AmishWarlord

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geh3 there is a nice set of plans with a built up wing linked in the first page of this thread.

you just have to keep an eye out for them. Then when you see one take the price you think it's worth and triple it. Then you stand a chance of winning it.

karasr

My Feedback: (1)

If you make some modifications such as:
Get rid of the foam top and replace it with cross grained 1/16 balsa.
Use 1/16 ply for the bottom
in the nose laminate 1/32 ply inside the balsa sides.
Use carbon fiber to reenforce the wing
mounta strongelevator servo behind the wing
Mount a Rossi 21 with a tuned pipe and a 7/5 prop
And
You will have a genuine 200MPH airplane.
of course it's no longer a 1/2a airplane.
Be sure you have experience with fast airplanes

Bob K

AmishWarlord

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I don't think that one has seen 200 MPH is quite awhile.

eddieC

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phatboy

You guys are just fuuuull of great information! Mike acctually has the build instructions on the way to me already.

Yes Amish, if you build the wing from balsa then yes it does have a leading edge like that. I however will be using the foam main wing because I doubt this particular one will ever see the 200mph Karasr spoke of. Im not ready for a plane with those speeds YET!

Any idea when you will be doing that lazer cut kit Amish?

I have no idea what engine I will be using, I guess whatever I can find when the time comes.

karasr

My Feedback: (1)

Now I'm into turbines.
That GLH has not flown in 10 years. It had about 75 flights.
It gets a little dusty sitting in a crawl space.
BUT, it was fun!
Bob K

phatboy

Do you still have and would you sell the engine? lol

OH BTW, do these planes utilize a rudder, or just ail/ele, and maybe throttle?

combatpigg

My Feedback: (3)

Let's see...200MPH with a 7x5 prop..

OK, all the engine needs to provide is:

43,000 RPM
13.3 pounds of thrust
6.8 horsepower

Imagine a plastic APC prop supporting 13.3 pounds of thrust and the centrifical forces involved.

cfircav8r

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Back in the Early 90's I flew one with a Cox Tee Dee .09. It was fast but not excessively fast, Very maneuverable and no bad habits. It finally succumbed to fuel soaking. Mine was just aileron and rudder, and that was all I had room for. With todays servos and engines a full house control system is very doable.

karasr

My Feedback: (1)

By your reasoning a modern FAI pylon racer can't go that fast either.
Drag is the biggest component of the velocity equation.
Pitch speed does not take into account the lift produced by a prop.
FINI

combatpigg

My Feedback: (3)

Wrong. I know from personal experience what it takes to go 200 MPH and a FAI .40 engine spinning a 7x7 carbon fiber prop on the very cleanest of airframes with a cowled in engine [and at least partially cowled pipe] is how to get there with mathematical feasibilty and in reality.

I doubt that a APC sport prop would last very long past their self imposed limit of 190,000 divided by prop diameter. 190,000 divided by 7 equals just about 27,000 RPM.

If this combination was able to last long enough to make some recorded passes at 33,000 rpm the resulting speed would be 156 MPH and the developed HP would be about 3...which means that the Rossi .21 would still need to develope 7.8 pounds of thrust to turn that trick.

phatboy

I would be happy with 100mph! The size of this plane will make 100 seem like its a demon jet on steroids!

And yes I have already named it "The Screamer", maybe I should install some of those nerf football whistles in the wings just to make it louder and really piss people off, lol!

combatpigg

My Feedback: (3)

Someone was selling a wind powered whistle a few years back, but the word was it wasn't loud enough to be heard over a really screaming set up.
The original "Diamond Dust" deltas can make a loud snare drum sound that comes off the covering that sounds pretty cool. Problem is, it takes power to create airframe noise...so the quieter your plane is, the better.
It would be pretty comical to have a way to duplicate that screaming dive bomber sound that the old Stukas used to make....

coriolan

Bob K, you have obviously never seen a genuine 200mph model flight as achieved by top level flyers. The plane picture you provided in post #52 show minimal effort in drag reducing. The pitch speed CP gave you are self explanatory and a Rossi .21 would be hard pressed to provide that kind of rpm(43000 rpm)with a 7"X5" APC, assuming the prop doesn't self destruct before getting there
Looking at what shows of that plane I can imagine the covering peeling away even before the engine get on pipe

combatpigg

My Feedback: (3)

I looked at the numbers claimed for the Rossi .21 car eangine and they rate it at 3.1 HP at 42,500.

So...200 mph might be feasible if...

this engine can spin a 6x5 carbon fiber prop at 42,500....

and....

you can put it in a clean enough / small enough package to allow a 6 inch diameter prop to make it happen.

This scenario would still require 3.5 HP, so let's assume that Mother Nature chips in with .4HP after the intial dive to get up to fully unloaded rpm.

A "GLHish" ship has the drawback of the sweptback wing. It makes building strong, thin and light more complicated for extreme speed.

mikegordon10

Now, now boys let's get back to the "doable" if that's a word. I've raced 1/2 A for about 15 years and I've seen many GLH's equipped with a hot TD or a "Toad" Norvel exceed the 100 MPH figure easily. The hard part is keeping it in sight.
Because of the lack of 1/2 stuff that was available last year we have gone to a 300 sq in class running Magnum 15's. They also make that 100MPH figure but they are a heck of a lot easier for my tired old eyes to see. Check us out at the CUPRA web site at http://sites.google.com/site/cuprapylons/home
Under the models section there are PDF plans for my Veepia, feel free to download and use them.

combatpigg

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Mike, do you guys run stock thickness wings on the GLHs...?

mikegordon10

Ya but Pig, how the heck is anyone gonna be able to fly that small of a plane at 200 MPH?
Certainly not I said purple duck!

combatpigg

My Feedback: (3)

Mike, for some reason I thought you guys had no restrictions on airfoil thickness...?

The GLH isn't that much less of a plane to track than a 32 inch span delta. It's those moments that you see it "edge on" that make it disappear. If you were to explore going faster and faster and faster, I think you'll find that other than needing to turn more often that it doesn't require special eye sight to keep up with what's going on. I've still got correctable vision with glasses, so I can't speak for those with eye trouble that glasses can't fix.

Even at 200 MPH, the 32 inch span delta is a piece of cake...just don't do any "free style" hotdogging with it, be nice and smooth. I've got to admit that pylon racing at 200 mph is out of my comfort zone.....that's a whole different story..!

Those guys ARE incredible.

mikegordon10

It's been a few years since anyone ran a GLH around here.
Now those who can, design their own models and sell to those who are not up to the task.
Of the GLH's I was aware of, the built up wings were not stock thickness. The foam wings probably were stock.
We don't fly 1/2 A Glow anymore cause engines and parts were getting hard to come by.
We now have an electric class that is 200 sq in and the new glow class is 300 sq in. the thickness on most of the 200 sq in wings at the root is 1/2" AND on the 300 sq in wings, 5/8" at the root.
The E-200 class are running right around 115 mph and the 15-300's at 100-105mph.
I have given up on the electric class cause my eyes just ain't up to the task.
When I did try the E-200's I'd have my 18 year old son stand with me at the races and when I'd loose sight of it, I'd hand the radio to him, he'd get it back in sight and I'd go on racing. THEN the little s**t went and got a real job with Tuesday's & Wednesdays off. Now I just fly the 15-300 Glow class cause "Electric's Suck"!

karasr

My Feedback: (1)

Your personal experience and mine are different.
I had a police radar unit time mine at 199+
The unit did not go any higher. Newer ones might.
The prop I used was not an APC. The prop you see in the picture was used after the Graupter (sp?) was no longer to be had.
As to RPMmy ace (analog)tach only went to 25k. The needle was pegged before the airplane went on the pipe in the air.
Let's stop this sillyness and stick to the original question.
No one needs to impress anyone here.

The point of all this is the original question of what engines might go into the GLH
Ithink I answered that question.
Bob K

Toad

hmmmm I thought I answered that. Just put a good .049-.061 on it. keep it 1/2a

a .21 isnt even close to 1/2a.

The built up wings on the GLH stock were 7/8ths inch thick as per ama rule. the ones I built, I cheated em to 3/4" then later to 5/8" when the rules relaxed. I went to a Laminar airfoil with the high point set 45% back. a Hot TD or Revlite and some nice 40% fuel and had a ball.

phatboy

All this talk about 200mph planes got me thinking about a video I saw a while back! Check this out. Oh and Pigg, maybe this plane has the sound your looking for! Proof that a small plane can be flown at 200+ if you can see it, and after seeing this I seriously doubt my little GLH will go like this!!!

Funny enough those of you who have seen my foamy build, the is the guy who inspired the build.

[youtube]http://www.youtube.com/watch?v=vwJ5WiQmMFE&list=UUhYRHiZxieuTrVCeVDTqdYQ&index=2&feature=plcp[/youtube]

DeviousDave

There are a lot of guys flying F5D that would like to open up that .21 sized GLH and let the magic dust spill out, just to smell it.

AmishWarlord

My Feedback: (5)

What is this laser of which you speck?

I do my cutting with a scroll saw!