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wood ribs on tailfeathers on a Kitfox 4

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thesupe(at)hotmail.com
Guest

Posted: Wed Jun 09, 2010 4:13 pm Post subject: wood ribs on tailfeathers on a Kitfox 4

Hi all,  When I got my unfinished Kitfox 4 kit, it had wood ribs glued in on the horizontal stabalizer, and not on the rudder or elevator.  I see in the manual that they can be added to the rudder, verticle stabilizer, and elevator also.  No other wood ribs came with my kit to do the rest of the tailfeathers, and I'm wondering if I should make some up and put them in or not.  The earlier Kitfoxes and Avids didn't use them, and I'm wondering how much of an improvement they are.  I have the wings covered and ready to spray (after I iron the edges of the finishing tapes) and am ready to start the tailfeathers or fusaloge next.  I took a year off to do some other things, but got back to work about 1 1/2 months ago.  I got the wings covered in that time, working on and off about 80 hrs in that month and a half.  At least now I'm making progress again.  Take care all,  Jim Chuk  Mn

 Avids, Kitfox 4 (building)

 		 	   		  Hotmail is redefining busy with tools for the New Busy. Get more from your inbox. See how.  [quote][b]

larry huntley

Joined: 19 Jul 2008
Posts: 149

Posted: Wed Jun 09, 2010 4:52 pm Post subject: wood ribs on tailfeathers on a Kitfox 4

Jim,

   I made ribs for the HS and elevators on my 4-1200.  Don't know if they did any good ,but I like them for whatever reason. I believe  they do no harm.          Larry  Huntley   4-1200 EA-81 Soob, 550 hrs

 [quote]   ---

_________________
Larry Huntley,Dundee,NY
Kitfox 4-1200 N234EE
EA81,AMAX Redrive Warp 3 blade

Lynn Matteson

Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan

Posted: Wed Jun 09, 2010 5:43 pm Post subject: wood ribs on tailfeathers on a Kitfox 4

Jim-



When I first got on this list, folks told me that if the vertical was  

left '"skinny" it would "hunt"...that is, the tail would move from  

side to side as the air pressure tried to equalize on either side of  

the vertical. Others said they had skinny tails and they didn't  

notice it. My unfinished plane came with the hort. stab and elevator  

airfoiled, so I elected to do the vertical and rudder as well. I  

haven't regretted that move. A bit of work....making your own  

ribs....but it was fun, and I learned a lot.



Lynn Matteson

Kitfox IV Speedster, taildragger

Jabiru 2200, #2062, 968.8 hrs (since 3-27-2006)

Countdown to 1000 hrs~31.2 to go(47 days to go)

Sensenich 62"x46" Wood (summer)

Electroair direct-fire ignition system

Rotec TBI-40 injection

Status: flying (and learning)

On Jun 9, 2010, at 8:12 PM, Jim_and_Lucy Chuk wrote:



 	  Quote: 	
		   Hi all,  When I got my unfinished Kitfox 4 kit, it had wood ribs  

 glued in on the horizontal stabalizer, and not on the rudder or  

 elevator.  I see in the manual that they can be added to the  

 rudder, verticle stabilizer, and elevator also.  No other wood ribs  

 came with my kit to do the rest of the tailfeathers, and I'm  

 wondering if I should make some up and put them in or not.  The  

 earlier Kitfoxes and Avids didn't use them, and I'm wondering how  

 much of an improvement they are.  I have the wings covered and  

 ready to spray (after I iron the edges of the finishing tapes) and  

 am ready to start the tailfeathers or fusaloge next.  I took a year  

 off to do some other things, but got back to work about 1 1/2  

 months ago.  I got the wings covered in that time, working on and  

 off about 80 hrs in that month and a half.  At least now I'm making  

 progress again.  Take care all,  Jim Chuk  Mn

 Avids, Kitfox 4 (building)



 Hotmail is redefining busy with tools for the New Busy. Get more  

 from your inbox. See how._- 

 ============================================================ _- 

 ============================================================ _- 

 ============================================================ _- 

 contribution_- 

 ============================================================

_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM

thesupe(at)hotmail.com
Guest

Posted: Wed Jun 09, 2010 8:07 pm Post subject: wood ribs on tailfeathers on a Kitfox 4

Thanks Lynn and Larry for the replys.  I guess I should have mentioned that my kit is a Kitfox 4 Classic 1200.  Did a little more looking in the manual, and it seems that the wood ribs on the rudder and such were for the Speedster model.  Not sure why mine has the ribs on the horizontal stabalizer though???   Anyone else have an opinion?  Thanks,  Jim Chuk,  Avids,  Kitfox 4 building

 

 	  Quote: 	
		   From: lynnmatt(at)jps.net

 Subject: Re: wood ribs on tailfeathers on a Kitfox 4

 Date: Wed, 9 Jun 2010 21:36:50 -0400

 To: kitfox-list(at)matronics.com

 

 --> Kitfox-List message posted by: Lynn Matteson <lynnmatt(at)jps.net>

 

 Jim-

 

 When I first got on this list, folks told me that if the vertical was 

 left '"skinny" it would "hunt"..that is, the tail would move from 

 side to side as the air pressure tried to equalize on either side of 

 the vertical. Others said they had skinny tails and they didn't 

 notice it. My unfinished plane came with the hort. stab and elevator 

 airfoiled, so I elected to do the vertical and rudder as well. I 

 haven't regretted that move. A bit of work....making your own 

 ribs....but it was fun, and I learned a lot.

 

 Lynn Matteson

 Kitfox IV Speedster, taildragger

 Jabiru 2200, #2062, 968.8 hrs (since 3-27-2006)

 Countdown to 1000 hrs~31.2 to go(47 days to go)

 Sensenich 62"x46" Wood (summer)

 Electroair direct-fire ignition system

 Rotec TBI-40 injection

 Status: flying (and learning)

 

 

 

 

 

 

 On Jun 9, 2010, at 8:12 PM, Jim_and_Lucy Chuk wrote:

 

 > Hi all, When I got my unfinished Kitfox 4 kit, it had wood ribs 

 > glued in on the horizontal stabalizer, and not on the rudder or 

 > elevator. I see in the manual that they can be added to the 

 > rudder, verticle stabilizer, and elevator also. No other wood ribs 

 > came with my kit to do the rest of the tailfeathers, and I'm 

 > wondering if I should make some up and put them in or not. The 

 > earlier Kitfoxes and Avids didn't use them, and I'm wondering how 

 > much of an improvement they are. I have the wings covered and 

 > ready to spray (after I iron the edges of the finishing tapes) and 

 > am ready to start the tailfeathers or fusaloge next. I took a year 

 > off to do some other things, but got back to work about 1 1/2 

 > months ago. I got the wings covered in that time, working on and 

 > off about 80 hrs in that month and a half. At least now I'm making 

 > progress again. Take care all, Jim Chuk Mn

 > Avids, Kitfox 4 (building)

 >

 > Hotmail is redefining busy with tools for the New Busy. Get more 

 > from your inbox. See how._- 

 > =================================== _- 

 > =================================== _- 

 > ========== _- 

 > contribution_- 

 >  Archive Search & Download, 7-Day Browse, Chat, FAQ,

&gt===
	


[quote] 

 

 

 		 	   		  The New Busy think 9 to 5 is a cute idea. Combine multiple calendars with Hotmail.  Get busy.   	  Quote: 	
		  [b]

Tom Jones

Joined: 12 Mar 2006
Posts: 752
Location: Ellensburg, WA

Posted: Thu Jun 10, 2010 4:16 am Post subject: Re: wood ribs on tailfeathers on a Kitfox 4

Jim, my classic 4 kit came with wood ribs for the horizontal stab only.  I asked the old Skystar factory why not the elevator too and he said it would not matter, that it was mostly just for looks.  Being anxious to finish I built it with the ribs just in the horizontal.



I haven't flown one with the elevator or vertical and rudder air foiled so I can't comment on their being any difference.  Mine does fly straight and smooth.



I seem to remember some chat that if installed by the book the ribs in the horizontal don't line up with those in the horizontal and that makes it look funny.  You might check that and line them up if you decide to put ribs in the elevator too.

_________________
Tom Jones
Classic IV
503 Rotax, 72 inch Two blade Warp
Ellensburg, WA

Tom Jones

Joined: 12 Mar 2006
Posts: 752
Location: Ellensburg, WA

Posted: Thu Jun 10, 2010 7:00 am Post subject: Re: wood ribs on tailfeathers on a Kitfox 4

I got to thinking more about this so went out and looked.  My horizontal has only six wood ribs.  They are each positioned with one end in the V formed by the 4130 tubing braces.  This placement does not match any of the ribs shown in the speedster airfoil tail instructions.   I think their primary purpose is to brace the opposite leading/trailing edge to prevent it from bending when the cover is shrunk.



Here's my builder's documentation book photo.

Horizontal Stab ribs.jpg.jpg

Description:

Filesize:

71.68 KB

Viewed:

13672 Time(s)

_________________
Tom Jones
Classic IV
503 Rotax, 72 inch Two blade Warp
Ellensburg, WA

taildragon(at)msn.com
Guest

Posted: Thu Jun 10, 2010 8:37 am Post subject: wood ribs on tailfeathers on a Kitfox 4

<?xml:namespace prefix="v" /><?xml:namespace prefix="o" /><![endif]-->  I bought my Model IV 1200 with the optional Speedster tail feather rib kit  in 1993. The HS and elevator ribs line up. The VS and rudder ribs line up. The  Speedster was designed with the VS and rudder as a single airfoil but I changed  that so the VS was one air foil and the rudder was another airfoil. In  consultation with the Skystar factory at that time, they indicated that the  separate VS and rudder airfoils might actually be a lower drag design,  especially if the gap between the VS and rudder is filled. I believe they used  this design on their Model V demonstrator that I saw at the Watsonville Airshow  in the mid 1990"s and is where I originally had the idea to build mine that way.  So Tom, you have flown in a Model IV with "the elevator AND vertical and  rudder air foiled"!

  

 Roger 

 [quote]   ---

Tom Jones

Joined: 12 Mar 2006
Posts: 752
Location: Ellensburg, WA

Posted: Thu Jun 10, 2010 9:39 am Post subject: Re: wood ribs on tailfeathers on a Kitfox 4

Yes, I guess I have to retract that statement.  I have flown in an airfoil tail kitfox IV.  And it is a very nice flying airplane.  Blame my poor memory on the 60s.  Im 60 now.



Thinking about it now handling is very similar between my long wing slab tailed 4 and the air foil tail speedster.  Both behave well.

_________________
Tom Jones
Classic IV
503 Rotax, 72 inch Two blade Warp
Ellensburg, WA

markdonahue(at)earthlink.
Guest

Posted: Thu Jun 10, 2010 6:22 pm Post subject: wood ribs on tailfeathers on a Kitfox 4

Hi Jim  

I think that fairing/streamlining the vertical stab and rudder, aside from looking much cooler, aids in attached air flow, reduced resistance and, as Lynn says, reducing “hunting”.  I liken it to a rudder on a boat that I had, where the rudder was a flat plate, and at certain speeds it would start vibrating and hum like heck.  I am not suggesting that would happen if you left the rudder flat, as there are many out there like that, but that having a foil shape reduces that tendency.  I know for a fact, as a naval architect, that we have streamlined rudders on tugs and similar vessels, from flat plate design, and the operators can notice performance improvement.  

And as I say, it looks much cooler.  

Mark Donahue,  

Kitfox 4, 912 ul  

(building, very slowly, a rv 9a)  

       [quote][b]

egp8111

Joined: 25 Mar 2010
Posts: 49

Posted: Fri Jun 11, 2010 3:46 am Post subject: Re: wood ribs on tailfeathers on a Kitfox 4

the KFIII manual calls for wood stiffeners in the HS but they are not airfoil shape.  Does anyone have the template for the airfoil ribs on the HS and elevator that they could post ?  What material is used to make them, the plans are not specific on this.  thanks

lcfitt(at)sbcglobal.net
Guest

Posted: Fri Jun 11, 2010 10:38 am Post subject: wood ribs on tailfeathers on a Kitfox 4

Being experimental, I suppose you could use about anything.  I used 1/4" 

urathane foam with light weight glass laminated on each side.  I think the 

factory uses birch plywood 1/4" thick.  I doubt the airfoil is critical, 

meaning engineered.  I think what I would use in similar circumstances is 

1/8" plywood with a half inch stiffener hysoled to the side, making a "T" 

with the top of the tee being the rib.  Use a fillet on the hysol.



If you want to send your address - off list, direct - I have a partial set 

of ribs you can have for postage.



Lowell



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

From: "egp8111" <egp8111(at)aol.com>

Sent: Friday, June 11, 2010 4:46 AM

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

Subject: Re: wood ribs on tailfeathers on a Kitfox 4



 	  Quote: 	
		   



 the KFIII manual calls for wood stiffeners in the HS but they are not 

 airfoil shape.  Does anyone have the template for the airfoil ribs on the 

 HS and elevator that they could post ?  What material is used to make 

 them, the plans are not specific on this.  thanks





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=300923#300923

clint_bazzill(at)hotmail.
Guest

Posted: Sat Jun 12, 2010 10:12 am Post subject: wood ribs on tailfeathers on a Kitfox 4

Actually Kitfox uses 3mm 5 ply aircraft birch plywood.  .118 inch thick.



Clint



 	  Quote: 	
		   From: lcfitt(at)sbcglobal.net

 To: kitfox-list(at)matronics.com

 Subject: Re: Re: wood ribs on tailfeathers on a Kitfox 4

 Date: Fri, 11 Jun 2010 11:04:48 -0700

 

 --> Kitfox-List message posted by: "Lowell Fitt" <lcfitt(at)sbcglobal.net>

 

 Being experimental, I suppose you could use about anything.  I used 1/4" 

 urathane foam with light weight glass laminated on each side.  I think the 

 factory uses birch plywood 1/4" thick.  I doubt the airfoil is critical, 

 meaning engineered.  I think what I would use in similar circumstances is 

 1/8" plywood with a half inch stiffener hysoled to the side, making a "T" 

 with the top of the tee being the rib.  Use a fillet on the hysol.

 

 If you want to send your address - off list, direct - I have a partial set 

 of ribs you can have for postage.

 

 Lowell

 

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

 From: "egp8111" <egp8111(at)aol.com>

 Sent: Friday, June 11, 2010 4:46 AM

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

 Subject: Kitfox-List: Re: wood ribs on tailfeathers on a Kitfox 4

 

 > --> Kitfox-List message posted by: "egp8111" <egp8111(at)aol.com>

 >

 > the KFIII manual calls for wood stiffeners in the HS but they are not 

 > airfoil shape.  Does anyone have the template for the airfoil ribs on the 

 > HS and elevator that they could post ?  What material is used to make 

 > them, the plans are not specific on this.  thanks

 >

 >

 >

 >

 > Read this topic online here:

 >

 > http://forums.matronics.com/viewtopic.php?p=300923#300923

 >

 >

 >

 >

 >

 >

 >

 >

 >

 > 

&gt=========
	


[quote] 

 

 

 		 	   		     	  Quote: 	
		  [b]

lcfitt(at)sbcglobal.net
Guest

Posted: Sat Jun 12, 2010 12:42 pm Post subject: wood ribs on tailfeathers on a Kitfox 4

Hi Clint,

  

 The ribs from the 1992 kit I am building had  quarter inch ribs or the mm equivalent, They went into the mail this  morning.  It wouldn't surprise me that the newer models had the thinner  ribs.  I recall in the day that some builders were complaining about  warpage and the idea to blue in a stiffener.

  

 Lowell

  



  From: Clint Bazzill (clint_bazzill(at)hotmail.com) 

 Sent: Saturday, June 12, 2010 11:09 AM

 To: Kitfox list (kitfox-list(at)matronics.com) 

 Subject: RE: Re: wood ribs on tailfeathers on a Kitfox  4

 



Actually Kitfox uses 3mm 5 ply aircraft birch plywood.  .118  inch thick.



Clint



[quote] From: lcfitt(at)sbcglobal.net (lcfitt(at)sbcglobal.net)

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

  Subject: Re: Re: wood ribs on tailfeathers on a Kitfox 4

  Date: Fri, 11 Jun 2010 11:04:48 -0700

 

 --> Kitfox-List  message posted by: "Lowell Fitt" <lcfitt(at)sbcglobal.net (lcfitt(at)sbcglobal.net)>

 

  Being experimental, I suppose you could use about anything. I used 1/4" 

  urathane foam with light weight glass laminated on each side. I think the  

 factory uses birch plywood 1/4" thick. I doubt the airfoil is critical,  

 meaning engineered. I think what I would use in similar circumstances  is 

 1/8" plywood with a half inch stiffener hysoled to the side, making  a "T" 

 with the top of the tee being the rib. Use a fillet on the  hysol.

 

 If you want to send your address - off list, direct - I  have a partial set 

 of ribs you can have for postage.

 

  Lowell

 

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

 From: "egp8111"  <egp8111(at)aol.com>

 Sent: Friday, June 11, 2010 4:46 AM

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

 Subject: Re: wood ribs on  tailfeathers on a Kitfox 4

 

 > --> Kitfox-List message  posted by: "egp8111" <egp8111(at)aol.com>

 >

 > the KFIII  manual calls for wood stiffeners in the HS but they are not 

 >  airfoil shape. Does anyone have the template for the airfoil ribs on the  

 > HS and elevator that they could post ? What material is used to  make 

 > them, the plans are not specific on this. thanks

  >

 >

 >

 >

 > Read this topic online  here:

 >

 >  http://forums.matronics.com/viewtopic.php?p=300923#300923

 >

  >

 >

 >

 >

 >

 >

  >

 >

 > 

=========

 

 

 

 	  Quote: 	
		  
	




href="http://www.matronics.com/Navigator?Kitfox-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com

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[b]

dholly

Joined: 19 Dec 2006
Posts: 40
Location: Upstate NY

Posted: Tue Jun 15, 2010 5:45 pm Post subject: Re: wood ribs on tailfeathers on a Kitfox 4

I have the horizontal tail intercoastal installation instruction pages from both the Model III and IV manuals. Both call for 6 Mil aircraft ply material, however, there are some notable differences. Ie., intercoastal ribs are used in both horizontal stabilizer and elevator on the M-III (6 ribs in each), and it appears only the horizontal stabilizer on the M-IV used the ribs (6 ribs). The shape and length of the intercoastal ribs between Models are different as well, due in part to tubing dia. differences.

_________________
-Kitfox III 582 Blue/C Grove Spring / Aerocet 1100 Amphibs
-Airdale Avid+ (project) TD / W.I.B. Gear

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