RE: PHOENIX MODELS F-20 TIGERSHARK ?  
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RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/17/2008 10:03:03 PM   
dorset john



Posts: 38
Joined: 10/15/2002
From: Wimborne Dorset, UNITED KINGDOM
Status: offline 		Hi Liquid, that really is a cut and shut job - do you have any difficulties getting the plane off the ground? With my standard setup I usually aim to leave the ground only when I hit a decent bump. I have also found that the early vertical performance is not much different to level flight in terms of perceived prop speed, it's almost as if the slight tail-down attitude is causing drag. P.S I moved the C-of-G forward and the tail drop got worse - so I moved it back again.
Has anyone taken the C-of-G further back than 150mm to see if it goes any faster?

(in reply to liquid_TR)
       Post #: 576

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/18/2008 1:24:45 AM   
liquid_TR



Posts: 455
Joined: 4/8/2007
From: ISTANBUL, TURKEY
Status: offline 		Well the stable and realistic take off roll of this plane, in stock setup is abit long, just like a real jet. with the clipped wings its about the same, maybe a little longer than stock setup.

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LiQuid TR

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RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/24/2008 6:05:59 PM   
the trums


 

Posts: 56
Joined: 8/30/2007
From: , FL, USA
Status: offline 		Does anyone have a real real nice F20 for sale?

(in reply to liquid_TR)
       Post #: 578

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/28/2008 10:03:43 AM   
PlaneHeli


 

Posts: 603
Joined: 2/1/2006
From: Australia & Asia &, NEW ZEALAND
Status: offline 		What are everyones views on the supplied blue engine mount.

Is is plastic, nylon.

Ive found it to be slightly small for my OS46AX engine.

The manual requires it to be mounted 100mm (from memory) from the bulkhead. This does not suit the supplied engine mount. Ive fouund it too tight which spleys the engine mount ends outwards at the prop end.

I think ill replace it. What are others thoughts on this.

Ive tried 11x6, 10x7 & 9x8 props. 9x8 seems too high reving. 10x7 best so far but will try a 10x8 if I can find one. (only using 5% nitro at the moment).

What aileron differential has worked best for you. ive used 10% so far but appears to still have bad adverse yaw at slow speeds. Will have to experiment more with that.
Also set up 40% flap so far.

< Message edited by PlaneHeli -- 6/28/2008 10:04:06 AM >

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Useless Things...Runway behind you, Sky above you, Air in your Tanks, Engine Oil in the Hanger.

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       Post #: 579

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/28/2008 9:23:24 PM   
dorset john



Posts: 38
Joined: 10/15/2002
From: Wimborne Dorset, UNITED KINGDOM
Status: offline 		Blue plastic engine mount is good, you just need to chamfer the inside edge a little to fit your midrif bulge. I always drill through and use screws and nyloc nuts rather self tappers, this involves flattening sections of the diagonal support fillet for the nuts and washers. 10x8 apc is good for a .55 Webra GT, might be too much for .46 unless you've got a pipe. Aileron differential is difficult with this plane - you need none at high speeds, quite a lot at low speeds, I personally stick to high speed to avoid the issue.
A word of warning, the supplied self tap screws for the nose wheel mount will penetrate the fuel tank if you push it fully forward through the hole in the former - drill out the screw holes in the former and mount machine screws from the rear with nuts to the front in the wheel bay.
Flaps may be uneccessary as this model lands like a trainer and loses speed easily with tail down landing approaches.

(in reply to PlaneHeli)
       Post #: 580

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/29/2008 5:19:00 AM   
PlaneHeli


 

Posts: 603
Joined: 2/1/2006
From: Australia & Asia &, NEW ZEALAND
Status: offline 		dorset john,

Thanks. Ive already filed the engine mount a bit to try and take the strain off it.

If the concesus is the engine mount is good I wont replace it but file it some more.

Ive also used bolts so had flatten the diagonal for the bolts.

Thanks for the heads up with the tank.

I wonder if the more expensive radios give you the option of setting differential aileron to a switch (eg when flaps set) and none when switched back for higher speed.

Ive been reading the thread on the best high speed prop for the OS55AX. Seems 10X7 keeps being mentioned, so you may be right about a 10x8 being too much for an OS46AX.

How do you think the balance is with your Webra 50.

I thought about putting an OS55AX on this plane, but dont wont to put the balance off too much with a heavier engine on the front. There must be a limit as to when the wing loading / balance will be detrimental to its flying. OS55AX may be OK, OS61, OS75AX too much?.

_____________________________

Useless Things...Runway behind you, Sky above you, Air in your Tanks, Engine Oil in the Hanger.

(in reply to dorset john)
       Post #: 581

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/29/2008 6:39:35 AM   
dorset john



Posts: 38
Joined: 10/15/2002
From: Wimborne Dorset, UNITED KINGDOM
Status: offline 		The Webra .55 balances perfectly with no additional weight needed (but see my earlier posting about there being a manufacturer built-in slab weight in the tail). Most of these .50 - .55 size motors are bored-out .40's anyway so they shouldn't weigh more - a .60+ is a different matter altogether. You may also struggle with prop/ground clearance if you use > 10" pitch - I strimmed the runway with an 11x7!
You have the option of opening up the tail under the fin and sticking your battery in there as an alternative to adding weights. But I'm not sure that this model would handle a bigger motor for more speed - the fus' is quite lightly build and I can imagine it folding or pulling out the wing mount on a high G pitch manouvre if it had to change the direction of more mass.

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       Post #: 582

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/29/2008 7:05:14 AM   
PlaneHeli


 

Posts: 603
Joined: 2/1/2006
From: Australia & Asia &, NEW ZEALAND
Status: offline 		dorset john,

Yes noted your comment on the lead weight in the rear. I removed it as im using two batteries, so position them to balance the plane. To remove it I had to cut it out as it was well glued in. So the rear has a panel on it. I found the CofG to rearward with a battery in there though.

It appears the Webra 55 is slightly lighter than an OS55AX. I certainly wouldnt go bigger than an OS55AX. It should be OK with one.

Generally im very happy the way this plane flies.

Another problem was the throttle wire being too short. I had to mount the servo 180* from the manual for it to reach.

Cheers



< Message edited by PlaneHeli -- 6/29/2008 7:07:29 AM >

_____________________________

Useless Things...Runway behind you, Sky above you, Air in your Tanks, Engine Oil in the Hanger.

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       Post #: 583

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/30/2008 6:24:19 PM   
the trums


 

Posts: 56
Joined: 8/30/2007
From: , FL, USA
Status: offline 		Anyone, I just bought a Phoenix f20 What is the sleekest aluminim prop spinner available? I will run a 9x8 apc O.S. 50sx with Jett Muffler. as I did in my flutter explosioned delta.

(in reply to PlaneHeli)
       Post #: 584

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/30/2008 6:34:25 PM   
liquid_TR



Posts: 455
Joined: 4/8/2007
From: ISTANBUL, TURKEY
Status: offline 		you can go for the truturn ultimate spinners, which are way too expensive for my taste. Im using a basic JP brand aluminum spinner which I balanced myself and Im quiet happy with it.

9x8 pulls this airframe nicely, but with the jett muffler you can go up to 9x9 for alot more speed as the engine will still be turning very high rpms.

Im running mine with 55AX + ultrathrust muffler and APC 10x9. unloads nicely in the air and takes the airframe above 200km/h. (with clipped wing)

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LiQuid TR

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RE: PHOENIX MODELS F-20 TIGERSHARK ? - 6/30/2008 7:34:19 PM   
the trums


 

Posts: 56
Joined: 8/30/2007
From: , FL, USA
Status: offline 		liquid TR thanks for the help! This is a great forum.

(in reply to liquid_TR)
       Post #: 586

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 7/2/2008 6:47:43 PM   
toro_0397


 

Posts: 75
Joined: 12/12/2006
From: medellin, COOK ISLANDS
Status: offline 		hi, i am need to speed so i would like to know some things
what do you think would be the estimated speed for a phoenx f 20 with an os 55 ax with the stock muffler. since i am not a great builder i am not planning to modify mine into a clipped wing... so i am intersted is in the stock version? and also i would like to know which one would be faster, the f20 or nitro models bobcat? thanks for the help

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       Post #: 587

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 7/3/2008 12:19:54 AM   
liquid_TR



Posts: 455
Joined: 4/8/2007
From: ISTANBUL, TURKEY
Status: offline 		stock F20 and stock muffler 55ax will give about 130-140km/h of speed. Im thinking a bobcat will turn out more speed.

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LiQuid TR

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       Post #: 588

RE: PHOENIX MODELS F-20 TIGERSHARK ? - 7/3/2008 5:49:52 AM   
toro_0397


 

Posts: 75
Joined: 12/12/2006
From: medellin, COOK ISLANDS
Status: offline 		i forgot also to ask about the phoenix models strega...do you think that it could be also a nice choice for speed?

(in reply to liquid_TR)