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What angle should this custom gyro hang at http://skywolverines.com/viewtopic.php?f=2&t=4961	Page 1 of 1

Author:	ALL IN [ Sat Jun 24, 2017 9:07 pm ]
Post subject:	What angle should this custom gyro hang at
Got a newbie who has no computer. Hard to believe. He's asked me to ask you. What angle is he suppose to make the cheek plate hang to.

Author:	MadMuz [ Sun Jun 25, 2017 4:45 am ]
Post subject:	Re: What angle should this custom gyro hang at
The keel should be about 9-12 degrees down at the front.... With 2 people and full fuel about 12 degrees down and with one front pilot and low fuel about 9 degrees down (keel from Horizontal) That is how I would set it up Edit: So, assuming the head/mast piece is the usual 9 degree back from vertical.... when hanging, the keel should be nose down and the main rotor bearing bolt should be vertical, or the normal 2 degrees that people who measure at the mast would measure.... Because of the mast configuration of this one, the keel is what to go by imo...

Author:	JAKE! [ Sun Jun 25, 2017 9:12 am ]
Post subject:	Re: What angle should this custom gyro hang at
MadMuz wrote: The keel should be about 9-12 degrees down at the front.... With 2 people and full fuel about 12 degrees down and with one front pilot and low fuel about 9 degrees down (keel from Horizontal) That is how I would set it up Edit: So, assuming the head/mast piece is the usual 9 degree back from vertical.... when hanging, the keel should be nose down and the main rotor bearing bolt should be vertical, or the normal 2 degrees that people who measure at the mast would measure.... Because of the mast configuration of this one, the keel is what to go by imo... Not always true MUZ. The initial hang test is designed to center the controls in flight. Your description may hold true, but be careful of the advice you are giving without knowing the idiosyncrasies of the design. Have you taken thrust line , parasitic drag and fuel weight offset into consideration ?

Author:	MadMuz [ Sun Jun 25, 2017 9:54 am ]
Post subject:	Re: What angle should this custom gyro hang at
Just the only recommended numbers allowed in Australia Jake... and followed up by the fact it is 'That is how I would set it up' .... In Australia, we have to send pictures of the hang test, with the pilot and equipment and no fuel... and with full fuel... and both with passenger with no fuel and with full fuel.... if those numbers are not shown (you have to draw lines on the pics to show angles) .... then it wont be registered until it does.... The thing I did forget to mention, is that the stick has to be held in the center position (or wedges between cheek plates and head to make sure head is in central position).... that is important The pic is Waddles and Murray hang testing Waddles Butterfly.... The same numbers have to be reached on a forward leaning mast machine like a modern clone or a single place machine. The reason given for this setup is so in a true engine out vertical descent, where the rotor is flat (on a zero wind day) then the keel should be down at the front the 9-12 degrees which should allow the stick to be centered giving the pilot an easy forward stick to glide forward out of the descent... or to stick back to glide rearward.... but the nose being already down at the front makes it easiest to go into a forward glide, which is usually what is required... Yes, I took into account the drag of the air framework... however, here the same 9-12 degree nose down is required for the sleekest, least drag canopied gyro and the draggiest open frame thing... because in general, the difference in drag from the airframe is inconspicuous, compared to the amount of drag, or removal of drag that the rotor can cause..... which is why a gyro as aerodynamic as a brick can still fly quite nicely.... Is that ok? works for me Making gyro hanging great again Don't forget Farmer Jim! The BIG ficker!

Author:	ALL IN [ Sun Jun 25, 2017 4:09 pm ]
Post subject:	Re: What angle should this custom gyro hang at
Thank you my friends. I past along both of you posts. I also told him that the double hang test will tell him where his thrust line is. So he can adjust the weight to get it as close to CLT as possible. Then make the new cheek plates to CLT and take it to Mark an expert builder and have him test fly it and do the final adjustments and make new cheek plates as needed. Is this the correct advice?

Author:	Hellified [ Sun Jun 25, 2017 4:29 pm ]
Post subject:	Re: What angle should this custom gyro hang at
John- Just a tip for CG calculations. The percentage of the gross weight that is moved up, will raise the CG times that same percentage times the distance you moved it up. In other words....say you have an 800 pound gross weight...including pilot. Your engine weighs 200 pounds. If you move the engine up 4 inches....you are moving 25% of the gross weight. Since you moved it up 4 inches...multiply that by 25% and you effectively raised your CG one inch.

Author:	ALL IN [ Mon Jun 26, 2017 12:42 am ]
Post subject:	Re: What angle should this custom gyro hang at
Hellified wrote: John- Just a tip for CG calculations. The percentage of the gross weight that is moved up, will raise the CG times that same percentage times the distance you moved it up. In other words....say you have an 800 pound gross weight...including pilot. Your engine weighs 200 pounds. If you move the engine up 4 inches....you are moving 25% of the gross weight. Since you moved it up 4 inches...multiply that by 25% and you effectively raised your CG one inch. This is great to know and pass on. Thank you Bro

Author:	ALL IN [ Tue Jun 27, 2017 6:27 pm ]
Post subject:	Re: What angle should this custom gyro hang at
OK my guru friends... Here is a question he has: I WOULD LIKE TO KNOW THE REASONS FOR NEEDING MORE NOSE DOWN WITH ADDED WEIGHT. IT MAKES SINCE THAT WHEN YOU ADD THRUST AND ROTOR BLADE DRAG IT MIGHT HAVE A TENDENCY TO CAUSE THE AIRCRAFT TO ROTATE TOWARD NOSE UP? IT WOULD SEEM THAT ADDED WEIGHT IN THE PASSENGER AREA WOULD ACTUALLY HOLD OR SLOW THE PIVOTING TENDENCY TOWARDS NOSE UP.

Author:	MadMuz [ Wed Jun 28, 2017 5:18 am ]
Post subject:	Re: What angle should this custom gyro hang at
You dont add weight usually John, you rearrange the weight you have already... and have cheek plates so you can position the head back or forward as need be.... if the mast is at an angle that requires long cheek plates to correctly balance it, then the mast angle can be altered (or should have been designed) so the cheek plates are as small as required. The nose down of the keel in straight hang, is so in a true vertical descent (on a wind free day) the machine is in a position where the pilot is looking forward and down (where he wants to go) rather than descending looking up at the sky and the machine wanting to go backwards easiest.... Also, as you say... with the nose a few degrees lower, adding thrust will bring it level.... rather than the keel being level.... adding thrust and the nose being high..... Looking at a takeoff with the machine hung nose down 9 degrees.... you clear the runway and are climbing.... the motor stops .... the machine levels out then basically goes into a nose down attitude... so it sets the machine up for a good engine out landing... This is how I see it anyway...

Author:	Gabor [ Wed Jun 28, 2017 7:30 am ]
Post subject:	Re: What angle should this custom gyro hang at
The way I understand it is that the smaller 22-25 footer rotors create about 4-5* drag so you end up with 4-5* nose down without thrust. Larger 26-30 footers have 5-8* drag effect so you still end up with the same nose down attitude. Disclaimer: I know nothing about nothing I only try to remember things that way smarter people than me are saying.....

Author:	MadMuz [ Wed Jun 28, 2017 9:47 am ]
Post subject:	Re: What angle should this custom gyro hang at
Something I think people dont understand about gyros... is that they are slow things (in the world of flying machines) Annnnd... they are designed to go slow. Just as an example.... if you have an open frame, draggy as anything gyro, and a sleek machine like a cavalon or whatever... they can both fly at roughly the same speeds. My Turbo subaru machine was good for 90 kts... couldnt open your mouth after about 70kts without instant 'fish face' but it could go very fast. Nothing could keep up with it... but I could also fly it down to about 5-10 kts on a windless day.... A cavalon or something streamlined, will also do about that speed and be able to slow to 10kts or so.. so the fairing/canopy is really for comfort, rather than practicality... My point is, at our low speeds the parasite is only negligable.... the drag of the rotor disk is enormous..... well, it can be.... or not depending on the stick position. Of course, things that go as fast as the carter copter.... the fairings need to be far more aerodynamic and are functional.... you couldnt fly a 200kt machine open frame That is why, with gyros, people can/have imagined a nice LOOKING canopy/pod.... made it and stuck it on and voila.... it worked .... one guy in Australia put a robinson fuselage on a gyro.... really blunt and bulbous.... others make them pointy like a dart and voila.... that works too So, to me, with our machines... the parasite drag part of the equasion, although it is there, it is so outweighed by the tons of drag the rotor can produce any time you want. Me and Sam (Titanium) tried making mast fairings out of clear lexan .... others made nice plastic or fiberglass airfoil covers for masts and things... but I didn't feel any difference in how it flew... It is like, you have a ferrari car doing 100mph.... streamlined, beautiful.... then you have a 69 impala (convertible) running along at 100mph... about as aerodynamic as a house brick.... but at that speed, the extra drag of the impala, although noticable, doesnt stop it from being driven at that speed.... the ferrari's aerodynamics arent hardly working yet.... So now, if you add a huge amount of drag to them both... like a caravan (trailer home) .... the impala would hardly notice it (except for the fuel burn increase) and the ferrari (if it had a hitch) couldnt even tow it... its aerodynamics would be wasted... it cant go fast enough to have the aerodynamics actually work... So, that example really sums up gyros... you can have as much aerodynamic kafuffel on the airframe.... it will make it nice to look at, and nicer to fly in cold weather, but the aerodynamics dont have to be wind tunnel tested for perfection, because the rotor wont let the machine fly fast enough for the aerodynamics to do anything other than looks and comfort. I saw a program on TV about the Lamborghini... they have a rear wing that helps with braking and gives downforce at speed.... but the wing doesnt start working until 150mph and the speed limit is 55mph? But never mind me... I am like Nabs... we are in a race to see who know least As you were gentlemen....

Author:	ALL IN [ Wed Jun 28, 2017 7:17 pm ]
Post subject:	Re: What angle should this custom gyro hang at
Thank you all!!! I passed it all along. He is so very great-full

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