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Posted by DownUnderPilot | Jan 31, 2012 @ 04:43 PM | 12,398 Views
Most of my time recently has been spent re-building (and re-engineering) my Ninja Speed. This is a F3 electric speed plane designed in Germany and flown sucessfully in the German Speedcup series.

The build log is here:

It crashed on it's maiden flight due to an ESC failure. The fire was so hot it melted solder connections and also destroyed the external UBEC. The plane definitely shows a lot of potential though and it was rock solid in flight and pretty quick.

I've re-engineered the damaged parts - the fuse was pretty badly burnt and the wing had a large dent in the L.E.

The repaired Ninja will be as follows:

Scorpion HK4020-1100KV
APC 7x10
CC Ice Lite 160HV
8s 2700 65C lipo (2x4s)

Peak current 165A
28K rpm (pitch speed 265 mph / 426 Km/h)
4500 watts

So all going well it should be ready in a few weeks. How fast will it go? Time will tell! 220 MPH? Any guesses?
Posted by DownUnderPilot | Apr 10, 2011 @ 04:59 PM | 13,078 Views
That is a first for me - flying 2 brand new planes on the same day. To top it all off I also had a new radio, a 2nd hand Futaba 9CAP with Frsky 2.4 module.

Talk about a lot of setting up...

The first was my new Mini Topsky 1m DLG. What a load of fun! Pretty easy to fly, although I suspect getting those last 5-10 m launch height is all technique. My best time in dead air was 55 seconds, so I was thrilled!

The second was my "Gull" scratch built glider - actually I renamed it to The Albatross, it just kind of looked like a bird in the flesh. This was a great result as well, 45 climb out, with a very flat glide. The airfoil is Ag03 root -> ag11 tip... final specs are:

1900mm span
AUW 1000g
~200 watt outrunner, turning an 8x5 folder.
4 servo wing

Wing is constructed of CNC core cut eps foam with several layers of .75oz glass /epoxy, finshed with WBPU/baby powder.

After successfully flying two new planes on the same day - what a great feeling!
Posted by DownUnderPilot | Mar 10, 2011 @ 05:05 PM | 13,918 Views
It's been a while since I updated this blog...mostly been pretty busy, with several plane projects.

So, what have I been up to? Here are the projects of interest:
  • VQ Models Pilatus PC6 Turbo Porter ".46" size
  • Monster Wing
  • Coreflute "2 hour" wing
  • Airsail Auster
  • FrSky and the Turnigy 9X... goodbye Spektrum...
  • 2m "Gull" glider
  • TopSky Mini DLG

VQ Models PC6 Turbo Porter

This has turned out to be a lovely model! I was a bit apprehensive getting such a model since I've never seen a VQ models ARF in the flesh. I needn't have worried... it's a really nice plane, well put together. I'm running a Scorpion SII 3020-1100KV on 3s with a 11.5x5.5 prop, for around 500 watts. This plane flies very light for its size, and has an extremely scale like sound! Touch and goes are easy peasy.

The other cool thing about this plane is it won't stall! Definitely good for confidence

Monster Wing
New batteries and a tweaked airframe sees this consistently hitting 150 mph. I sort of killed the old 2200 mah lipos by asking 45C of them! So I went to 3000 mah 40-50C Turnigy lipos (2 x 3s). Should be good for 120A theoretically, which is great since my setup won't go over 100A. I'm planning another sortie very soon, the batteries are only going to improve, and I'll be using a 6.5x6.5 up from a 6x6, so I think it should get faster. I really want to push it past 160!!!

Coreflute "2...Continue Reading
Posted by DownUnderPilot | May 09, 2010 @ 03:15 AM | 14,871 Views
The Monster flew today - and went fast! Link is here:

Looks to be 150+ mph

Update - have been dopplered at 159 mph so far!
Posted by DownUnderPilot | Jan 15, 2010 @ 05:17 PM | 16,442 Views
The Shark was officially Dopplered by TheDon at 144.9 mph. Unfortunately I'd mised the Fastest Foamie ruling about Hot wiring wings, so it was not allowed

However it DID spark an enormous debate on the thread, which eventually led to two new threads being created, each a competition for fast foam.

The first, by TheDon, is here:

2010 Flat Foam Speed Challenge

.. basically the idea of this thread is limited power by keeping the lipo to under 130g. Good idea, should produce some interesting entrants!

The second, by Jackomeister, is here:

Fastest Foam Plane Challenge - The Unlimited Class > #1 DownUnderPilot 144.9mph <

... which has fewer rules and the idea is how fast can you actually make a piece of (almost) foam go. I'm entered here, in fact Jacko generously let The Shark posthumously enter!

But I' building a new one, called the Monster. Details include 6s, 1200-1700W, and hopefully should be able to easily surpass 150 mph. Watch this space!
Posted by DownUnderPilot | Dec 23, 2009 @ 08:50 PM | 16,550 Views
Well I flew it on 4 cells today - Wow! Very stable and definitely quicker.

Here is the thread:

And here is the video, hopefully someone can get a doppler speed reading:

The Shark on 4 cells (1 min 12 sec)

Posted by DownUnderPilot | Dec 21, 2009 @ 05:51 PM | 16,428 Views
After the wing went down, I tried again, this time paying more attention to the aerodynamics and the system for enclosing the battery etc. Also mounted the motor on the front, which allowed my to put the battery right on the C of G. I named it The Shark.

Maiden flight was awesome, and the How Fast recorded 215 km/h and then 220 km/h on the second flight.

Unfortunately the video Doppler pass only got 116 mph (186 km/h). Here it is:

Shark Pass #1 (0 min 11 sec)

It has a 29" wingspan and weighs 650g with a hyperion 3s 2200. With a 4x4.75 prop it was pulling 50A for 550 watts.

Since then, I have a 4s battery and it runs up at around 61A, for 850 watts with a 4.1x4.1, so this might make a bit of difference! The goal is to surpass PDawg's amazing Gordo, which got to 139 mph on around 250 watts!
Posted by DownUnderPilot | Dec 21, 2009 @ 05:43 PM | 16,848 Views
So The Stingray got to 180 km/h. The issue was roll instability - I could not keep it under control. So she has been parked. In fact ripped apart, all the carbon and electrics have been kept.

My next idea was to build a foam Slipso, with a monster power system. So I built one. Wingspan is 700mm, around 50-60mm less than stock. It has a wider body, to accommodate at the least a G3 3s 2200, so definitely a slim 4s pack.

It had a single 8mm servo in the wing behind the spar for the aileron. It crashed on the maiden flight! I eventually discovered it had a tailplane failure. Not fun

My next idea to go fast made from some old foam wing cores I had. I knocked it together in a few hours, total cost about $5 for the balsa elevons.

This plane showed lots of promise. Powered with the same motor as the foam slipso (Turnigy 2836-3700). It flew very well, but had a mid air explosion! If you've seen Dons shuttle explode in mid air, then you have an idea of what it looked like. Foam everywhere, and I found the lipo 130m away from the site of destruction!
Posted by DownUnderPilot | Mar 15, 2009 @ 11:25 PM | 16,974 Views
So testing has progressed with the Stingray, had a decent flight on the weekend and recorded 171Km/h. Next steps are:

3.1x5 prop for more pitch speed
extend winglets to cover elevons
fillets and more rounding on airframe
cover airframe with so-lite
heat sink on motor (was getting pretty warm)

My next immediate goal is to get to 120 MPH (193 Km/h).
Posted by DownUnderPilot | Mar 10, 2009 @ 12:28 AM | 16,688 Views
I know this name has been used a lot before for RC models, so I hope I'm not upsetting anyone...

The Stingray is nearly complete. Flight tests on 2 cells showed, after some poor C of G issues, that it flies ! Specs in previous entry. There was an issue with some Dutch Roll, so I added winglets. I was planning to do this anyway to reduce a bit of drag with any luck. Seemed to work very well.

Surprisingly the elevons needed almost no reflex.

So then onto 3s. This with a 3.75x4.1 prop, supposedly turning at around 40K rpm. Well it flew all right - pottered around on 50% throttle for a minute or two to get used to the handling with a heavier battery. Then I lined her up and nailed the throttle... wow. It actually looked like the afterburners got turned on. I have not installed the airspeed How Fast yet so not sure how quick it went, but looks promising

Anyway after about what seemed like a long time but probably only 3 seconds the esc cut out, so I'm probably running over 25A. Must get a Watt Meter...

I borrowed a 30A esc out of another plane so that might just do it. Tests will continue this weekend...
Posted by DownUnderPilot | Feb 07, 2009 @ 08:54 PM | 16,308 Views
So I have decided to enter into the Fastest Foam challenge:

After subscribing to this thread, I just can't stop thinking about what would work if I were to build something! In fact, I suspect even if I fail miserably, at least I'll stop thinking so much about it

My plan is to build a small delta wing elevon only model. Slippery as possible. Here is the power system:

GWS 4600kv inrunner ($31.40)
25A GWS esc ($29.30)
1700 3s 20c lipo ($34.63)

Total 95.37 USD (phew). Cash is a bit scarce so I've used the motor and esc outta my GWS warthog. The prices are still the same for these components from when I bought them so this should be OK.

Here is some of my logic:

Delta wing necessary for (relatively) slower take off and landing.
Very high pitch speed - need to turn a 3.5" prop at ~41000 rpm to get 160 mph pitch speed
Lamitated wing (2x 6mm depron) with a nice sleek airfoil. Allowed to use a bit of carbon so I'll use a spar, plus maybe a strip on the trailing edge.
Optimised airframe with lowest possible drag. Also where the model presents itself to the airflow, it's got to be able to flow easily....

So I'm ordering the depron now, watch this space!
Posted by DownUnderPilot | Jan 11, 2009 @ 01:58 PM | 17,453 Views
So here are some of my planes...

Parkzone P51 Mustang
The model I have flown the most - probably 500 flights. Now runs a Dynam 22-20L 200W outrunner. I also added a carbon spar to the wing, and servos for each aileron. Flies with great authority on props from 10x6 to 9x9. I put in an airspeed measurement (winged shadow) the other day and recorded 71 Km/h with the 10x6 prop and 121 km/h with the 9x9. With the 200+watts it flies how Parkzone should have made it in the first place.

Parkzone J3 Cub
This is one heck of a war horse with a range of motors being installed in it. The latest is a Ecoflight outrunner running a 8x4 prop and about 140 watts. I made the wing flat bottomed to cope with wind a little better and it goes well.

This has GWS 4600kv motors, 25A esc's and uses a Hyperion 3s 2500 LVX battery. Approx 400 watts. Enough thrust to fly vertically (almost unlimited). Pretty fast and can slow down nicely.

By far the fastest model I own. Built from a kit after reading this thread
Have a bit of trouble at the moment landing it in the space available at the local park, but a heck of a lot of fun to fly. Also the only model I've built that required zero trim adjustments on it's maiden flight. I plan to measure it's speed directly, but have dopplered it at 171 km/h. Have disabled the break on the esc so hopefully the prop windmills and slows the plane down on landing....Continue Reading