Hello friends!

I have this kit Midifan Pro 90mm / ARC3655-2 / ESC 100 / 8S 3700 45/90C that gives me 2020 watts 67amp.

But then I saw this other very similar configuration that gives more watts but of course consumes more!

Midifan Pro 90mm / ARC3675-1 / ESC 120 /
3000 watts to 105amp

Is there another configuration with the Midifan Pro or Stumax 90mm 8S comes close to the 2800 watts without consuming more than 90 amps or something?

arc 75-1 with change sun 90mm fan is about 2.45 kw on 8s

Any time you want more watts but less amps you will need to add cells to increase volts..then get a motor with the correct KV to get the correct rpm

12s2200mAh, Midifan, ARC 36-55-2.5
With bigger cells you'll hit 3kW

M4V01712.MP4 (0 min 37 sec)

Originally Posted by Ruyman

Is there another configuration with the Midifan Pro or Stumax 90mm 8S comes close to the 2800 watts without consuming more than 90 amps or something?

No - that's not possible. The maths is pretty simple:

8S * 3.7V = 29.6V
2800W / 29.6V = 94.6A

So you need more than 90A! Unless your packs can hold more than 3.7V/cell, which I doubt.

Jacques

The problem is that it is to ride in a Bae Hawk Jet teng and clear more than 8 cells, I will be very nose heavy and I like the idea of 3000 watts with ARC3675-1 to the 2020 watts with ARC3655-2 but of course more consumption and less flight time!

So I wanted to know if there was another setting that at least will not exceed the 2600 watts 90 amps the consumer to not have to buy another drive.

He had also thought about Stumax because they say the sound is very real to a turbine, but of course if the results are the same as the Midi would rather pay less and stay with the Midi.

Did you choose that setting? Will some 2020 watts to climb this vertical model?

2kW will not keep your jet permanent in vertical climb. You need more than 1:1 thrust/weight ratio. Thrust=weight won't make it because you'll convert dynamic thrust to static when slowing down and intakes are not designed for static thrust in most ARF kits. If you manage to accellerate in vertical your in winner circles and will be able to feed the fan properly. IMO For small high speed edf the vertical accelleration is a needed feature to build up max speed in our small visible area we fly in. I don't want to slow down my jet in vertical!


Toy around with fancalc to get some experience on weight of hardware and performance:
http://www.ecalc.ch/fancalc.htm?s4a
You will notice you have to make many compromises in your hardware.
Vertical peformance is still a very rare feature in the edf scene. I am hoping to get close to 2:1 ratio this summer, evaluating my setup for 1.5yrs now. It's a PITA

My late Super Sniper for a broken wing in midair vertically up pretty well with the 2020 watt but clear teng Jet Bae weigh more and do not know exactly how I can lose in speed. Also if I stick a drive 120 and batteries from 4000 to 4500 to be around 3000 watts most likely have to put the brakes on the wheels and landing will be critical while the Sniper did not need!

Super Sniper 90 V3 (4 min 17 sec)

I purchased a Midi fan PRO EDF unit for a project
that only needed 65-70oz of thrust.
The --advertisement-- where i got it from stated:
Input power 200-1000w
http://www.ductedfans.com/Wemotec_midi_fan.html

Will this unit "REALLY" pull 2500w ??
REALLY--without blowing up; and what
rpm and thrust do you get from that ??

After finding This thread; i was Happy i ((Ran-dumm-ly))
selected the Midi Fan Pro, even if i Don't use all it's
capability !!!
I will be adding more cells though--My Hacker can handle
it.

Bille

A Midifan Pro will run at 3.5kW if care is taken during assembly ensuring the motor is properly mounted and the rotor assembly runs true without any vibration. The rotor itself is dynamically balanced, but adding the spinner sometimes introduces an imbalance.

2500W will be around 8lbs of thrust.

Originally Posted by Erik v. Schaik

2kW will not keep your jet permanent in vertical climb. You need more than 1:1 thrust/weight ratio. Thrust=weight won't make it because you'll convert dynamic thrust to static when slowing down and intakes are not designed for static thrust in most ARF kits. If you manage to accellerate in vertical your in winner circles and will be able to feed the fan properly...

Since i'm Scratch building my F-35((C)) around a 90mm Midi--
I can adjust the size of my intakes a bit for "stand off scale"
I'm more interested in vertical acceleration mostly because
there is quite a bit more aria on a C model than the Airforce version;
so it Won't be nearly as fast.

There is about 6,361 square mm on a 90mm fan divided by 2=
(3,180 squ mm) each minimum opening size.
What size would You go for if the Static thrust was going to
be of more importance because it is a slower model ??

Thanks Bille

Bille,

Here 2 posts of my setup for your interest:
http://www.rcgroups.com/forums/showp...&postcount=101
http://www.rcgroups.com/forums/showp...&postcount=127

As you can see this setup was a compromise for high speed edf and because of this it lacks batt capacity thus short fligh time. For a scale project you only want this for maiden flight but you need to use bigger cells for decent flight time which cancelles out vertical flight. Just like 3D planes you cannot get away with 1:1 thrust/weight ratio to fly with authority. You need power which accellerates your plane in vertical or it will stall eventually. As I mentioned in my previous post, toy with fancalc to see what you're dealing with . The total weight of your plane ROG should be in the 75% thrust range to achieve your goals.

For intake I'd go for 105-110% catchement area, mainly because the intakes are quite boxy and will cause losses in the corners.

Good luck on this nice project,
Erik

Originally Posted by Erik v. Schaik

Bille,...

...For intake I'd go for 105-110% catchement area, mainly because the intakes are quite boxy and will cause losses in the corners.

Good luck on this nice project,
Erik

Erik
First of all:
GOOD LOOKING FAMILY !!
Looks like your child is destined to become a flier...

Your a good shaper and looks like your really into mold making.

I got some interesting insight into how your brain works as
i scrolled through the pictures. That was FUN !!
Wish more people were into building .
I fear that in this world of "ARF" and "plug & play"
Most humans have gotten away from the passion of
their own creation.Trying to explain to people is near
impossible. They have no time and no interest other than
plopping on the couch and watching TV.

I lost both legs below the knee 3 years ago,and while i
was still in the wheelchair for that first year, i built my own
Kite-Board.Then went and Re-learned how to use it.

Kiteboarder mag
NO need to open PDF file -- to viewmor pictures,,just scroll down.
http://www.thekiteboarder.com/wordpr...e-billy-floyd/

Bille...

Hi Bille,

You have an interesting background yourself!
It's amazing how some of us get so expanded in their hobbys LOL! I am happy you still can enjoy your hobby!!
I have been building edf for about 13years now and it was time for a composite project
Take your time on edf. It can get pretty complex. Take it easy and enjoy while learning!

best regards,
Erik

This is Still on topic since i plan to make my F-35C around the
90mm Midi.

The plane project will go slow till i finish my next set of prosthetics;the
ones i have are all used up and summer is coming.

I posted a "How To make PFP Molds"" on the scratch build for EDF
forum.That is how i intend to mold the project i'm building.

This Thread was a GOOD find for me since i had NO idea the Midi 90mm
could take that much power !!!

Most will think this mold making topic kinda dry to read except those who are into making molds.
No i'm Not cutting the people that purchase Foamies, or buy their jets
from a shop !!
For Me it's kinda more fun than watching TV.

http://www.rcgroups.com/forums/showt...9#post17118106

Bille