SSDC: ICBING 60" Racer * now with video - RC Groups
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Jun 24, 2007, 03:28 AM
ajroahkni's Avatar

SSDC: ICBING 60" Racer * now with video

60" EPP racer

Last edited by ajroahkni; Sep 27, 2007 at 06:46 AM. Reason: video
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Jun 25, 2007, 05:10 PM
ajroahkni's Avatar

Why EPP?

Why EPP sucks
  • Not smooth = you can see tape lines
  • Soft building material requires large chords = not sexy
  • Building strong tends to mean building heavy
  • Gets bashed, gets spongy/floppy
  • Promotes careless pilot mentality

Why EPP good
  • Anti-hangar rash
  • Easier to transport - no blankets needed

The Icbing will be a 60" racer-type model. Inspired from current design styling, the goal is a model that I hope will meet the gold standard "as good as glass" objective.

To do this, I feel the model will need:
  • a strong, stiff spar
  • thin chords
  • thin, smooth, stiff fuse
  • to be ballastable
  • good clean looks (no "panty lines")

  • area: 345 sq inch (bird60/Mini NYX/Nemesis=356 sq inch)
  • foil: mh43 (as used on ScorpionII)
  • length: ~35"
  • loading: Goal 12-15 oz/sqft
Last edited by ajroahkni; Jun 25, 2007 at 05:20 PM.
Jun 25, 2007, 05:19 PM
Free as a bird now.
Looks great John! Sorta kinda Shrike-like. Love the upturned tips. Get 'er done!
Jun 25, 2007, 05:54 PM
Nucking Futs
I'm Rick James's Avatar
BNF? (blunt nose fetish!)

Looks good. Looks like a bit of a PIA to keep the fuse in line and keep that Vtail incidence correct.

Please keep us posted.

Jun 25, 2007, 07:09 PM
Registered User
looks Great,
were can i get rc cad?
Jun 25, 2007, 07:18 PM
A10FLYR's Avatar
Originally Posted by Ryan Archer
looks Great,
were can i get rc cad?

You can download a freebee copy for trial..
Jun 25, 2007, 08:45 PM
Registered User
Mike Furcolow's Avatar
You mean, kinda like this?

All EPP construction

Fuselage; EPP with CF central longeron
Wing; 60" span, airfoil RG14-7% thickness, EPP w CF spars and X-pattern taping to resist twist, upswept "winglets" for reduced drag, better roll control for landing
AUW; 22 oz

This plane likes LOTS of ballast...I end up taping lead to the top of the wing, 'cause I made the fuse so small for low drag. If I was doing it over again, I would build it MUCH heavier...that's easier than light, anyway...
Last edited by Mike Furcolow; Jun 25, 2007 at 08:50 PM.
Jun 25, 2007, 08:48 PM
ajroahkni's Avatar
Thanks for the interest guys. I am excited. This was inspired on Friday after seeing Kawika's Bird60...I love to build, and until I get a vac system, won't make the jump to carbon scratching out in EPP it is!

I got the cores going thanks to Nauga, and have placed my orders around the net for balsa, CF, etc. I hope to start by next week! Can't wait.

Wingtips and tail feathers will be balsa and I am going use a RAPTR DLG boom from atlantahobby to keep it stiff/light out back. The fuse will be wrapped in foam to some extent, though I may have to substitute foaming PU glue for EPP where it gets real skinny.

I'll make sure to show how I set the incidence, I've done it before w/ an EPP plane and it came out pretty good.


Originally Posted by Mike Furcolow
You mean, kinda like this?
edit - thanks to Mike F, my dreams are shattered...

I will now move over to my alternate original idea: EPP Jart... (joking)

Last edited by ajroahkni; Jun 25, 2007 at 09:59 PM. Reason: Mike beat me to it...
Jun 25, 2007, 11:53 PM
Registered User
Mike Furcolow's Avatar
Uh-oh. Don't shut down your idea--make it better!!! I just posted that to "second" your ideas and your plans. I've been flyin' mine for 2 years, and I can sure tell you that you won't be disappointed with the results when you get it in the air. Your current plan for the ICBING racer is a winner! Go for it!!
Last edited by Mike Furcolow; Jun 25, 2007 at 11:59 PM.
Jun 26, 2007, 12:45 AM
Insert custom witicism
Jeff Charlot's Avatar
I like it! Same foil and specs as some of the top racers, but with EPP? Cool! Go man! I wanna see you win some races with this thing!
Jun 26, 2007, 12:52 AM
Vitruvian JART
Reed's Avatar
Jun 28, 2007, 01:21 PM
ajroahkni's Avatar
UPDATE: I got the word from Nauga today that my cores are in the mail - what a great guy. I also called lonestar-balsa to find out that they did take my paypal $, but lost my order - good thing I called them. Anyway, balsa shouuld be in the mail too! I may not start this weekend, but I'm a happy guy.
Jul 08, 2007, 06:06 AM
ajroahkni's Avatar

Building starts

Nauga's core cutting special offer for SSDC is/was something that anyone should take advantage of. Very nice, clean cuts. He does it for love of the hobby, an awesome guy.

I requested a spar channel of 3/16" across my cores, he did it no problem...problem is that I gave the wrong measurement - meant to say 3/8". Oops.

Some passes with a blade, some cautious, nekkid routing with a dremel, and the channels were widened for the CF Ribbon (it's the same ribbon that LJ kits come with, I'm not cutting it though).

I requested full airfoil cuts because I wasn't sure how much ailerons I'd put on until I actually saw it...anyway, cut 1 5/8" off the TE.

Ever since seeing Don Thuren's bulletproof spar, I have wanted to try my hand at one. I won't wrap it in a kevlar braid, but will end up doing some wrapping of sorts.

Cut #1 - 14 more to do. Using 1/8" and 3/16" balsa sheet, cut vertically.

It was a lot quicker than I thought it'd be to cut my wood

I put the top & bottom CF in the groove and then placed my balsa in. Going to let the wood and CF get used to the EPP, and tomorrow or Monday get to gluing and sanding. I err'd on the side of waste when cutting - quite a bit of sanding ahead, need to buy a few new masks.
Jul 08, 2007, 11:01 AM
Mr. Innocent's Avatar
I always enjoy your build threads John, keep it up!

Jul 10, 2007, 05:00 AM
ajroahkni's Avatar

Vtail blanks

A buddy of mine that's a great furniture maker/woodworker ripped me some 1/8" balsa from his gigantic slab of the stuff. I'll be using this for my V-tail stock.

I will use 2 1/8" pieces, sandwiched together to make my V-tails.

Grooves pressed into one sheet of balsa

Slathered finishing epoxy on the blank sheet of balsa, wiped off, set to the side

Epoxy to the grooved side, pressed/saturated carbon tow into the grooves. Wiped excess.

Mated, pressed for the eve.

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