FWIW, I tried them and the front tire had bad vibrations at speed. Dumped them out (PITA!) and bought a Marc Parnes and balanced with weights and all was good.
Snake oil.
Snake oil.
Dyna Beads - Do they work? If so, how?
- Thread starter Fred W
- Start date
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The wings only know or react to the airflow. The rotation speed of the tires or ground speed has nothing to do with the takeoff. As some one else suggested...lets say normal takeoff speed is 70 MPH. If on the the runway with a 70 MPH head wind the plane would takeoff and remain stationary above the ground but flying normally. Increase the wind speed to 80 MPH, the plane would be fine but travelling backwards above the ground at 10 MPH. Damn I can't believe myth busters and that pilot were so ill informed. Bill
PhilJet09
Nondescript FJR Hierarchy Displayed
I hear ya and agree, that's a bad thing, but I'm sure the limitation we're given is conservative. The 10kts for the Sovereign (Pratt and Wobbly engines) didn't exist when I did my initial type training. Cessna came out with that some time after. I just wonder how conservative some of these numbers are.
PhilJet09
Nondescript FJR Hierarchy Displayed
Mostly correct. It's true that if you could hold an aircraft stationary ( maybe with some sort of tether) and then blow air over its wings at a speed great enough, that it would achieve flight. However, that's not exactly the parameters of the conveyor belt experiment. The aircraft isn't held, somehow, in a fixed geographic position. If the engine wasn't running, the belt would carry the aircraft backwards, at a speed that would approach the speed of the belt and never fly, even if the wind were blowing very hard. Why? No forward thrust and because the friction produced through the tires, carried through the wheel bearings that act upon the axles of the plane, pushing it backward. In order for the plane to fly, it has to overcome the bearing friction and accelerate to its takeoff AIRSPEED. Airspeed on the takeoff roll is any combination of ground speed (not tire speed along a conveyor belt) plus headwind component.
Btw, I've flown a small aircraft backwards across the ground in a very strong wind. Unfortunately, when the wind is blowing that much, it tends to not be constant. One minute it's blowing hard enough to maintain stable flight, the next moment the gust stops and the ground rushes up at you very quickly. You don't want to be very close to the ground.
I agree 100% which also casts some additional doubt on the efficacy of dynamic balancing beads. Certainly they would have already tried such a demonstration, right? So maybe it did not show something that they wanted to share?
The Centramatic demo does show the big steel balls "working", but unfortunately they don't do the high speed video analysis that shows how the balls get to where they need to be.
The only way I can see these things working is if the wheel tries to spin on its center of mass (maybe only above a certain critical rotational speed) and that pushes the light side away from the axle. Then the beads or balls would migrate there until the wheel balanced.
FWIW
The point you missed is the plane flew. The idea that it would not is full of errors. The airplane is propelled by it's prop. the wheels unlike a car are freewheeling with just a bit of bearing drag. The friction on those bearing doesn't change with higher speeds. So all it takes is a bit of engine power to overcome that friction. Apply take off power and the plane moves forward. YES it moves forward which is clearly seen in the video. As it moves forward along the ground and thru the air it builds lift on the wings. When the pilot sees take off speed he rotates and the plane flys away. Not a mystery to me.Mostly correct. It's true that if you could hold an aircraft stationary ( maybe with some sort of tether) and then blow air over its wings at a speed great enough, that it would achieve flight. However, that's not exactly the parameters of the conveyor belt experiment. The aircraft isn't held, somehow, in a fixed geographic position. If the engine wasn't running, the belt would carry the aircraft backwards, at a speed that would approach the speed of the belt and never fly, even if the wind were blowing very hard. Why? No forward thrust and because the friction produced through the tires, carried through the wheel bearings that act upon the axles of the plane, pushing it backward. In order for the plane to fly, it has to overcome the bearing friction and accelerate to its takeoff AIRSPEED. Airspeed on the takeoff roll is any combination of ground speed (not tire speed along a conveyor belt) plus headwind component.
Btw, I've flown a small aircraft backwards across the ground in a very strong wind. Unfortunately, when the wind is blowing that much, it tends to not be constant. One minute it's blowing hard enough to maintain stable flight, the next moment the gust stops and the ground rushes up at you very quickly. You don't want to be very close to the ground.
Bill
ionbeam
2 FUN
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Umm, you are aware that PhilJET is a professional jet pilot and knows his shi.. stuff. He even does some real flying in planes with a prop as Dog intendedThere is nobody on this Forum that understands flying as good as he does unless they are a professional pilot too.
Now that's a funny post and it must be a sarcastic comment, if so even more funny. Commercial pilots have shown their stupidity on this argument, boasting that they have thousands of hours of experience. Trust me that means nothing. A knowledge of physics is more important. Personally I know more about aviation but less about physics and find this whole discussion laughable. The correct answers if you don't like mine are all over the internet. Many like me cuckle at the ignorance of basic physics of those that don't know the answer to this. Especially pilots. Guess they've never set power on ice with brakes locked and noticed the airplane accelerates but the wheels aren't turning. Too funny.
Bill
ionbeam
2 FUN
Umm, you are aware that PhilJET is a professional jet pilot and knows his shi.. stuff. He even does some real flying in planes with a prop as Dog intendedThere is nobody on this Forum that understands flying as good as he does unless they are a professional pilot too.
Now that's a funny post and it must be a sarcastic comment, if so even more funny. Commercial pilots have shown their stupidity on this argument, boasting that they have thousands of hours of experience. Trust me that means nothing. A knowledge of physics is more important. Personally I know more about aviation but less about physics and find this whole discussion laughable. The correct answers if you don't like mine are all over the internet. Many like me cuckle at the ignorance of basic physics of those that don't know the answer to this. Especially pilots. Guess they've never set power on ice with brakes locked and noticed the airplane accelerates but the wheels aren't turning. Too funny.
Bill
Now there is a quote!
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PhilJet09
Nondescript FJR Hierarchy Displayed
Actually, that is EXACTLY the point I was making in an earlier post.The point you missed is the plane flew. The idea that it would not is full of errors. The airplane is propelled by it's prop. the wheels unlike a car are freewheeling with just a bit of bearing drag. The friction on those bearing doesn't change with higher speeds. So all it takes is a bit of engine power to overcome that friction. Apply take off power and the plane moves forward. YES it moves forward which is clearly seen in the video. As it moves forward along the ground and thru the air it builds lift on the wings. When the pilot sees take off speed he rotates and the plane flys away. Not a mystery to me.Mostly correct. It's true that if you could hold an aircraft stationary ( maybe with some sort of tether) and then blow air over its wings at a speed great enough, that it would achieve flight. However, that's not exactly the parameters of the conveyor belt experiment. The aircraft isn't held, somehow, in a fixed geographic position. If the engine wasn't running, the belt would carry the aircraft backwards, at a speed that would approach the speed of the belt and never fly, even if the wind were blowing very hard. Why? No forward thrust and because the friction produced through the tires, carried through the wheel bearings that act upon the axles of the plane, pushing it backward. In order for the plane to fly, it has to overcome the bearing friction and accelerate to its takeoff AIRSPEED. Airspeed on the takeoff roll is any combination of ground speed (not tire speed along a conveyor belt) plus headwind component.
Btw, I've flown a small aircraft backwards across the ground in a very strong wind. Unfortunately, when the wind is blowing that much, it tends to not be constant. One minute it's blowing hard enough to maintain stable flight, the next moment the gust stops and the ground rushes up at you very quickly. You don't want to be very close to the ground.
Bill
PhilJet09
Nondescript FJR Hierarchy Displayed
This post here.
I have a feeling we're pushing the limits of off topic crap in this thread.
Oh, it's already been moved to NEPRT status, so there is no longer any "off topic".
Nobody really seems all that interested in the physics behind why balancing beads would (or would not) work, so you may as well continue on the airplane flying off a conveyor belt tangent.
FWIW, the entire premise of the original "myth" is flawed. The way the myth was supposed to be was that the conveyor belt would be running below the plane and the plane would only use enough engine power to hold it stationary (not moving forward) while the belt would pass below the plane at or above take-off speed. In that circumstance, with no air speed the plane would obviously not have taken off.
What they tested was allowing the plane to apply normal power and just take off from the moving runway (conveyor belt), which as has been discussed already is of no consequence other than the added wheel bearing resistance the moving runway produces. The plane could care less what the runway speed is. The only speed of any consequence is the air speed.
Either way, I don't see where there is much mystery as to how these results would have happened. In fact, prior to it showing up on Mythbusters I had never even heard of this supposed "Myth." I think maybe it was just a fabrication for the show?
Nobody really seems all that interested in the physics behind why balancing beads would (or would not) work, so you may as well continue on the airplane flying off a conveyor belt tangent.
FWIW, the entire premise of the original "myth" is flawed. The way the myth was supposed to be was that the conveyor belt would be running below the plane and the plane would only use enough engine power to hold it stationary (not moving forward) while the belt would pass below the plane at or above take-off speed. In that circumstance, with no air speed the plane would obviously not have taken off.
What they tested was allowing the plane to apply normal power and just take off from the moving runway (conveyor belt), which as has been discussed already is of no consequence other than the added wheel bearing resistance the moving runway produces. The plane could care less what the runway speed is. The only speed of any consequence is the air speed.
Either way, I don't see where there is much mystery as to how these results would have happened. In fact, prior to it showing up on Mythbusters I had never even heard of this supposed "Myth." I think maybe it was just a fabrication for the show?
PhilJet09
Nondescript FJR Hierarchy Displayed
Sorry Fred.
If nothing else, it kept bumping the thread up so maybe others would comment on the Dyna Beads.
If nothing else, it kept bumping the thread up so maybe others would comment on the Dyna Beads.
dcarver
Well-known member
Fred, I have supportive evidence for DynaBeads working after all.
You know that I live at the end of a 3 mile long dirt road. Lots of fluffy dirt which accumulates everywhere, but particularly so on the rear rim.
Well, I got to looking at dust distribution. Using a laser depth mic calibrated to +/- 2 uInches uncertainty with NIST traceability, I have confirmed the hypothesis that the depth of dirt on the rim at the lightest position of the rim, as determined by using a RotaMassMeter tm is indeed greater than the heaviest point of the rim in a logarithmic ratio of wheel rotational velocity and road dirt depth and density. An amazing discovery which will alter the course of motobiking.
This test was conducted under the most stringent laboratory road conditions as delineated in NIST white paper 'Particulate Matter Distribution Analysis on Rotational Circular Objects', authored by dCarver. It’s also interesting to note that no lead weights were hurt or killed during this investigation.
You are welcome!
You know that I live at the end of a 3 mile long dirt road. Lots of fluffy dirt which accumulates everywhere, but particularly so on the rear rim.
Well, I got to looking at dust distribution. Using a laser depth mic calibrated to +/- 2 uInches uncertainty with NIST traceability, I have confirmed the hypothesis that the depth of dirt on the rim at the lightest position of the rim, as determined by using a RotaMassMeter tm is indeed greater than the heaviest point of the rim in a logarithmic ratio of wheel rotational velocity and road dirt depth and density. An amazing discovery which will alter the course of motobiking.
This test was conducted under the most stringent laboratory road conditions as delineated in NIST white paper 'Particulate Matter Distribution Analysis on Rotational Circular Objects', authored by dCarver. It’s also interesting to note that no lead weights were hurt or killed during this investigation.
You are welcome!
wheatonFJR
...
Yeah, but since your road is so rough, it is impossible to determine on your test track whether your wheels are in balance.
White Paper flawed.
White Paper flawed.
Flaw #2
Once it is electrostatically deposited on the rim/wheel the dust is not mobile and cannot migrate around to the light spot.
Oh and Carver... https://www.fjrforum.com/forum//public/style_emoticons/default/****.gif
Once it is electrostatically deposited on the rim/wheel the dust is not mobile and cannot migrate around to the light spot.
Oh and Carver... https://www.fjrforum.com/forum//public/style_emoticons/default/****.gif
FJRay
Well-known member
Damn Don !!! I hope none of that BS gets on me while I'm working on the KZ. It could have a detrimental effect on the assumed quality of the eventual outcome. See it's heppening already. Make it STOP.
Bustanut joker
Well-known member
Carver got into the weed again I see.....
beemerdons
Certifiable Old Fart
Still is more like it...
Isn't it legal for recreation in Cali yet?
Isn't it legal for recreation in Cali yet?
