Sunday, June 28, 2009

The Mojo Conversion - a smashing success!

Today at around 11am I maidened the converted Mojo 3D profile plane that I blogged about earlier.

Here's what I flew with today:

  • 12x8 APC prop - a little under-sized, but worked well enough
  • Suppo 3520/06 800kv (Axi equivalent: 2826/12)
  • 6S1P A123 (2x3S1P packs in series) - the plane balanced laterally perfectly with this setup
  • CG @ 4 7/8" (per forum post by Paul Swany the recommended CG for this plane is 4 1/4" - 5 1/2"). I am 1/8" past mid-point - I find that CG mid-points work well for most conversions. I'll do the inverted flight test next weekend to re-check the CG. So far, so good!

With this setup my power meter read 61 amps WOT and 948 watts!At 4.5lbs that about 210 watts/lb - extreme aerobatics requires about 130 watts/lb. It's always nice to have that reserve power. I ALWAYS prefer over-powered versus under-powered.

I flew with barely any trim adjustments (thanks Bob K. for the sharp eyes on the aileron settings and with the assist on the mechanical adjustments). With just under 4 minutes of flight time I consumed 1000mAh out of one pack and 954mAh out of another pack. 5-6 minutes of aerobatics is going to be a safe range.

Take off and landing were uneventful - which is EXACTLY what I was shooting for!

Another successful conversion under the belt!

Quick and important note: I might stop by the SEFSD field next weekend and fly with those guys for an hour or two.


Sunday, June 21, 2009

Mojo .40 Project

While at the DiscountHobbyWarehouse Father's Day swap meet today, I met a seller (Chris) who promptly went out of his way to remove the engine that was in this really interesting and great looking plane. That allowed me to buy it at a slightly lower price from him and convert it to electric power (EP).

Here are the specs for this project (so far):

  • Mojo .40 3D profile (
  • 60A ESC
  • either 4S A123 or 6S A123 (to be determined after static thrust testing)
  • 12x8 APC prop (or something close)
  • AXI equivalent: 2826-4T (this motor is rated to support up to a 5.5lb plane)
  • total wattage: 600 (very acceptable - especally if the thrust tests produce the desired results)
  • 2.5lbs (1150g) plane with servos
  • 2lbs (915g) prop, 2826-4T motor, ESC, BEC, rx
  • 4.5lbs (2065g) AUW (all-up-weight) - estimated with current design
  • -OR- I could go with 6S1P A123 + A3520/06 (AXI 2826/12 equivalent) which would bring the plane weight up an additional .5 lbs (230g) for an AUW of 5lbs and the power system to approx. 900 watts <-- this looks like a ridiculous and fun setup!
  • I will most-likely use larger motor (designed for approx 6+ lb aircraft) but I'll wait and see what the initial testing results are.
Here are some obligatory pics after I got home and set her down...

Chris, if you're reading this, thanks again for the great plane! It's a solid beast and if my work week isn't too hectic, I'll fly her in Poway next weekend. By the way, the new Poway location is Pomerado Road and Stonebridge Parkway. Drive east on the parkway until you reach a gate. Drive through the gate and after a short dirt road you will see a wide open and flat paved asphalt rectangle in the middle of nowhere (we still speculate as to what it might have been used for).



Saturday, June 20, 2009

Hyperion Sukhoi Repair

Well, when landing after her maiden flight one of the wheels simply shattered and the landing gear dug into the tarmac. Needless to say, this caused the landing gear to rip apart the lower part of the fuselage.

After finally getting a quiet hour I was able to repair her and she's better than when I first buoght her!

Time to "take 'er up" tomorrow morning!

The damage...

The parts...

All done!


-- Post From My iPhone

Saturday, June 6, 2009

Hyperion Sukhoi SU-31 25e

Today was another fun-filled plane-building day. Below are the specs on this particular plane:

  • 1165g (2.5lbs 3S) OR 1260g (2.75lbs 4S)
  • Suppo 1100kv outrunner (AXI 2826-14 equivalent) for a 2.5lb - 5lb plane
  • Suppo 60A ESC
  • 5A BEC
  • Spektrum AR500 rx
  • APC 12x10 prop (4S)

End result: 1870g (4.2lbs) thrust with this setup at 700+ watts!!!


  • 610g = Empty plane (kit only):
  • 255g = 3S1P A123
  • 315g = 4S1P A123
  • 300g = Prop/BEC/ESC/BL2826
  • 36g = Misc (screws, glue, linkage assemblies, etc)

Hyperion Sukhoi build log in German:

Monday, June 1, 2009

Great Planes ElectriFly Fokker DVII WWI ARF

First of all: what a great plane! Within a few hours of purchasing this little bad boy, I had her up and flying all with a few trim clicks - nothing else. I did follow the manual (surprise, surprise) and applied the recommended throws. After over 20 flights I'm still using the same throws and 30% expo.

Here are my build specs, some pics and a link to a video:

  • AUW with battery is 665g (about 1.47 lbs)
  • 3S1P (A123) 1100mAh pack (130g)
  • 40A ESC - that's what I had laying around - ordered a smaller ESC to save overall weight
  • 2200kv small outrunner ($9 shipped - eBay)
  • APC 8x3.8 Slowflyer prop
  • Spektrum AR6100 rx
  • (4) Hitec HS-55 servos (2/ailerons, 1 rudder, 1 elevator) - I don't care for these servos, but they were sitting on the bench but I was awaiting my hobbycity HXT900 servos (and I get impatient)

With this setup I get anywhere from 7-8 minutes of flight time. I have (finally) made it a habit to to land her with elevator up to avoid nose-overs - so landings are now smooth, boring and quite uneventful :)

She doesn't need a lot of runway and looks great when performing a smooth rolling takeoff - tail up, wheels still rolling and a gently nudge on the elevator and she's aitborne. As far as I'm concerned she's got zero bad-habits. The same applies to touch-and-go's and landings - gear on deck, tail up, lose the throttle and apply full up elevator. It's a pretty sight to see her land and taxi smoothly.

Below are the obilgatory pics and video - my thanks to Tom for the time he took from his flying to take these!

Looking great!

A great back-shot

Setting throws...

Landing approach


Nose-overs... too easy with the Fokker!

All-in-all, a great plane!