helicopter aerocynamics

Fiesty

Member
Re: helicopter aerocynamics

Question:  Can you have a 2 per rev vibration in a rotor with more than two blades?
 

Fiesty

Member
Re: helicopter aerocynamics

Welcome aboard Steven.  How about entering the discussions.<br>Jumpin the water is warm.
 

Fiesty

Member
Re: helicopter aerocynamics

Question: Can anyone explain the Rotormatic rotor system?<br><br>Al__________________Steven____________________
 

Al_Hammer

Platinum Member
Re: helicopter aerocynamics

Welcome Steven. :D<br><br>The  vibrations associated with a rotor(in addition to the simple 1/rev) are generally in the form of N per rev where N is the number of blades.<br><br>In adddition to what Steven said , there is a nice explanation here about the Hiller paddles and the Bell-Hiller system used on models.<br>http://www.w3mh.co.uk/articles/html/csm9-11.htm<br><br>The Hiller paddles are controlled by the pilot and they then control the rotor. There is a certain amount of lag involved.<br>The Bell hiller system combines the paddles with swashplate control via a mixer so that the control is speeded up yet still retains the stability of  the paddles.<br><br><br>
 

Fiesty

Member
Re: helicopter aerocynamics

;)Good information.  Thanks Steven and Al.  In 1950 thru 1954 I flew the H-23A and H-23B teaching U.S. Army Test Flight procedures at Tulsa, Okla.<br>Randy<br><br><br>Question:  Who invented the Stablizer Bar used on the Bell 47 Helicopter?  Give purpose and technical aspects.
 

Al_Hammer

Platinum Member
Re: helicopter aerocynamics

Since my plan is to primarily fly gyrocopters (2 place, with my wife as passenger), what kind of training would you recommend? <br><br>Gyro training somehow comes to mind, Steven :p<br>You can always learn helicopters later. <br><br>Its not necessary to fly a helicopter  first because the two skills are substantially different. <br><br>Its cheaper, to get a fixed wing PPL and then get a gyro add-on later. <br><br>The only snag with starting in gyros is the transition to solo in your own machine after what usually is minimal hours dual in a heavier machine like the RAF.<br>The light machine with open cockpit will feel very diferent and it is good to have some tail dragger time or any kind of fixed wing solo time to give you some basic flying skills.<br> A gyro tow glider is a great way to go, if you know anyone who has one(and there aren't many.)<br><br>I personally got a lot out of using a simulator (with homemade helicopter controls) when learning to fly a helicopter, and that's a topic for another post sometime.<br><br>
 

Fiesty

Member
Re: helicopter aerocynamics

Steven:  As Al said gyro glider is cheapest.  I would recemmend that you start with fixed wing tail dragger.  This will develop your air sense and control of the aircraft.  I do not believe that gyro training will help you to fly helicopters.<br><br>A note:<br>Colin Mill is giving theory from a RC model concept.  His theories are good, but some do not apply to man carrying helicopters.  For example the the Bell-Hiller control sytem has never been used  except on model helicopters.
 

Fiesty

Member
Re: helicopter aerocynamics

Al. how about giving us some information on your Helicycle.  Construction etc.
 

Al_Hammer

Platinum Member
Re: helicopter aerocynamics

Randy, thanks for asking.<br><br>The  turbine is being used in 99% of the machines, but I opted for the Rotax. My engine is not mounted yet, so technically I could still go with the turbine,  The construction is otherwise mostly complete except for wiring, painting the cabin, installing fuel tanks and engine.<br><br>There is almost every kind of construction required in the kit, except welding. You quickly learn to use metal snips, rivet tool, cleco pliers, clamps, drill press, reamer, grinder, sander, paint gun, etc. Lots of fun if you like to build.<br> For example, the builder fabricates the main rotor root end "doublers" from sheet stock and bonds them to the blades.<br>http://was.kewlhair.com/hammer/jpegs/doublers.jpg<br><br>Then the end plugs, tip weights, lag bolt attachment, prepping , and painting must be done. <br><br><br><br>http://was.kewlhair.com/hammer/chopper/ForSale.htm<br>
 

Fiesty

Member
Re: helicopter aerocynamics

<br><br><br><br><br><br><br>Al the helicycle looks wonderful.  It should be a buy for some one.  Thanks for information.
 

Fiesty

Member
Re: helicopter aerocynamics

Steven-<br>The Bell Stablizer Bar did not stay level with horizon.  It followed the mast in certain time period.  This was accomplished by two hydraulic shock absorbers bolted onto the mast with connections to the bar.  In rigging they had a special timing tool for adjusting the following time.
 
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