RE: Refinished DC F-20  
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RE: Refinished DC F-20 - 12/17/2007 1:54:25 PM   
vicman



Posts: 6059
Joined: 12/8/2002
From: Valdese, NC, USA
Status: offline 		How much diffrence are you looking for? There won't be much.
The Juno will be a much better plane over the long haul but may be a little heavier depending on how you build it.


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RE: Refinished DC F-20 - 12/17/2007 2:43:24 PM   
Flyboy Dave



Posts: 13359
Joined: 3/20/2002
From: San Bernardino County, CA, USA
Status: offline 		Like Vic says....there isn't much difference between all 4 or 5 of the 40 size F-20's.
If you are building one from a kit, you should minimize the size of the air intakes
on the sides of the fuse, and use retracts for all out speed.

The real key to the speed of the plane is the engine and prop. I use skinny wheels
instead of retracts, and the plane is plenty fast....in fact, too fast....because it has
flutter issues. The planes were design to go 100 mph top speed. Once you get above
110-115 problems arise.

FBD.

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RE: Refinished DC F-20 - 12/17/2007 3:26:43 PM   
toro_0397


 

Posts: 75
Joined: 12/12/2006
From: medellin, COOK ISLANDS
Status: offline 		do you think that the juno would be a better plane? what do you recomend to avoid flutter? and what kind of servos shuold i use?

thanks

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RE: Refinished DC F-20 - 12/17/2007 4:56:03 PM   
bob27s



Posts: 4712
Joined: 4/9/2002
From: Cleveland, OH, USA
Status: offline 		The Juno F-20 is a great kit, and results in a VERY good flying airplane....

Flutter is not prevented by the servos. Too many folks look for servos that can survive flutter. Best to address the source of flutter.

Seal the control surfaces gaps. That is the best way to prevent flutter. And be sure your torque rod linkages are properly installed.

Either aircraft does not need anything special servo wise. Anything you would trust in any decent aircraft is good. The F-20 I had a few years back had basic JR 517 ball bearing sport servos in it. Any decent BB modern BB sport servo would be good.

Although from a weight/size standpoint, you may want to consider some mid-size digital servos. Save an ounce or three in weight, and easier to fit into the plane.

As for engine choice..... the OS55AX will be ok. Keep in mind, the engine prefers lower rpm, but it can do ok for itself in a speed application. With either the stock muffler or at tuned muffler such as the Jett-Stream, select a prop that allows the engine to turn between 14,500 and 15,500 rpm peak rpm. With the stock muffler, a 9x8, 9x9 or 10x6, 10x7. With the tuned muffler, 10x7, 10x8, maybe the 9x9.


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RE: Refinished DC F-20 - 12/17/2007 5:05:30 PM   
vicman



Posts: 6059
Joined: 12/8/2002
From: Valdese, NC, USA
Status: offline 		I have read other places here in RCU that several PHX models have suffered from poor hardware. (especially control horns) If you don't mind building get the Juno, they look great when done and will allow retacts, something the other .40 size F-20s don't. FBD's is a .60 size.
Bob said it right about flutter. I have never had a problem with flutter on any of mine. Usually it's poor piloting skills


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RE: Refinished DC F-20 - 12/17/2007 5:14:16 PM   
toro_0397


 

Posts: 75
Joined: 12/12/2006
From: medellin, COOK ISLANDS
Status: offline 		thanks for all the help.
the only concern i have is that i have only built two kits, both of them profile 3d's, is the juno difficult to build what tips can you give me?

thanks

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RE: Refinished DC F-20 - 12/17/2007 6:07:16 PM   
bob27s



Posts: 4712
Joined: 4/9/2002
From: Cleveland, OH, USA
Status: offline 		It is a fairly straight-forward kit.

Just spend a night or two looking over the plans and reading the instructions before building. You can usually identify a few things you will want to plan-ahead for.


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RE: Refinished DC F-20 - 12/18/2007 2:03:36 AM   
toro_0397


 

Posts: 75
Joined: 12/12/2006
From: medellin, COOK ISLANDS
Status: offline 		do you think that a 61 can be fitted on the f 20

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RE: Refinished DC F-20 - 12/18/2007 11:59:09 AM   
burgh_guy61


 

Posts: 250
Joined: 7/13/2005
From: Trafford, PA, USA
Status: offline 		Here is a pic of the nose of my DC (Juno) F-20. There is not a whole lot of nose room. This is a OS 46sf ABC in mine just to give you an idea of space. By the way, it has no retracts and has been on the radar gun at 105 straight and level.

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Hey do that again...Lower this time!

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RE: Refinished DC F-20 - 12/18/2007 11:38:09 PM   
vicman



Posts: 6059
Joined: 12/8/2002
From: Valdese, NC, USA
Status: offline 		Nice install.

My Kangke was radar'd at 106-110 consistantly over 8 or 9 passes. I have a stock clapped out .46 FX, no fancy pipe like yours


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RE: Refinished DC F-20 - 12/19/2007 11:42:36 AM   
burgh_guy61


 

Posts: 250
Joined: 7/13/2005
From: Trafford, PA, USA
Status: offline 		Laughing at the fancy pipe, actually that is one of the Tower cheapie pipes for a 46. I have yet to really lean on that 46 so far as it is still new with only about a gallon thru it and didnt try a 9x8 yet either, but never the less no complaints....except i didnt build it with retracts.

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Hey do that again...Lower this time!

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RE: Refinished DC F-20 - 12/19/2007 4:26:41 PM   
toro_0397


 

Posts: 75
Joined: 12/12/2006
From: medellin, COOK ISLANDS
Status: offline 		what spinner is that, it fit perfectly the plane. is the one of dc.
did the towers muffler show a notisable difference in comparisson to stock muffler.

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RE: Refinished DC F-20 - 12/19/2007 6:26:22 PM   
burgh_guy61


 

Posts: 250
Joined: 7/13/2005
From: Trafford, PA, USA
Status: offline 		The spinner is from Juno (dot) com. It is a 2 1/4" jet style that like you said looks and fits the kit perfect. As for the Tower muffler it did add a few rpm..about 600, but looks better than a stock muffler too

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Hey do that again...Lower this time!

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RE: Refinished DC F-20 - 12/20/2007 2:23:53 AM   
vicman



Posts: 6059
Joined: 12/8/2002
From: Valdese, NC, USA
Status: offline 		That pipe looks like a pspec copy.

BG61, I was just up in your hood last week. I had to go to Chesswick for a meeting.


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RE: Refinished DC F-20 - 12/20/2007 7:00:35 PM