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Old Aug 29, 2009, 10:36 AM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
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Build Log
DS-75/Neu/XPS 4500watt Scratch Build by Team Wesley !Video Added Post #112!

The Dream:
Every year we build "The One". The One is the aircraft that we've been dreaming of since the previous year's Arizona Electric Fest. What's going to turn heads? What is something that no one else will have there? And what can we enjoy even on our little runway up here in Colorado?
Last year, The One was the Spatha Jet. And although a 70mm to many of you isn't a big deal, it was to us. Our early attempt at an EDF was a great success. Read what Mickydee had to say after seeing it at '09 AEF:

"...your Spatha was the most impressive 70 MM EDF that I have ever seen fly. Speed, vertical, duration, all in one package."

From that moment on, we decided that EDFs are our new thing, and we can stay up with the best of them. This time, however, we are not competing with the HETs, GWSs and Sapacs, we are competing with the big boys: BVM, CARF, TamJets etc...

Here are the Must Haves of our design:

1. Greater than 1:1 Thrust to Weight
2. Greater than 160mph in level
3. Must have a wing loading under 30oz sqft
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Old Aug 29, 2009, 11:02 AM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
1,139 Posts
The Power System

After much research and budget consideration we decided on the power system.

Fan: Schubeler DS-75-DIA HDT 110mm Carbon Fiber 4 Bladed Fan
Motor: Neu 1527/2.5D 925kv
ESC: Castle Creations PH-110HV
Batteries: 12s1P 4900-6400mah 30C+

Thanks to some tests performed by Whistling Watts I determined that this combo would provide the desired thrust and speed that I need to reach my goals. At sea level, with an 85% exhaust pinch, the system should push with 14.5lbs of thrust and an eflux velocity of 240mph while drawing 112amps on 12s. Perfect! At our elevation we'll see about 12.3 lbs of thrust at 96amps, but the speed should still be there.

I know the Schubeler fan has a more offensive sound than other fans, but from what I've read, it's top of the line in efficiency and performance. Not to mention I don't have the $$ for a Stumax.
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Old Aug 29, 2009, 11:15 AM
EDF Jet Jam May 2014
Robert Belluomini's Avatar
United States, KY, Crestview Hills
Joined Dec 2000
6,311 Posts
I look forward to seeing your design.
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Old Aug 29, 2009, 11:27 AM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
1,139 Posts
Configuration

Every chance we get, we are drawing pictures and discussing (sometimes fighting over) different designs for aircraft. For a over a year now we've been in search of the perfect configuration for a single engine sport EDF with retracts. From flying wings, to canards, to HE-162 looking things, we've discussed every imaginable configuration. And yet, we keep returning the the Spatha Jet configuration.

(Pronounced Spaytha)

Similar to an F-4, the Spatha Jet's configuration has short intakes and exhaust for improved fan efficeincy, low wing to hide retracts in, easy to balance, and great access to systems and batteries. Not to mention we already know the design works! I love the Spatha! I think the Spatha has accumulated more flight hours in it's 9 month existance than any of my other airplanes, including my Groove!

Here are some Photos of the original 70mm Spatha Jet
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Last edited by Joshua Wesley; Aug 29, 2009 at 11:33 AM.
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Old Aug 29, 2009, 11:28 AM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
1,139 Posts
Quote:
Originally Posted by Robert Belluomini
I look forward to seeing your design.
Ya, me too. I'm so fired up, I can't wait to get it done!
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Old Aug 29, 2009, 11:47 AM
Registered User
Edmonds Wa. (Seattle)
Joined Nov 2003
3,926 Posts
I am not sure if you have seen the new Littlescreamers Extreme Scream motor?

in the dynamax fan

Cells: 12S 5000mAh XPS

RPMS: 25960
AMPS: 105A
Thrust: 15.01 pounds

That was with no inlet ring just the fan and motor on the test stand. we should get around #17-18lb with proper ducting and an inlet lip.

cost for package total $399 fan and motor

This is what will be flying our planes at the AZ event next time.

Scott
Littlescreamers.com
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Old Aug 29, 2009, 12:07 PM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
1,139 Posts
Weights, Wing Loading, and Density Altitude

This is the most critical part of the design. We must keep the wing loading down and here's why: Out club field is at a 5000ft elevation. And while that doesn't sound too bad, density altitude in the summer can exceded 10,000ft! The ground speed of the models is much higher up here. We are always caught of gaurd by the way our aircraft slow down and float when we fly at AEF versus here.

The Grand Junction Modeleers don't have an 800ft long, 50ft wide runway, Our runway is 400ft long and about 20ft wide. I'm not complaining! Many of you fly off dirt, or grass or streets. I'm very lucky to have such a nice facility, but it does make for a bit of a challange with more high performance aircraft. And I'll tell you right now, that there is no way a 12s CARF Spark can make it in and out of that runway on a hot, calm day. Maybe out... but not in without going in the weeds. Even a BVM Electra would be pushing it.

After adding up the weight of all the "guts", we've decided that we can build the jet at our around 10lbs AUW. At the most 10.5lbs. With a wing area of 800 squares, we will get a wing loading of about 28.8 to 30.24 oz per sqft. Perfect!

If we can reach our goals, this jet will weigh 1.25lbs less than a Spark, and about 3.5lbs less than an Electra with similar power systems.
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Old Aug 29, 2009, 12:09 PM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
1,139 Posts
Quote:
Originally Posted by Littlescreamers
I am not sure if you have seen the new Littlescreamers Extreme Scream motor?

in the dynamax fan

Cells: 12S 5000mAh XPS

RPMS: 25960
AMPS: 105A
Thrust: 15.01 pounds

That was with no inlet ring just the fan and motor on the test stand. we should get around #17-18lb with proper ducting and an inlet lip.

cost for package total $399 fan and motor

This is what will be flying our planes at the AZ event next time.

Scott
Littlescreamers.com
Whoa! Sounds like a screamer! I didn't now know about this system! Unfortunately we have already purchased the other system. But I must say I have a JetScream 1400 in a Wemo MiniPro and I LOVE IT!!! I look forward to seeing it in AZ!!!
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Old Aug 29, 2009, 12:44 PM
DELTAS RULE
corsair nut's Avatar
tehachapi, CA
Joined Jan 2006
21,589 Posts
very cool guys. i look forward to seeing it at AEF this year ill have a couple jets there, and probably az jets too. you guys going to that one? ill have the cougar that had the 90mm last year, and converting it over to the 12s turbax system(with the neu motor) and im finsihing off my JHH sabre that has the old 12s 90 setup from the cougar. she hits just about 160 straight and level

good luck with the build, should be a sweet bird if its anything like the 70mm version! thats a great flying bird. i really liked watching it at az jets....and i dont normally like sport jets!
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Old Aug 29, 2009, 02:09 PM
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Joshua Wesley's Avatar
United States, NV, Sparks
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corsair nut,

We want to thank you for all the inforamtion you have provided to us both in AZ and over the interenet. Encouragement from people like you helps us bring our aircraft to life. And yes, we are going to pinch that exhaust!

Look forward to flying with you!

-Joshua
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Old Aug 29, 2009, 02:43 PM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
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Misc Guts, and I need a little Advice

Here are the misc accessories I've decided will work on this aircraft and fit in my budget:

Servos:

Six HS-225MGs for Ailerons, Flaps, and Rudder. One HS-5245MG on the Elevator, one HS-81MG for nose wheel steering and one HS-65 for the retract valve.

Retracts:
Spring Air 202HD with 3/16" struts. I like Spring Air products, we have 4 sets already, and they've never failed. However their customer service has been on the unsatisfactory side during the last two purchases. It been month since I've ordered them, and they're still not here. I can't get a reply to my emails either!

Radio
JR R770 and a JR 9303. I know, I know, I'm flyin in the stone age. But I can't afford the switch to 2.4g.

HELP ME HERE:
What should I use to power the radio system? It needs to be light and affordable. Should I use a two cell 1320 and a Castle 10amp BEC. Or should I use an A123 pack... or??? I've had a couple suggestions, but I'm just not convinced on any of the systems. Help me out here guys!
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Old Aug 29, 2009, 02:57 PM
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eatond's Avatar
United States, MO, St Charles
Joined Nov 2002
1,733 Posts
Quote:
one HS-81MG for nose wheel steering
Hi Joshua,
nice project you got going. Check that HS-81MG over carefully. I'm not the only one who had problems with them not centering very well. The HS-82MG seems to work much better in that regard.

Dan Eaton
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Old Aug 29, 2009, 03:29 PM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
1,139 Posts
Quote:
Originally Posted by eatond
Hi Joshua,
nice project you got going. Check that HS-81MG over carefully. I'm not the only one who had problems with them not centering very well. The HS-82MG seems to work much better in that regard.

Dan Eaton
Thanks! Ya, I know the 81s aren't the best. Its what I have, and I fiured that the nose wheel steering would be the best place for it. I think I have an 82 and and 85 that need gears... maybe I'll swap out to one of those.

-Joshua
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Old Aug 29, 2009, 03:45 PM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
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The Design

We have decided to make it look almost idenitcal to the Spatha as I pointed out in the "configuration" post. However, we plan to clean up the lines around the canopy and turtle deck. Rather than harsh, squared off canopy outline, the edges will be rounded, and the canopy angles down to match the slick nose. The turtle deck will start much higher and taper down to the tail, unlike the flat deck on the Spatha. The fuselage bulkheads will also be more round, and scale like. Other than that... just a big Spatha!

The fan unit is 57% bigger in diameter than the 70mm. To keep weight down, and give it a tougher look, we decided that the big jet would be 50% larger in linear deminsions than the original Spatha.

Rough Specs:
Span: 58"
Length 66"
Area 810 sqin
AUW 10-10.5lbs

Material used will be primarily balsa, with some hardwood and carbon rod reinforcement. Dad's decided to go old school, and cover the entire aircraft in Silkspan and then paint it. Ok.... whatever makes ya happy Dad.
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Last edited by Joshua Wesley; Aug 29, 2009 at 06:39 PM.
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Old Aug 29, 2009, 04:04 PM
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Joshua Wesley's Avatar
United States, NV, Sparks
Joined Oct 2004
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The Build Begina: Motor Tube

As usual I'm funding the project while Dad builds it. Thanks to the crappy housing market, he's been forced into an early semi-retirement, which gives him lots of time to build. But thankfully for me the Biz Jet industry is staying afloat... so far.

The first part of the build that Dad started on is the motor tube. The intake will be roughly 112% FSA and the exhaust will be 85% FSA. The fan unit will be accessable by removing the exhaust cone and sliding it out. This will also give us the ability to make multiple exhaust nozzels for different shapes to optimize performance.

These components are made of laminated balsa, and it's very, very strong. Are you can see from the photos, he starts out with a former. He then wraps the sheets of balse around this former and glues them in place. Once all the laminations are in place, he simply breaks out the former. Tight fit!
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Last edited by Joshua Wesley; Aug 29, 2009 at 04:13 PM.
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