RC Natter

[burkefj]

Reading the thread on the norris Natter kit, got me to dig back into my plan from 2008 when I did a 30" long profile natter RC RG. I had flown that on E-9's with the end plugged and on E-6 motors. Since it was short and the CG needed to be near the leading edge of the wing, the AUW was 13 oz rtf, and it wasn't much of a glider, but it worked ok. I decided to upscale it 136% which would give me a 41" length and just fit onto a depron sheet, and that gave me almost a 1.9x increase in surface area. Since I have the same tail weight but a longer nose moment, It didn't require as much nose weight, but since it is larger it came out slightly heavier at 15 oz painted rtf but is a real floater now. I added two carbon struts on the tail to prevent slight twisting under hard roll inputs.

The original tail was full flying but it was pretty large on this model, so I fixed the inboard pieces to the tail which aided in stiffening it, and just move the outer surfaces. I used a bit of thin styrene to stiffen the tail where the surfaces pivot and a bit on the bottom to prevent landing rash, and to support on each side of where the rail buttons attach. Model master olive and some flat gull gray were used for color, and then a silver sharpie for panel lines, and some trim monokote for the canopy markings.


Here are a couple of flights from this morning.

https://www.youtube.com/watch?v=5xs0itTlhDQ&feature=youtu.be

 

[Leo]

Very cool

 

[rstaff3]

Yup, that is very very cool!

 

[Daddyisabar]

Very cool. Natters everywhere! After the Noris flew at NARAM I heard of a planned high power project slated to fly in the open desert. If it comes to fruition it will be awesome. Everybody is liking the Natter these days.

 

[burkefj]

I thought about re-vising the Natter today, thought about 4" tube, 2.6" tube and E-6 or 18mm powered models and wasn't sure which one to do.
So, after a long morning walk and mindsim...I decided on a micro Natter for 18mm D2.3 motors.

I did the same sort of design with my latest Buzzbomb, sort of semi profile where I used a 6mm center core with vertical stab and sub fin and profile, center hollowed out to allow servo wire routing, two 6mm side plates hollowed out ahead of the wing slot and 3mm side panels. I did some quick mass balancing in openrocket to see if a 21" long 4" deep model would work ok and turned out it did.

I did increase the chord of the wing to 5" and lengthened the span a bit and moved it back slightly for CG reasons. For the horizontal stab I lowered it a tiny bit so it could be supported by the top of the fuse doublers instead of just going through the 6mm stab unsupported. Because the stab has the control surfaces and have to roll the model I wanted the stab to be supported. This meant I also increased the vertical stab chord a bit so it could surround the slot for the horizontal stab. I used 6mm for the wing and tail as well with single 2.5mm carbon spars glued and taped in place. I mounted the rail buttons on the side of the model by adding some stryene disks inside and outside the 6mm/3mm outer profile. I completed some test glides in the house to confirm my CG location and things are looking pretty good.

I did a pseudo test scheme with winter camo splotches applied with paint and a bit of sponge, some hand cut vinyl and sharpie panel lines and simulated the booster rato motors with vinyl since if I made them in 3-d they would have interfered with the elevon movement. Hatch cut into the nose for receiver, battery and nose weight access. Right now it sits at 2.3 oz dry, rtf should be about 5.6 which is ok for the motor. Wing area is a little more than half a square foot so wing loading in glide around 9 oz/sq foot. I'm pretty happy with how this one turned out. In order to meet CG with minimal nose weight(still needs about 15 grams)

In order to minimize nose weight I have to mount the servos in the fuse behind the cockpit and run pushrods with support tubes.

 

[burkefj]

More construction, 21" long, 16" wingspan.

 

[burkefj]

Finished up w balast at 5.6 oz rtf, here is the servo install, not terribly obvious..

 

[burkefj]

You can see from the top the servos are fully nested and hardly visible

 

[neil_w]

I’m contractually obligated to ask about that paint job…

 

[burkefj]

I’m contractually obligated to ask about that paint job…

I dipped my cats paws and let him at it...just a piece of sponge dabbed in gray and black

 

[neil_w]

I dipped my cats paws and let him at it...just a piece of sponge dabbed in gray and black

Is that based on a prototype paint job? I’m not familiar with that plane.

 

[burkefj]

Is that based on a prototype paint job? I’m not familiar with that plane.

Red and white was used on a prototype, so was splotchy camo, I sort of mashed the two because I liked it, I used that on one of my upscale Mach 10 models too. I think it looks eastern front german...I couldn't have weight added for a full gray or green paint job and all white looked a little sparse

Sort of how this is ..

 

[burkefj]

 

[Daddyisabar]

Late war paint schemes are whatever primer you have left over.

 

[burkefj]

Late war paint schemes are whatever primer you have left over.

Applied with a broom ..