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John Bolding

Joined: 23 May 2006
Posts: 281

Posted: Tue Jul 21, 2009 2:53 pm Post subject: VGs

Hi John,  Wish you were coming to OSH again  this year,  we could continue the short visit we started when you were  here.

  

 As always I enjoy your testing, do you have any  theory on why the spread widens at higher speeds?  200fpm is pretty  substantial.

 LO&SLO    John  Bolding

 [quote]   ---

vgstol(at)bigpond.net.au
Guest

Posted: Tue Jul 21, 2009 4:12 pm Post subject: VGs

Gday John,

 Yeh, maybe someday I might get back to OSH but don't know when...

  

 Yeh, I think the spread increases because the drag of the slats increases with the square of the airspeed.  All that difference isn't due to lift, but rather to drag.  The reduction in drag allows all that spare power to go into climb instead.

   

 Cheers,

 JG

 



 On Wed, Jul 22, 2009 at 8:53 AM, John Bolding <jnbolding1(at)teleshare.net (jnbolding1(at)teleshare.net)> wrote:

 [quote]  Hi John,  Wish you were coming to OSH again this year,  we could continue the short visit we started when you were here.

  

 As always I enjoy your testing, do you have any theory on why the spread widens at higher speeds?  200fpm is pretty substantial.

 LO&SLO    John Bolding

 [quote]  ---

graeme(at)coletoolcentre.
Guest

Posted: Tue Jul 21, 2009 5:24 pm Post subject: VGs

do not archive

  

 approx a week ago there was alink to zenith and  alloy VG's for elevator alloy CH701.

 could some one repost 

 Thanks Graemecns

   [quote][b]

dwilde(at)clearwire.net
Guest

Posted: Tue Jul 21, 2009 5:42 pm Post subject: VGs

ronlee wrote:

 	  Quote: 	
		   



 That is very nice of John G. at Stolspeed to offer  to replace broken VGs. 

 I have them on my 701( no slats) and they perform excellent. I wouldn't go back to slats on a bet. It's just a much easier plane to fly.



 --------

 Ron Lee

 Tucson, Arizona

   

Jeez.  I didn't know my plane was hard to fly.
	




Dan Wilde

peterlthomson(at)gmail.co
Guest

Posted: Tue Jul 21, 2009 11:52 pm Post subject: VGs

I have the Stolspeed VG's on wings and elevator.



I took my slats off, and I'll never re-fit them.



 I think the only time you'll find a difference (if one exists) is

when the nose is pointing at an angle which would scare most people to

death.



The Vg's on the elevator make it easy to hold the nose off at very

slow touchdown speeds.



Key advantages are the loss of drag, better fuel economy and ease of

cruise near the maximum.



Peter

CH701 SP (CZAW)

912ULS

VG's - no slats

JohnDRead(at)aol.com
Guest

Posted: Wed Jul 22, 2009 6:15 am Post subject: VGs

Why bother to build a STOL aircraft if you take away the things that make  it so? VGs only make poor airfoils work better, they do not make a STOL wing out  of any airfoil. Flame away!

  

 John  Read

CH701 - Elbert CO - Jabiru 3300



Phone: 303-648-3261

Fax:  303-648-3262

Cell: 719-494-4567   

  In a message dated 7/22/2009 1:52:36 A.M. Mountain Daylight Time,  peterlthomson(at)gmail.com writes:

  	  Quote: 	
		  -->    Zenith701801-List message posted by: Peter Thomson    <peterlthomson(at)gmail.com>



I have the Stolspeed VG's on wings and    elevator.



I took my slats off, and I'll never re-fit them.



I    think the only time you'll find a difference (if one exists) is

when the    nose is pointing at an angle which would scare most people    to

death.



The Vg's on the elevator make it easy to hold the nose off    at very

slow touchdown speeds.



Key advantages are the loss of drag,    better fuel economy and ease of

cruise near the    maximum.



Peter

CH701 SP (CZAW)

912ULS

VG's - no  ========================= Use   utilities  Day  ================================================               - MATRONICS WEB FORUMS  ================================================             - List Contribution Web Site  sp;                             ===================================================



	




 What's for dinner tonight?  Find quick and easy dinner ideas for any occasion.

  [quote][b]

cscsail(at)gmavt.net
Guest

Posted: Wed Jul 22, 2009 8:02 am Post subject: VGs

I'm with you 100% John. People that like the planes flying characteristics  with the slats removed, probably selected the wrong plane to build. 

 Gordon 

 [quote]   ---

john.marzulli(at)gmail.co
Guest

Posted: Wed Jul 22, 2009 9:04 am Post subject: VGs

Has anyone experimented with "gap sealing" the slats to the wing to "complete" the airfoil while using VGs?



This seems like a more reasonable solution than simply pulling the slats off and would probably result in less drag when flying in cruise than presenting the unslatted wing.

 



John Marzulli



http://www.GenevieveMarzulli.org/

http://MarzulliPhoto.net/

 http://701Builder.blogspot.com/

 



On Wed, Jul 22, 2009 at 8:57 AM, Gordon <cscsail(at)gmavt.net (cscsail(at)gmavt.net)> wrote:

[quote]        I'm with you 100% John. People that like the planes flying characteristics  with the slats removed, probably selected the wrong plane to build. 

 Gordon 

 [quote]

   ---

John Bolding

Joined: 23 May 2006
Posts: 281

Posted: Wed Jul 22, 2009 9:41 am Post subject: VGs

Gilpin (among others) has.  Found that the  center of lift moved forward, lending credence to the notion that the slats do  nothing/very little in cruise. I'll provide the nose ribs if anyone with a  flying airplane wants to test the full airfoil. Mine is still a year or better  in the future.

 John

 [quote]   ---

arno7452(at)bellsouth.net
Guest

Posted: Wed Jul 22, 2009 9:43 am Post subject: VGs

Hey John,

 There have been some efforts.  However, Vne is a  troublesome factor.  Covering the struts and waxing a painted CH701 reduces  drag such that Vne is too close. 

  

 Talk with Roger at Zenith.  He is a  CH701 expert.  Per his recommendation, I installed plastic VGs on the  elevator.  Works great since they are only used during slow speeds such as  landing.

  

 Regards,

 Ken

  

 do not archive

  

  

  

  

 [quote]   ---

vgstol(at)bigpond.net.au
Guest

Posted: Wed Jul 22, 2009 1:41 pm Post subject: VGs

Yes, I tried sealing the gaps between the slats and the wing.  Cruise speed was the same as no slats, but the centre of lift had moved forward such that there was a more aft CofG that didn't feel good in my aircraft.  Turns out that the slats don't act like part of the lifting wing at cruise, which was proven in that there is no change in cruise trim with slats/no slats.  

   

 Closing those gaps effectively extends the the chord of the wing much farther forward, thus moving the centre of lift farther forward and increasing the wing area considerably. This is much like the extended leading edge that John Bolding has been considering.  I think it has real good possibilities for a better balance for 701's with heavy car engines and floats.  

   

 JG  

  

  

 

 

 On Thu, Jul 23, 2009 at 3:00 AM, John Marzulli <john.marzulli(at)gmail.com (john.marzulli(at)gmail.com)> wrote:

 [quote]Has anyone experimented with "gap sealing" the slats to the wing to "complete" the airfoil while using VGs?  



 



 This seems like a more reasonable solution than simply pulling the slats off and would probably result in less drag when flying in cruise than presenting the unslatted wing.

 



 



  John Marzulli



http://www.GenevieveMarzulli.org/

http://MarzulliPhoto.net/

 http://701Builder.blogspot.com/



 On Wed, Jul 22, 2009 at 8:57 AM, Gordon <cscsail(at)gmavt.net (cscsail(at)gmavt.net)> wrote:

 [quote]  I'm with you 100% John. People that like the planes flying characteristics with the slats removed, probably selected the wrong plane to build. 

 Gordon 

 [quote]  

   ---

vgstol(at)bigpond.net.au
Guest

Posted: Wed Jul 22, 2009 2:19 pm Post subject: VGs

No we didn't choose the wrong aircraft at all.  The 701 is a great aircraft, and we've found ways to make it even better for our use.  As Peter has testified, we lose very little, (if any) STOL capability, and gain much better x-country cruise capability and handling.  It really expands the aircraft's envelope.  It's like the difference between an original Willys Jeep and a Suzuki 4WD; the Suzi can match the Jeep anywhere off-road, and is a whole lot better on the highway.  There's nothing that can't be improved, and this is just evolution in action....

 

 JG

  

 Do not archive



 On Thu, Jul 23, 2009 at 1:57 AM, Gordon <cscsail(at)gmavt.net (cscsail(at)gmavt.net)> wrote:

 [quote]  I'm with you 100% John. People that like the planes flying characteristics with the slats removed, probably selected the wrong plane to build. 

 Gordon 

 [quote]  

  ---

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Wed Jul 22, 2009 4:54 pm Post subject: Re: VGs

John, 



No flames needed, no one says VGs make a poor airfoil into a helicopter. Only that VGs do perform close to the slats and improve other aspects of the 701 performance and handling. And that they help less STOL airfoils some. CH has given his stamp of approval on this 701 mod from an engineering stand point. Though he does reserve the performance stamp of approval. 

My guess is it is a marketing issue, but who knows?

Are they for everyone... nope, but they are for me. I have spoken to the John Gs customers and they support his claims 100%. And as for the idea that he is selling something, so buyer beware... run the numbers, he is providing a product that gets him some gas money, he really does not have $ signs in his eyes.



Kevin

CH 701 SN 7172

N701DZ



[quote="JohnDRead(at)aol.com"]Why bother to build a STOL aircraft if you take away the things that make  it so? VGs only make poor airfoils work better, they do not make a STOL wing out  of any airfoil. Flame away!

  

 John  Read

CH701 - Elbert CO - Jabiru 3300



Phone: 303-648-3261

Fax:  303-648-3262

Cell: 719-494-4567   

  In a message dated 7/22/2009 1:52:36 A.M. Mountain Daylight Time,  peterlthomson(at)gmail.com writes:

  	  Quote: 	
		  -->    Zenith701801-List message posted by: Peter Thomson    <peterlthomson>



I have the Stolspeed VG's on wings and    elevator.



I took my slats off, and I'll never re-fit them.



I    think the only time you'll find a difference (if one exists) is

when the    nose is pointing at an angle which would scare most people    to

death.



The Vg's on the elevator make it easy to hold the nose off    at very

slow touchdown speeds.



Key advantages are the loss of drag,    better fuel economy and ease of

cruise near the    maximum.



Peter

CH701 SP (CZAW)

912ULS

VG's - no  ========================= Use   utilities  Day  ================================================               - MATRONICS WEB FORUMS  ================================================             - List Contribution Web Site  sp;                          ï¿½  ===================================================



	




 What's for dinner tonight?  Find quick and easy dinner ideas for any occasion.

   	  Quote: 	
		  [b]

_________________
â€œAlways do what you are afraid to do.â€
R.W. Emerson (1803-1882)

"Real freedom is the sustained act of being an individual." WW - 2009

"Life is a good deal...it's worth it" Feb 1969
Dorothy McCune

d.shrader

Joined: 21 Nov 2008
Posts: 38

Posted: Thu Jul 23, 2009 4:33 pm Post subject: Re: VGs

John,



  vg's are part of all modern airfoil design STOL included from boeing on down to cessna.  If it didn't come equiped that way there is a STC for it.  All the aircraft I work on have them and most of the ones that fly out of this reagon have them.  Cub's & 185's included.  I'm not  trying to stoke the flames at all just pointing out vg's will improve almost any airfoil (not lamanar flow)  study it for your self and make an informed decision and good luck in your build.



Dave

JohnDRead(at)aol.com
Guest

Posted: Thu Jul 23, 2009 8:53 pm Post subject: VGs

I am familiar with vgs and how they work. The fact is that  a slotted  wing is the best way to get STOL characteristics. And I'll repeat vgs make a  poor (or under performing) airfoil work better. They will not make a regular  airfoil into a STOL airfoil. Find a copy of Abbot and Von Doenhoff, they explain  slots very well. 

  

 John  Read

CH701 - Elbert CO - Jabiru 3300



Phone: 303-648-3261

Fax:  303-648-3262

Cell: 719-494-4567   

  In a message dated 7/23/2009 6:34:59 P.M. Mountain Daylight Time,  chilledj(at)yahoo.com writes:

  	  Quote: 	
		  -->    Zenith701801-List message posted by: "d.shrader"    <chilledj(at)yahoo.com>



John,



  vg's are part of all    modern airfoil design STOL included from boeing on down to cessna.  If it    didn't come equiped that way there is a STC for it.  All the aircraft I    work on have them and most of the ones that fly out of this reagon have    them.  Cub's & 185's included.  I'm not  trying to stoke    the flames at all just pointing out vg's will improve almost any airfoil (not    lamanar flow)  study it for your self and make an informed decision and    good luck in your build.



Dave





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  [quote][b]

jpspencer(at)cableone.net
Guest

Posted: Sat Jul 25, 2009 2:17 am Post subject: VGs

Guys

 I sincerely want to know...have any of you who  don't believe in vgs on the 701 ever flown a 701 first with slats and then with  properly placed vgs? I mean, really? If so, please speak up. I'm not being  confrontational here, I really would like to hear from you and get your first  hand experience for the group.

 The 701 is a different animal from anything else I  have ever flown. The lowspeed handling really sucked when slowed up to below say  40 mph, til I replaced the slats with vgs. Then it settled down to an acceptably  flying airplane...not the best, just acceptable.

 Like I said before, don't knock it til you have  tried it...but if you have tried it and didn't like it let us hear from  you.

 Thanks

 Joe

 Hitting the road for the big shindig up  nawth

   [quote][b]

keninalaska(at)gmail.com
Guest

Posted: Sat Jul 25, 2009 6:14 am Post subject: VGs

Watch this video, and tell me again how sucky the 701 is at slow speed:



http://www.youtube.com/watch?v=YlgfTV3Jpio



I don't think the problem is the slats!

 



On Sat, Jul 25, 2009 at 2:15 AM, Joe Spencer <jpspencer(at)cableone.net (jpspencer(at)cableone.net)> wrote:

[quote]        Guys

 I sincerely want to know...have any of you who  don't believe in vgs on the 701 ever flown a 701 first with slats and then with  properly placed vgs? I mean, really? If so, please speak up. I'm not being  confrontational here, I really would like to hear from you and get your first  hand experience for the group.

 The 701 is a different animal from anything else I  have ever flown. The lowspeed handling really sucked when slowed up to below say  40 mph, til I replaced the slats with vgs. Then it settled down to an acceptably  flying airplane...not the best, just acceptable.

 Like I said before, don't knock it til you have  tried it...but if you have tried it and didn't like it let us hear from  you.

 Thanks

 Joe

 Hitting the road for the big shindig up  nawth

    	  Quote: 	
		  



ist" target="_blank">http://www.matronics.com/Navigator?Zenith701801-List

tp://forums.matronics.com

_blank">http://www.matronics.com/contribution



	


[b]

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Sat Jul 25, 2009 9:00 am Post subject: Re: VGs

But this is what happens if you pull the power too high.

http://www.youtube.com/watch?v=f4KKH_AIXaw

 Luckily Gus is a pretty good pilot and the 701 is pretty tough. The point is how much STOL do you need and would a little more speed or less fuel burn or easier low speed manors be preferable. The VGs are not for everyone, I do not believe that they are as good as slats in extreme nose high attitude's at slow speeds. And the induced drag really is a good air brake. But we all have our check list, mine includes very good  STOL, high wing, relatively easy plans building, low cost, reasonable cruise and low fuel burn. I do not need to drop into clearings twice the length of my garage with 30 foot trees all around it. So the VGs are better for me. Why is this so hard for some, to under stand? 



Now if Zenith offered a Pegstol like wing, none of us would be having this conversation. But I guess some would need to claim that the slats may not extend and that they are not as safe as fixed slats?

Kevin

NYTerminat(at)aol.com
Guest

Posted: Sat Jul 25, 2009 3:44 pm Post subject: VGs

Has anyone actually flown with the Pegastol wing on a 701? I sure am  curious as to the performance.

  

 Bob Spudis

 N701ZX

  

  

  

 In a message dated 7/25/2009 1:01:38 P.M. Eastern Daylight Time,  kmccune(at)somtel.net writes:

  	  Quote: 	
		  

Now    if Zenith offered a Pegstol like wing, none of us would be having this    conversation. But I guess some would need to claim that the slats may not    extend and that they are not as safe as fixed  slats?

	


 

  

 A Good Credit Score is 70001462830/aol?redir=http://www.freecreditreport.com/pm/default.aspx?sc=668072&hmpgID=115&bcd=JulystepsfooterNO115>See yours in just 2 easy steps!

  [quote][b]

kmccune

Joined: 22 Sep 2007
Posts: 577
Location: Wisconsin, USA

Posted: Sat Jul 25, 2009 3:52 pm Post subject: Re: VGs

Yes, but they need to chime in themselves.



Kevin

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