EDF Hovercraft WIP

[Kelownan]

Well Im back with some build pics. At the moment im still prototyping but i started with a paper cardboard version and worked from my 3d model just so i could get a idea of how i would size and place things. I moved to a polystyrene version but it was far too flimsy and bent when i mounted the parts. but it did give me a god reference to place place things and get my CG right.

So ive now moved up to a Balsa version for testing.

More as it happens.

Shes powered by 2 74mm EDF's at 860+ gms of thrust each and a 1800mah 3cell Lipo

[metroidrc]

looking good there, its gonna be powerful!... but I can make a few suggestions?

it may be already too late for this, but...
You are pulling out alot of amps with those two fans.
Your runtime is going to be very short.
I suggest a bigger battery, or a smaller motor for hovering.
Are you doing skirt or skirtless?
Make sure to put a BIG RUBBERY BUMPER on the front.
That thing is gonna be fast. You will crash it into something. One crash with that thing, the way its constructed, it looks like it will explode into many pieces.
If you play it safe and drive it in a big area and don't open up the throttle too much you might be ok.

I did a similar looking hovercraft once using Don's wicked edf motor/Alfa fan and another 64mm fan for hover. It was FAST. I flipped it a few times and then moved onto the next test.

Good luck, I'm looking forward to some video!
-Josh

[Kelownan]

Thanks josh and thanks for the pm (i ordered a reciever ready version as i allready have a DX6 to use with it.

Im not so worried about the battery for now, im mostly woried about my
ESC's. i have 2 25amp brushless ones and it got a lil warm during my test today.


EDF Fan Unit 74mm / 2570kv / 860g thrust w/ Motor:-
*Motor Type: 2409A-7T Delta Turn
*Outer Dimensions: 84 x 74mm
*Shaft: 3mm
*Weight: 104g
*Kv: 2570rpm/v
*Fan Diameter: 74mm(3 Blade)
*Voltage: 14.8v (4s)
*Current: 45A
*Thrust: 860g+
*Power: 840W

The esc's came bundled and i suspect theres to much draw.

Been doing some more work on it today,
and have got a vid ive loaded onto youtube, will post the link - its still uploading

Man its satisfying to see it float so nicely like that, 1st sucess i guess.

[metroidrc]

DX6 would work fine...
Looking forward to the video! :D
-Josh

[Kelownan]

Well, have completed the deck now and the rear Edf mount.
Josh im curous as to how you mounted the edf's on your axon.
watching squrrels vids i cant tell. and i know they have screws but the middle section between the 2 slabs of EPP looks too flimsy.

Heres the vid, just a bit of hover but its a start. I hope to have my balsa model running in a few days.

http://www.youtube.com/watch?v=xLpIRQh7IBU

[Kelownan]

Ok Latest news. Prototype 2 is near completion and i shall give it a test run soon.

And have also attached Cad design model.

Im tending towards the idea of making a bag skirt.

[metroidrc]

are the two motors the same kv? You might have a problem with it lifting off like an airplane... when I was first making my prototypes, I realized that I had to tone down the power of the lift fan, otherwise at would lift off the ground too much and make it un-driveable.

[hover dude]

Hi. . . nice work so far. I agree with metroidrc. Is that the 74mm fan from hobby city? If it is a 25amp esc will not be enough. I run mine on a 40 amp esc using a 3 cell 2200 mah lipo and the esc gets fairly hot quite quickly. Usually a rule of thumb you want to have about twice the trust power compared to the lift. So you really wont need that much lift power. Just somthing to keep in mind.

[Kelownan]

THANNKKYOOUU! this i tried to explain to my supplier. Thats good info cos i was worried about mine. One problem, Im new to my DX6 and when i plugged in the Second ESC for thrust either onto the elev. channel or paired by a Y connector i cant get the thrust EDF to respond even though both motors give the 4 startup beeps.

Could this be because they both need to be powered by batteries?
Or does it ned to be re programmed?

Also any tips on how to adjust the throttle range for the stick. I get the neccisary power about 1/3rd up the stick and want some more fine tuning,
Can i do this by switching to heli mode and changing the throttle curve?

Hope to get a vid of a test run soon.

[Kelownan]

Ok, Next update - i havnt got a vid ready yet as ive just been messing about with a bag skirt, but ill load some pics on soon and hopefully have a test run,

Funny story, Was sewing up my skirt the other day and dad popped his head round the door - "what are-you doing????" :confused: of course ive been watching lots of anime lately so i couldnt help but go :D "Heeee Mini skirt," :D of course an un fitted bag skirt is kinda convincing as a mini skirt, "Hovercraft skirt" - then came the Ohhhhhhhh.....

Oh and hoverdude - it is the 74mm EDF from hobby city.

Ive now come to a bit of a conundrum, If the EDF for thrust issnt very efficient then Ill have to buy another brushless motor and build a squirrel cage fan... If it does work then im gonna have to shell out and buy some better ESC's

Either way i have to spend more money :(

[hover dude]

Cool that EDF has lots of power. I am waiting till christmas to run it on 4 cells.

[Xmodgeek]

Looks interesting any updates?

[metroidrc]

yeah hover dude, I'm curious to see how this came out :)