Tee Dee Performance Crank

I use 1/64th top and bottom in the center of the wing to protect the balsa from the fuselage.
I use a 3mm carbon tube for a dowel. and steel piano wire in the back for dowel to clear the pushrods.

Leading edge tricks are good and trailing to help protect the soft balsa you have to go out far enough as the rubber bands will slide out far during a crash and can crush the balsa ( I know) happend to my Lil Speedy had to do a fix. So when I made the Skorch I went with a wide section of thin ply. I see you didn't tapper the tail of the fuselage as much is that rear former glued in? The flat bottom wing will turn better if you only have rudder, should sand in some washout at the wing tips and really need (some) dihedral.

Just use your gut feelings, best and past experience to solve design aspects as you go along and you should have a nice flying plane. Everything I did with the plane was carefully thought out for best overall performance of each part, for looks and for flying.

You can wick in thin CA into the balsa grains to add strength prior to monokote or some sort of covering can fuel proof with paint if desired.

Tapperd tail to reduce drag / weight

Looking at Freds numbers and knowing the max recommended rpm I wonder if Cox meant 24000 rpm in the air unloaded or 24k static??  

Here is the prop I used a 3g Tornado 6x2 wood but note the other prop:

Carbon / plastic prop 4 x 4.5 pitch
- If static 24,000rpm 102.3 mph
- unloaded 26,00rpm 111 mph

LOL yes would be a major feat to do that type of sanding!

You could go with 3 ply dihedral braces, cut the wing in half and sand a tad angle in both halfs for when you butt joint them together. Notch for the two main braces rear one is just to help with the rubber bands more so than anything. Could use a strip of fiberglass or cloth and wick in some CA across the butt joint.

5x4 black nylon should lose a tad pitch loaded in the air say 5x3.7 or more -if with the cox black flexible prop.

- 26,5k while slightly diving. 93 mph / 3.7P

- static measures 22,5k. - 74.6 mph / 3.5P

Here are three in 1/2A range I have them all.
I took the 4.5 x 4.5 and reshaped the tips down a 1/8th each.  
The 4.75 x 4.75  I plan to take to 3.8 x 4.75 if at 26k /117mph
I have their 6 x 5 (not shown) same hub size and blade width if 3.8 x 5 at 26K /123mph
Stiff blades wont lose their pitch.

http://www.ebay.com/itm/4-75X4-75-E-4-75X4-75E-Propeller-Prop-airplane-park-fly-/140386536469#ht_2257wt_1018

http://www.ebay.com/itm/4-5X4-5-E-4-5X4-5E-Propeller-Prop-for-airplane-park-fly-/130390633710#ht_2291wt_927

http://www.ebay.com/itm/3PCS-RC-Propeller-EMP-4-1x4-1E-Prop-Motor-Shaft-Adaptation-for-RC-Aircraft-plane-/140897059386#ht_2310wt_1018

RC Propeller EMP

Something to consider the blade material is great reshaping, I have concidered taking the
4.7 5 x 4.75 to a 4 x 4.75 with reduced trailing edge to have a 4in dia prop.
All can have a thinner cord to keep dia. up.

For me I just remain behind the prop at all times after I have started an engine.

I have tested the 4.1 x 4.1 prop to 31.4k with a 140w 11.2v brushless motor. The blade is thicker at the hub / more robust compared to other electric props of this size, a stock uncut 4.5 x 4.5 did just fine on the bench with a throttled TD.

Soon I will flight test with throttle. For my own past testing efforts the best and safe way to induce and force the possibility of  shearing a blade: while in flight power down during a vertical climb till the plane is on the edge of falling off then bang full throttle inducing maximum loading at the hub testing the materials limits. Do that a few times and then if no failure land and check for stresses at the hub if no stress then press on and enjoy the attributes of the prop design. Thus far these EMP props are the best molded electric props I have seen / used other than APC and some German Speed props.

I own a 7000 watt 9.4hp outrunner with a 32x15 prop the material appears to be same type. The first time I applied 60v my heart beat out of my chest impressive amount of thrust even the sound of the prop 2ft away was shocking. Two geared motors to a 48in 3 bladed prop could lift a man straight up. I plan to buy 3 more and make a quad copter to fly around. I have calculated for 15-18 min flights 3/4 throttle with Li poly cells. 36 x 8 props 34 lbs of batteries. 4 150A esc's.

I don't start engines or fly unless spectators are well behind me and when running boats the ducks, turtles have the right away.


The quad copter market is starting to make all carbon props, I have been keeping an eye on potential props for anything from .010 to .061  thus far only one suitable found for a .020... there is hope.

That foam delta looks good and all the foam planes have opened up some additional small IC fun. I have balsa planked a foamy with sorghums and covered with monokote made for a very strong lightweight plane.
Some of the scale planes have been calling my name.

This balsa / ply delta comes with a fuel proof finish and RTF less gear for $50.56 to $66
http://www.hobbyking.com/hobbyking/store/__56286__delta_rocket_high_speed_wing_red_640mm_arf_.html

USA warehouse:
http://www.hobbyking.com/hobbyking/store/__68858__delta_rocket_high_speed_wing_red_640mm_arf_us_warehouse_.html

Made to run up to 200 watts so TD.09 to TD .15 should make a nice screamer.

If 14 deg has worked for you 14 to 16 degree should be enough. If this plane flies faster than the mid wing it will respond better in the turns in theory.

Could go with a flat top and only dihedral where it counts.