Mirage2000 scratch parkjet from parkjet.com

[Babylon5]

Hi Viper, I will send you Pm with regards to the 3 bladed EDF.



Cheers

[viper1990]

Heres my lastest progress for the mirage2000.

-Cut away burned part
-Cut out new depron parts to fix back the giagantic hole
-Cut 6bladed into 3 bladed edf
-Borrowed my friend's Ace 40A esc

While running the 6bladed edf,the prop adapter jumped out at full throttle and the blade dug a minor hole (lucky me) intenally inside the duct tube. No worries. Just scary when i heard the *BANG* sound.

Took me 5hours to fix back the plane,from noon to afternoon ,then when i was about to step out my house.., it started raining
wanted to test fly it so badly. haha.

Bad weather recently isn't it? Hope friday dosen't rain!

[viper1990]

Hi, i have tested the 3bladed and 6bladed setup today on the 3550kv align motor.

I know that this has been discussed alot on the 3bladed topic many months back.

I'm just showing my perspective and opinions for the 3bladed and 6bladed setup. each has its pros and cons.


3bladed-
I noticed a significant increase in flight duration. When i landed after 5minutes, the pack still has juice ,voltage around 11.6v. Which means i can fly more! On the other hand, the had difficulty hand launching the plane, i need a very strong toss against the wind to get it flying because of reduced thrust.Motor stays cool.

6bladed
More thrust, plane is actually more maneuverable in the air... but the duration of the flight time was around 4-5mins when it hits 11.1volts on the lipo. Motor was much hotter then the 3bladed setup.

[viper1990]

Now i'm playing around with what airfoil should i use for my mirage2000.

I done research over the net and found some good airfoils (for low drag high lift ratios)

I came across the NACA 2412 airfoil that is used in cessna 172 skyhawk. It stalls at 12degree AOA. which probably give me a good slow landing speed for my mirage2000.

My usual airfoil on my mirage is just a symmectrical airfoil with blunt leading edge and shallow tapered down trailing edge.

I took 4hours to finish building my mirage a new set of wings, Building a airfoil on a delta plane is harder then on a simple rectangular wing.

Another thing i found out as i was researching about airfoils that is, airfoils produce lift even if its flying inverted, just that now that effective as when it's in the upright position(see picture)

Thats about it, i have done some test flight this evening with my new airfoil.
Some noticeable changes were:

1) i can fly the mirage at a lower throttle level , about 4-5 clicks downwards while maintaining straight level flight.
2) Climb rate was more significant
3) I can bring my plane down to jogging speed for landing while maintaining some speed above stalling speed.


Shall run more test tomorrow such as aerobatics, barrelrolls, inverted flying and high alpha flying. Loops? no...not enough power. haha.

[viper1990]

Brand new nosejob over my spare time
uh.., don't know whether a cleaner nose will help improve the plane's performace,nevertheless it looks nicer then the previous ugly nose.

[Babylon5]

Wow very nice nose job.
You did a great job on the Mirage.
How did you shape the nose so well?



Cheers

B5

[viper1990]

I made the head with depron and blue foam.

Blue foam for the nosecone while depron for the other half. So incase of nosedive, the head is built to break and acts as a cushion for the other parts of the plane

Erm, anyway i went jw field yesteday, lost control of the plane and it did nose dive, the whole nose was compressed but saving the main fuselage and the wings Proving that my thoery works but i lost 4hours of hardwork in constructing the nose

Ok anyway heres the steps how i made the head.
1) make hollow depron and join with solid bluecore at the nosetip.
2) sand like crazy over the edges to make it round.
3)100 plus bottle cut-out for the plastic cockpit
4)painted with my desired theme on the plane
5)put scotchtape all around the plane then use hairdryer to Shrink wrap tightly , people in jw field mistaken that i expoxy the plane from far.

I made a new head once again... over my sparetime.

pic 1) 2 broken heads , building a new one.
Pic 2) I added bluecore inside the nose
Pic 3) Painting the head
pic 4) add cockpit plastic
pic 5) after shrink wrapping the tape over the cockpit

[GreenJoshy]

I've began my work on my 3rd mirage2000! making even more improvement to various parts of the plane.

This time the fuselage will be in blue foam
wings will be hotwired airfoil
Downsize my mirage by 10%

I've completed the wing so far, This project will take me another 1 week to get it done. I'll continue posting my updates.

(the last picture is my 2nd mirage fitted with led lights)

[viper1990]

My bad, i accidentally use my friend's account to make my posting

[fuse]

i think you should reduce it by 20 percent, your current edf setup does not have enough power to fly the current big one you have. make it 20% smaller should be able to fly

[Babylon5]

Hi Viper, since your mirage is quite reasonably big , you should experiment with the 80 to 90mm EDF. They are more efficient then the 68mm size EDF if you match the 80-90 mmedf with the correct KV and size motor.


Reduction in area is another way to improve your flying characteristics if you want to maintained 68mm edf size, but there is however a trade off in terms of higher wing loading . You need to re-calculate your wing loading .

I also notice the thrust generated by your systems in your previous flight was rather weak. You may want to try to improve in areas like focusing the intake ducting and outlet or resort to a strategically located cheater hole.

Just my suggestion.

Cheers

[viper1990]

Hey,thanks for all your suggestions

By the way, i have calculated my wing area for my 2nd and 3rd mirage.

Heres the excat numbers

mirage2 : 1938cm sq
mirage3: 1292cm sq

Downsized by excatly 33.34% (for the wing area)

The fuselage size will still stay the same to accomodate my 68mm edf.

Anyway results for putting in the intake ring inside the tubing.
Answer is. yes my mirage fly faster by a whole lot so a cleaner duct really plays a role it keeping the thrust efficient!

[viper1990]

Ducted tubing 50% completed. just need to do the other half now!

Took me around 3hours of hot wiring...

the surface appears rough because i didn't sand it yet

I'll keep updating my progress.

[fuse]

nice

[Babylon5]

Ducted tubing 50% completed. just need to do the other half now!

Took me around 3hours of hot wiring...

the surface appears rough because i didn't sand it yet

I'll keep updating my progress.

Very nicely done . Good Job.
BTW I check the internet , experience EDF guys suggested you wrap a kind of polyester film or smooth paper at the exhaust side of the fan before mounting the EDF.The Idea is to make sure the airflowing out is smooth at the exhaust end. This will increase the EDF efficiencies.

One of my ED-fan comes with this sort of film wrapping at the exhaust side of the fan. Don't have the picture yet but will post one when I have the time.

Cheers