Ultra Flash - Ultra Fast with ATJ 140SV
 

Hey guys,

here is a video from flying this morning in Ein Yahav, Israel:
https://www.youtube.com/watch?v=TIG6hTYTsgg
I am testing the new ATJ 140SV on the Ultra Flash, flying together with my WDT - Wireless Data Terminal.
Hope you guys like the video. NO GYROS ;)

Lior.

A couple of shots from this morning...

http://www.rcuniverse.com/forum/atta...mentid=2184949
http://www.rcuniverse.com/forum/atta...mentid=2184950

Lior,
that is insane! Can you get it clocked in Mph? Or Maybe Km/h?

We estimate it at 500-550 Km/h

You wouldn’t happen to remember what gap you left between the turbine exhaust and the pipe? I’ve just bought the same turbine for my Flash to replace my P-100rx which failed.

Simon

i always use 1" from turbine exhaust to begining of the straight part of the pipe (after the cone).

Cheers mate, will do the same.

Simon

What servos and servo arms are you using Lior?

In dream land maybe...

The UF was built several years ago, and i used Savox 1256, with i believe 1", to be honest not sure about arms 100% this is just from memory.

but in all my last years jets i have been using these bad boys - much more powerful, very smooth, super quiet and cost the same!
BLS-3507 - Servos - RC Electronics

We are all dreamers Dave :)

Any of you ever heard of an UF having flutter issues on alierons in the 250-300 mph ranges?

I have not seen it with my eyes, but someone has showed me pics of an ultra flash that blew up. Guy said he had never seen anything flying that hard and it was full throttle. I don't doubt it though especially if the pilot was yanking and banking; These planes aren't meant to handle that. If I go full throttle it's normally for a speed pass or four point roll and I try to be as smooth as possible.

Was it a fly navy one and happened this summer?

We have a UltraFlash here, powered by a ATJ 220 SV, clocked at 524 km/h.
He was flying with another Ultraflash powered by a Jetcat 140, and that was so Much
slower.

Lior,
I know you built this a while ago, but did you have to do any mods to get the ATJ140SV to fit? Just had a quick look at mine, and with the mounting strap hard up against the former I can only get 20mm max gap to the start of the pipe (not the bell mouth). Looks like I might have to remove a little of the former to allow the motor to come further forwards.

Just wondered if you remember doing anything similar, or if you have a photo knocking about somewhere of the ATJ140 in your Flash?

Cheers,

Simon

Judging from memory, i think youre right.
i just pushed the engine as forward as it will go (against the former) and bolted in - it works fine.

Got a Atj 190sv as far forward as possible full ducting no issues.

Leaves me around 20mm to the pipe (maybe a bit less). Seems a bit close?

Its fine - do it dont worry.

Must be F A S T !

Sure is not pushing it 444 kph level flight and the 190 is 22mm longer then the 140.

Just took some measurements. With the turbine mount up hard against the former I get 26mm. Might add bit of extra ply to widen the mount as the mounting screws are a bit too close to the edge of the wood for my liking. Shouldn't take long tomorrow to get the turbine in, will need a few wires moving about compared to the P100rx it is replacing.

Simon