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Hi,

No video or pictures but i did manage to fly this one today,

And It flies although i need to do some repairs as it has a indoor receiver in it and it was flown out side of its range .

Easy to repair and hopefully the light will be better for my camera.

But at least know it will work.

Steve

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Hi,

Ok so i broke it,

ooopsb.jpg

Not worried about it, as i can re-build it.

More of a question for Simon as he has more experience than me with these small EDF jobs and having just watched his 25 inch Vampire i guess he is the right man to ask.

So now it`s in bits i have the opportunity to re-site the edf if it would help.

resiteb.jpg

closeupb.jpg

Steve

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So i am concerned about the narrowing at the rear of the EDF unit .

I am also considering in changing the EDF unit.

twinedf.jpg

As you can see the one on the right has a smaller bell motor so i am thinking that would be better to use as the air might not be as restricted as it comes out the back although it is a lower power unit the loss may be better and my run time should be better.

What do you think ?

Steve

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So i have decided to go for the lower power EDF unit and although it pained me to cut open the model i preceded anyway.

Spiting open the model turned out to be the best option for me.

totheback.jpg

I decided to cut off a bit of the rear and have the EDF unit make up for the lost material.

start1.jpg

With the EDF unit glued in place i made the formers thinner so that i could add sheeting to make the inner Ducting.

start2.jpg

Steve

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Ok ,

So managed to get some work done on this one tonight.

remove intakes.jpg

I have removed the Intakes and made larger holes in the sides of the body and made a bigger hole to let more air in.

Also added internal sheeting to allow the air to move freely.

enlargehole.jpg

Two nice Big holes and the body is still nice and strong in fact it seems stronger than before.

 

 

Steve

 

Edited By Stephen Jones on 25/04/2017 23:09:19

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Two new larger intakes added.

newintakes.jpg

Finished and does not look to different.

finshed.jpg

through.jpg

Ok so not as pretty as 1st built but it is a crash and make do.

If it flies ok i may make a new one from scratch purpose built for the EDF unit.

I may be able to make it lighter if i sand the sheets thinner at present the AUW is 119g and feels as though their is more puff and blow coming out of the back which is a good sign.

It was a toss up as to which EDF unit i use as the more powerful EDF unit weight more and would need a larger battery.

So what i would of gained in power i would of lost in performance.

Steve

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  • 3 weeks later...

Flight Report...

Well this evening was bright sunny and claim,

I got home early for once and my tea was on the table for 18:30 Great.

So a quick charge and gathered up my EDF Sipa and My Camouflage Sipa and of to the field i went got there for 19:30 and apart from a dog walker i had the field to myself.

My Edf Sipa weight without battery was now 105 grams yes i removed the choc block i had left connected to the Esc and motor wires they have been soldered on and that choc block weight 4 grams.

Now with a 240ma battery in it weights in at 119g .

1st test flight it was ballooning so i dialed all my down trim still it was ballooning .

So 2nd flight moved the battery right up front in the nose better and flying ok but just did not feel right with nose held high.

So i put a large 450ma battery right up front now it was balancing on the leading edge and a slight breeze was getting up so i hand launched it into the wind. WOW what a difference a better battery makes now it was flying much faster and more stable and i could fly it around with confidence on a quarter throttle.

So it works, but i guess i will have to figure out what is going on with that Cog that last crash must of knock something out of alinement, does down and right thrust still applies to Edf models question.

Happy with that flight i then flew my Camouflage Sipa which i have not flown for some time which i why i took it out and i had forgotten just how fast it is on a good battery in fact my nerves where going some, after i settled down i flew her around on half throttle a few loops rolls and circuits later i decided to land it as the sun was now low and getting in my eyes a nice touch down and happy that i rushed out for a quick test flight in the evening sun.

Steve smiley

Edited By Stephen Jones on 10/05/2017 23:33:40

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Hi Mowerman,

Thank you, Yes i have built a fair few and i think their is still room for a larger size .

But half size would make for a 13 foot wing span. Which of coarse is do able but there is good reason why all my models are small it reflects my surplus expenditure or should i say lack of it wink.

Steve

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Hi,

Not had time to work on this little fellor yet but i have weight it with the 450ma battery in it.

Wow 135 grams that is too heavy for indoor flying.

Also checked the tail plane incidence , yep it is well out no wonder it was ballooning so i will have to cut it free of the booms and set it level and then i should be able to reduce the nose weight .

I guess i should of checked that before i took it out for a second test flight.

Steve

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Posted by Stephen Jones on 10/05/2017 23:33:12:

 

So it works, but i guess i will have to figure out what is going on with that Cog that last crash must of knock something out of alinement, does down and right thrust still applies to Edf models question.

Up and down thrust will affect EDF flight as will left and right thrust . Generally no left or right thrust is needed on an EDF as this is primarily for prop driven models to get a good air flow over the stabiliser/ Fin. Up or down thrust is used if the thrust line/ EDF unit is off center from the models centerline . ie, mounted on top of or below a wing.. If thrust is wrong then ballooning or diving can result. . We have a club member who plays a lot with EDF powered flying wings and even a Wot 4 XL EDF powered model /www.youtube.com/watch?v=e6D98N8TJqw&feature=youtu.be The thrust line is critical especially on Flying wings or models with a short moment. Even the wot XL thrust line had to be tweaked to get airbourne. Sudden motor stop was an ECU failure 

Edited By Engine Doctor on 12/05/2017 07:39:19

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Thank you for your replay Engine Doctor,

I had assumed that thrust line would still play apart in stable level flight,

But had questioned my thinking seeing foamy edf models with a large tunnel through the body and thought how are they going to off set the thrust line.

I had also observed that the full size Sipa s-200 appears to have the nozzle pointing down some.

I could be wrong but i think i read some where that the full size sipa would tare up a grass landing strip due to the nozzle being so close to the ground.

i Have now sett the tailplane level and awaiting some calm weather to re-test the model.

Indoor flying this Sunday and it`s the last of the season.

Steve

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I have a 70mm EDF waiting in the wings, (haha! pun intended! smile p ) The plan is to attach it t oa "Zephyr type flying wing. And I had already determined that I should knock up a nozzle type outlet for it, so that I can easily adjust the TA after fixing the housing firmly in place. My idea is to use a section of plastic or foam picnic cup.

Too big for indoor though. Ahem.

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Hi,

Success,

Well today i went to the indoor meeting at rochdale it was very busy there so i flew my usual stuff waiting for a quiet time where i could test fly the Edf Sipa without risk of hitting someone or someone hitting me.

Put a fresh battery in and checked the CoG and she flew straight from the hand launch and Boy is it fast, well for indoors that is .

So my next task is to see if i can make a fresh one that is lighter so that i can fly slower.

I will keep this one as it is. Hopefully we will get some nice weather soon so that i can do a video of it.

Steve ( well please Dept) smiley

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  • 3 weeks later...

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