HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old May 19, 2006, 08:15 AM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,789 Posts
Discussion
Boomerang

Well I have finished off the latest toy, couldnt resist the sale at Saturn, 70 bucks for what is really a very nicely packaged ARF aircraft.

AUW without battery stands at 530g right now, my Rx is a bit heavy at 36g but its all I have for the mo'. I fitted the spare Align 450L 1000Kv outrunner I had running 1047SF APC, supposedly good for 700+ grams thrust. Depending on the weather will find out tommorrow if this is true or not!

Sounds nice though at WOT, one thing I have noticed with warbirds on flybys is the electric ones seem to sound very much like the real thing, cant wait to see if this plane has the Boomerang "whistle"
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Sign up now
to remove ads between posts
Old May 19, 2006, 08:21 AM
I failed linkage geometry
salisbug's Avatar
Melbourne, Australia
Joined Jun 2002
4,292 Posts
Mocca,

Looks cool.

I have one on the shelf. Any pearls of wisdom regarding the build?

Cant wait to hear the flight report.

Glenn
salisbug is offline Find More Posts by salisbug
Reply With Quote
Old May 19, 2006, 08:42 AM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,789 Posts
I dont think there was anything of significance in the build that I did that was different to the plans!! amazing really.. First time for everything!

I was thinking of using epoxy due to the white crap you get from CA but I decided to go with CA as I like things to glue instantly I think its good I did because epoxying the canopy hasnt seemed to work too well, its easy to peel off. I might remove it, paint the cabin area black and find a pilot for it, then CA it back on.

When you cut the engine dummy out, instead of trying to cut around the cylinders, just cut the back as if you were going to slice a mil or so off the thickness of the moulding. Will make it come out nice, and gives you lots of cooling gaps. Looks heaps better than leaving the front open.

Only other thing is the engine mount is very far back, as it was originally designed for that huge revolting cobalt motor. I had to space my prop forward with thick washers on the prop adaptor to get it to clear the cowl. I didnt want to have to remove the front engine mount and bring it forward, would be nice to find a prop adaptor that had a longer shaft, the Himark ones are only just enough to fit with spacers.

With my small 100g & 128g battery packs pushed right forward, and my Rx up near the LE of the wing, CG is still 70mm, should be 60. I will try using my 145g pack first to maiden it then see how it reacts to the lighter packs. Only worry with CG is the short fuselage.

Cant wait to see it fly too!!
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old May 19, 2006, 10:25 AM
Good Better Best quest.
olmod's Avatar
Australia, VIC, Cranbourne East
Joined Apr 2004
10,553 Posts
That looks good Mocca I didnt know tony was having a sale but i do now
olmod is online now Find More Posts by olmod
Reply With Quote
Old May 19, 2006, 10:33 AM
It's a trap!
GotrekGurnisson's Avatar
Brisbane, Australia
Joined Feb 2006
3,143 Posts
Cool. Didn't know anyone made Boomerangs. Such a nice little warbird. The wings look a fair bit over-scale on that model, but that's to be expected I guess. I'll have to keep my eyes peeled for somone selling them up this way.
GotrekGurnisson is offline Find More Posts by GotrekGurnisson
Reply With Quote
Old May 20, 2006, 06:36 AM
Registered User
Melbourne, Australia
Joined May 2006
7 Posts
Tony always gives good deals.
Younggun is offline Find More Posts by Younggun
Reply With Quote
Old May 20, 2006, 06:54 AM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,789 Posts
Well, interesting maiden!! bad run off the grass due to wheels too small to really get it rolling nice, its like alot of warbirds i spose, will drop a wing on takeoff if the airspeed is too low. Massive handful to get up and trim out, even though all the surfaces are even. Definitely not good for someone moving off a trainer..

Also does not like to fly slow in any sort of breeze, loses control input quickly. Ailerons are screwy, I need to free up the movement even more and stick a bigger servo in there. The motor is not so suitable, needs higher Kv and smaller prop, the 1000Kv and 1047SF gives great thrust but the prop speed is too low. It does look pretty cool in the air though!

It needs 2000Kv and an 8060 prop at least, my CG was about 68mm, factory setup should be 60, but it was designed to carry one of those huge cobalt motors, so I need to replace the Align 62g motor with something around 80 grams. Taping weight to the underneath of the cowl brought the CG forward and the flight characteristics went haywire again! Tip stall at lower speeds is a certainty, it definitely needs speed and a much higher prop speed. Got some video so will take a look at it and copy a bit to post up.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old May 20, 2006, 08:32 AM
de-registered abuser
gouch's Avatar
Lake Macquarie, Aust.
Joined Dec 2002
14,284 Posts
Is this a wattage plane? I noticed the other day whilst browsing at modelflight website they have the wattage stuka, 1 meter span and $69. I like the stuka and the boomerang not only because they are different from all the usual stuff you see.

Cheers
Paul

P.S I can't get Saturns new website working properly? I can click on the P-51 sloper they have on the main page, (mmm, nice, wonder who makes that one?) but can't nav through the menu on the side. Any ideas ??
gouch is offline Find More Posts by gouch
Reply With Quote
Old May 20, 2006, 11:32 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,789 Posts
Their website has no content, hasnt had for ages, best to ring them. There is a stuka in the range, along with a Harvaard, PC9, etc. They are called the club flyer series, from Model Engines. I was going to get the PC9, I might still get one, its a lovely looking plane.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old May 21, 2006, 12:31 AM
PLD
Magicsmoke maker
PLD's Avatar
Australia, QLD, Charters Towers
Joined Dec 2003
17,407 Posts
Mocca,


Looking forward to seeing the video of this - let me know if you want it "flashed"

Paul.
PLD is offline Find More Posts by PLD
Reply With Quote
Old May 21, 2006, 12:57 AM
Good Better Best quest.
olmod's Avatar
Australia, VIC, Cranbourne East
Joined Apr 2004
10,553 Posts
Mocca

I think a 2000kv might be a bit over the top some of your probs may be with your prop being a slofly there designed for g/box use , for example an apce 8x6 @10000rpm @10v =30oz of thrust. going up to 12500rpm at the same v & prop will give you 48oz, how heavy is it all up at the moment?
a 2000kv motor @ 20000 with a slowfly prop on ive already been around one that shed a blade i wont use them again at high rpms,lucky my workshop is made of steel,and i was out of the line of danger but the richocheying blade went into fuz side on a biplane after bouncing of the roof and a benchtop
olmod is online now Find More Posts by olmod
Last edited by olmod; May 21, 2006 at 02:22 AM.
Reply With Quote
Old May 21, 2006, 01:30 AM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,789 Posts
I certainly wouldnt be using a SF prop with the 2000Kv motor! My align is 1000Kv and turns the 1047SF nicely, prop speed is below 7000 from what I am seeing, havent had a chance to stick the meter on it yet.

I was going to fit the 8060E I had but the damn cowl is in the way, I need a long prop adaptor, otherwise am going to have to take the motor mount off the front and extend it out 5mm. Very annoying.

30oz of thrust?? I gather you are calculating this at 10,000rpm?? taking into account motor efficiency this is going to drop around 25%.

My tests with the 2409-18 motor which is 1000Kv using 8060E @ 11v was 8500rpm. Unloaded is 11000rpm therefore efficiency was around 77%.

I will pull the cowl later and stick the 8060E on there and measure the RPM. Main thing is getting prop speed up and maintaining reasonable thrust. AUW without battery is 530g. I am using the 100g Hyperion 3s1200 battery aswell as a 128g 3s1500 JP batt. CG is still the problem, as is the aileron throw, need to work on all the linkages and most likely dump the Blue Arrow servo, its a piece of
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Old May 21, 2006, 02:15 AM
Good Better Best quest.
olmod's Avatar
Australia, VIC, Cranbourne East
Joined Apr 2004
10,553 Posts
Pardon me i didnt get much sleep last night ,have a sick daughter to tend to
i will edit the way it should have read sort off what amps were you pulling at 7k ?
olmod is online now Find More Posts by olmod
Last edited by olmod; May 21, 2006 at 02:26 AM.
Reply With Quote
Old May 22, 2006, 10:14 AM
Registerd Beaver
Smokin' Beaver's Avatar
Australia, WA, Warwick
Joined Jul 2003
3,585 Posts
My experiences to share here too?
I used the recomended brushless setup on mine & she runs & flies really, really well.
1200 kv motor (15amp max), APCE 9060 & 2000 ma/hr Lipo
Nice looking model. Though a shame I had to butcher the out of it after I'd built it to get the CG right. Model Engines have a lot to answer for here...(They wrote their own assembly manual on this Aussie release so god knows what the factory one was like!! ) no-where does it say - The Himark 1200 motor we tell you to use weighs 3 oz less than the design motor! Oh & by the way we also advise you to use a 2000 ma/hr battery because it has (at the time of design) the closest weight to an 8.4V SubC Nicad pack!!
Note: this kit is now dubiously listed as a "Wattage" kit by Model Flight (same kits in USA received the same label)
It is not.
It is made by a factory in China & they sell them to anyone who will buy enough of them.
I am by no means knocking that fact but if you look on the box, you will not find Wattage mentioned anywhere in or on the packaging. Nor will you find any reference to Wattage in the instruction manual.
In the UK they go by a different name because it is a different importer.
They were designed around the profoundly unreliable Wattage 480 Cobalt which was a heavy engine. Also Nicd sub C packs.
So...anyone reading this who expects an "out of the box" ARF should speak to all the guys here first before it ends in tears.
These planes (by virtue of their design) do not handle crashes well at all, they are a moulded plastic fuselage which disintegrates on impact.
Eyewitness experience speaking here - I saw a PC9 crash after a mid-air and the fuselage was unrecognizeable when we arrived at the wreckage.
Now, aside all that annoying introduction the plane flies quite nicely.
It is not a really an aerobatic plane because the ailerons are undersized (imho) and the dihedral built in gives it a slow roll rate. but that is scale-like = OK
Forget the wheels if you do not ROG bitumen/concrete.
Everthing about them is trouble in disguise.
a) Oversize colletts, screwing onto an undersize axle = wheel wobble.
b) Fitting into the wing socket will last about 10 grass landing before the hole becomes so enlarged that he gear wobbles in-situ
c) Angle of U/C legs is wrong - needs to have the wheels at least 12mm to 15mm further forward. Bending the U/C strut works here. She will stand on her nose as soon as you look at it otherwise.
I also left off all the plastic blisters etc etc until I eventually install retracts.

Anyway enough of all that, we build to fly. Right?
Well she does a good job of that & is easy to land too.
Good value for money but definitely not a beginners/transition plane.

Phil
Smokin' Beaver is offline Find More Posts by Smokin' Beaver
Last edited by Smokin' Beaver; May 22, 2006 at 10:26 AM. Reason: add pic
Reply With Quote
Old May 22, 2006, 07:46 PM
Extreme CNC Alloy EDF
Extreme_RC's Avatar
Australia
Joined Mar 2006
11,789 Posts
Have to agree with most of that, except I did take off on grass LOL. I decided on Sunday to cut open the firewall behind the motor so I could slide the battery further forward, rather than stuffing around with weight, its already heavy enough at 530g without a batt pack. In light of what you said I think it does actually fly pretty well, even with the 1047 and 1000Kv motor its quick, just too quiet! It does have some very alarming traits at slow speed though, definitely not a beginners plane by any means, couple of times I had to save it from a self induced spin on a slow turn crosswind until I figured out what it was doing...

How did you mount your prop? Did you have enough shaft length or a long prop adaptor to clear the cowl? I just clear the cowl with the SF prop but couldnt get the APC E's anywhere near it to try out. I need a prop adaptor longer than the himark ones.
Extreme_RC is offline Find More Posts by Extreme_RC
Reply With Quote
Reply


Thread Tools