Multiplex Fun Jet 150mph

[flyer88]

Trying my luck at a fast plane.

The guys at the flying field are running these Fun Jets to about 200mph(so they say) with 5s. They've given me a conservative setup running 3s then stepping up to 4s, that should produce about 150mph. The motor is only $17 from HCity and speed control is about $40. Only requires two high quality servos and away you go !! Can't wait, but admit am alittle nervous.

[badlands]

Just watched a few of these on YouTube - wow. I thought jet performance was only for fuelled RC planes.

Nice plane to aim for.

[flydiver]

I suspect they are full of it. Got radar or doppler proof?

Not saying they aren't fast. Mine likely goes 60-70 with a stock Stryker set-up, plenty fast for me. Takes a fair amount of power to break 100, LOTS of power to break 130, HOARDS of power to break 150 and can't say I've EVER heard of breaking 200 with a FJ and I subscribe to the FJ thread.
www.rcgroups.com/forums/showthread.php?t=474757
Currently 517 pages and 7741 posts.
Massive amounts of info. If you think the dithering about motors, props, ESC, and batteries is something here you just get drowned over there.

Beautifully engineered plane. Really nice right out of the box. Suggest you 'work up' if you are not accustomed to that speed. Make SURE to get the top and bottom looking differently, otherwise you'll be sorry.
It ain't a Cub.

[mrmugen]

A 150mph funjet is not that far fetched. I plan to build mine soon with a 160+ set up in it. I get almost 140mph (138 to be exact) on my stock ctryker frame. It is not a stock stryker by any means but the airframe is not altered in any way9 like shaved or shortened). I bought a funjet a year or so back with plans to beat the stryker at it's own game but haven't touched it yet....still new in box. I WILL see 160+ with it I know that much. I have solid proof of guys hitting 165mph and know I can push harder with the cool temps up here in winter. My eagle tree logger logs al the data a guy can handle which allows to to collect vital data. I see it costing around 500 bucks by the time its said and done. I already have the packs, esc, and props, and plane. Now for the custom motor beiing built for us from Mega motors. It will haul that for sure.

Good luck with your venture. High speed is a lot of fun. Once you go there you dont wanna come back.

[flydiver]

Jan 23, 2009 2:25:35 GMT 1 mrmugen said:

I see it costing around 500 bucks by the time its said and done.

I didn't say it was impossible-just not as easy as some folks seem to think. Fast is fun, otherwise I wouldn't have one. For the $67 he's going to throw at it he's not likely to get anywhere near those kind of speeds. It takes a LOT of watts, those cost plenty. I think after 100mph it's kind of a logarithmic scale. Like you said-$500, not trivial.

[mrmugen]

Hell it's gonna cost someone a lot more than 500....thats just what I have left to put into it.

Plane- 100 bucks
ESC- 170
Battery- 180-250
Motor- 125-175
rx of choiice- 100 (I bought a 2.4 futaba)
servo's- 50
opto isolator- 25
connectors- 15 ( I use 6mm neu)
Misc stuff and few more bucks...horns, hinges, cf etc...and hours of beefing it up.

Of course there are cheaper options for all the equipment used. I use Castle Creation esc's and TP batteries when I buy big ones.

Not matter which way you go have fun with it and make sure everything is beefy enough. Even see a plane explode from G- Force...lol. You will if it isn't built enough.

Good luck and keep us posted on progress.

Kevin

[flyer88]

Thanks for the info. As I said, I'm new to the FJ scene. The guy running the fastest FJ is producing 1200+watts on his current setup. I don't know what it takes to break the 150 barrier but thats allot of power. I'll get some more info and relay it back to the post.

[mrmugen]

Here is 130 in a stryker. I bet it pushes a FJ much faster than 130 since the air frame drag is much less.

[mrmugen]

Oh yeah another few bucks for the charger needed for your packs....with a balancer of course. I ended up getting 2 TP 1010C's with 2 tp210 balancers. I use the crap out of these chargers and wouldn't sell them for nothin. Same goes for the balancers. Just a heads up that these are great solid chargers.

Kevin

[flydiver]

Jan 23, 2009 4:35:04 GMT 1 flyer88 said:

I'll get some more info and relay it back to the post.

Ask him what it cost?
Kevin is spot on. You have to upgrade everything when you go that big. Then you have to be able to keep up with it! Zow!

[flyer88]

Here some links to the gear Im gonna use:
esc

Cont Current: 80A
Burst Current: 90A
UBEC Mode: 3A/5v out
Voltage Range: 5.6v ~ 26v
Weight: 91g
Size: 88x31x14mm

www.hobbycity.com/hobbycity/store/catalog/hw_p80a.jpg


Motor Size: 2845 (380L)
Speed: 2700kv
ESC Required: 40A
Voltage Range: 6~16v
No Load Curr: 1.1A
Max Load: 40A



Diameter: 28.2mm
Length: 47mm
Front Mounting Hole Distance: 19mm
Front Mount Thread Size: M3
Shaft Diameter: 3.175mm
Shaft Length: 12mm
Weight: 123grams
Power: 275W

Battery

www.hobbycity.com/hobbycity/store/catalog/EC2500-20-4.jpg


Ive seen these components in action and they work very well.

[mrmugen]

Only issue I see is the motor is only a 275W motor. Gonna need to upgrade to get more speed. WHo knows though...my motor is rated at 30amps and I push it over 100Amp a lot.

Kevin

[flyer88]

This motor is currently producing over 1200 input watts ! Still running perfectly fine. The guys run this motor on all their FJ's and Strykers, with no apparent malfunction ?

[mrmugen]

I believe it. How these motors stay together is beyond me. On my logger I saw over 125A at one time before it unloaded...only a quick shot at that draw but still.....it's a 30 amp motor! I;m not sure if I will ever understand it fully but hey...who cares it works! Good luck man. Hope you have many successful flights and fast ones at that.

Kevin

[mrmugen]

Hey any chance of build pics as you go? I just may end up expediting my build along with yours. You got me thinking speed again.

Kevin