OOPS I used my outside voice again. DOH!

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.

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.

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!!

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.

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.

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.

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

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

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.

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.

Hats off too you, excellent job!![sm=thumbs_up.gif] 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. [8D]

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


Shane

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,

Can you post any video of the gear and doors in action?


Shane

I maidened mine yesterday at 6000 ft of actual altitude, higher density altitude cause it was so hot.

Took off great, a little long. Flew great, nice and level, very high. Landed great, perfect flair. Only change I did was raise the flaps to mid-position. I am using the stock prop, engine, etc.

Not sure where all these issues are coming from if I can fly it at such a high altitude with literally no major issues, and one very minor one.

Sorry, double post.

They're coming from the normal range of performance you see from almost anything that is manufactured with less than rigid quality control. There seems to be a significant variance in how the locked-in needle valve limiter is set by the mfg. There seems to be quite a variance in almost all ARFs' wood selection, and therefore the balance and strength of each one. There seems to be differences in the power output of the engines.

For example, your "one very minor one". If every other owner doesn't see it, how did it happen to your example? Same way others saw something you didn't.

what was the cost to do the retracts?

All I'm saying is either quality has improved overall, or I got better parts. But at my altitude, I should have seen something bad that others saw.

It's probably better quality, but I am using the Evolution .46 with trainer prop, and everyone thought that was a plane-killer, when it really performed great.

by the time I finished the modification, wih all the parts includin wood and glue amd misc parts I a think its about 300.00 maybe more I didnt add it up. the retracts were 165.00 the air kit was about 55.00 and the rest was misc parts the biggest thing was I had about 80 hrs in the project it tool alot of time to just figure out the way I wanted to install the retracts to make them come out just right, the rest was make things up as you go to make it function right as well as make it look good, I have made many scratch built planes, it talkes alot of research, patients ,and most of all it helps to have knowledge of all functions to the mechanics of a airplane. I have been flying real ones for over 30 years and have about 13500 hrs of stick time in many different planes (I am a retired LT Col, Air force), but most of all I enjoy building and flying models, it is so relaxing and enjoying to see the finished product, Ill post a video of the retracrs with the new and up and commig completed planes soon

A technical question:

Just wondering -- for those that have increased engine size, is there any significant pitch trim changes required when flying between wot and low power cruise? The reason I ask is that I held straight edges up to the profile picture (on the end of the box) and noted ~0 incidence for horizontal stab with positive on the wing and lots of downthrust in the engine. Was this all designed into the airframe to allow low power requirements to benefit the novice? Earlier posts described flights that sounded like the airplane was flying slower than the pilots typically expected and seemingly on the verge of a stall when in fact maybe it likes to fly with a high deck angle? I was thinking of increasing engine size and reducing the amount of downthrust (the airplane's designers would probably be rolling their eyes) but now I'm not sure...

New Raptor Pilot, signing on!

Callsign: Markind

I just got done reading all 10 pages of this thread, thanks all for the great chat and pics!!!

I am a perfect customer for this plane. I have lots of stick time on full-house controls, and can fly my Multiplex MiniMag and F-27C Stryker with confidence. I like to think I am well within the Intermediate pilot skill level. I like the look of this bird, too. I like the PTS features.

I now belong to a club where nitro is the norm and was looking at stepping up into my next plane.

This Raptor ARF looks like a fun way to go. I read all the on-line reviews, two mag articles, and have been playing with the FSOne sim model of this plane.

That is some pretty intense marketing, that sim model. I found myself just taxiing around, going OOooohhh, Ahhhhhh...

Based on what I have read, plus what I see in the sim model, I am going ARF and I am going with OS .55ax. I already have an AR6000 on hand, but I'll still need everything else.

I'll post up and throw up a pic or two as I progress.

Cheers!

Hmm the OS .55 ax is about $160 new... I'm tracking down a friend that may sell me a Super Tigre .51 for a lot less while I wait for parts to arrive... [&:]

I tried the sim with the 2-bladed prop option. The stock motor then gives a pretty good pull. I'll venture a guess that to get unlimited vertical you need thrust > weight of plane which is about 7.5 pounds.... hmm...

Hmm the ST .51 is not quite what I want. For one thing, the needle valve is too close to the prop. I could make it work, and chop the cowling up, but...

Looking more like an EVO .46 again... Still looking at the OS .46 LA though... Anybody have a preference?

My ARF is due in any day, stay tuned...