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HKs Twinstar with vg's

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robcannon

Joined: 22 Jun 2008
Posts: 39
Location: British Columbia

Posted: Sun Oct 12, 2008 8:52 pm Post subject: HKs Twinstar with vg's

ck: Unbelievable !!  A couple days ago I went to do some more test flying but it rained all day.  Instead I spent the day making and installing some vg's on my wings as I was unhappy with the twinstars 38-40 mph stall speed. To design and place them, I read all I could find on this list and a bit more, and came up with what I thought looked best (intuitive engineering) 

   Stall went down to 26 indicated !??!  The plane will now mush along at 25-27 indicated with no scary tendancies.  Yes, my airspeed may be lying when I get that slow, but the improvement is dramatic.

   I now fly approaches comfortably at 45-50 (instead of 55-60).

   Now, I need longer gear, as with the plane that slow the nose is high and the tail wants to hit first.

    Top end speed still seems fine, and with the hks is not an issue. The hks will easily accelerate the twinstar beyond vne. (I'm calling 80mph vne.)

  Sincere thanks to all those ahead of me who experimented with different shapes and positions, and made my desisions much, much easier.  Cheers !  Rob Cannon

smlplanet(at)msn.com
Guest

Posted: Mon Oct 13, 2008 2:26 am Post subject: HKs Twinstar with vg's

Like you I installed the VG's  a couple weeks ago on my Mark 111/912UL and 

still amazed at the difference.

I did find something to be careful about. I did my first nose over dual with 

a CFI on board who had never been in a Kolb. I had been use to setting the 

trim and using it for take offs and landing with out any problems. When I 

went to full power the nose went over before I could react resulting in some 

damage to the FG but easy repair other than matching the paint design. I 

learned real quick to have the trim full nose up both dual and solo. Solo 

isn't bad but the rate of climb is much higher now so I adjust the trim just 

after leaving the ground. I would rather spend my time flying and less time 

on repairs. Like you I have noticed that the tail drops sooner on landing an 

am glad I have the taller steel legs.

Even though I am happy with the results of the VG's I still like to tweak 

things. I am using the small alum ones with the dual fins. I have them set 

between every other rib and 10" back from the leading edge and 3 on the gap 

cover.

How do you have yours set?

I leaned Saturday how effective they was in a cross wind lands. I took off 

and lost most of the rudder control do to S hook connecting the tail wheel 

to the rudder breaking and wrapping around the rudder post binding the 

rudder.

Like I said the take off and climb rate has changed so much I didn't react 

soon enough and was up and climbing.

Knowing I had a problem I landed in a 15 mph wind at  90 deg with out full 

rudder usage. The VG's gave me more control with the ailerons in cross 

winds. I had done cross wind landings and take offs  in 20-25 mph winds 

before but never realized how much difference they made until then.



--------------------------------------------------

From: "robcannon" <leecannon(at)telus.net>

Sent: 2008-10-13 00:52

To: <kolb-list(at)matronics.com>

Subject: HKs Twinstar with vg's



 	  Quote: 	
		   



 ck: Unbelievable !!  A couple days ago I went to do some more test flying 

 but it rained all day.  Instead I spent the day making and installing some 

 vg's on my wings as I was unhappy with the twinstars 38-40 mph stall 

 speed. To design and place them, I read all I could find on this list and 

 a bit more, and came up with what I thought looked best (intuitive 

 engineering)

   Stall went down to 26 indicated !??!  The plane will now mush along at 

 25-27 indicated with no scary tendancies.  Yes, my airspeed may be lying 

 when I get that slow, but the improvement is dramatic.

   I now fly approaches comfortably at 45-50 (instead of 55-60).

   Now, I need longer gear, as with the plane that slow the nose is high 

 and the tail wants to hit first.

    Top end speed still seems fine, and with the hks is not an issue. The 

 hks will easily accelerate the twinstar beyond vne. (I'm calling 80mph 

 vne.)

  Sincere thanks to all those ahead of me who experimented with different 

 shapes and positions, and made my desisions much, much easier.  Cheers ! 

 Rob Cannon





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p 8478#208478

robcannon

Joined: 22 Jun 2008
Posts: 39
Location: British Columbia

Posted: Mon Oct 13, 2008 6:09 am Post subject: Re: HKs Twinstar with vg's

Very interesting guest........ I did notice that I needed more nose up trim on take off, but I hadn't clued in that it was the vg's. I suppose the vg's move the center of lift back, resulting in more nose up trim needed. I have a bungee around the stick trim system(which works great by the way), and was wondering if the bungee had stretched.

  I made the vg's approx. 3" wide by 1.5 deep with two bent up fins (.25"), and put them between every rib and false rib staggered by 1" on the whole wing.

   You say the "s" hook broke.  Why did it break? I'm using the connector that came with the compression springs from aircraft spruce, and I don't really like the way it atttaches to the stock kolb tailwheel arm ( seems like a bad wear point.)

  Does your plane have the nose hoop?

  Rob

smlplanet(at)msn.com
Guest

Posted: Mon Oct 13, 2008 6:51 am Post subject: HKs Twinstar with vg's

I do have the nose skid hoop or I would have had more damage. I had thought 

about removing it before BUT not now..LOL

The S hook bent the first time and came off causing the chain and spring to 

fly forward and wrapping around the rudder post restricting movement of the 

rudder. I notice when I put the S hook back on the tail wheel that it had 

weakened from rust under the paint as a result of setting so close to the 

ground. Then I got back to my main field the end of the S hook had broken 

off completely. I looked for stainless hooks but couldn't find any the right 

size so I am going to use the steel again but use a heavy saftey wire as a 

back up. I do a lot of off short field T/L's which the tail wheel takes a 

beating at times and I do have the larger tail wheel.

I have two springs on my trim which I had to adjust a little shorter mainly 

for dual. I can fly hands and feet off

and the yaw string is down the middle and elevation hold where I set it 

other than thermals when flying low.

I drop my stall 8 mph solo and 10 mph duel and increased the rated of climb 

to 900 fpm solo and 600-700 fpm

dual with 13 gals of gas..10 main and 3 reserve in the nose. Ground roll 

aprox. solo 125-150 ft duel 200-300 ft

Now that the VG's are helping I need to work on the prop pitch for better XC 

fuel savings with out loosing short field T/L's



--------------------------------------------------

From: "robcannon" <leecannon(at)telus.net>

Sent: 2008-10-13 10:09

To: <kolb-list(at)matronics.com>

Subject: Re: HKs Twinstar with vg's



 	  Quote: 	
		   



 Very interesting guest........ I did notice that I needed more nose up 

 trim on take off, but I hadn't clued in that it was the vg's. I suppose 

 the vg's move the center of lift back, resulting in more nose up trim 

 needed. I have a bungee around the stick trim system(which works great by 

 the way), and was wondering if the bungee had stretched.

  I made the vg's approx. 3" wide by 1.5 deep with two bent up fins (.25"), 

 and put them between every rib and false rib staggered by 1" on the whole 

 wing.

   You say the "s" hook broke.  Why did it break? I'm using the connector 

 that came with the compression springs from aircraft spruce, and I don't 

 really like the way it atttaches to the stock kolb tailwheel arm ( seems 

 like a bad wear point.)

  Does your plane have the nose hoop?

  Rob





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p 8503#208503

smlplanet(at)msn.com
Guest

Posted: Mon Oct 13, 2008 7:09 am Post subject: HKs Twinstar with vg's

Rob I forgot to mention one of the reasons I am tweaking things for short 

fields and fuel, being I live in So Florida.

I am planning to fly over to the Bahamas and then do some island hopping. I 

waiting for the information and permits now and hope to go after the 

hurricane season is over. The VG's will help a lot with the ocean breezes 

that blow all the time. I have bought a head mount video camera and hope to 

get some great footage over the water and islands. I plan to have the new 20 

gal fuel tank made and in by then just in case, 23 gals can get most any 

where over there.



--------------------------------------------------

From: "robcannon" <leecannon(at)telus.net>

Sent: 2008-10-13 10:09

To: <kolb-list(at)matronics.com>

Subject: Re: HKs Twinstar with vg's



 	  Quote: 	
		   



 Very interesting guest........ I did notice that I needed more nose up 

 trim on take off, but I hadn't clued in that it was the vg's. I suppose 

 the vg's move the center of lift back, resulting in more nose up trim 

 needed. I have a bungee around the stick trim system(which works great by 

 the way), and was wondering if the bungee had stretched.

  I made the vg's approx. 3" wide by 1.5 deep with two bent up fins (.25"), 

 and put them between every rib and false rib staggered by 1" on the whole 

 wing.

   You say the "s" hook broke.  Why did it break? I'm using the connector 

 that came with the compression springs from aircraft spruce, and I don't 

 really like the way it atttaches to the stock kolb tailwheel arm ( seems 

 like a bad wear point.)

  Does your plane have the nose hoop?

  Rob





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p 8503#208503

JetPilot

Joined: 10 Jan 2006
Posts: 1246

Posted: Mon Oct 13, 2008 7:43 am Post subject: Re: HKs Twinstar with vg's

I am always glad to see reports of guys that have tried VG's and found them to be a huge improvement in their Kolbs.   For anyone else out there that has been thinking about installing VG's on their Kolb but are not sure yet, lots of reports like this and the video link below make this choice a no brainer.  Adding VG's to your Kolb is the single most important thing you can do to increase its slow flight performance and SAFETY.  If your engine quits and you are going to put it in down in a field, would you rather touch down at 40 MPH or 30 MPH,  would you rather have a mushy approach at 50 MPH, or have your Kolb fly rock solid at 40 MPH with no mushing and full aileron authority ???  You can see all this at:



http://www.vimeo.com/1480667



Mike

_________________
"NO FEAR" - If you have no fear you did not go as fast as you could have !!!

Kolb MK-III Xtra, 912-S

NeilsenRM(at)comcast.net
Guest

Posted: Mon Oct 13, 2008 7:45 am Post subject: HKs Twinstar with vg's

I had my tail wheel springs come off a few times. When I switched to 

compression springs I installed some "connector links" they are built like 

safety rings so they can't disconnect. I found them at Aircraft Spruce part 

number 06-15400 page 250 in the current catalog.



Rick Neilsen

Redrive VW powered MKIIIC



---

lcottrell

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

Posted: Mon Oct 13, 2008 3:31 pm Post subject: HKs Twinstar with vg's

Mike B:

  

 Terribly sorry, but I do not experience what you describe  below in my mkIII or any other model Kolb.

  

 My mkIII breaks at 30 mph IAS in ground effect.  It  has flown as slow as other mkIII's with VG's installed on them.

  

 Guess I am still satisfied with the way my mkIII flies and  don't have a need for VG's.  I have demonstrated over the years, miles and  hours, my mkIII is safe to fly, as is, in many different and varied weather and  geographic conditions.  If it was unsafe, I would surely run right out and  buy a set of VG's for her.

  

 PS:  Using Larry Cottrell's email.  Makes it a  lot faster for me to read and reply to messages this way, rather than using web  mail.

  

 Take care,

  

 john hauck

 mkIII

 Rock House, Jordan Valley, Oregon

  

 PSS:  Many of us have no qualms landing in fields,  with or without power.  Some of us fly out of cow pastures.  These are  our home bases.  I have been flying out of a cow pasture for 24  years.  When one flies out of 3, 4, and 5 thousand ft paved airports, one  finds it difficult to land in small fields.  Good idea to get as much  experience as possible landing out.  Never know when you might need to land  in a field and wait out weather.  That's much better than deviating 70  miles to the nearest airport with good weather.

  

  

 [quote]    Adding VG's to your    Kolb is the single most important thing you can do to increase its slow flight    performance and SAFETY.  If your engine quits and you are going to put it    in down in a field, would you rather touch down at 40 MPH or 30 MPH,     would you rather have a mushy approach at 50 MPH, or have your Kolb fly rock    solid at 40 MPH with no mushing and full aileron authority ??? 

   

Mike



 

[b]

_________________
do not archive

lcottrell

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

Posted: Mon Oct 13, 2008 3:32 pm Post subject: HKs Twinstar with vg's

Rick N:

  

 I use those also.

  

 Work good.

  

 john h

 mkIII

 hauck's holler remote, SE Oregon

 [quote]    I had my tail wheel springs come off a few    times. When I switched to 

compression springs I installed some "connector    links" they are built like 

safety rings so they can't disconnect. I found    them at Aircraft Spruce part 

number 06-15400 page 250 in the current    catalog.



Rick Neilsen

 

[b]

_________________
do not archive

pj.ladd(at)btinternet.com
Guest

Posted: Wed Oct 15, 2008 9:55 am Post subject: HKs Twinstar with vg's

If it was unsafe, I would surely run right  out and buy a set of VG's for her.>>

  

 Hi John,

 of course you would and so would everyone  else.

 I don`t think anyone has ever suggested that our  planes are unsafe without VG`s. Just that with them they are, maybe, just a  little safer.

  

 "In what way?"  I am not even going down that  road. Its been done to death

  

 Cheers

  

 Pat

 



   [quote][b]

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