RE: Hangar 9 F-22 Raptor PTS  
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RE: Hangar 9 F-22 Raptor PTS - 7/7/2007 2:41:26 PM   
da Rock



Posts: 6722
Joined: 10/11/2005
From: western, NC, USA
Status: online
quote:

ORIGINAL: octane-link

So just out of curiosity, I am at about 5500' of pressure altitude, probably higher density altitude (stupid Denver heat). It will be a real test, anyone got any tips on a prop to go with the stock engine to help this bird out? I am new to flying, I can fly in the sim with ease, which is why I upgraded to this plane right away. I have been building for a while, so I have some experience.

I suppose my runway is about 300 or 400 ft (not sure), so I should have enough room to abort if things look iffy. We usually tend to abort halfway down if it isn't gonna go, the city won't let us plow down the weeds around the field.

Thanks!



Swapping props isn't that simple. The airplane I encountered yesterday has gear that limits the fan size. I suggested to the owner and his mechanic that they bend new gear for the airplane for two reasons. Both reasons seemed equally important to me. The 3blade issue prop sucks on that engine. And two blades on that airplane won't improve over the issue prop unless they're larger diameter. And that's going to take appreciably taller gear. Mains and nose gear. And the mains definitely need 15-20degrees of aft rake.

With your altitude, I'd suggest one thing right up front. YOU are really going to need fan size. We could only get an extra inch on our prop over the issue one. We're on grass, but it's manicured. But even off the paved runway I fly sometimes, I doubt very strongly that the sucker would take the next size up from our inch increase. Because we don't usually have available props in half inch increments. And since you're probably going to benefit most from a bigger prop while other places might get by with just an inch bigger, I'd suggest you definitely bend new mains and look for a taller nose strut.

But take my advice with some reservation. It's often very simple in our hobby to try out something first before going the next step. We did just that yesterday. We tried the next diameter prop larger than the issue prop. It cut some grass, but did improve things measurably. So you can try that too.

But if it were mine, I'd have bent some new gear last night.

(in reply to octane-link)
       Post #: 176

RE: Hangar 9 F-22 Raptor PTS - 7/9/2007 3:28:53 PM   
ag4ever


 

Posts: 298
Joined: 10/5/2004
From: Richmond, TX, USA
Status: offline 		I have run an 11" prop on mine with no problems.

How big of a prop do you think this plane should run?

I personally think the smaller diameter and moderate pitch are best. It allows the engine to really rev up and get the plane moving.

(in reply to da Rock)
       Post #: 177

RE: Hangar 9 F-22 Raptor PTS - 7/9/2007 8:52:25 PM   
509thBoomer



Posts: 133
Joined: 5/2/2005
From: Fairchild AFB, WA, USA
Status: offline 		It funny, I put a 10X9 on mine yesterday just for s--ts and giggles and whoa, it really woke up. This think is almost as fast as my Cermark F-16 with the big honkin 91 in the nose. I love this plane more and more everyday!!


_____________________________

Phil
Fairchild AFB WA

(in reply to ag4ever)
       Post #: 178

RE: Hangar 9 F-22 Raptor PTS - 7/9/2007 9:52:34 PM   
da Rock



Posts: 6722
Joined: 10/11/2005
From: western, NC, USA
Status: online
quote:

ORIGINAL: ag4ever

I have run an 11" prop on mine with no problems.

How big of a prop do you think this plane should run?

I personally think the smaller diameter and moderate pitch are best. It allows the engine to really rev up and get the plane moving.



How big a prop?
Whatever the flying field and the engine both allow.
Of the three grass fields I fly, my experience with the Raptor was at the closest cut. We went up in diameter 1" and the blades showed green after one flight.
I try to suit the propeller to the engine a bit more rigorously than just "smaller diameter and moderate pitch". I try to find a combination the allows the engine to turn in its best rpm range with a prop that has the most suitable pitch for the airplane to do what's expected and to do it with as much diameter as possible since more fan area beats less every time. That's three different parameters all trading off against each other.

(in reply to ag4ever)
       Post #: 179

RE: Hangar 9 F-22 Raptor PTS - 7/9/2007 10:27:23 PM   
ag4ever


 

Posts: 298
Joined: 10/5/2004
From: Richmond, TX, USA
Status: offline 		OK, my point is, the plane has plenty of clearance for a "normal" prop.

I am running a 10X8, and might even try a 10X7 to see if the extra RPMs will help or if the 10X8 is the best.

Also, I am suiting the propeller/engine/plane combo a bit better than you try to claim, as I have actually tried 5 different props on my engine/plane to SEE which is actually better. I can't imagine a larger prop would do any good as every time I decreased the diameter, the plane flew even better. I have even tried multiple brands to see what is the best.

I still have not seen where you have said what prop you are running, but just that you are running a more rigerously suited prop.

And more fan area does not beat less everytime. Just look at the pylon racers. (Well, if you are into 3D, then you do want excessive fan area, but that is a different topic.)

(in reply to da Rock)
       Post #: 180

RE: Hangar 9 F-22 Raptor PTS - 7/10/2007 2:09:59 AM   
da Rock



Posts: 6722
Joined: 10/11/2005
From: western, NC, USA
Status: online
quote:

ORIGINAL: ag4ever

OK, my point is, the plane has plenty of clearance for a "normal" prop.

I am running a 10X8, and might even try a 10X7 to see if the extra RPMs will help or if the 10X8 is the best.

Also, I am suiting the propeller/engine/plane combo a bit better than you try to claim, as I have actually tried 5 different props on my engine/plane to SEE which is actually better. I can't imagine a larger prop would do any good as every time I decreased the diameter, the plane flew even better. I have even tried multiple brands to see what is the best.

I still have not seen where you have said what prop you are running, but just that you are running a more rigerously suited prop.

And more fan area does not beat less everytime. Just look at the pylon racers. (Well, if you are into 3D, then you do want excessive fan area, but that is a different topic.)



I'm not trying to claim anything. I recounted an experience with the RTF and my opinions of that airplane as trainer. Answered some questions and made some general suggestions.

Go argue with someone else.

(in reply to ag4ever)
       Post #: 181

RE: Hangar 9 F-22 Raptor PTS - 7/10/2007 5:26:50 PM   
ag4ever


 

Posts: 298
Joined: 10/5/2004
From: Richmond, TX, USA
Status: offline 		I am not arguing with you, just recounting my experiences with my ARF and my opinions of the airplane as supplied by Hanger 9.

I also made some general suggestions.

Don't like it fine.

(in reply to da Rock)
       Post #: 182

RE: Hangar 9 F-22 Raptor PTS - 8/10/2007 6:12:26 PM   
FLIGHTJOCKEY


 

Posts: 20
Joined: 3/15/2005
From: Palm Desert, CA, USA
Status: offline 		Well I have heard alot of bad things about the f-22 I think it comes from inexperienced flyers, I have been flying for many yeas and have a many types of planes, I lke the f-22 I have even gone to the extreem of installing retracts, this is for you guys who have asked about installing retracts , her a few of photosof the construction, to makeit easier I baught grey ARF and stripped the covering off the fuse, to make the work easier. I usd robart retracts for a coursair, the mains rotate to make it tuck away eaiser , I also built spring open and cloes doors. take look and let me know what you think


Bill

Palm Desert, Ca
www.coachellarc.com

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(in reply to ag4ever)
       Post #: 183

RE: Hangar 9 F-22 Raptor PTS - 8/10/2007 6:21:39 PM   
nothinbetr2do


 

Posts: 2495
Joined: 2/27/2006
From: elkton, MD, USA
Status: online 		that, pretty cool. i like the way the mains come out the sides, but do you think the openings will hinder take offs, as the plane needs some speed for lift

_____________________________

just say no to "shelf queens"

(in reply to FLIGHTJOCKEY)
       Post #: 184

RE: Hangar 9 F-22 Raptor PTS - 8/10/2007 7:07:17 PM   
FlyingGreg



Posts: 582
Joined: 1/21/2002
From: West Chester, OH, USA
Status: offline 		I agree with Rock. We had one of these show up at our training sessions after having seen one in the hands of an experienced flier. The first one, with the capable flier was less than impressive. When we finally flew the newbies it was quite a handful. We had a buddy cord but were afraid to hit the switch. It ran out of fuel early (we thougth--don't know what size tank) and learned that it glides like a brick. The guy flying it basically pointed it at the ground and we walked a long way to pick it up. Finally bit the dust a few weeks later at some other field. Lesson learned was to call the LHS that is selling and attempt to have the owner dissuade anyone from buying as a trainer. The experience flier eventually put a larger engine in his and it looked a lot better.

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...nothing in moderation...

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       Post #: 185

RE: Hangar 9 F-22 Raptor PTS - 8/10/2007 7:46:59 PM   
da Rock



Posts: 6722
Joined: 10/11/2005
From: western, NC, USA
Status: online 		FLIGHTJOCKEY,
That is awesome. It deserves a thread of it's own. Got a couple of somewhat unique ideas in it.

It really should have a thread of it's own.

(in reply to FlyingGreg)
       Post #: 186

RE: Hangar 9 F-22 Raptor PTS - 8/10/2007 8:35:45 PM   
Pit-Viper 1



Posts: 913
Joined: 9/14/2005
From: Westminster, CO, USA
Status: offline 		Hats off too you, excellent job!! Looks as if a little sheeting on the sides to fill in the opening will take care of any problems there. Not sure from the pictures, but is there enough room to make a small wheel well in there also? That is great looking and congrats on being the first to step up and try it. Been wanting to get one but had to have retracts in it as did my P-51 PTS. As far as flight goes, a little larger motor and she should be just fine.

I agree with da Rock, it deserves it's own thread. Way to go!!


Shane

_____________________________

www.colorado-rc.com

(in reply to da Rock)
       Post #: 187

RE: Hangar 9 F-22 Raptor PTS - 8/13/2007 7:27:49 PM   
FLIGHTJOCKEY


 

Posts: 20
Joined: 3/15/2005
From: Palm Desert, CA, USA
Status: offline 		I had the first flight today on my motified f-22 with the retractcs, I had no problem taling off. the opening will cause a bit of drag but that is eaisly over come with more speed it took about 100 feet to take off, it flys gret with the os 55ax in couple of weeks Ill get one of the guys with a radar gun to speed check it, I will also post some completed potos next week, need to get those photos taken I actually changed the main gear door openog since the last photos, I used air cylinders to open and clost the main doors the spring system didnt work too well in the first flight they kept closing ill see how the new system works out,

< Message edited by FLIGHTJOCKEY -- 8/14/2007 6:18:34 PM >

(in reply to Pit-Viper 1)