have more than 2 antennas. So I got a set behind and below the wing as well as in front and slightly above. As high and as far away as these fly in competitions, I wanted to play it safe.
Apr 16, 2019, 10:18 PM
Registered User
cloudsplitter's Avatar
Thanks for the tip!
Apr 18, 2019, 06:22 AM
Registered User
Jason how did you mount the R3 antennas ?
Apr 18, 2019, 06:28 AM
RCG Admin
Jason Cole's Avatar
Thread OP
They just pass through some rubber tubing.
Apr 22, 2019, 10:08 AM
in awe of glide...
Kirkerik's Avatar
Looks like a ton of fun! What did your wingloading work out to? Making them so light now!

Does the Neu P22 gearbox have a smaller bolt pattern than the P29 or is it the same?

I see neither the 1102 motor or the newer Neu P22 gearbox is listed on Neu's website.
Last edited by Kirkerik; Apr 22, 2019 at 10:13 AM.
Apr 22, 2019, 10:46 AM
RCG Admin
Jason Cole's Avatar
Thread OP
Mine is right at 6.10 ounces per square foot, but production models will be around 4.75! Not sure on the gearbox bolt pattern, but here's the page on Soaring USA's site for this motor/gearbox combo https://www.soaringusa.com/neumotor-...2-gearbox.html
Apr 22, 2019, 11:18 AM
Registered User
doo's Avatar
The P22 gearbox has 4 holes on a 17mm diameter bolt pattern, the same as the Powerline Micro series.
Apr 29, 2019, 03:18 PM
jbitz's Avatar
I watched in AWE as Jason flew this fantastic bird at Kenny World this past weekend for a FSS event. All told, 16 rounds all on time and on target. I got the privilege of timing for him on Sunday.

Thanks again

Apr 29, 2019, 03:36 PM
RCG Admin
Jason Cole's Avatar
Thread OP
Thanks John! The Neutrino impressed the heck out of me too. Hope to fly with you guys again soon.
Jun 09, 2019, 06:12 AM
Registered User
Hi Jason, nice glider.... question -- was the receiver battery for redundancy purposes and if so, how do you go about hooking that up? I have a simliar glider and would like to run with a backup battery.... appreciate any insight... Thanks
Jun 09, 2019, 07:26 AM
RCG Admin
Jason Cole's Avatar
Thread OP
Hi, not a backup, but main power for receiver and servos. The 3S battery only powers the motor and the 2s only powers the receiver and servos.
Jun 10, 2019, 03:24 PM
in awe of glide...
Kirkerik's Avatar
A good discussion on a battery backup system:


Definitely worth it in my opinion.
Aug 12, 2019, 04:55 AM
Registered User
akrobatikus's Avatar
Hello, i got the Neutrino now....
can me somone say where the point of gravity is? - and has somone the balast set? how is it installed? or somone has Fotos from that?

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