Henke Torphammar

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Turbo Funjet Ultra

Thought I might share my Funjet Ultra experience here on the forums. Things that go fast are always fun and seeing that a beefier version of the funjet arrived I thouht I would give it a try. Turbine planes are expensive things and a Funjet would bring the same sort of speeds in a much more affordable envelope

For going fast things need to be as good as they can, starting with the assembly :-)

The airframe goes togeather with CA-glue and kicker. The kicker (ofcause) hardens the glue instantly, but also makes it expand like a PU-glue which helps filling gaps - perfect for high speed use. Also notice I removed the ridge that runns around the nose as it will force tha plane in to a dive as higher speeds. I filled the little airvent with foam too as it would pop open the canopy at speed.




I use BB-links with a M3 rod dressed in carbon fibre tube fastend with thin CA-glue, bullit proof and perfect for the job :-) Servos are Hitec HS-65BB. I mechanicly set up the servos for the recommended throws to keep away from dual rates reduceing the resolution.




I choose to solder new longer leads to the servos rather then useing extentions. I don't vant an extention to pop out due to the foam wings flexing Rx is a Spektrum AR6200.




to be continued

Craig B.

Cool thread. Keep it coming! I have one of the original Funjet. What is the difference with the new Ultra?

My flying buddy has used his for FPV....great model for that. Just fit pan servo and you get a great ride!

Craig.

Henke Torphammar

The original one weighs 165grams empty while the Ultra is just above 300grams empty. More foam in the moulds for a more rigid aiframe capable of higher speeds without any tendensy of the high tech NASA wingwarping stuff going on

RUFTER

Henke, you are giving a whole new meaning to the word "overkill"! BB-links and carbon tubes on a Funjet? That has got to be a first

Are you by any chance attending the RCFF Shootout in Hultsfred this year?

Cheers, Bart.

Henke Torphammar

The BB-links are left overs from a F3A project, so i thought I might as well use them.

I do not know about Hultsfred, I do not know the RCFF guys at all.

Henke Torphammar

Unfortunately my ESC would't fit in the Funjet so I had to go for the backup plan with another smaller setup [:@]




apparantly the electrics to reach good speeds don't fit so I thought I'd try another approach. Alot of power needs alot of input, no matter if it is electrics or gas. I started making a plug to mould a tank to hold maximum amount of fuel still on the CG. Useing parts from the original fuselage combined with styrofoam.




The plug is sanded, sanded, sanded, glassed, filled, sanded, and painted with car paint to make a good mould for the glass fibre tank.

marc s

Interesting shape to mould, how are you going to split that out?

marcs

Henke Torphammar

From the looks of the finnished tank the mould were devided in top/bottom and the top pars split in two. I'll upload more in a bit, dinner and some flying first

Henke Torphammar

Fueltank out of the moulds, weight is 34grams and it holds 380cc/13oz of fuel. The result is not perfect, but it's it does not leak and has the right shape, so absolutely good enough for testing :-)




While at [link=http://www.hab.se]HAB Electronic[/link] to pick up the tank we also draw some small parts to make the tank unit that fits in the tank. Push "print" and the DIY router goes to work, kind of nifty

[youtube]http://www.youtube.com/watch?v=c09ubYYvFVI&feature=player_embedded[/youtube]


Tank + the milled tank unit CA-glued in place, we also added a little tongue to hold the canopy.

Henke Torphammar

Now for engine choice. There are many minds out there, all with their own preferences. I'll try to explain my thinking and why I made the choice I did.

Buying a turbine is always alot of money, there for finding a setup that suits you well is very important. I went through many factors ending up looking at the "new" nano size turbines. Mostly because the size would make it easy to fly where ever and when ever I want, not being limited to paved/large airfields. There are three nano turbines available out there, Jet Joe Junior, Lambert Kolibri and Jetcat P-20. I found proven technical issues with the JJ Junior so that one fell out pretty early. Left to compare was the Kolibri and the P-20.

Aftar alot of research, and seeing the new Kolibris with the same thrust as the P-20 the decision were even harder. After talkning with Jetcat and Lambert at Jetpower and asking both Ali and Dave for advice I finally settled for the Kolibri T25. I really appreciate Ali and Dave being honest with my questions even though they are jetcat dealers. (that really is a proof of your proffesionality guys!)

Kolibri is 100grams lighter then P-20, 5mm smaller diameter and about 30mm shorter, still with the same thrust.

Manufacturers numbers are not always true so I thought I would see what it is in reallity. weight: 265grams!




First testrun at [link=http://www.hab.se]HAB Electronic[/link] who is the dealer in the nordic area, verifying the thrust to more then the promised 2.5kg @ 241000rpm. EGT stable at 580°C, ambient about 10°C




I forgot to put my phone in HD-mode but you can clearly read the scale anyway, and that's the most important :-)

[youtube]http://www.youtube.com/watch?v=9a9d1siDp18&feature=player_embedded[/youtube]

Henke Torphammar

How many turbine planes can you fit in your car?




Funjet ready to start the engine, I choose external gas as I always start the plane on a table and the gas is only needed for a couple of seconds.




After the start up sequence the idle is 95000rpm and I'm given full controll over the throttle :-)




Big and small - 55lb and 5.5lb thrust. Which one is the faster?

Henke Torphammar

What about flying then... Hand launching your first ever turbine plane your self on the maiden might seen a bit brave, but with this setup there are no problems at all. The Funjet instructions recommends a start mode with 2mm up elevator dialed in which is perfect. The turbine provides thrust equal to a 2500watt pylon racer setup but with no torque at all. In other words, you can launch the plane with full power without having to compensate for torque, or launching at idle just to be able to get your hand out of the way of the prop. Just throttle up to about 1:1 thrust/weight ratio and give it a gentle toss and off you go. The dry weight is just 930grams/2lb, the 380cc tank carries 300grams of fuel, so for take off the Jet is a little bit heavier then a normal sporty electric setup, but at landing the weight is less. With a full tank thrust to weight ratio is 2:1, at the end of the flight you are getting closer to 3:1

Spool of the turbine is new to me, even though understanding the means of it, and running a 700hp 1.87litre 4cyl car with a turbonetics GT-K 650, flying it is pretty cool new feeling. For this little Jet the spooltime does not mean a crash if you miss judge, just needing to add the power ontop of the loops to have the requested output ready when going up again. The turbine is not slow spooling, rather the Funjet beeing a quick ride that uses idle alot, it does still fly at idle. (Throtteling from 1kg to 2.5kg of thrust is blistering fast!!)

Acceleration is outstanding, it does really look lite a bunge launch when you throttle up from a slow pass to full power. With 2:1 thrust to weight ratio atleast it's pretty cool to fly the plane in to a hover and accelerate like a rocket up towards the skies.

Topspeed is only 297kmh / 185mph in this kinda draggy airframe, but for it's size it looks kind of fast anyway.

I'm really happy with my choice of engine and useing the Funjet Ultra as a turbine trainer, it is a very smooth ride and very diffrent from a prop driven FJU in that way. Flight times are equal to what I would expect from an electric setup. I start the timer set at 6min just before starting the engine. The engine has been ran for a little more then 5 hours with no problems. The guys as [link=http://www.hab.se]HAB Electronic[/link] and Martin Lambert has been very good answering questions, but in the end just read the manuals at first and you are fine.


I will try to get some video posted this weekend.

Just a pic of the HAB guys planes(with the mighty Hawk engines) togeather with my Funjet Ultra.

Henke Torphammar

55years differ the two, today 2011 they do both cost roughly the same

Henke Torphammar

I read that Martin Lambert are getting very close to 3kg / 6.6lb of thrust now :-) My engine does 2.5kg or so at only 560 degree celcius EGT. I guess I could turn the revs up a bit more :-)

Henke Torphammar

More flying today, the little engine performs extremely well, working flawlessly provideing 6min of fun at a time :-) Today the goal was to fly from our local rc field which never before has been though of as capable of turbine flights. The Funjet does what it's best at performing very well in the airfield where you normally are most comfortable flying .40-.60 size planes or so.

It really is hard to get good photos of this little fellow, my friend did a good job today snapping a couple of picts that atleast captured the plane in the frame haha.

(Video is uploading now by the way)

Henke Torphammar

Starting at 50% throttle reduceing to idle as soon as I can get my hands at the stick, also fliping to flightmode 1 from my launch setup where the elevators are up by 2mm.


[youtube]http://www.youtube.com/watch?v=QqfuJBSTOdQ[/youtube]

i3dm

My Feedback: (51)

I just love my FJ Ultra ! on a 2000W electric setup it was closked at 276 Km\h which is pretty good considering the entire electric setup (with battery) was less than 100$

Yours look awesome as a jet ! can you post some pics of the engine mount and final install in the fuse ?

Henke Torphammar

I've seen logs of an electric showing just over 300km/h but you can not compare it to a turbine as there is no torque. I did't think it would make such a big diffrence before trying it my self.

requested pics

Ragz

FANTASTIC.... congratulations....

1_helihover_1

Hello Henke

Great bird, and great thread. As you know am I just waiting for the winter so that I can get my BaioJet underway with one of these little jewels

Henke Torphammar

Yeah that would be great :-) Baiojet is slightly larger then the Funjet, a bit heavier(650grams empty) but probably much faster due to lower drag on the fully moulded GF airframe. As it too is a delta and has a good hand grip moulded in the fuselage I think it will hand launch just as well as the Funjet.

siclick33

Did you make any modifications to the kit? In particular, did you add any reinforcement to the control surfaces/hinges or were they ok out of the box?

juanjulian

My Feedback: (9)

Great post probably the best I read about the funjet and Kolibri turbine.

Love small planes and having a bug for jumping into turbines,For the moment dealing with EDF which is what I can afford.

This site can offer a future home for that turbine mbs-rcmodels.se, Like the draken a lot.

Cheers,

Juan

Henke Torphammar

I pretty much used it as is came out of the box, you can see all mods here in this thread.

Henke Torphammar

The T15 with manual start is cheaper and still alot of fun :-) I also have the MBS Draken kit, maybe I'll put it togeather soon :-)