Scott1968

Well this weekend I got my little Junior and ran it up twice at the Innisfail fathers day meeting at night, what a beautifull sight and sound...
it is now in the process of being installed in a foam Mirage 2000, made by Fly Fly hobby  ( http://www.flyflyhobbie.com  )
Ill try to post the build on the ausjet web as i get time.

Scott White
Cairns 

knobby1

Hey Scott,

Good to see your little Junior runs ok, Christian tells me you were quite surprised at how small the Junior is..!!

Be sure to post some pics of it fitted to the Foamy Mirage, should push it around quite nicely.



Cheers,
Smithy.

Scott1968

G'Day Smithy.

Yes I did the guesstimate with a ruler and thought yeah it will be xxxx size but to see it in the flesh took me quite by surprise.
It realy is very light too..

It starts very easily and runs up to idle reasonably quick, also the throttle response is typical turbine up to half stick..  after that id compare it to a glow engine for pick up..

How do I insert image on here?????

Anyhow thanks for your wonderful work looks like ill be selling the other 3 turbines i have ....
desperate to get another Jr and build an A10 in a size i can get in to the VW Golf

knobby1

Hi Scott,
To insert an image/photo, while you're typing a response, at the bottom-left of the page there is a "Click here to upload images and files", just click on that and you'll be good to go.

With the throttle response of the Junior at the low end, I can get them to spool up a little quicker but there is a "flame-out" and "torching" possibility, so with the customer engines I adjust them to be more on the safety side of things, in the mid-range to max they can be nearly "piston engine like".

The "development engine" I have at home will go from idle to max in ~2.2-2.3secs...very quick indeed, but it is on the ragged edge of flaming-out sometimes when the air is not so good. With good, cool, dense sea level air and low-ish relative humidity it's an absolute rocket.

Cheers,
Smithy.

Scott1968

Hmm  seems I dont have the insert image tab.

causeitflies

You have to hit the "POST REPLY" button first...

Scott1968

Ahhh thankyou Mark P... You are truly a Master of this website!!!

Here is a photo taken last night of the miniscule JetJoe Jr in its nozzle ....
and a few images of the nozzle being re-enforced with some 0.4mm ply.

Scott

jamiechip

my funjet is all finished now ready to fly just waiting for a good day

also i will be starting a build thread for a funjet like plane with a few mods made from fiberglass i am currently in the process of building a plug to make a mold of this plane and will be offered for sale to anyone wishing to buy one will be equiped with brakes and retracts air operated should still be under the 1500 gram weight mark and far stronger that the foamies and all ready to go all the hard work done there will be a few options offered for everyone also for shipping to anywhere outside australia there will be a model offered in 3 peices with the fuse seperate to the wings any one interested in the model pm me and i will ad you to a list of people that are after one it should be avalable for sale in the next few months and anyone out there can follow the progress as i go

Xairflyer

My Feedback: (1)

Looks great, Funjet is a great flyer, will go brilliant with a turbine.

knobby1

Hey Jamie,
Nice install....Let me know when you're going to maiden, I'd love to come and watch.

Cheers,
Smithy.

dw_crash

My Feedback: (6)

Gents,

I know it's slightly off topic, sort of. But what happened to the 44 mm Jet Joe engine? I have an AMD Hawk that it would work well in. And, there are not many choices in this size.

DW_Crash

littlepiston

My Feedback: (12)

Ok so Australia has JJJ that run well ,good? as good as other engines? I about ready to order one or two I have a hand full of jet in this size. I would like more pics of the fuel set up and fuel pump also what size of fuel line 3mm 4mm? thanks

jamiechip

the fuel lines going to the trubine is 3mm after the fuel pump the fuel pump at the moment the turbines run the fuel pump for the jj1200 with a buy pass in the line as the voltage drop without the buy pass would be to low the flightworks 100b fuel pump works fine and jet joe is in the stage of developing a new pump

ill put some pics up of my set up for you if you wish in close detail

jason

My Feedback: (1)

We managed to fly two JJJ today. Me and Andy from jetline put at least 10 flights each on our Multiplex Twinjets today. They really go very very well indeed!! Unfortunatly my engine don't work anymore... I think the NGV has gone out of shape slightly because it's touching when cold and makes the most awfull noise at 225k rpm, I think the wheel is rubbing. This has made the bearings sound a little rough so they need replacing and the NGV needs the high spots removing. I'll see if JJ will send me the bearings.

Jason

littlepiston

My Feedback: (12)

This wing looks to be a good test bead for the JJJ.
http://www.mecoa.com/modelerdirect/ look for the ducty arf

chichisport

WOW!!!

Sound like I will finally get into turbines myself . I have flown ,and set up a few but never owned . I always dreamed of a Lambert but is too steep for me and with Ausjets knowledge .....
it´s going to be a bargain.

chichisport

Hi again,

Can it be ran on the marine (tcw3)oil ?

Thanks

jason

My Feedback: (1)

Jet Joe has refused to supply me bearings under warranty saying it's already had two sets fitted under warranty... So I have bought two sets and will fit them as soon as they turn up. I'm still sure the current bearings were knocked out by the wheel hitting the ngv at high revs so I'll grind some more off it and see what happens. I'm not really annoyed because when I ordered it I thought it would be a complete pile of trash and it actually is not as bad as that.

Jason

chichisport

That´s why I plan on getting mine from OZ . I like
his straight way of explaining things .

jason

My Feedback: (1)

.

jason

My Feedback: (1)

Yes, and he helped me get mine running cool and if I were to buy another I'd get it through smithy too.

Jason

knobby1

Hi Guys,
Thanks for the kind words. Yes, the Junior can be run using TCW-3 spec synthetic two stroke oil, I have used it often, any of the main turbine oils are also suitable, some do leave more carbon deposits than others, however, I do recommend 2.5-3% oil content in the fuel. I personally use Mobil Jet-II and Mobil 254 turbine oils @ 2.5% in Jet A-1.

When using 5% for extended periods the carbon build-up inside the engine can be a little excessive. The 12 fuel ring needles are very small and carbon build-up can be a problem for them.

The J-Junior engine is by no means a perfect engine and is obviously not up to the quality of the beautiful little Lambert Kolibri, we all know this. It still has it's fair share of problems but we are trying our best to get them running as well as possible. We're battling each problem as it arises and I'll let you all know of any progress we have in regards to a fix/repair etc....

If you like to "tinker" with your engines as I do, the J-Junior is a good way to go, but when running well they are a nice thing to behold and will provide a good amount of enjoyment.

If anybody requires any info or help, feel free to drop me a pm or post here on RCU and I'll do my best to help.

Cheers and all the best,
Smithy.

chichisport

Thanks Smithy and Jason .

What the main caveats of such small turbines appart from bearing life (not a problem with very good balancing) , carbon deposits and dirt in the oil lines?
Are you working in a full auto one?

knobby1

Hi Gents....and Ladies!

The main dramas we are having at the moment is the shaft and bearing preload, the shaft tends to flex a little at higher rpm's, this gives rise to the compressor wheel fouling the inlet housing and a noise not dissimilar to compressor surge. We're not sure what the shaft material actually is though. I believe we have all but rectified the bearing preload issue, more testing is required but so far it looks to be working reasonably well.

The tiny lube line which feeds the front bearing has a very small internal diameter ~0.25-0.30mm and is very susceptible to any dirt dust etc...a good quality filter or two in the system is essential. Carbon deposits are an issue with nearly all turbine engines, not just the Junior, but due to the tiny size of the fuel needles it does give cause for concern, hence the 2.5% oil content recommendation.

Accurate balancing goes without saying and is critical to these little engines, readings of 1mg-in or less on both planes is required, any higher than this contributes to the above problem of the shaft flexing at higher rpm's.

A "full auto" version is in the works but is a way off yet, the ECU is already "starter capable", we're having difficulty finding a good quality small electric brushed motor capable of ~65k-70krpm, these engines require ~60k-65k to self sustain. If anybody knows of one please let me know, I would greatly appreciate it.

Cheers,
Smithy.

Laura H

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