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Planecrazzy!

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Ralph Hoover

Joined: 09 Jan 2006
Posts: 206
Location: Central Ohio

Posted: Wed Oct 04, 2006 12:59 pm Post subject: Planecrazzy!

Planecrazzy, Probably never thought of your name in BOLD, but there it is a topic addressed as Planecrazzy.



Brother of the sky. You put a bug in my ear a while back about "you have the 5 inch spacer?", regarding the prop distance from the back of the wing.



I thought hard and long about that and it f, for whatever reason, stuck with me. Today I moved my prop in line with the front mount tabs for the wings and discovered that it is within 39 1/2"  of the tabs in front. The prop therefore is within 4.7 inches from the rear of the front of the aileron tube. 

However, it is within 2.7 inches of the Aileron horn when it is in the up position. Now, the Aileron horn is midway (approximately ) or greater to the center of the prop . Therefore, the prop tip would not be coming close to it. When IVO states in their installation instructions: " five inches from any obstruction." I find it hard to imagine, but I must believe, that the prop could flex BACK 5 inches and Front 5 inches, or 10 inches total, at the tip!



What has been your experience? Because â€œin the air is the last place to actually experiment with things that go boomâ€œ!



Ohio Ralph



See picture of existing prop mount. Stack-up from â€˜Bâ€ box prop mount to prop centerline is 2.0â€.

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planecrazzzy
Guest

Posted: Wed Oct 04, 2006 2:35 pm Post subject: Re: Planecrazzy!

Hey Ralph,

                I didn't say I had a 5" spacer...I said IVO calls for 5" of clearance...



  I have a 3" spacer... ( $80 bucks )



 Jack Hart has done some experimenting with the flexing....



 He taped paper to the aileron and Flew.... Then he looked at the paper streamers that he had placed in the area of the prop arc...



  Jack....Do you have that page or data handy ???



     Here's a picture of my prop extention...



           Gotta Fly...

Planecrazzzy   ( That's 3 - Z's )

Prop Extention - 3 inch.jpg

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Ralph Hoover

Joined: 09 Jan 2006
Posts: 206
Location: Central Ohio

Posted: Wed Oct 04, 2006 3:09 pm Post subject: Re: Planecrazzy!

Hey, Planecrazzy, Sorry. But what I said was " "you have the 5 inch spacer?" There was a Question mark refering to you (first person)  asking me if I had the 5" spacer. 



That covered, That is the largest 3" I have ever seen. Must be the angle.



Any help would be appreciated.



Ohio Ralph

David.Lehman

Joined: 10 Jan 2006
Posts: 265
Location: "Lovely" Fresno CA

Posted: Wed Oct 04, 2006 3:15 pm Post subject: Planecrazzy!

Educate me, why do you need the spacer and is it only required on an IVO?..

_________________
Ã´Â¿Ã´

"Both optimists and pessimists contribute to the society. The optimist invents the aeroplane, the pessimist the parachute."

--- George Bernard Shaw

Ralph Hoover

Joined: 09 Jan 2006
Posts: 206
Location: Central Ohio

Posted: Wed Oct 04, 2006 5:02 pm Post subject: Re: Planecrazzy!

David, According to IVO's installation instructions, because of flexure of their brand prop, clearance between the leading edge at the end of the prop (my assumption), can be as much as 5". I'm not sure if the fact thta the prop could be used on a pusher as well as a puller if the 5" clearance is total fore and aft or per side. Thats a lot of movement in my humble opinion. Now if that is only at the ends of the blades (tips), then half way up on each blade half (or 1/3, if three blade) would not flex any where nera that amount. 



I really don't want to stick a spacer that long on the back of my gear box. If I am anywhere near correct in my math, the longer a moment is the more foot pounds at distance it has to work with. Even if the clearance is minimal between the bolt shank and the individual mounting holes, it has a larger moment of purchase. I also know that the sheer rating on these bolts is pretty high but man.



Ohio Ralph

David.Lehman

Joined: 10 Jan 2006
Posts: 265
Location: "Lovely" Fresno CA

Posted: Wed Oct 04, 2006 6:07 pm Post subject: Planecrazzy!

I agree with your concerns Ralph...  That's why I asked, because it just didn't make sense to me to put more stress on the gearbox and bolts..

  

 Of course, this is coming from a guy who just lost his prop and hub in flight...

  

 DVD



 

 On 10/4/06, Ralph Hoover <flht99reh(at)columbus.rr.com (flht99reh(at)columbus.rr.com)> wrote:  	  Quote: 	
		  --> Kolb-List message posted by: "Ralph Hoover" < flht99reh(at)Columbus.rr.com (flht99reh(at)Columbus.rr.com)>



David, According to IVO's installation instructions, because of flexure of their brand prop, clearance between the leading edge at the end of the prop (my assumption), can be as much as 5". I'm not sure if the fact thta the prop could be used on a pusher as well as a puller if the 5" clearance is total fore and aft or per side. Thats a lot of movement in my humble opinion. Now if that is only at the ends of the blades (tips), then half way up on each blade half (or 1/3, if three blade) would not flex any where nera that amount. 



I really don't want to stick a spacer that long on the back of my gear box. If I am anywhere near correct in my math, the longer a moment is the more foot pounds at distance it has to work with. Even if the clearance is minimal between the bolt shank and the individual mounting holes, it has a larger moment of purchase. I also know that the sheer rating on these bolts is pretty high but man. 



Ohio Ralph





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lcottrell

Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or

Posted: Wed Oct 04, 2006 6:15 pm Post subject: Planecrazzy!

Ralph,

   In 1997 I bought a used IVO 68 inch prop from Dennis Souder at Old Kolb. 

With it came a 2 1/2 inch spacer. I used it until this year when I wrecked 

the plane and the prop. I had no problems with the prop or the gear box.

Larry,Oregon



---

jbhart(at)onlyinternet.ne
Guest

Posted: Wed Oct 04, 2006 6:31 pm Post subject: Planecrazzy!

At 03:35 PM 10/4/06 -0700, you wrote:

 	  Quote: 	
		  



Hey Ralph,

                I didn't say I had a 5" spacer...I said IVO calls for 5" of clearance...



  I have a 3" spacer... ( $80 bucks )



 Jack Hart has done some experimenting with the flexing....



 He taped paper to the aileron and Flew.... Then he looked at the paper streamers that he had placed in the area of the prop arc...



  Jack....Do you have that page or data handy ???


	


http://www.thirdshift.com/jack/firefly/firefly83.html



Jack B. Hart FF004

Winchester, IN

John Hauck

Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)

Posted: Wed Oct 04, 2006 7:42 pm Post subject: Planecrazzy!

Thats a lot of movement in my humble opinion. Now if that is only at 

the ends of the blades (tips), then half way up on each blade half (or 

1/3, if three blade) would not flex any where nera that amount.

|

 |

| Ohio Ralph

Ralph:



I believe the blades flex most on start up and shut down.  Hooking a 

strobe light with sensor to your airplane, and shooting it at night 

will show you just how much the blades dance.



Early on with my 912 and again on my 912ULS I had blade strikes on 

start up, but it took a long time to determine that this was when the 

strikes were actually happening.  A two inch extension on the 912UL 

and a 4 inch extension on the 912ULS took care of that problem.



Coning of the prop can best be demonstrated with the main rotors on a 

helicopter.  If you get a chance to watch a Flying Crane pick up a 

heavy load to a hover, you will see what coning is.  That's because he 

is maintaining an operational rotor rpm and increasing pitch and 

power.



I don't know how much coning effect we get with IVO's or Warp Drive 

props in flight.  Perhaps Jack Hart has done some extensive 

experimentation in that area.  I doubt that there is very much based 

on prop speed and fixed pitch props.  As rpm and airspeed increases, 

seems like centrifugal force would reduce coning.



I don't think you can see how much the prop blades flex on start up 

and shut down, but when you get a good blade strike, you can feel and 

hear it.



Take care,

john h

_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama

Ralph Hoover

Joined: 09 Jan 2006
Posts: 206
Location: Central Ohio

Posted: Thu Oct 05, 2006 5:33 am Post subject: Re: Planecrazzy!

Well, thanks to Jack Hart, John, H., Planecrazzy, Larry and others, I heard what I didn't want to hear.



Know the feeling. You hear something and hope that it isn't true, only to find out it is. Couldn't you guys all just lie one time? Ha, HA!



I'll tell ya one thing, when Jack Hart sinks his teeth into something he was the one the word "tenacity" was created from. Jack, your a benchmark!



And John Hauck, yes Sir I have seen some of them big house movers here in Ohio and know what you speak as the coning. I see that as the load is applied the beaters reach higher and higher until the weight of lift is equal or exceeds the weight of the lifted. That also concerns me in the coming and the going: full throttle at takeoff and pull power to land! Smack, smack, smack coming from behind me doesn't excite me in the least. Now I question as to 5" spacer (which adds some of its own problems), or get another blade. Had a nice Tennessee woody on before. Never gave consideration to flexure. Guess I ASS UMED there would be very little and that any would be the nature of the beast. Therefore corrected for in the design.



What IVO is telling us is that even though the flexure is "designed in", we need to deal with it by correcting at our end.



This 5" extension also gets us into another subject area. Not C.G., for that has changed very little but for and aft of C.G. effect. If 1# at 10 feet equals 10# then what does thrust at 5" farther aft do to thrust line? I know it may be trivial, but in the initial design all these things are taken into consideration, only to be altered down the road by our modifications. I know, John Hauck, That's why they call it "experimental".

Live and learning here in Ohio Ralph!

planecrazydld(at)yahoo.co
Guest

Posted: Thu Oct 05, 2006 8:54 am Post subject: Planecrazzy!

there are also fabulously different flexure modes present in mode blades. There are several modes where the tips are flexed one way and the span is arched in the opposite direction. there are others where one tip is aft and the other is forward, both tips are forward or both aft and on and on and on.

   

  Short: don't make dynamic assumptions based on static observations!



John Hauck <jhauck(at)elmore.rr.com> wrote:

  [quote]--> Kolb-List message posted by: "John Hauck" 

Thats a lot of movement in my humble opinion. Now if that is only at 

the ends of the blades (tips), then half way up on each blade half (or 

1/3, if three blade) would not flex any where nera that amount.

|

|

| Ohio Ralph

Ralph:



I believe the blades flex most on start up and shut down.  Hooking a 

strobe light with sensor to your airplane, and shooting it at night 

will show you just how much the blades dance.



Early on with my 912 and again on my 912ULS I had blade strikes on 

start up, but it took a long time to determine that this was when the 

strikes were actually happening. A two inch extension on the 912UL 

and a 4 inch extension on the 912ULS took care of that problem.



Coning of the prop can best be demonstrated with the main rotors on a 

helicopter. If you get a chance to watch a Flying Crane pick up a 

heavy load to a hover, you will see what coning is. That's because he 

is maintaining an operational rotor rpm and increasing pitch and 

power.



I don't know how much coning effect we get with IVO's or Warp Drive 

props in flight. Perhaps Jack Hart has done some extensive 

experimentation in that area. I doubt that there is very much based 

on prop speed and fixed pitch props. As rpm and 	  	 		Get your own [url= http://us.rd.yahoo.com/evt=43290/*http://smallbusiness.yahoo.com/domains]web address for just $1.99/1st yr[/url]. We'll help.

planecrazzzy
Guest

Posted: Thu Oct 05, 2006 1:38 pm Post subject: Re: Planecrazzzy!

Hey Ralph,

                I've also heard that the spacer helps make it quiter...



 Somethin about getting the prop away from the other surfaces...



  I've had people comment on how quite my plane was....They wanted to



know how I did it..... after muffler or intake silentsers....



  I don't have any of that stuff .... Just a prop extention...



              Gotta Fly...

Mike in MN



 PS I've been thinkin about one of those "Balancers" that uses Mercury in them... I've heard their "spendy" but they work good....

 Anybody know where I can find them....My wallets just too fat...

Ralph Hoover

Joined: 09 Jan 2006
Posts: 206
Location: Central Ohio

Posted: Thu Oct 05, 2006 2:42 pm Post subject: Re: Planecrazzy!

Plaincrazzy,



I had one of the dynamic vibration dampeners on ( ready for this?), a Harley. Didn't do squat. They will offset and correct for minimal amount of dynamic disturbance, Ie:pulley balance, transient and transmitted intermittent vibration.



Remember they use a small amount of mercury in a track around the circumference that is contained within a diameter. In hearing about them, the theory sounds really great but not worth the money. MHO. Something about equal and opposite forces canceling out each other. They have to be equal, and you wonâ€™t feel the small amount that the mercury offsets. The opposite is somewhat true because the mercury seeks to go opposite of the heavy side, like a tire balancing weight, always seeking the opposite at what ever speed. 



There used to be a Company in Worthington, Ohio that did industrial dynamic and static balance monitoring for electric motors, pumps, gear boxes and other rotational equipment. I had a friend that worked there and their equipment could see the effects of this type balancing. It was masked, not corrected for.



Perhaps someone has had a different experience than the above. Sometimes when I have spent good hard earned money to buy a â€œpig in a pokeâ€, I wanted so bad for it to work, that I convinced myself that it did. Even when it didnâ€™t!



As they say, its your money. 



Ohio Ralph

Michael Sharp

Joined: 10 Jan 2006
Posts: 118
Location: Oak Grove, MO (Kansas City)

Posted: Sat Oct 07, 2006 10:03 am Post subject: Planecrazzy!

Is this the Engine Balancer you speak of?



http://www.balancemasters.com/ultralights.html



Mike 



--

_________________
The air up there in the clouds is very pure and fine...And why shouldn't it be?-
--It is the same the angels breathe.
Mark Twain,
Roughing it' 1886

Mike

planecrazzzy
Guest

Posted: Sat Oct 07, 2006 10:36 am Post subject: Re: Planecrazzy!

Thanks Michael,

                        I've only "heard" of the balancers....But the address you gave looks good , I tried to order the balancer for the 503 ($90 ) but their not open til Monday.....



  I'm gonna buy one .....



 Gotta Fly...

Mike & Jaz in MN

.

.

.





 	  Michael Sharp wrote: 	
		  Is this the Engine Balancer you speak of?



http://www.balancemasters.com/ultralights.html



Mike 



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