RC Groups

RC Groups
    Foamies (Scratchbuilt)
        Discussion The NutBall, best damn RET foamy yet.....

#1 goldguy Mar 20, 2008 01:02 AM

The NutBall, best damn RET foamy yet.....
9 Attachment(s)
The NutBall..........it's round and flies like crazy, hence the name. It's been built in many sizes, from 7" span versions with electric power to a 7' monster powered by a 120 4S glow, even a two foot 26 ounce :eek: cardboard sloper.

It can be setup for flying from mild to wild. It's a super simple inexpensive easy quick build, so repairs are a breeze. There's no nose or tail to break off and the wing can't fold. As a trainer with low control inputs it can fly slow, is super stable and has no bad habits. Great for just cruising around. Or, turn up the volume for advanced aerobatics and silly fun. It flies 'almost' as if it has ailerons.......rolls, loops, snaps n' spins, flies 'forced' inverted and can prop hang n' toque roll like a full blown 3D machine. Mount the battery with Velcro so you can adjust the C of G for the flying conditions. Adjust to 25% for those windy days and for training. Move it back for nutty aerobatics and super slow high alpha, perfect for indoor flying. Keep in mind that tail heavy will cause major tucking at speed. Set the dihedral between 12 and 18 degrees EACH tip for best effect, it's not too critical. The difference between more or less is in the rudder authority.

You'll find a plan on the next page that can be sized to give you the lowest possible wing loading for the weight of the flight equipment your using. LIGHT IS MIGHT.

Cutting the circle is as simple as drawing it on the foam using a string, a small nail and a pen. Cut along the line with a new sharp blade, turning the foam as you go. The hinges and dihedral joint are melted out of the EPP foam using a modified 30W solder iron. File the tip into a wedge, use a wheel collar as a depth gauge and run it along a steel ruler. CF flats are installed across the wing in two locations into melted out slots with another modded tip. Other methods and glues can be use according to the foam your using. Add a bottom spine and a foam box for attaching the motor mount. The landing gear is a wire 'V' lashed to the motor mount with carpet thread n' CA glue.

If you need more information on recommended sizes based on the electronics you have, just use the search feature.

CAUTION: Never attempt the maiden voyage at high throttle settings. This will control any unwanted torque effect and/or pitch until you get it trimmed and gain confidence in how it flies.

Use this plan to build any size.......... http://www.rcgroups.com/forums/showp...5&postcount=16

Enjoy and have fun, silly fun that is :D.

#2 Nigelp Mar 20, 2008 01:27 AM


Thanks for the pictures etc. That is one neat build - love the idea of the bracing wires underneath the EPP (why didn't I think of that ?).

You were right about the Smart Dart XS and I have no doubt you are right about the Nutball - thanks.....Now, where is that scalpel?


#3 Boxhead Mar 20, 2008 01:34 AM

You Beauty Frank. I can stop dribbling now and finish my NutBall. I, like everybody have been really looking forward to it. Its now here.

Thanks :D

B :) x

#4 goldguy Mar 20, 2008 01:45 AM

Nigel: I just use very thin wire, run it through a wire eye in the spline, cut slits, insert the wire, adjust until flat and then attack it with the hot melt. I tried dental floss, but it didn't work. Got this idea from floppy 6mm EPP PBFs. With the thicker EPP I've had no proplems with warps.


#5 jkarnacki Mar 20, 2008 02:00 AM

I don't really understand the method for inserting wire as bracing. Is it the same as CF, only with thin pushrod wire (.032/.064)? Do you cut a small slit in the EPP and then the wire fits snuggly into it?

I've been flying your dart longer than any of my other models mostly because I never crash it, but it's also just so much fun. It's my "old reliable." When my EPP comes from rcfoam (as well as some Depron!) this will be the first thing I build out of EPP - from scratch, that is. I have a flightflex yak in works :D

- Jeff

#6 goldguy Mar 20, 2008 02:09 AM

Yup, I just used thin music wire, as in pushrod material, it's all I had and my patience was running low. I ran the wire up through a long slits, at the same angle. After I adjusted and glued it, I then just clipped off the excessive.

If you like your Dart, you'll love the NutBall, it flys better and you can do more with it, it's way easier to build and I think kinda pretty too, pretty simple.

#7 Mchone, Jake Mar 20, 2008 03:13 AM

Looks right up my PBF allie!!! :cool:

Great job! All I need now is some more foam :D

#8 wrugen Mar 20, 2008 03:37 AM

Kinda a newby to Darting, Just finished # 6! So I need a little help. I "discovered "Hobby City and am now Platimum. Cant beat em. The 3.7 servos they sell are EM.
In your list you used EU 3.7 servos. Are these the same or did you find a better source than HC?
Thanks for the help. Just got a batch of .9 hot cut EPP. Time to build a round one.

#9 dekan Mar 20, 2008 04:24 AM

Good job...looks right Gold... even Gpw should be happy....after all it is Round.

We might need a plan......for the guys who like to hold something in their other hand while building!

I have just ordered another 10grm motor so.....

#10 teched88 Mar 20, 2008 04:43 AM

So 10g United Hobby motor for the 16" and 24g blue for the 20"? Sounds good to me, I will break out the chalkboard compass and get to work. Don't think Drawings are necessary for this one.

easier and better than the dart......... sounds like blasphemy to me.

Thanks Gold

#11 Flywellnz Mar 20, 2008 04:59 AM

I have my EPP ready to cut!
How are you doing the control horns? (close up pic would be great)

#12 firetrappe Mar 20, 2008 05:03 AM

Nice one Frank! Can't beat a quick, easy build...looks good too.

Now we just need Gene to post his plans and Box to put on the MelonCam™ and grab us a video :D

Congrats on another winner,


#13 gpw Mar 20, 2008 05:04 AM

Cool!!!:D :cool:

#14 artlane Mar 20, 2008 06:32 AM

What? A round (toit) NutBall Dart????
Darn nice looking PBF Frank, wonder if I could modify my Rountoit, to resemble this??
Just checked my EPP stock, all I got left is 2 sheets of 5.5mm... That's gonna have to do it.... (Must get another order off to supplier, I can see many roundies in the future.)
It is a beauty to behold Frank, and thanks for another successful flyer!
Oh ya, and I'll allow this for the Postal... Get those flights in before the 31st!
Now, like Nigelp, where the heck is my knife?

#15 FirstShirt Mar 20, 2008 06:50 AM

Frank, I love the Dart and I thought the R1 was even better. Can't wait to try your NB. I love your innovation on the fuse bracing and the v-grove construction technique. The latter sounds like something I'll want to practice before giving it a try on a larger piece of epp. Thanks! Pat

All times are GMT -5. The time now is 04:13 AM.