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Rudder Rib #7 and #8 Underfitting in Spar

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bill_dom(at)yahoo.com
Guest

Posted: Sun May 28, 2006 1:31 pm Post subject: Rudder Rib #7 and #8 Underfitting in Spar

I have all my rudder parts built as per plans. I did a

test fit clamping the ribs to the spar and rib #7 and

#8 (6T4-7 and 6T4- are narrower right where it meet

the spar. My rudder spar is within .5 millimeter

accurate from top to bottom. According to the plans,

rib #2  is 340 mm and #3 is 590 mm from the beginning

of the doublers, that are 30 mm extended from the

bottom of the spar. 



The width of the spar at the point where rib #2 should

be located is 91 mm however, the plans call for rib #2

to be 88 mm in its wide side (projected). Im getting

exactly 1.5 mm difference in each side between the

flange of rib #2 and the flange of the spar. For rib

#3 the difference is 2 mm in each side. I presented a

piece of .016 skin and this difference would be

noticeable. My rudder spar flange has the correct

angle. I even presented the ribs in a drawing template

of the spar that is 100% accurate with the plans

dimensions and still getting this difference.



If I slide up the ribs to the point where they fit

correctly, #2 would have moved 35 mm and #3 would have

moved 80 mm.



I searched the archives and no one has had this

problem so I dont know what to do. It seems that I

might misinterpreted the plans but I cant see where.



I have measured my parts several times and they are

accurate with the plans.



Any thoughts?



William Dominguez

Plansbuilt Zodiac 601XL

Working on the rudder

__________________________________________________

Afterfxllc(at)aol.com
Guest

Posted: Sun May 28, 2006 1:52 pm Post subject: Rudder Rib #7 and #8 Underfitting in Spar

did you extend your doublers behond the spar by 30 mm? If not that is your  

problem.

larry(at)macsmachine.com
Guest

Posted: Sun May 28, 2006 2:07 pm Post subject: Rudder Rib #7 and #8 Underfitting in Spar

William,

You might shim your form a bit and stretch out the rib width or consider 

shims.  It's not uncommon to

have to add shims between rib and skins to get perfect skin alignments.  

In your case, the difference could

be had by reforming your ribs a little.  Better to reform than shim if 

it's possible.



Larry McFarland - 601HDS at www.macsmachine.com



William Dominguez wrote:



 	  Quote: 	
		  



I have all my rudder parts built as per plans. I did a

test fit clamping the ribs to the spar and rib #7 and

#8 (6T4-7 and 6T4- are narrower right where it meet

the spar. My rudder spar is within .5 millimeter

accurate from top to bottom. According to the plans,

rib #2  is 340 mm and #3 is 590 mm from the beginning

of the doublers, that are 30 mm extended from the

bottom of the spar. 



The width of the spar at the point where rib #2 should

be located is 91 mm however, the plans call for rib #2

to be 88 mm in its wide side (projected). Im getting

exactly 1.5 mm difference in each side between the

flange of rib #2 and the flange of the spar. For rib

#3 the difference is 2 mm in each side. I presented a

piece of .016 skin and this difference would be

noticeable. My rudder spar flange has the correct

angle. I even presented the ribs in a drawing template

of the spar that is 100% accurate with the plans

dimensions and still getting this difference.



If I slide up the ribs to the point where they fit

correctly, #2 would have moved 35 mm and #3 would have

moved 80 mm.



I searched the archives and no one has had this

problem so I dont know what to do. It seems that I

might misinterpreted the plans but I cant see where.



I have measured my parts several times and they are

accurate with the plans.



Any thoughts?



William Dominguez

Plansbuilt Zodiac 601XL

Working on the rudder

bill_dom(at)yahoo.com
Guest

Posted: Sun May 28, 2006 3:05 pm Post subject: Rudder Rib #7 and #8 Underfitting in Spar

Yes. 



William Dominguez

Plansbuilt Zodiac 601XL



--- Afterfxllc(at)aol.com wrote:



 	  Quote: 	
		   

 Afterfxllc(at)aol.com

 

 did you extend your doublers behond the spar by 30

 mm? If not that is your  

 problem.

 

 

 

 



 browse

 Subscriptions page,

 FAQ,

 http://www.matronics.com/Navigator?Zenith-List

 Admin.



 

 

 

  

  

  

 

 

 

 


	




__________________________________________________

bill_dom(at)yahoo.com
Guest

Posted: Sun May 28, 2006 3:05 pm Post subject: Rudder Rib #7 and #8 Underfitting in Spar

Thanks. What do you mean by reforming?



By shim, do you mean adding material as spacer?



William Dominguez

Plansbuilt Zodiac 601XL



--- LarryMcFarland <larry(at)macsmachine.com> wrote:



 	  Quote: 	
		   

 <larry(at)macsmachine.com>

 

 William,

 You might shim your form a bit and stretch out the

 rib width or consider 

 shims.  It's not uncommon to

 have to add shims between rib and skins to get

 perfect skin alignments.  

 In your case, the difference could

 be had by reforming your ribs a little.  Better to

 reform than shim if 

 it's possible.

 

 Larry McFarland - 601HDS at www.macsmachine.com

 

 William Dominguez wrote:

 

 >

 Dominguez <bill_dom(at)yahoo.com>

 >

 >I have all my rudder parts built as per plans. I

 did a

 >test fit clamping the ribs to the spar and rib #7

 and

 >#8 (6T4-7 and 6T4- are narrower right where it

 meet

 >the spar. My rudder spar is within .5 millimeter

 >accurate from top to bottom. According to the

 plans,

 >rib #2  is 340 mm and #3 is 590 mm from the

 beginning

 >of the doublers, that are 30 mm extended from the

 >bottom of the spar. 

 >

 >The width of the spar at the point where rib #2

 should

 >be located is 91 mm however, the plans call for rib

 #2

 >to be 88 mm in its wide side (projected). Im

 getting

 >exactly 1.5 mm difference in each side between the

 >flange of rib #2 and the flange of the spar. For

 rib

 >#3 the difference is 2 mm in each side. I presented

 a

 >piece of .016 skin and this difference would be

 >noticeable. My rudder spar flange has the correct

 >angle. I even presented the ribs in a drawing

 template

 >of the spar that is 100% accurate with the plans

 >dimensions and still getting this difference.

 >

 >If I slide up the ribs to the point where they fit

 >correctly, #2 would have moved 35 mm and #3 would

 have

 >moved 80 mm.

 >

 >I searched the archives and no one has had this

 >problem so I dont know what to do. It seems that I

 >might misinterpreted the plans but I cant see

 where.

 >

 >I have measured my parts several times and they are

 >accurate with the plans.

 >

 >Any thoughts?

 >

 >William Dominguez

 >Plansbuilt Zodiac 601XL

 >Working on the rudder

 >

 >

 >

 >

 > 

 > 

 > 

 >

 >

 >

 >

 >

 >

 >  

 >

 

 

 

 

 



 browse

 Subscriptions page,

 FAQ,

 http://www.matronics.com/Navigator?Zenith-List

 Admin.



 

 

 

  

  

  

 

 

 

 


	




__________________________________________________

larry(at)macsmachine.com
Guest

Posted: Sun May 28, 2006 4:06 pm Post subject: Rudder Rib #7 and #8 Underfitting in Spar

William,

If you've got the forms you used to bend the rib/flanges, you could re 

cut the form and spread the rib

outward some and re-bend the rib to pick up the 1.5mm.  Or you could 

just remake the ribs with new

forms.  You're only talking small parts and an hour and a half at most.  

I misspoke on the shims because

the skin material is too thin to accept the shift from shim to rib 

flange.  I have 3 shims on my center section

ribs that are tapered to nothing to gain precise support and alignment 

of the skin from rib to rib, but the

skins are thicker.



Larry McFarland

William Dominguez wrote:



 	  Quote: 	
		  



Thanks. What do you mean by reforming?



By shim, do you mean adding material as spacer?



William Dominguez

Plansbuilt Zodiac 601XL



--- LarryMcFarland <larry(at)macsmachine.com> wrote:



  



>

><larry(at)macsmachine.com>

>

>William,

>You might shim your form a bit and stretch out the

>rib width or consider 

>shims.  It's not uncommon to

>have to add shims between rib and skins to get

>perfect skin alignments.  

>In your case, the difference could

>be had by reforming your ribs a little.  Better to

>reform than shim if 

>it's possible.

>

>Larry McFarland - 601HDS at www.macsmachine.com

>    

>

admin(at)arachnidrobotics
Guest

Posted: Sun May 28, 2006 4:53 pm Post subject: Rudder Rib #7 and #8 Underfitting in Spar

You must come from the same type of fabrication background I did William.  I made the exact same mistake you did when I first began my project.  

 

     The 88mm dimension on Rib #2 is NOT the width of the rib.  It's the width of the rib's FORMING BLOCK.  If you add two materials (roughly 0.8 mm) and account for spring-back during forming you will end up with a 91mm wide rib, or very nearly so.  As I formed these on a CNC brake, the forming block dimension didn't even register in my head.  I have since added 1.5 mm to each dimension when omitting the forming blocks.  Everything has fit well since then.

 

     I sent an email to Zenith months ago regarding this very subject.  I was informed that many of the dimensions are to the limits of the forming blocks, and not the parts themselves.  I find this to be very in-exact and confusing at times, but manageable. 

 

     It would pay DOUBLE my plans price to receive fully dimensioned prints from Zenith with the FINISHED dimensions depicted.  When I began laying out the parts in Solidworks (3D CAD) to throw at the CNC punches and lasers, I had no end of compounding calculations to arrive at the finished product.

 

     I'm hoping one day that Chris at Zenith actually reads some of these posts and shells out the $ for a professional to re-work the drawings.  Heck, I'd offer mine if I thought he'd take them.  lol  Anyway, I hope this helped you.

 

 

 

    

  



    



William Dominguez <bill_dom(at)yahoo.com> wrote: 



I have all my rudder parts built as per plans. I did a

test fit clamping the ribs to the spar and rib #7 and

#8 (6T4-7 and 6T4- are narrower right where it meet

the spar. My rudder spar is within .5 millimeter

accurate from top to bottom. According to the plans,

rib #2  is 340 mm and #3 is 590 mm from the beginning

of the doublers, that are 30 mm extended from the

bottom of the spar. 



The width of the spar at the point where rib #2 should

be located is 91 mm however, the plans call for rib #2

to be 88 mm in its wide side (projected). Im getting

exactly 1.5 mm difference in each side between the

flange of rib #2 and the flange of the spar. For rib

#3 the difference is 2 mm in each side. I presented a

piece of .016 skin and this difference would be

noticeable. My rudder spar flange has the correct

angle. I even presented the ribs in a drawing template

of the spar that is 100% accurate with the plans

dimensions and still getting this difference.



If I slide up the ribs to the point where they fit

correctly, #2 would have moved 35 mm and #3 would have

moved 80 mm.



I searched the archives and no one has had this

problem so I dont know what to do. It seems that I

might misinterpreted the plans but I cant see where.



I have measured my parts several times and they are

accurate with the plans.



Any thoughts?



William Dominguez

Plansbuilt Zodiac 601XL

Working on the rudder

__________________________________________________

bill_dom(at)yahoo.com
Guest

Posted: Sun May 28, 2006 5:39 pm Post subject: Rudder Rib #7 and #8 Underfitting in Spar

Thanks. My forming block is 88mm. But I used the

bending brake only to pre-bend the part, then I used

the mallet to complete the bend and the part came up

just a fraction of millimeter bigger than the forming

block.



Thanks. My forming block is 88mm. But I used the

bending brake only to pre-bend the part, then I used

the mallet to complete the bend and the part came up

just a fraction of millimeter bigger than the forming

block.



Right now Im leaning toward remaking the parts

completely using new forming blocks with the right

dimensions.



William Dominguez

Plansbuilt Zodiac 601XL

--- Tom and Bren Henderson

<admin(at)arachnidrobotics.com> wrote:



 	  Quote: 	
		   

 Henderson <admin(at)arachnidrobotics.com>

 

   You must come from the same type of fabrication

 background I did William.  I made the exact same

 mistake you did when I first began my project.  

  

      The 88mm dimension on Rib #2 is NOT the width

 of the rib.  It's the width of the rib's FORMING

 BLOCK.  If you add two materials (roughly 0.8 mm)

 and account for spring-back during forming you will

 end up with a 91mm wide rib, or very nearly so.  As

 I formed these on a CNC brake, the forming block

 dimension didn't even register in my head.  I have

 since added 1.5 mm to each dimension when omitting

 the forming blocks.  Everything has fit well since

 then.

  

      I sent an email to Zenith months ago regarding

 this very subject.  I was informed that many of the

 dimensions are to the limits of the forming blocks,

 and not the parts themselves.  I find this to be

 very in-exact and confusing at times, but

 manageable. 

  

      It would pay DOUBLE my plans price to receive

 fully dimensioned prints from Zenith with the

 FINISHED dimensions depicted.  When I began laying

 out the parts in Solidworks (3D CAD) to throw at the

 CNC punches and lasers, I had no end of compounding

 calculations to arrive at the finished product.

  

      I'm hoping one day that Chris at Zenith

 actually reads some of these posts and shells out

 the $ for a professional to re-work the drawings. 

 Heck, I'd offer mine if I thought he'd take them. 

 lol  Anyway, I hope this helped you.

  

  

  

     

   

 

     

 

 William Dominguez <bill_dom(at)yahoo.com> wrote: -->

 Zenith-List message posted by: William Dominguez 

 

 I have all my rudder parts built as per plans. I did

 a

 test fit clamping the ribs to the spar and rib #7

 and

 #8 (6T4-7 and 6T4- are narrower right where it

 meet

 the spar. My rudder spar is within .5 millimeter

 accurate from top to bottom. According to the plans,

 rib #2  is 340 mm and #3 is 590 mm from the

 beginning

 of the doublers, that are 30 mm extended from the

 bottom of the spar. 

 

 The width of the spar at the point where rib #2

 should

 be located is 91 mm however, the plans call for rib

 #2

 to be 88 mm in its wide side (projected). Im getting

 exactly 1.5 mm difference in each side between the

 flange of rib #2 and the flange of the spar. For rib

 #3 the difference is 2 mm in each side. I presented

 a

 piece of .016 skin and this difference would be

 noticeable. My rudder spar flange has the correct

 angle. I even presented the ribs in a drawing

 template

 of the spar that is 100% accurate with the plans

 dimensions and still getting this difference.

 

 If I slide up the ribs to the point where they fit

 correctly, #2 would have moved 35 mm and #3 would

 have

 moved 80 mm.

 

 I searched the archives and no one has had this

 problem so I dont know what to do. It seems that I

 might misinterpreted the plans but I cant see where.

 

 I have measured my parts several times and they are

 accurate with the plans.

 

 Any thoughts?

 

 William Dominguez

 Plansbuilt Zodiac 601XL

 Working on the rudder

 

 

 __________________________________________________

 

 

 

 

 

 

  

  

  

 

 

 

 

 

 

 

 



 browse

 Subscriptions page,

 FAQ,

 http://www.matronics.com/Navigator?Zenith-List

 Admin.



 

 

 

  

  

  

 

 

 

 


	




__________________________________________________

hewettproperties(at)cox.n
Guest

Posted: Sun May 28, 2006 7:42 pm Post subject: Rudder Rib #7 and #8 Underfitting in Spar

Did you build the spar closed 5.5 degrees?



--

taffy0687(at)yahoo.com
Guest

Posted: Mon May 29, 2006 5:44 am Post subject: Rudder Rib #7 and #8 Underfitting in Spar

William-- with the aft rudder ribs, I found it much easier to do the complete bend on the bending brake as they have straight edges and not bother to build the forming blocks.   ( it might be necessary to "tweak" the narrow edge (10 mm) with the hand seamer pliers.

  Fritz-- Corvair



William Dominguez <bill_dom(at)yahoo.com> wrote:

  



Thanks. My forming block is 88mm. But I used the

bending brake only to pre-bend the part, then I used

the mallet to complete the bend and the part came up

just a fraction of millimeter bigger than the forming

block.



Thanks. My forming block is 88mm. But I used the

bending brake only to pre-bend the part, then I used

the mallet to complete the bend and the part came up

just a fraction of millimeter bigger than the forming

block.



Right now Im leaning toward remaking the parts

completely using new forming blocks with the right

dimensions.



William Dominguez

Plansbuilt Zodiac 601XL

--- Tom and Bren Henderson

wrote:



 	  Quote: 	
		   

 Henderson 

 

 You must come from the same type of fabrication

 background I did William. I made the exact same

 mistake you did when I first began my project. 

 

 The 88mm dimension on Rib #2 is NOT the width

 of the rib. It's the width of the rib's FORMING

 BLOCK. If you add two materials (roughly 0.8 mm)

 and account for spring-back during forming you will

 end up with a 91mm wide rib, or very nearly so. As

 I formed these on a CNC brake, the forming block

 dimension didn't even register in my head. I have

 since added 1.5 mm to each dimension when omitting

 the forming blocks. Everything has fit well since

 then.

 

 I sent an email to Zenith months ago regarding

 this very subject. I was informed that many of the

 dimensions are to the limits of the forming blocks,

 and not the parts themselves. I find this to be

 very in-exact and confusing at times, but

 manageable. 

 

 It would pay DOUBLE my plans price to receive

 fully dimensioned prints from Zenith with the

 FINISHED dimensions depicted. When I began laying

 out the parts in Solidworks (3D CAD) to throw at the

 CNC punches and lasers, I had no end of compounding

 calculations to arrive at the finished product.

 

 I'm hoping one day that Chris at Zenith

 actually reads some of these posts and shells out

 the $ for a professional to re-work the drawings. 

 Heck, I'd offer mine if I thought he'd take them. 

 lol Anyway, I hope this helped you.

 

 

 

 

 

 

 

 

 William Dominguez wrote: -->

 Zenith-List message posted by: William Dominguez 

 

 I have all my rudder parts built as per plans. I did

 a

 test fit clamping the ribs to the spar and rib #7

 and

 #8 (6T4-7 and 6T4- are narrower right where it

 meet

 the spar. My rudder spar is within .5 millimeter

 accurate from top to bottom. According to the plans,

 rib #2 is 340 mm and #3 is 590 mm from the

 beginning

 of the doublers, that are 30 mm extended from the

 bottom of the spar. 

 

 The width of the spar at the point where rib #2

 should

 be located is 91 mm however, the plans call for rib

 #2

 to be 88 mm in its wide side (projected). Im getting

 exactly 1.5 mm difference in each side between the

 flange of rib #2 and the flange of the spar. For rib

 #3 the difference is 2 mm in each side. I presented

 a

 piece of .016 skin and this difference would be

 noticeable. My rudder spar flange has the correct

 angle. I even presented the ribs in a drawing

 template

 of the spar that is 100% accurate with the plans

 dimensions and still getting this difference.

 

 If I slide up the ribs to the point where they fit

 correctly, #2 would have moved 35 mm and #3 would

 have

 moved 80 mm.

 

 I searched the archives and no one has had this

 problem so I dont know what to do. It seems that I

 might misinterpreted the plans but I cant see where.

 

 I have measured my parts several times and they are

 accurate with the plans.

 

 Any thoughts?

 

 William Dominguez

 Plansbuilt Zodiac 601XL

 Working on the rudder

 

 

 __________________________________________________

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 



 browse

 Subscriptions page,

 FAQ,

 http://www.matronics.com/Navigator?Zenith-List

 Admin.



 

 

 

 

 

 

 

 

 

 


	




__________________________________________________





		

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

 Everyone is raving about the  all-new Yahoo! Mail Beta.

bill_dom(at)yahoo.com
Guest

Posted: Mon May 29, 2006 7:10 am Post subject: Rudder Rib #7 and #8 Underfitting in Spar

Yes.



William Dominguez 

Plansbuilt 601XL



--- Hewett Properties <hewettproperties(at)cox.net>

wrote:



[quote] 

 Properties" <hewettproperties(at)cox.net>

 

 Did you build the spar closed 5.5 degrees?

 

 --

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