Not to shabby for a Scale Warbird
02-16-2012, 10:02 PM
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RE: Not to shabby for a Scale Warbird
ORIGINAL: freakingfast
It's lookin real good Chuck. I haven't been out to the field yet this year. hope to see (hear) it fly.
It's lookin real good Chuck. I haven't been out to the field yet this year. hope to see (hear) it fly.
I did'nt even bother to renew at my local club. now I spend 2 hrs round trip, and 20 bucks gas driving, to burn 30 bucks through Rare Bear, and I'm finally having a blast! (when I can afford the time and money), go figure [sm=50_50.gif]
I hope very much that you keep finding ways to keep it fun regardless of any work, club, etc. issues too!
IMO, any club would be priveliged to have you around, with the special airplanes you build and fly!
Sincerely, Chuck
02-16-2012, 11:58 PM
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RE: Not to shabby for a Scale Warbird
ORIGINAL: combatpigg
The prop really looks like a toothpick in that last shot.....!
I'd have to have a couple drinks just to work up the nerve to taxi that bad boy.
The prop really looks like a toothpick in that last shot.....!I'd have to have a couple drinks just to work up the nerve to taxi that bad boy.
Here's a tidbit for ya though, we do rake the tip itself just a hair before flying them, but notice that the prop is wider (obviously) across the tip stations than the APC, or any other model engine speed prop you'll normally see.
Because we waste an extremely low amount of the available HP on the inefficient inboard stations just to hold the tip on, we can carry a bigger pitch, AND do it across a proportionally wider and longer outer section than other props.
Because the prop does all that, we are able to fine tune it so that the engine dwells around it's optimum rpm, while the tip itself runs at a certain magic percentage of mach speed that is just fast enough to keep lift from spilling off the tip without causing shock waves across the working blade area and wasting HP. Basicly the prop makes it's own invisible compression duct to run in.
This holistic set of strategies starts to knock prop efficiency clear out of the park, but the Coup De Grace is another feature which oddly enough, has to do with the inboard stations again. When my partner came up with the idea, and explained it to me, it freakin' blew my mind.
The clarity of his idea is astounding, brilliant, and I've never heard of it being done on any prop, anywhere, ever. It only applies to certain categories of racing props, and I really can't share it yet, but when the props are out, the idea will be out.
P.S. I would never consider flying Bear, much less risking breaking my buddy's stupid prop, without getting plowed either (afterwards). [sm=wink_smile.gif]
P.P.S. Soarrich, this post is for you too.
02-17-2012, 08:17 AM
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RE: Not to shabby for a Scale Warbird
ORIGINAL: C_Roundy
P.S. I would never consider flying Bear, much less risking breaking my buddy's stupid prop, without getting plowed either (afterwards). [sm=wink_smile.gif]
P.S. I would never consider flying Bear, much less risking breaking my buddy's stupid prop, without getting plowed either (afterwards). [sm=wink_smile.gif]
Thanks for posting the videos and information!
Can't wait to hear more about that prop design, sounds like you guys have a real winner for a product...
02-17-2012, 07:30 PM
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RE: Not to shabby for a Scale Warbird
I only recently spent a week myself studying supercritical aerofoils for my DF powered warbird prop project. I was shocked to learn how wrong our prop tips are when they approach .75 Mach. Even the APC, thou they work the best simply because of how thin and raked back the tips are.
These example pics are close to what I'm looking at, but not perfect for my needs. Still too much top camber at the tip and too narrow.....ya think
These example pics are close to what I'm looking at, but not perfect for my needs. Still too much top camber at the tip and too narrow.....ya think
02-17-2012, 07:44 PM
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RE: Not to shabby for a Scale Warbird
ORIGINAL: iron eagel
It must be a bit unnerving to fly a museum quality model, I'd get hammered myself.
It must be a bit unnerving to fly a museum quality model, I'd get hammered myself.
Problem is: If you build an airplane to last for an unlimited service life, you might as well body work it and paint it to be beautiful since it may be around for you to have to look at for a looong time, then of course it makes sense to do the highest quality electronics and equipment installation you can. Now that you've done all that, it would be a waste not to go terminally serious in the power department to achieve the airplanes full potential, now that you done that, its a crying shame that the available propellers are so dismally wrong for the combo, etc...etc...etc.................... IT IS A VERY SLIPPERY SLOPE.
No Stress, No Stress, No Stress..........
Regardless, the airplanes are built to fly, they are a joy to fly, and they ARE extremely tough.
Here is a picture at a race a couple yrs ago, of my buddy's 14 yr old Stilleto (early example of the way my Rare Bear is constructed). It has been raced and otherwise flown hard it's whole life, strained through trees, belly landed in every kind of field imaginable over and over, cartwheeled and flipped over on the runway a number of times, stalled from 6-8 ft onto the runway repeatedly, survived midair collisions, dropped from the garage rafters, fallen out of trucks, blown of the pit tables, backed into, stepped on, had fuel tanks burst in it, etc, etc, etc, etc, etc.........
But its still going strong. It still flys exactly the way it did when it was built (better than any ARF ever could), It is still 100% structurally sound, it will take any G-load you could ever manage to slam it with, and any HP you could ever fit onto it.
Now that, in my humble opinion, is an airplane truly born to fly.
02-18-2012, 12:12 AM
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RE: Not to shabby for a Scale Warbird
ORIGINAL: airraptor
Chuck what does your 170 register on the DB meter when on 30% or higher?
Chuck what does your 170 register on the DB meter when on 30% or higher?
Jeff, first off, its so happy on 50% and above, that in the foreseeable future I intend to be running our props at ambitious diameters and pitches which require big fuel. Truth be told, it is quite loud. I don't know how many decibels, I've never put meter on it. But its gotta be clear on the wrong side of the limit, at any club that has a specific DB limit.
I know where your trying to go with your question though, and I thank you for it!
For regular extreme speed forum contributers that don't know, Airraptor has taken the the reigns, and accepted a tour of duty as our local (Vaca Valley Radio Control) club president. I for one, am Very, Very proud of him. His growth in the sport as a pilot, builder, performance tuner, and now as a contributing citizen has been phenomenal, top 1% in every way.
What he is looking for with his question, is a way to integrate something like my Rare Bear into the VVRC club without insurmountable problems. I knew he would, and thats just one example of the many kinds of things that will make him a good president (even on his first go 'round).
Salute Airraptor, If there is ever anything I can do for you, wherever you are concerned, I will work for free.
Sincerely, Chuck Roundy
02-18-2012, 12:58 AM
#34
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RE: Not to shabby for a Scale Warbird
Thanks chuck. yes this is a new experience for me but one I look forward to. Yes I am working on some old rules and rules that were not written. i would every one to fly anyplane at anytime but I also want to keep the club going as long as we can. I do hope one day that you three will make it back out to fly. plus I will need your help with a F3D plane I have now with that FIRE nelson. I have been in the AF for 20 yrs now and have 15yrs MX experience so if you ever need any help with that A&P let me know. I will get my A&P soon also as I have enough time to take the tests but I would need some help someday on the Recips and how to stich some ribs 
.
.
02-18-2012, 02:14 AM
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RE: Not to shabby for a Scale Warbird
ORIGINAL: freakingfast
I only recently spent a week myself studying supercritical aerofoils for my DF powered warbird prop project. I was shocked to learn how wrong our prop tips are when they approach .75 Mach. Even the APC, thou they work the best simply because of how thin and raked back the tips are.
These example pics are close to what I'm looking at, but not perfect for my needs. Still too much top camber at the tip and too narrow.....ya think
I only recently spent a week myself studying supercritical aerofoils for my DF powered warbird prop project. I was shocked to learn how wrong our prop tips are when they approach .75 Mach. Even the APC, thou they work the best simply because of how thin and raked back the tips are.
These example pics are close to what I'm looking at, but not perfect for my needs. Still too much top camber at the tip and too narrow.....ya think
Obviously the ZERO chord taper design we favor, design, and implement for our needs looks crude in comparison. We are literally faced with an opposite design imperative. The imperative is: How close to non-existant can we make the inboard stations, and still keep our working, outboard station's (s) integrity, with a neccessary safety margin that is still way more than worst case scenario (at the instant of a violent engine stoppage etc.).
One of the reasons I made sure I made it to Reno race week last year was because I absolutely had to have up close and personal pictures of Tom Aberle's Phantom prop!
It so happens that we will finally be getting back to our SlipStream in the not too distant future. The 9x12 we originally used was horrible, and I'm sorry, but ***** copying an APC 9x10 in carbon and calling your airplane good, potential reached.... We will be doing a damn sight better than that. Also, I have come to the realization that even if they finally gave some up, I would not not run the specialist European props no matter how good they are, even if they paid me.
I have a clear understanding of the multitude of dynamic features that need to be encompassed by the perfect prop you need too. Even though you will be de-tuning to a lower rpm range, and it will be on a warbird [X(], Yours will not be inherently different by design, from SlipStream's optimum....
02-18-2012, 07:40 AM
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RE: Not to shabby for a Scale Warbird
ORIGINAL: C_Roundy
It so happens that we will finally be getting back to our SlipStream in the not too distant future. The 9x12 we originally used was horrible, and I'm sorry, but ***** copying an APC 9x10 in carbon and calling your airplane good, potential reached.... We will be doing a damn sight better than that. Also, I have come to the realization that even if they finally gave some up, I would not not run the specialist European props no matter how good they are, even if they paid me.
It so happens that we will finally be getting back to our SlipStream in the not too distant future. The 9x12 we originally used was horrible, and I'm sorry, but ***** copying an APC 9x10 in carbon and calling your airplane good, potential reached.... We will be doing a damn sight better than that. Also, I have come to the realization that even if they finally gave some up, I would not not run the specialist European props no matter how good they are, even if they paid me.
02-18-2012, 07:49 AM
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RE: Not to shabby for a Scale Warbird
ORIGINAL: C_Roundy
Even though you will be de-tuning to a lower rpm range, and it will be on a warbird [X(], Yours will not be inherently different by design, from SlipStream's optimum....
Even though you will be de-tuning to a lower rpm range, and it will be on a warbird [X(], Yours will not be inherently different by design, from SlipStream's optimum....
02-18-2012, 09:34 AM
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RE: Not to shabby for a Scale Warbird
ORIGINAL: C_Roundy
Ironicly, back in the stone age last century, the whole reason we began molding is because we wanted tougher airplanes that would take more abuse, less repair, and less maintenance, so we would'nt need to worry about them, or hassle with them so much.
Problem is: If you build an airplane to last for an unlimited service life, you might as well body work it and paint it to be beautiful since it may be around for you to have to look at for a looong time, then of course it makes sense to do the highest quality electronics and equipment installation you can. Now that you've done all that, it would be a waste not to go terminally serious in the power department to achieve the airplanes full potential, now that you done that, its a crying shame that the available propellers are so dismally wrong for the combo, etc...etc...etc.................... IT IS A VERY SLIPPERY SLOPE.
No Stress, No Stress, No Stress..........
Regardless, the airplanes are built to fly, they are a joy to fly, and they ARE extremely tough.
Here is a picture at a race a couple yrs ago, of my buddy's 14 yr old Stilleto (early example of the way my Rare Bear is constructed). It has been raced and otherwise flown hard it's whole life, strained through trees, belly landed in every kind of field imaginable over and over, cartwheeled and flipped over on the runway a number of times, stalled from 6-8 ft onto the runway repeatedly, survived midair collisions, dropped from the garage rafters, fallen out of trucks, blown of the pit tables, backed into, stepped on, had fuel tanks burst in it, etc, etc, etc, etc, etc.........
But its still going strong. It still flys exactly the way it did when it was built (better than any ARF ever could), It is still 100% structurally sound, it will take any G-load you could ever manage to slam it with, and any HP you could ever fit onto it.
Now that, in my humble opinion, is an airplane truly born to fly.
ORIGINAL: iron eagel
It must be a bit unnerving to fly a museum quality model, I'd get hammered myself.
It must be a bit unnerving to fly a museum quality model, I'd get hammered myself.
Problem is: If you build an airplane to last for an unlimited service life, you might as well body work it and paint it to be beautiful since it may be around for you to have to look at for a looong time, then of course it makes sense to do the highest quality electronics and equipment installation you can. Now that you've done all that, it would be a waste not to go terminally serious in the power department to achieve the airplanes full potential, now that you done that, its a crying shame that the available propellers are so dismally wrong for the combo, etc...etc...etc.................... IT IS A VERY SLIPPERY SLOPE.
No Stress, No Stress, No Stress..........
Regardless, the airplanes are built to fly, they are a joy to fly, and they ARE extremely tough.
Here is a picture at a race a couple yrs ago, of my buddy's 14 yr old Stilleto (early example of the way my Rare Bear is constructed). It has been raced and otherwise flown hard it's whole life, strained through trees, belly landed in every kind of field imaginable over and over, cartwheeled and flipped over on the runway a number of times, stalled from 6-8 ft onto the runway repeatedly, survived midair collisions, dropped from the garage rafters, fallen out of trucks, blown of the pit tables, backed into, stepped on, had fuel tanks burst in it, etc, etc, etc, etc, etc.........
But its still going strong. It still flys exactly the way it did when it was built (better than any ARF ever could), It is still 100% structurally sound, it will take any G-load you could ever manage to slam it with, and any HP you could ever fit onto it.
Now that, in my humble opinion, is an airplane truly born to fly.
I had people comment about the amount of work I put into a plane and my response to them pretty much mirrors yours. I just build them to fly, hopefully well.
Not that the quality of my work is as good as yours by any means, but our ideals are the same.
I build my planes to fly, and I like them to look half way decent.
Truth be know the second flight of my Hybrid delta first launch with the catapult resulted in a nose plant due to prop adapter coming loose. While there was no damage to the airplane, because of the construction, still it was humbling to be bit in the butt by something so simple I had not checked after installing the new motor.
It seems that you have the same view towards ARF's that I do.
Edit to add:
I hear what your saying about props, I am having the same problem as you with what I am doing using high KV electrics and trying to get a prop that works. Unfortunately I don't have access to the same type of resources that you do, let alone the skill set to make a better prop for my application so I am going to have to settle for something that is close. It would be nice to have a prop that is matched to the airframe, power and available RPM but right now that's not in the cards. I cant wait to see the results that you get when you get your setup dialed in, it's already impressive!
02-19-2012, 09:47 AM
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RE: Not to shabby for a Scale Warbird
Prop trends on F5D pylon are changing from small high revving to long high pitch slow turning. This is an example of a prop that caused big comotion at the worlds last time. It is for a F5D project I am working on for the next cycle... 200mph and very quiet.
Beautiful airplane BTW
DE
Beautiful airplane BTW
DE
