Brushless EDF: Ofna Ultra GTP
 

Let's do some math!

...Ofna Ultra GTP Chassis Kit
+ MaxAmps 5s 5000mAh Lipo (x2 for 10s)
+ Great Planes Silver Series 100A HV ESC
+ Lehner 1950/9 Motor
+ RC Hydros PiStix Adapter
+ DF90 Ducted Fan

= :surprised: :yipi:

Updates will follow. Please be patient. :na:

What motor mount will you use?

you forgot to mention a custom molded batmobil body. i think it would be sweet and turn many heads.

I hope the ducted fan is a joke..

Nope, EDF= Electric Driven Fan

Its gonna be a Jet powered car Serum, albeit an EDF jet = fun, rather than a serious attempt at making a racing car.

Having seen a few prop- driven cars in the past, I know this will be fun project, if just a tiny bit bonkers....

I didn't know you airsofted Neil. Sucks about the ban. (sorry for thread jack)

lol owned. :wink:

Why not the 120mm fan dude... :)

I think it would be top-heavy with a 120mm fan. But hey we'll see. If this project works out I might do another one like it. Maybe a DM-1. THAT would be sick with a 120mm fan and a Neu 1521.

Yes, Serum. I am serious about the fan, but it is just a fun project car. I have no plans to even attempt to be competetive with it, mostly because there are no tracks anywhere near me.

Oh, and sssp I'm working on a custom mount for the fan, using Autodesk Inventor (my favorite), which will be made out of 6061. The motor will, of course, be mounted in the fan.

new meaning to blowing away the compitition.

If you are going nutty why not use this http://www.wrenturbines.co.uk/product.php?pid=6
33 pounds of thrust

Body paint scheme (see pics below)
 

nuff said!

HAHAH.. that's F*cking hilarious....:lol:

I thought so too! All he needs is the harpoon launcher and weapons systems! :diablo:

I dont, but I do love all things firearm related- the mods & alot of members on UKASF are a bunch of funts who take themselves too seriously :no:. Arnies airsoft is my new airsoft home- much nicer people & I follow the Candyman's exploits whenever he builds a new gun from scratch; he'd be so good at custom building more RCs with his skills, its strange that he doesnt spend more time on RCM.:neutral:

I cant wait to see this new fan-car finished and running.... even if it is straight into a wall at 50+mph!:whistle: :lol:

lol, it should be sick.

I too love all things firearm related. My motto is cars, guns and huns with buns :).

Why not something like this F1. Have it suck air from under the car so you can have tons of downforce.

http://www.youtube.com/watch?v=kWhd8rt64GI
I hope you have more succes then this ^^^^

must not have been speed rated hehehe.

Moral of the story, "Never buy a used tire for your 300mph jet car".

I thought they used tires made out of solid rubber.

I wonder if that tire had "Road Hazard" on it?

:lol:

The world's fastest Hamster! That was truelly terrifying when I first watched it back at the start of the current series- he is one lucky man Hammond is.

Man that guy is lucky!

Back to business: Here are some current pictures of the car.

The completed kit minus the engine related stuff-
http://i52.photobucket.com/albums/g4...DSC00005-3.jpg

No more bumper, made Poly/Al battery/ESC tray, different rear shock tower for better clearance, dual brakes-
http://i52.photobucket.com/albums/g4...DSC00009-4.jpg

The tape on the rear tower is to mark where they'll be cut down to.
http://i52.photobucket.com/albums/g4...DSC00010-4.jpg

Close up of dual brake setup. When I get around to cutting the center axle I'll have separate F/R brake adjustment.
http://i52.photobucket.com/albums/g4...DSC00011-4.jpg

I've figured out that this is going to weigh almost exactly 9 pounds fully RTR. The manufacturer of the fan says it can be operated in excess of 27000 rpm. We'll definitely find out how far in excess with this project. I'm shooting for ~50000 rpm with the current choice of electronics (10s, 1950/9). It should make more than 10 pounds of thrust since the power curve on the fan is exponential to a degree. Even if I need to replace a rotor here and there, only having 1 heavy motor in the car will be great.

Oh I forgot to mention the fan will be mounted/exhausted in line with the rear-right camber link. The batteries are going front-left in the tray and the ESC will be rear-left in the tray. First person to tell me why I placed the fan off-center gets a GOLD STAR!

One motor two power two fans?...

Here are some renderings of the fan mount I have in mind:

http://i52.photobucket.com/albums/g4...5-55-42-53.jpg

http://i52.photobucket.com/albums/g4...5-56-49-53.jpg

Circled in RED are the points on the chassis where the fan will mount:
http://i52.photobucket.com/albums/g4...ountlayout.jpg

Nope. Just one fan now.

Oh right, I see. That really is one huge fan dude.... :oh:

rotational torque.

Of-course! Two counter rotating fans would be the ideal solution, but also much more costly $ wise. Just need to figure out the after burner feature; might hang out the back a bit though....

And the winner of the GOLD STAR is- DrKnow65! :yipi: :party: :yes:

Exactly. Rotational torque, and a lot of it with this thing at 50000 rpm. If that fan was in the middle of the chassis it would probably flip over during on-power right-hand turns! I've had it happen with previous versions of this type of craft (yeah I've built them before).

Neil I've looked all over for a set of fans that could be used for a counter-rotating setup. The only ones I found are way too small (50mm) and nowhere near as powerful.

Hey DrKnow65 I like your signature a lot. The only difference is I can draw pretty good :mdr:, but I'm still dirt poor.

one day cnc's will be dirt cheap... I'll be dead just before that happens hehehe.

When I read "nitro" it dosn't look like it spelled with four letters, but I know better :)

Answer me this:
 

Have any of you guys ever run a Lehner reliably at high speeds? Like in the 46-50K RPM range? I'm having second thoughts about dropping a $330 motor into this car, only to have it self-destruct on the first run. :no:

Is there anything I could do to further protect the rotor from the huge centrifugal forces that are put on it? The Plettenberg motors have wrapped rotors - would this be possible on a 1950? Given what I've seen/heard about Feigao, I would never attempt this with their motors even though they're cheap to replace.

I have been past the 50K with a Basic 5300. Lehner claims the 19 series can go up to 50K and I've heard of some guys going up to 100K in those crazy fast planes.

I think the lehner claims up to 100K with the 19 series... before they had English on their websites, they use to post that the 19 series can do 100000u/min.. I'm guessing that's the same as rpms.. ?
.. ... anyways.. the 1930/6 was my first good brushless motor.. went into stock emaxx... I ran at 12 Cells (around 45-50K).. no problem.. I then ran 18 Cells(70-75K).. although it got hot... it was never damaged...

i've melted a bearing in a 5300 on 12 cells (75k rpm). but I ran that setup in my tc3 for about two three months before I had any problems. the rotor came apart on one of my Hacker 8S' on 16 cells (75k rpm). that was when i blipped the throttle unloaded. loaded, I never had any problems w/ my other 8s on 16 cells.. I'd stay away from 75k, as that's the only time i've had motor problems.. 50k, I don't worry though.