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Mike Hoffman

Joined: 11 Mar 2006
Posts: 54

Posted: Sun Jul 19, 2009 3:02 am Post subject: VGs

Has anyone bought the new aluminum VGs that Zenith now has. What was the cost? Would they be a better choice than the plastic ones being offered by other vender's such as Stol Speed?



Mike Hoffman

ronlee

Joined: 25 Dec 2006
Posts: 141

Posted: Sun Jul 19, 2009 6:05 am Post subject: Re: VGs

I have had home made ones that I made that look just like the ones Zenith is selling. I have these on the underside of the elevator on my 701 and they work fine. I have the plastic vgs on my wings and they too work fine. I have broken two of the plastic in two years so they certainly aren't as durable as aluminum. I pressed my original aluminum vgs myself for a Ttitan I sold. I had enough left to do the elevator on the 701, that is the reason I have them only on the elevator. It was lots of work to make all those aluminum vgs, that is the reason I now have a combination of each on my plane. Had the aluminum been available when I bought the plastic I certainly would have done that instead of plastic

_________________
Ron Lee
Tucson, Arizona

arno7452(at)bellsouth.net
Guest

Posted: Sun Jul 19, 2009 6:11 am Post subject: VGs

I did the plastic ones and am very happy with them.

Regards,

Ken

do not archive



---

dlorrzen701(at)earthlink.
Guest

Posted: Sun Jul 19, 2009 7:53 am Post subject: VGs

I beleive they were only 85.00$ the last time I looked on the Zentih page. 



--

vgstol(at)bigpond.net.au
Guest

Posted: Sun Jul 19, 2009 6:39 pm Post subject: VGs

Ron,

  

 You got the earliest Stolspeed VGs.  Since then they've been considerably strengthened.  I'll send you replacements, no charge.  Anyone else with the early Stolspeed VGs that have broken, let me know and I'll replace them with the newer ones, no charge.

   

 JG

 On Mon, Jul 20, 2009 at 12:05 AM, ronlee <rlee468(at)comcast.net (rlee468(at)comcast.net)> wrote:

 [quote]--> Zenith701801-List message posted by: "ronlee" <rlee468(at)comcast.net (rlee468(at)comcast.net)>

 

I have had home made ones that I made that look just like the ones Zenith is selling. I have these on the underside of the elevator on my 701 and they work fine. I have the plastic vgs on my wings and they too work fine. I have broken two of the plastic in two years so they certainly aren't as durable as aluminum. I pressed my original aluminum vgs myself for a Ttitan I sold. I had enough left to do the elevator on the 701, that is the reason I have them only on the elevator. It was lots of work to make all those aluminum vgs, that is the reason I now have a combination of each on my plane. Had the aluminum been available when I bought the plastic I certainly would have done that instead of plastic

 

--------

Ron Lee

Tucson, Arizona





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[b]

bobkat

Joined: 07 Sep 2008
Posts: 143
Location: Bismarck, ND

Posted: Mon Jul 20, 2009 4:12 am Post subject: VGs

I put JG's VG's on the tail and yes, they really do  work!  Fantastic, as a matter of fact.  

   Next project is to pick a nice day and run  all my V speeds with and without the slats, and then with the wing  VG's.   It will be interesting to see what I find out.   Unfortunately my plane is not painted yet so I might have to put them on, then  take them off for painting, then back on again.   Oh well, I love to  tinker anyway....

 Hope to meet some of you guys in  Oshkosh.   I wonder if there is some way of identifying the guys on  Matronics who will undoubtedly be hanging around the Zenith Display -  everybody wear some wierd bit of clothing, a particular hat or something simple  so Joe builder could say "Hey, there's a guy with an A5 rivet  through his  left ear and a silver cleco through the right side of his nose so he must  be one of those reprobates on the Matronics 701/801 group - I'd  better go meet him!"  LOL

 Anyone have any ideas for a simple ID method?   

 [quote]   ---

zeus45601(at)yahoo.com
Guest

Posted: Mon Jul 20, 2009 8:51 am Post subject: VGs

I've seen the ones that Zenith sells that attach to the elevators and I've seen the SpeedStol's VGs that attach the the forward wings as an alternative to Leading Edge Slats (LES).  I'm sure this is a stupid question to most of you experienced flyers, but can you use both or would it create too much drag or turbulance or would it totally screw up the characteristics of the Zenith STOLs, or do they serve different purposes when they are attached to the wings as opposed to the elevators.  Opps, that was a whole series of stupid questions in one sentence.  Sorry.  Basically, I just want to know the difference between them.  The ones that Zenith sells, it appear to still require the LES and appear to help in slow speed landings, while the ones SpeedStol sells  allows for the LES to be taken off with pretty much the same slow landing characteristics as having them on, but with more stability in flight, slightly higher cruise speeds, and less fuel consumption.  Anyone have any thoughts?

  

 Jay



 

   From: BokKat <bobkat(at)btinet.net>

To: zenith701801-list(at)matronics.com

Sent: Monday, July 20, 2009 8:11:49 AM

Subject: Re: Re: VGs



   I put JG's VG's on the tail and yes, they really do work!  Fantastic, as a matter of fact.  

   Next project is to pick a nice day and run all my V speeds with and without the slats, and then with the wing VG's.   It will be interesting to see what I find out.  Unfortunately my plane is not painted yet so I might have to put them on, then take them off for painting, then back on again.   Oh well, I love to tinker anyway....

 Hope to meet some of you guys in Oshkosh.   I wonder if there is some way of identifying the guys on Matronics who will undoubtedly be hanging around the Zenith Display - everybody wear some wierd bit of clothing, a particular hat or something simple so Joe builder could say "Hey, there's a guy with an A5 rivet  through his left ear and a silver cleco through the right side of his nose so he must be one of those reprobates on the Matronics 701/801 group - I'd better go meet him!"  LOL

 Anyone have any ideas for a simple ID method?  

 [quote] ---

Jon(at)joncroke.com
Guest

Posted: Mon Jul 20, 2009 10:12 am Post subject: VGs

In the soon to be released Zenair Newsletter &  DVD (in approx 2 weeks) Roger at Zenith provides a nice, clear presentation on  their VGs: performance and installation.

  

 You will enjoy watching this and a bunch  of enlightening innterviews from builders at the recent ZAC fly-in at the  factory!

  

 Jon

 editor/ Zenair Newsletter

 www.zenair.org  

  

 [quote]   ---

john.marzulli(at)gmail.co
Guest

Posted: Mon Jul 20, 2009 10:28 am Post subject: VGs

Can anyone give their opinion on the difference between the STOLSpeed and Zenith VGs as far as the tail feathers are concerned?

Thanks,

John Marzulli



http://www.GenevieveMarzulli.org/

 http://MarzulliPhoto.net/

http://701Builder.blogspot.com/

 



On Mon, Jul 20, 2009 at 11:11 AM, Jon Croke <Jon(at)joncroke.com (Jon(at)joncroke.com)> wrote:

[quote]        In the soon to be released Zenair Newsletter &  DVD (in approx 2 weeks) Roger at Zenith provides a nice, clear presentation on  their VGs: performance and installation.

  

 You will enjoy watching this and a bunch  of enlightening innterviews from builders at the recent ZAC fly-in at the  factory!

  

 Jon

 editor/ Zenair Newsletter

 www.zenair.org  

  

 [quote]   ---

n752ms(at)softcom.net
Guest

Posted: Mon Jul 20, 2009 11:43 am Post subject: VGs

It was with the encouragement of Roger and  Sebastien at the Cloverdale fly in that I bought the VG's.  They didn't say  at the time that the VG's were available from Zenith.  I bought mine from  JG.

  

 Mark S.

  

  

 [quote]   ---

vgstol(at)bigpond.net.au
Guest

Posted: Mon Jul 20, 2009 1:24 pm Post subject: VGs

Gday Bobkat,



Just a tip for mounting the VGs temporarily.  Just use a 3/8" strip of adhesive and place the VGs across it side by side and then cut between them.  Much easier than cutting all around each, and still plenty of holding power for testing. Have fun tinkering.

 



JG



On Mon, Jul 20, 2009 at 10:11 PM, BokKat <bobkat(at)btinet.net (bobkat(at)btinet.net)> wrote:

[quote]        I put JG's VG's on the tail and yes, they really do  work!  Fantastic, as a matter of fact.  

   Next project is to pick a nice day and run  all my V speeds with and without the slats, and then with the wing  VG's.   It will be interesting to see what I find out.   Unfortunately my plane is not painted yet so I might have to put them on, then  take them off for painting, then back on again.   Oh well, I love to  tinker anyway....

 Hope to meet some of you guys in  Oshkosh.   I wonder if there is some way of identifying the guys on  Matronics who will undoubtedly be hanging around the Zenith Display -  everybody wear some wierd bit of clothing, a particular hat or something simple  so Joe builder could say "Hey, there's a guy with an A5 rivet  through his  left ear and a silver cleco through the right side of his nose so he must  be one of those reprobates on the Matronics 701/801 group - I'd  better go meet him!"  LOL

 Anyone have any ideas for a simple ID method?   

 [quote]   ---

ronlee

Joined: 25 Dec 2006
Posts: 141

Posted: Mon Jul 20, 2009 2:01 pm Post subject: Re: VGs

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

bobkat

Joined: 07 Sep 2008
Posts: 143
Location: Bismarck, ND

Posted: Mon Jul 20, 2009 2:34 pm Post subject: VGs

Thanks for the report Ron.  I'm looking forward to trying mine with no slats 

and VG's.    Most of us fly from pretty long fields anyway, and even if you 

have to give up a tiny bit STOL performance it's no big deal.

---

arno7452(at)bellsouth.net
Guest

Posted: Mon Jul 20, 2009 2:36 pm Post subject: VGs

Heck, just stick'em on any ol' way.  What's a little  airflow difference in the elevator?  I installed mine exactly as  specified.

 Regards,

 Ken

  

 do not archive

  

  

 [quote]   ---

dougsnash

Joined: 14 Apr 2008
Posts: 281

Posted: Mon Jul 20, 2009 7:47 pm Post subject: VGs

Jay, check out John Gilpin's (JG) website, www.stolspeed.com  With all due respect to JG, keep in mind that he is selling something when you read his site.



Essentially, by removing the slats from the 701 you are reducing the size of the wing (we are not talking VGs yet).  The higher loaded wing will fly faster because of less drag.  You also loose a good amount of the STOL capcability of the wing.



To fix this loss of low end STOL performance, you install vortex generators on the wing.  This returns most (but not all) of the STOL capability but leaves the higher top speed alone.  Now the question that everyone has to answer for themselves is, is the increase in top speed worth the minor degridation of the STOL capability.  The consensus of those that have made the change is that the very minor loss of STOL capability is very acceptible because the 701 has so much STOL ability to begin with.  What is another ten feet of take off roll when you are still getting up faster than almost any other aircraft out there.



To answer your other question, there is no advantage to using VGs and slats.  They accomplish the same goal of keeping the airflow attached to the wing at higher angles of attack.



While the above information may sound like I am firmly in the VG side of the debate, I actually am planning on installing my slats.  I just like to look at both sides of an issue.



Hope this clears things up a bit for you.



Doug MacDonald

CH-701 Scratch Builder

Final assembly

and getting my but kicked by a Citabria this past weekend

NW Ontario, Canada



Do Not Archive

--- On Mon, 7/20/09, Jay Parker <zeus45601(at)yahoo.com> wrote:



 	  Quote: 	
		   From: Jay Parker <zeus45601(at)yahoo.com>

 Subject: Re: Re: VGs

 To: zenith701801-list(at)matronics.com

 Received: Monday, July 20, 2009, 11:50 AM

 I've seen the ones that

 Zenith sells that attach to the elevators and I've seen

 the SpeedStol's VGs that attach the the forward wings as

 an alternative to Leading Edge Slats (LES). 

 I'm sure this is a stupid question to most of you

 experienced flyers, but can you use both or would it

 create too much drag or turbulance or would it totally

 screw up the characteristics of the Zenith STOLs, or do they

 serve different purposes when they are attached to the wings

 as opposed to the elevators.  Opps, that was a whole

 series of stupid questions in one sentence.  Sorry.

  Basically, I just want to know the difference between

 them.  The ones that Zenith sells, it appear to

 still require the LES and appear to help in slow speed

 landings, while the ones SpeedStol sells

  allows for the LES to be taken off with pretty much the

 same slow landing characteristics as having them on,

 but with more stability in flight, slightly higher

 cruise speeds, and less fuel consumption.  Anyone have

 any thoughts?

  

 Jay

 


	


      __________________________________________________________________

Looking for the perfect gift? Give the gift of Flickr! 



http://www.flickr.com/gift/

zeus45601(at)yahoo.com
Guest

Posted: Tue Jul 21, 2009 3:11 am Post subject: VGs

But what would happen if you use both kinds of VGs on the same plane......wing and elevators?  Again, would that really mess up the flying characteristics of the STOL?  Has anyone tried that before or is one or the other basically doing the same thing and which is better?  

  

 Jay



 [quote][b]

arno7452(at)bellsouth.net
Guest

Posted: Tue Jul 21, 2009 4:39 am Post subject: VGs

Hey Jay,

 Give it a try.  Might be interesting.  First  test would be to see if it would get airborne.

  

 Let us know how it works.

 Regards,

 Ken

  

 do not archive

  

  

 [quote]   ---

dougsnash

Joined: 14 Apr 2008
Posts: 281

Posted: Tue Jul 21, 2009 5:21 am Post subject: VGs

Sorry Jay, I missed mentioning the elevator VGs on my post last night.  The purpose of the VGs on the elevator is to keep the airflow attached at high elevator angles of attack.  On the elevator, this is during the flare for landing.  The VGs are installed in such a way that they do not actually see the airflow duing straight and level flight.  As the stick is pulled back during the flare, the nose of the elevator drops down into the airstream and the installed VGs then keep the airflow attached to the skin of the elevator.  This essentially gives far better elevator control during the flare.



Essentially, what I am saying is that VGs on the elevator have nothing to do with the VGs on the wings so therefore, it is quite acceptible to use both.  I plan on using the slats on the wings and VGs on the elevator.



Doug MacDonald

CH-701 Scratch Builder

NW Ontario, Canada

Final Assembly



Do Not Archive



--- On Tue, 7/21/09, Jay Parker <zeus45601(at)yahoo.com> wrote:



 	  Quote: 	
		   From: Jay Parker <zeus45601(at)yahoo.com>

 Subject: VGs

 To: zenith701801-list(at)matronics.com

 Received: Tuesday, July 21, 2009, 6:11 AM

 But what

 would happen if you use both kinds of VGs on the same

 plane......wing and elevators?  Again,

 would that really mess up the flying characteristics of the

 STOL?  Has anyone tried that before or is one or the

 other basically doing the same thing and which is

 better?  

  

 Jay

 
	


      __________________________________________________________________

The new Internet Explorer® 8 - Faster, safer, easier.  Optimized for Yahoo!  Get it Now for Free! at http://downloads.yahoo.com/ca/internetexplorer/

zeus45601(at)yahoo.com
Guest

Posted: Tue Jul 21, 2009 6:54 am Post subject: VGs

Thanks.  That makes a lot of sense to me now that I think about it.  Appreciate your insight.

  

 Jay



 

   From: MacDonald Doug <dougsnash(at)yahoo.com>

To: zenith701801-list(at)matronics.com

Sent: Tuesday, July 21, 2009 9:19:08 AM

Subject: Re: VGs



--> Zenith701801-List message posted by: MacDonald Doug <dougsnash(at)yahoo.com (dougsnash(at)yahoo.com)>

Sorry Jay, I missed mentioning the elevator VGs on my post last night.  The purpose of the VGs on the elevator is to keep the airflow attached at high elevator angles of attack.  On the elevator, this is during the flare for landing.  The VGs are installed in such a way that they do not actually see the airflow duing straight and level flight.  As the stick is pulled back during the flare, the nose of  the elevator drops down into the airstream and the installed VGs then keep the airflow attached to the skin of the elevator.  This essentially gives far better elevator control during the flare.



Essentially, what I am saying is that VGs on the elevator have nothing to do with the VGs on the wings so therefore, it is quite acceptible to use both.  I plan on using the slats on the wings and VGs on the elevator.



Doug MacDonald

CH-701 Scratch Builder

NW Ontario, Canada

Final Assembly



Do Not Archive



--- On Tue, 7/21/09, Jay Parker <zeus45601(at)yahoo.com (zeus45601(at)yahoo.com)> wrote:



 	  Quote: 	
		   From: Jay Parker <zeus45601(at)yahoo.com (zeus45601(at)yahoo.com)>

 Subject: VGs

 To: zenith701801-list(at)matronics.com (zenith701801-list(at)matronics.com)

 Received: Tuesday, July 21, 2009, 6:11 AM

 But what

 would happen if you use both kinds of VGs on the same

 plane......wing and elevators?  Again,

 would that really mess up the flying characteristics of the

 STOL?  Has anyone tried that before or is one or the

 other basically doing the same thing and which is

 better?  

  

 Jay


	


      __________________________________________________________________

The new Internet Explorer® 8 - Faster, safer, easier.  Optimized for Yahoo!  Get it Now for Free! at http://downloads.yah========================



 [quote][b]

vgstol(at)bigpond.net.au
Guest

Posted: Tue Jul 21, 2009 2:19 pm Post subject: VGs

Gday All,

  

 JG from Stolspeed chipping in here.  I'm still around and still testing and comparing STOL wings.  Whenever I hear claims and statements I just have to do tests to see if they stand up.  I'm a curious experimenter first and foremost.  I started out very sceptical of VGs, but curiousity led me to try them, and the results led to manufacturing them.  Since so many of you out there are sceptics, it's a small business, and pretty much just supports further work in experimenting and testing.  The results often disprove commonly held opinions and open new possibilities, which is really exciting and worthwhile for an experimental engineering type like me.  This is what drives me to do this work, not the business of selling VGs.  I'm no salesman, just an enthusiast.  I'm retired with enough to get by, and this business is just a means to support all the research.  Some of the results of that research has already been very useful to others who are open to change.

   

 I've just finished another round of extensive testing of a Savannah with slats, without slats, and with their 'VG' leading edge, and further tests loaded with sand bags to max gross weight.  Many hours of climb at full power for 1000 ft, followed by engine off prop-stopped glide back down the 1000 ft, timed with a stopwatch, over a range of speeds from 40 to 70 kts.  Have to do it all at sunrise to avoid thermal activity, and do several runs at each speed to eliminate spurious readings.  It gets tedious, but the results are enlightening and useful. I used several hundred dollars of fuel, and a lot of hard work for the engine, just on this last series....   I just finished that work yesterday, so it's going to take a little awhile to analyse and compile all the data, then I'll write it up and publish for all to use to make your own decisions.  This was done on a Savannah, but identical airfoil to the 701, so the results are very useful.  I'll let you know when it's ready.

   

 Some of the prelimary results are ready, and attached is a graph of the climb rates for Slats vs VGs.  Note that the climb rates for each version below 40 kts are pretty much the same, so the Angle of Climb will be pretty much the same, contrary to claims elsewhere.  Above 40 kts the difference is really significant.  These are real life results not just claims, so take what you will from them....   More to come later.

   

 JG

 

 

 On Tue, Jul 21, 2009 at 1:44 PM, MacDonald Doug <dougsnash(at)yahoo.com (dougsnash(at)yahoo.com)> wrote:

  	  Quote: 	
		  --> Zenith701801-List message posted by: MacDonald Doug <dougsnash(at)yahoo.com (dougsnash(at)yahoo.com)>

 



Jay, check out John Gilpin's (JG) website, www.stolspeed.com  With all due respect to JG, keep in mind that he is selling something when you read his site.

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