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Space Shuttle Depron Foam 64mm EDF - Scratch

Old 09-30-2010, 08:20 AM
  #51  
JetPlaneFlyer
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I share the concerns of the others regarding the ducting and inlet holes. The inlet area needs to be the same or at least very close to as the inlet area of the fan itself.. lots of small holes dont work as well as one large one because there is drag and turbulence as the air goes through all the small holes.

The standard way to tackle something like this would be not to put a duct in at all but simply to cut a large 'cheater hole' in the belly of the model in the area in front of the fan.. The hole should be as large as possible, two or three times fan area+.. bigger the better.

As for the wing testing.. When the streamers rise up away from the wing like they did in the video that indicates that the airflow has seperated from the wing surface.. That's commonly known as a stall, which is very bad
The streamers would do the same thing on a flat plate or cambered wing, in fact they might 'dance' more on the flat plate due to earlier stall.
Here is a video of 'tuft testing' (tufts is what the streamers are called) of a real plane wing.. notice how the tufts lay flat when the plane is flying normally but stand up and dance about when it enters a stall:
[media]http://www.youtube.com/watch?v=bIsWseMbDQU[/media]

Steve
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Old 09-30-2010, 10:27 AM
  #52  
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Originally Posted by JetPlaneFlyer View Post
I share the concerns of the others regarding the ducting and inlet holes. The inlet area needs to be the same or at least very close to as the inlet area of the fan itself.. lots of small holes dont work as well as one large one because there is drag and turbulence as the air goes through all the small holes.

The standard way to tackle something like this would be not to put a duct in at all but simply to cut a large 'cheater hole' in the belly of the model in the area in front of the fan.. The hole should be as large as possible, two or three times fan area+.. bigger the better.

As for the wing testing.. When the streamers rise up away from the wing like they did in the video that indicates that the airflow has seperated from the wing surface.. That's commonly known as a stall, which is very bad
The streamers would do the same thing on a flat plate or cambered wing, in fact they might 'dance' more on the flat plate due to earlier stall.
Here is a video of 'tuft testing' (tufts is what the streamers are called) of a real plane wing.. notice how the tufts lay flat when the plane is flying normally but stand up and dance about when it enters a stall:
[media]http://www.youtube.com/watch?v=bIsWseMbDQU[/media]

Steve
I Think Steve may have a good idea there, that would help to keep the sexy clean lines of the space shuttle a large hole or big wide slots on the bottom would work great IMHO, keep up the Super Nice work, Chellie
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Old 09-30-2010, 06:11 PM
  #53  
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Thumbs up Worked last night and finally finished!

Well Guys & Gals,

Another Marathon Night of finsihing up with this Build for the Space Shuttle!

I must have been so tired that I just do not remember what time I crawled to bed!

Anyway, I took off those Deflectors very carefully and now the Space Shuttle nose area looks as if no one ever installed any Ulgy Duck bill on top of it!





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Old 09-30-2010, 06:18 PM
  #54  
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Thumbs up Completed model and ready for Maiden Flight!

Wednesday night (09-29-2010), I completed the "DUCT" installation into the Space Shuttle's Payload Bay area primarily because I certainly received my new EM-Sport 2200mAH Li-POLY batteries from Esprit Model. They are have the best customer service and Shipping Department!

Here are a few pictures of the completed internals of the Space Shuttle! Notice the Dimension Engineering BEC on the Right Side of the FUSE.








Total weigh-in was 2lbs. and 1/4 oz.


Two pictures showing a comparison between the two different Batteries form factor (4-Cell and the (2) 2-Cell)

4-Cell, 2200mAH, Li-POLY



The Pair of 2-Cell, 2200mAH, EM-Sport, 25C, Li-POLYs:

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Old 09-30-2010, 06:24 PM
  #55  
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Thumbs up Additional Build Summary

Some detail as to where I placed those EM-Sport 2200's inside the FUSE, I believe that it was just too much nose heavy so, I moved them almost 2 inches rearward from where they are shown in this picture!





I had some distasteful swaying of the Main Gear and noticed that the securing screws were not screwed in all the way. I replaced the screws to the next slightly higher size and opened up the hole size for the Control Horn acting as my hold down clamp and pre-drilled into the plywood mount. Using smaller washers allowed for additional downward pressure on the nylon control horn section and thereby the main landing gear is nicely secured.

To reduced the swaying of the model sideways back and forth, I developed a wire brace and worked like a charm!






New batteries fully charged to 8.43 Volts each pack!


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Old 09-30-2010, 06:27 PM
  #56  
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If weather permits, I will be performing some Runway OPS to adjust the nose wheel steering and place the right amount of travel depending on what the model exhibits.

I will try to bring my Camera on a tripod to capture the action.

Otherwise, Sunday morning (weather permitting) will be the actual Maiden!

Carlos
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Old 09-30-2010, 08:29 PM
  #57  
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Thumbs up Awesme Power!

Guys & Gals ,

I just spooled up that EDF Unit and I was amazed at the power it produced and thrust.

I did not have the nerve to go FULL THROTTLE as I thought it was going to blow the camera down!

For a little 64mm EDF, it is very powerful! The Box says at or better than 1 kilio-grams of thrust!

That's more than 2lbs. of Static Thrust!!!! Wooo Hoooo!!

Here's the VIDEO:

[media]http://www.vimeo.com/15432943[/media]
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Old 09-30-2010, 08:53 PM
  #58  
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Thumbs up The "DUCT" seems to give this model a new Dimension!

Gerry! (simano)

You were absolutely correct!

That EDF produced lots of suction and my hairs on my arms were being pulled inside and I could feel the suction!!!

Just incredible power! I feel the "DUCT" has given it a new dimension but, of course the flight will be the determining factor!


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Old 09-30-2010, 09:30 PM
  #59  
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Default Power System

For those of you that might be interested:

EDF: Freewing Model 64mm EDF, 5-blade Unit (Outside Diameter: 77.2mm )

Motor: Freewing B2836 (3500kv), Unique Tail Cone Design, precision bearings.

ESC: Castle Creations Thunderbird 54-AMP

External BEC: Dimension Engineering 1.25 AMP continuous (1.5 AMP @ 60 Sec.) / 5 Volt Delivery BEC
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Old 09-30-2010, 09:38 PM
  #60  
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Nice work!.. I still think the inlet will be losing you a lot of thrust so you might be underpowered.... But i've been wrong before so go fly and prove me wrong again

One easy way to check thrust is to stand the model on it's nose on a set of scales. Give it full throttle and record the thrust by the change in readout on the scales.

Looking forward to the flight report, good luck with the maiden.

Steve
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Old 09-30-2010, 09:48 PM
  #61  
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Steve,

Thanks for the well wishes.

There is a large opening at the bottom chin nose area of the model with a slight 1/32nd birch Plywood action as the deflector. I have since removed much of the material so, as not to act as a deflector but, rather a large hole.

In any regard, I am pretty impressed with the Power and waiting for my Appliance Repairman to leave so, I can perform taxi tests!
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Old 09-30-2010, 10:37 PM
  #62  
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Thats nice Carlos Just a little reminder, The Transmitter is the first thing to be turned on and the last to be turned off, or the ESC wont be programed right, I noticed in the video that the battery was plugged in on the model first then the transmitter was turned on, that will cause you some problems, Take care, Chellie
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Old 10-01-2010, 01:06 AM
  #63  
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carlos,
be aware that cheater holes on the bottom of the airframe will cause the airframe to pitch DOWN when full power is applied rapidly!!
one of my club buddies had a Mig with bottom cheaters, it flew fine until he slowed it down way too much while on final approach, firewalled the throttle to the max, and it pitched down, and dug a hole just before the beginning of the runway. Situating to cheaters on the sides of the fuse are a more stable way of getting more air to the fan.Also those ribbed soda bottles do look like they may cause turbulence in the airflow to the fan.
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Old 10-01-2010, 02:17 AM
  #64  
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Originally Posted by CHELLIE View Post
Thats nice Carlos Just a little reminder, The Transmitter is the first thing to be turned on and the last to be turned off, or the ESC wont be programed right, I noticed in the video that the battery was plugged in on the model first then the transmitter was turned on, that will cause you some problems, Take care, Chellie

Please PM me to discuss this subject matter. Look in the manual it says you can do it either way (depending on the Receiver you use).
Please go to:
http://www.spektrumrc.com/ProdInfo/Files/DX7_Manual.pdf






Not trying to be rude especially with a Lady but, I like to keep on track with the discussion of the model.

Thanks!
Carlos

Last edited by guapoman2000; 10-01-2010 at 03:26 AM.
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Old 10-01-2010, 02:21 AM
  #65  
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Thumbs up Taxi Test Results!

Guys!

Just got back from the RC Club and I am amazed on the results of the TAXI test runs!

I went there expecting the worse such as a wheel falling off or steering veering the model to the grass shoulder or worse the main gear wabbling or bouncing the model as it went down the runway run.
Nope!

Very solid Mains and very soild nose wheel plus it tracked beyond my expectations! Did not dare go above 1/2 Throttle and it zoomed down the runway run very well and I was being real gentle with the throttle as there was a stiff breeze coming directly perpendicular to the runway (East).
A few post taxi run pictures sitting on the Setup Table we have at this RC Club (East Orlando RC Association).











Now for the VIDEO!
[media]http://www.vimeo.com/15442728[/media]
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Old 10-01-2010, 01:19 PM
  #66  
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Good Luck on the Maiden Flight
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Old 10-01-2010, 03:34 PM
  #67  
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Thumbs up

Hi Carlos
She looks wonderful
Best of luck with the maiden
Take care dear friend
Yours Hank
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Old 10-01-2010, 04:04 PM
  #68  
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Smile Okay you all Told me So!

Well, at this point, I don't know because of weather forecast conditions and I don't want to pressure anyone to get up so early on Sunday to take advantage of super calm conditions only to find Fog and thereby low visibility.

I did go this morning at the RC Club with Asphalt Runway and found Fog and had to wait until the Sun was over the tree tops to allow the fog to burn off.

Flight "Maiden" Attempt Summary:

The Full Throttle was a bit disappointing as the model did not get into step with that high speed that I was expecting. The UP Elevator movement was useless with the pronounced Nose down setup. My buddies Gerry, Mark and a few others here warned me of this as the Real Look of the Space Shuttle is Cool to look at but, not practicle for RC and Rise-Off-The-Ground.

While the morning progressed, a few came with their models and they took out their own EDF Jets and found my Space Shuttle pretty cool looking and I demonstrated yet again the Taxi run and they quickly told me that the frontal EDF needs lots of open Air available to the unit. My tube did nothing except to reduce the Airflow and that the Rear Tube is the one that helps the EDF provide thrust.

Okay, let my post here...... YOU ALL TOLD ME SO!

A few things I am doing right now is:

1. Reducing the Maing Landing Gear to nothing over 2 inched tall and which "is" the same height as that of the Nose Gear including the slope angle from the frontal FUSE.

2. Removed the entire "DUCT" Goodbye "DUCT"!

3. Building a floor to keep the small wires from the elevon servos, and
other wires from being sucked into the EDF!

4. Weather permitting, I will attempt to fly on Saturday morning as Sunday seem to be filled with just too much wind.


Here's the VIDEO of today's maiden Attempt!

[media]http://www.vimeo.com/15455544[/media]
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Old 10-01-2010, 04:07 PM
  #69  
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Default Other Post Maiden Attempt Details

Oh, I almost forgot!

During my demonstrations of subsequent Taxi run tests so, those with more experience with EDF than I could see the model go down the runway, I noticed the Payload Bay Door cover being "SUCKED IN" towards the inner cavity of the FUSE!

I quickly shut down the EDF and all went back okay. This right there gave me an indication that I am just starving the EDF for Air Flow!

It was a good morning as I am very pleased with my Custom made NOSE WHEEL STEERING it did not have any issues!!!

Carlos
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Old 10-01-2010, 04:18 PM
  #70  
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Ah, the shuttle budget lives on... : )

Might I suggest you stringer the interior of your bay and reduce the angle of attack to that parallel with the runway to reduce the
amount of power you need to rotate your roller skate... ; )
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Old 10-01-2010, 04:38 PM
  #71  
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Wink

Hi Carlos
Thats one great looking dragster
All kidding aside rome wasnt built in a day and im sure you will get the bugs ironed out asap
Looking forward to more seeing more of the flight testing
Take care dear friend
Yours Hank
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Old 10-01-2010, 04:43 PM
  #72  
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Default Yes, correct doing mods!

Thanks guys!

Yes, I really am pleased with my custom nose Wheel Steering setup so, this morning was not a total waste! It was really cool to see that Space Shuttle roll down the runway and all it needed was a drag chut at the end!

I am doing the man gear mod and reducing the length of it to have the Space Shuttle sit level with the nose wheel and will improve the chances of rotation at Take Off!

Carlos
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Old 10-01-2010, 10:58 PM
  #73  
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Originally Posted by guapoman2000 View Post
Thanks guys!

Yes, I really am pleased with my custom nose Wheel Steering setup so, this morning was not a total waste! It was really cool to see that Space Shuttle roll down the runway and all it needed was a drag chut at the end!

I am doing the man gear mod and reducing the length of it to have the Space Shuttle sit level with the nose wheel and will improve the chances of rotation at Take Off!

Carlos
Hi Carlos You took on one Heck of a Challange, pun intended Just need to work out the bugs now, I am sure it will be a Awesome Looking Model Flying in the air, Take care and have fun, Chellie


Hmmmm I was just thinking, do you think that a long v cut for a flap on both sides of the Shuttle would work as an extra air induction as the EDF is requiring more air flow, it would be flat when static and draw in for more air flow when needed Just My 2 cents worth.
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Old 10-02-2010, 03:22 PM
  #74  
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Thumbs up Maiden Complete and it is still in one piece!

She FLEW!

SUMMARY:

The Space Shuttle took off at 0737 hours Eastern time in Orlando, Florida at the East Orlando RC Association (Club).

The modifications were to add a wire brace (from a large Glow RC Airplane’s push rod) to keep the main landing gear situated forward and nearest to the Center-of-Gravity as possible. I used 1/32 Birch Plywood (Mid-West Product) cut into a small rectangle and placed the last reminding thicker plywood mount on top.

Using again a good size servo arm and one screw on each side gave a very solid feel to the main landing gear and I secured them together using wheel locks!

Another modification was to add a 3mm depron foam floor at the bottom of the FUSE such that I can hide some of the small servo extension wires so they would not be sucked in the EDF and additionally I used Industrial Strength VELCO for attaching the ESC, external BEC, Receiver and the Batteries to the best location within the FUSE cavity.

The take-off was pretty predicable but, the flight was quickly observed as somewhat tail heavy and I just do not like that fact that this model does not have a Rudder!! You need Rudder when coming for a landing otherwise, you need Airspeed to keep those Ailerons effective! Since I was tail heavy it was really hard to keep the model aligned to the targeted Runway run and it veered off a bit into the grass and the nose wheel bracket at the servo junction ripped off without “ANY DAMAGE” to the model nor the nose wheel servo!

I am just completely satisfied and this has been the best Project I have ever had and I have learned a great deal and have additional skills as a Modeler!

MAIDEN VIDEO!
[media]http://www.vimeo.com/15480251[/media]
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Old 10-02-2010, 03:27 PM
  #75  
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Thumbs up Final Modifications

Final Modifications:













Nose wheel will be installed and adjusted again soon!






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