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Reaming of spar and CM bushes

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jglazener

Joined: 14 Apr 2010
Posts: 76
Location: Schoonhoven, Netherlands

Posted: Wed Aug 07, 2019 4:51 am Post subject: Reaming of spar and CM bushes

I have finally got the wings on and the bolts in. Bit of a black art since you can't look in and have no idea what you are doing. Once the lift pins have been bonded that should at least be repeatable but I still foresee that getting the spar pins in and out easily will still be difficult. Reaming at that point, as mentioned by Ian Ricard in his instructions would be  the obvious choice. Any body done this, and if so do you still have the reamer and could lend it to me?

_________________
Jeroen

http://www.europaowners.org/main.php?g2_itemId=44165

wdaniell.longport(at)gmai
Guest

Posted: Wed Aug 07, 2019 8:50 am Post subject: Reaming of spar and CM bushes

Jeroen

I would hesitate to ream spar bushes.Â  My experience is that when the wings are in the right position the pins go in easily but when the wings are not in the right position putting the pins in is from tough to impossible.Â  In my case the right position requires adjustment to wing position both in dihedral (tip up/down) and cord (twist) if that makes sense.Â  The right combination results in the pins going in easily.

Will

William Daniell



LONGPORT



On Wed, Aug 7, 2019 at 8:54 AM jglazener <j.glazener14(at)gmail.com (j.glazener14(at)gmail.com)> wrote:



 	  Quote: 	
		  --> Europa-List message posted by: "jglazener" <j.glazener14(at)gmail.com (j.glazener14(at)gmail.com)>

 

 I have finally got the wings on and the bolts in. Bit of a black art since you can't look in and have no idea what you are doing. Once the lift pins have been bonded that should at least be repeatable but I still foresee that getting the spar pins in and out easily will still be difficult. Reaming at that point, as mentioned by Ian Ricard in his instructions would beÂ  the obvious choice. Any body done this, and if so do you still have the reamer and could lend it to me?

 

 --------

 Jeroen

 

 http://www.europaowners.org/main.php?g2_itemId=44165

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=490739#490739

 

 

 

 

 

 

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 eferrer" target="_blank">http://forums.matronics.com

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freddythek10(at)gmail.com
Guest

Posted: Wed Aug 07, 2019 9:31 am Post subject: Reaming of spar and CM bushes

 	  Quote: 	
		  On Aug 7, 2019, at 5:51 AM, jglazener <j.glazener14(at)gmail.com (j.glazener14(at)gmail.com)> wrote:

I have finally got the wings on and the bolts in. Bit of a black art since you can't look in and have no idea what you are doing. 

	


Jeroenâ€¦I too would caution against doing any reaming of the spar bushings.



While I marvel at the ability of some who have mastered single-handed wing installation, in my personal experience I have always depended upon having helpers on each wingtip who subtly adjust both dihedral and sweep while I insert the spar pins.



I also keep a tapered pin and rubber mallet handy in order to help achieve proper alignment.



â€¦this works for meâ€¦



Fred

freddythek10(at)gmail.com
Guest

Posted: Wed Aug 07, 2019 9:36 am Post subject: Reaming of spar and CM bushes

Jeroenâ€¦Iâ€™ve also found that a daub of axle grease works wondersâ€¦F.



 	  Quote: 	
		  On Aug 7, 2019, at 5:51 AM, jglazener <j.glazener14(at)gmail.com (j.glazener14(at)gmail.com)> wrote:

I have finally got the wings on and the bolts in. Bit of a black art since you can't look in and have no idea what you are doing. 

	


Jeroenâ€¦I too would caution against doing any reaming of the spar bushings.



While I marvel at the ability of some who have mastered single-handed wing installation, in my personal experience I have always depended upon having helpers on each wingtip who subtly adjust both dihedral and sweep while I insert the spar pins.



I also keep a tapered pin and rubber mallet handy in order to help achieve proper alignment.



â€¦this works for meâ€¦



Fred

budyerly(at)msn.com
Guest

Posted: Wed Aug 07, 2019 7:37 pm Post subject: Reaming of spar and CM bushes

Jeroen, 

Spar pip pins are just under .5 inches.  I’ve reamed the bushes on most of my aircraft.  I don’t do hammers, channel lock pliers, and crowbars to rig an airplane.  Pins should slide in with some effort but not be so tight, hammers must  be used.  Disassembly should not require wood, crowbars and vice grips. 

  

A word of caution.  DON’T OVER DO IT ON THE REAMING! 

  

If you did your initial pin alignment check with the wings off the plane and the incidence angle on each wing perfect when you set your bushes, and your bolts and sockets are nearly a zero tolerance fit, things will be pretty close.  If  the pins are hard to set in this position at this point, it will be worse in the plane. 

  

With the port wing in the fuselage, and the spar socket and incidence and sweep correct on the port wing, when you glue the cockpit bushes all should be OK, sort of.  There is a very good chance that the angle of the bush in the cockpit  will be just slightly off as the bolts you are using are rather sloppy at anywhere from .5 inches to .493 inches diameter depending on coating.  The Europa supplied raw steel alignment bolt is typically at the minimum dimension.  That is why I have tight fitting  pip pins or bolts to set my bushes during construction so I cut down the slop as the glue dries and use extreme care to align the incidence angle and dihedral for proper alignment. 

  

Bad news: 

Bushings are anodized and normally right at the .5 inch diameter. 

The SouthCo pip pin is nominally .4985 inches. 

The Allen bolt pin for the starboard side is .497 to .495.  Since it takes about .005 for any kind of tight slip fit, a .499 pip pin just won’t go in easy, ever.  No amount of grease will fix that fit, and you very well may destroy the  pip pin with rigging and derigging.  The average hardware uncoated steel bolt used in the assembly is a bit sloppier so a clean up of any redux in the wing spar bushes and anodizing in the sockets and the alignment may be necessary.   

  

With the port wing rigged, and the starboard pin inserted, use a straight flat tipped drift to check your spar to bush fit on the port side.  You should feel no hard lip in the cockpit to wing bush with the wing set properly in the cup  at incidence.  If there is a sharp edge, your bushings should be reset as you will be reaming a lot.  If it is a slight detent or rough spot, then ream it or reset the socket.  Rig the other wing and support it and check the wing socket fit.  It should be  nearly aligned.  Again use the drift to check, then determine if it must be reamed.  Yes, ream from the cockpit, all the way through both spars.  Insert the pin and check the other side.  Your plane will forever rig comfortably in only a few minutes.  No fussing  and fighting unless something is not aligned right.  Remember, you only want to ream a couple thousands not 10s of thousandths.  

  

Mic your bolts and pins, then mic your bushes.  If a bush in the cockpit is off slightly either heat a bolt and insert to soften the Redux and realign (always dangerous) or carefully ream the hole with the spar inserted and wing braced  into its position so there is no bending on the fuselage or wing spars.  Don’t hit the tank with the reamer!   

  

Your own .5 reamer is handy to have, as the door shoot bolts will need a touch up after glue in as will the washer on the port wing socket also.  So buy one.  A cheap Chinese reamer will do and it only cost a couple of beers.  For the cost  of a case of beer, you can get a set.  Reamer sets of 3/16 to ½ inch are really handy for reaming the engine mount to 5/16 for engine install, as well as cleaning many 3/16 bolt holes, cleaning out paint from all holes, aligning poorly welded and drilled parts  and the like.  Get a set and it pays for itself.  Cheap sets are $20-30 and excellent sets are $80. 

 

Best Regards, 

  

Bud Yerly 

Custom Flight Creations, Inc. 

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com <owner-europa-list-server(at)matronics.com> on behalf of William Daniell <wdaniell.longport(at)gmail.com>

 Sent: Wednesday, August 7, 2019 12:53:16 PM

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

 Subject: Re: Reaming of spar and CM bushes  

 

   Jeroen

 I would hesitate to ream spar bushes.  My experience is that when the wings are in the right position the pins go in easily but when the wings are not in the right position putting the pins in  is from tough to impossible.  In my case the right position requires adjustment to wing position both in dihedral (tip up/down) and cord (twist) if that makes sense.  The right combination results in the pins going in easily.

 Will

      William Daniell

 

 LONGPORT

 

 

 

 

 

 

 

  On Wed, Aug 7, 2019 at 8:54 AM jglazener <j.glazener14(at)gmail.com (j.glazener14(at)gmail.com)> wrote:

 

  	  Quote: 	
		   --> Europa-List message posted by: "jglazener" <j.glazener14(at)gmail.com (j.glazener14(at)gmail.com)>

 

 I have finally got the wings on and the bolts in. Bit of a black art since you can't look in and have no idea what you are doing. Once the lift pins have been bonded that should at least be repeatable but I still foresee that getting the spar pins in and out  easily will still be difficult. Reaming at that point, as mentioned by Ian Ricard in his instructions would be  the obvious choice. Any body done this, and if so do you still have the reamer and could lend it to me?

 

 --------

 Jeroen

 

 http://www.europaowners.org/main.php?g2_itemId=44165

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=490739#490739

 

 

 

 

 

 

 ===========

 pa-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?Europa-List

 ===========

 FORUMS -

 eferrer" target="_blank">http://forums.matronics.com

 ===========

 WIKI -

 errer" target="_blank">http://wiki.matronics.com

 ===========

 b Site -

           -Matt Dralle, List Admin.

 rel="noreferrer" target="_blank">http://www.matronics.com/contribution

 ===========

freddythek10(at)gmail.com
Guest

Posted: Wed Aug 07, 2019 9:31 pm Post subject: Reaming of spar and CM bushes

Budâ€¦you mention the use of the SouthCo pip pin on the port side and the Allen bolt pin on starboard.

Do you know the reason for using different types of pins here?



Is there any downside to using SouthCo pip pins both port and starboard?â€¦seems Iâ€™ve heard that some builders have done so.



Fred 	  Quote: 	
		  On Aug 7, 2019, at 8:35 PM, Bud Yerly <budyerly(at)msn.com (budyerly(at)msn.com)> wrote:



The SouthCo pip pin is nominally .4985 inches.

The Allen bolt pin for the starboard side is .497 to .495.

budyerly(at)msn.com
Guest

Posted: Thu Aug 08, 2019 5:43 am Post subject: Reaming of spar and CM bushes

One more thing. 

  

As Fred Klein reminded me, use of a tapered pin for initial alignment of the wings, especially during the build is critical.   

Most of us still use a taper pin (especially in cold weather, or when wing gap seals are renewed and the wing is held proud.  I just bought another starboard wing pin and ground it to a taper.   

  

For many, rigging is aided by doing the following:  With the slightly smaller diameter of the starboard now tapered pin, one can rig the port wing into the socket and support the port wing to relieve stress on the socket.  Insert the  taper pin in the port socket to “nurse” the wing in tight and aligned and then put in the starboard pin with ease.  
Withdraw the taper pin from the port side, as no harm can be done or sockets overstressed as the port wing is installed into its lift sockets.
Rig the starboard wing, using the taper pin, seat the taper pin home in the port side.  
 Seat the starboard pin now fully.
Support the starboard wing to relieve the socket from added stress with a good helper or a padded saw horse on the spar as you did on the port.  Insert the pip pin into the port side  securing the wing completely.   

  

Personally, 12AY being a Classic had many miss-alignment opportunities.  Over the last 12 years with 12AY, I have not had to use a taper pin to rig.  But I do bring saw horses so as not to overstress my rigging helper or sockets.  I also  pull my wings 2-3 times a year for inspection or minor mods I make so proper alignment is necessary.  The wing rig on my plane is a no brainer.  But it took time. 

  

Best Regards, 

Bud Yerly 

  

  

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com <owner-europa-list-server(at)matronics.com> on behalf of Bud Yerly <budyerly(at)msn.com>

 Sent: Wednesday, August 7, 2019 11:35:13 PM

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

 Subject: RE: Reaming of spar and CM bushes  

 

     

Jeroen, 

Spar pip pins are just under .5 inches.  I’ve reamed the bushes on most of my aircraft.  I don’t do hammers, channel lock pliers, and crowbars to rig an airplane.  Pins should slide in with some effort but not be so tight, hammers must  be used.  Disassembly should not require wood, crowbars and vice grips. 

  

A word of caution.  DON’T OVER DO IT ON THE REAMING! 

  

If you did your initial pin alignment check with the wings off the plane and the incidence angle on each wing perfect when you set your bushes, and your bolts and sockets are nearly a zero tolerance fit, things will be pretty close.  If  the pins are hard to set in this position at this point, it will be worse in the plane. 

  

With the port wing in the fuselage, and the spar socket and incidence and sweep correct on the port wing, when you glue the cockpit bushes all should be OK, sort of.  There is a very good chance that the angle of the bush in the cockpit  will be just slightly off as the bolts you are using are rather sloppy at anywhere from .5 inches to .493 inches diameter depending on coating.  The Europa supplied raw steel alignment bolt is typically at the minimum dimension.  That is why I have tight fitting  pip pins or bolts to set my bushes during construction so I cut down the slop as the glue dries and use extreme care to align the incidence angle and dihedral for proper alignment. 

  

Bad news: 

Bushings are anodized and normally right at the .5 inch diameter. 

The SouthCo pip pin is nominally .4985 inches. 

The Allen bolt pin for the starboard side is .497 to .495.  Since it takes about .005 for any kind of tight slip fit, a .499 pip pin just won’t go in easy, ever.  No amount of grease will fix that fit, and you very well may destroy the  pip pin with rigging and derigging.  The average hardware uncoated steel bolt used in the assembly is a bit sloppier so a clean up of any redux in the wing spar bushes and anodizing in the sockets and the alignment may be necessary.   

  

With the port wing rigged, and the starboard pin inserted, use a straight flat tipped drift to check your spar to bush fit on the port side.  You should feel no hard lip in the cockpit to wing bush with the wing set properly in the cup  at incidence.  If there is a sharp edge, your bushings should be reset as you will be reaming a lot.  If it is a slight detent or rough spot, then ream it or reset the socket.  Rig the other wing and support it and check the wing socket fit.  It should be  nearly aligned.  Again use the drift to check, then determine if it must be reamed.  Yes, ream from the cockpit, all the way through both spars.  Insert the pin and check the other side.  Your plane will forever rig comfortably in only a few minutes.  No fussing  and fighting unless something is not aligned right.  Remember, you only want to ream a couple thousands not 10s of thousandths.  

  

Mic your bolts and pins, then mic your bushes.  If a bush in the cockpit is off slightly either heat a bolt and insert to soften the Redux and realign (always dangerous) or carefully ream the hole with the spar inserted and wing braced  into its position so there is no bending on the fuselage or wing spars.  Don’t hit the tank with the reamer!   

  

Your own .5 reamer is handy to have, as the door shoot bolts will need a touch up after glue in as will the washer on the port wing socket also.  So buy one.  A cheap Chinese reamer will do and it only cost a couple of beers.  For the cost  of a case of beer, you can get a set.  Reamer sets of 3/16 to ½ inch are really handy for reaming the engine mount to 5/16 for engine install, as well as cleaning many 3/16 bolt holes, cleaning out paint from all holes, aligning poorly welded and drilled parts  and the like.  Get a set and it pays for itself.  Cheap sets are $20-30 and excellent sets are $80. 

 

Best Regards, 

  

Bud Yerly 

Custom Flight Creations, Inc. 

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com <owner-europa-list-server(at)matronics.com> on behalf of William Daniell <wdaniell.longport(at)gmail.com>

 Sent: Wednesday, August 7, 2019 12:53:16 PM

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

 Subject: Re: Reaming of spar and CM bushes  

 

   Jeroen

 I would hesitate to ream spar bushes.  My experience is that when the wings are in the right position the pins go in easily but when the wings are not in the right position putting the pins in  is from tough to impossible.  In my case the right position requires adjustment to wing position both in dihedral (tip up/down) and cord (twist) if that makes sense.  The right combination results in the pins going in easily.

 Will

      William Daniell

 

 LONGPORT

 

 

 

 

 

 

 

  On Wed, Aug 7, 2019 at 8:54 AM jglazener <j.glazener14(at)gmail.com (j.glazener14(at)gmail.com)> wrote:

 

  	  Quote: 	
		   --> Europa-List message posted by: "jglazener" <j.glazener14(at)gmail.com (j.glazener14(at)gmail.com)>

 

 I have finally got the wings on and the bolts in. Bit of a black art since you can't look in and have no idea what you are doing. Once the lift pins have been bonded that should at least be repeatable but I still foresee that getting the spar pins in and out  easily will still be difficult. Reaming at that point, as mentioned by Ian Ricard in his instructions would be  the obvious choice. Any body done this, and if so do you still have the reamer and could lend it to me?

 

 --------

 Jeroen

 

 http://www.europaowners.org/main.php?g2_itemId=44165

 

 

 

 

 Read this topic online here:

 

 http://forums.matronics.com/viewtopic.php?p=490739#490739

 

 

 

 

 

 

 ===========

 pa-List" rel="noreferrer" target="_blank">http://www.matronics.com/Navigator?Europa-List

 ===========

 FORUMS -

 eferrer" target="_blank">http://forums.matronics.com

 ===========

 WIKI -

 errer" target="_blank">http://wiki.matronics.com

 ===========

 b Site -

           -Matt Dralle, List Admin.

 rel="noreferrer" target="_blank">http://www.matronics.com/contribution

 ===========

budyerly(at)msn.com
Guest

Posted: Sat Aug 10, 2019 1:30 pm Post subject: Reaming of spar and CM bushes

Fred, 

Back before my time when mod 52 was done for the GW increase.  The classic had two 3/8 pins originally.  Mod 52 uses the ½ inch pins and a spar strap . 

  

As the wings pull forward under load, the fuselage would flex so they put in the cross bar and the new sockets. 

  

Then the concern was that the starboard wing spar could become dislodged from the socket and interfere with controls.  The quick fix was to hold in the spar tip with a pip pin.  The port wing was figured would stay put, and the spar strap  would prevent flexing of the spar. 

  

That is all I know.  Andy would have the particulars on the detailed history.  It sort of all makes sense.  

  

Best Regards, 

Bud Yerly 

  

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com <owner-europa-list-server(at)matronics.com> on behalf of Fred Klein <freddythek10(at)gmail.com>

 Sent: Thursday, August 8, 2019 1:29:43 AM

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

 Subject: Re: Reaming of spar and CM bushes  

 

 Bud…you mention the use of the SouthCo pip pin on the port side and the Allen bolt pin on starboard.  

 Do you know the reason for using different types of pins here?

  

 Is there any downside to using SouthCo pip pins both port and starboard?…seems I’ve heard that some builders have done so.

  

 Fred   	  Quote: 	
		   On Aug 7, 2019, at 8:35 PM, Bud Yerly <budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

     

  The SouthCo pip pin is nominally .4985 inches.

  The Allen bolt pin for the starboard side is .497 to .495.

peterz(at)zutrasoft.com
Guest

Posted: Sat Aug 10, 2019 1:49 pm Post subject: Reaming of spar and CM bushes

What i have never understood, is why the cockpit module spar pin bushings are not vertical slots, because when the wings are flexing under G, the lift pins take the fuse lift loads,  and the spar flexing (under positive G) actually force the spar pins _downard_  against the cockpit module....obviously totally counter-productive.

Pete 

A239



On Aug 10, 2019, at 5:29 PM, Bud Yerly <budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

 	  Quote: 	
		          

Fred, 

Back before my time when mod 52 was done for the GW increase.  The classic had two 3/8 pins originally.  Mod 52 uses the Â½ inch pins and a spar strap . 

  

As the wings pull forward under load, the fuselage would flex so they put in the cross bar and the new sockets. 

  

Then the concern was that the starboard wing spar could become dislodged from the socket and interfere with controls.  The quick fix was to hold in the spar tip with a pip pin.  The port wing was figured would stay put, and the spar strap  would prevent flexing of the spar. 

  

That is all I know.  Andy would have the particulars on the detailed history.  It sort of all makes sense.  

  

Best Regards, 

Bud Yerly 

  

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com) <owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com)> on behalf of Fred Klein <freddythek10(at)gmail.com (freddythek10(at)gmail.com)>

 Sent: Thursday, August 8, 2019 1:29:43 AM

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

 Subject: Re: Reaming of spar and CM bushes  

 

 Budâ€¦you mention the use of the SouthCo pip pin on the port side and the Allen bolt pin on starboard.  

 Do you know the reason for using different types of pins here?

  

 Is there any downside to using SouthCo pip pins both port and starboard?â€¦seems Iâ€™ve heard that some builders have done so.

  

 Fred   	  Quote: 	
		   On Aug 7, 2019, at 8:35 PM, Bud Yerly <budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

     

  The SouthCo pip pin is nominally .4985 inches.

  The Allen bolt pin for the starboard side is .497 to .495.

budyerly(at)msn.com
Guest

Posted: Sat Aug 10, 2019 6:23 pm Post subject: Reaming of spar and CM bushes

On first glance one would see it that way. 

  

The lift pins on the aircraft side (like most gliders) take all the lifting load so the wing spars don’t really bend much and the wing spar pins are in fact set properly to do their one and only job, absorb the bending shear load of the  two spars.  The force of the non bending spars put little force on the cockpit module (in theory).  I suppose one could take out the cockpit sockets and in a perfect positive load the spar pins would have no effect on the cockpit module.  However, as you intuitively  figured out, the spars have to be attached to the cockpit/fuselage to keep the wings from shifting laterally, as well as aft bending and forward bending and of course how the heck could we rig the wings without the cockpit module pins and sockets... 

  

We killed this horse some years ago and somehow all of us engineering types figured out John Bewley got it right when doing the original structural analysis when the prototype was built.  His testament is there are no ADs on his structural  work.  His rework of the glider wing spar (Mod78) makes that wing a brute.  No need for a spar strap for sure. 

  

  

Best Regards, 

Bud Yerly 

  

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com <owner-europa-list-server(at)matronics.com> on behalf of Pete <peterz(at)zutrasoft.com>

 Sent: Saturday, August 10, 2019 5:47:37 PM

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

 Subject: Re: Reaming of spar and CM bushes  

 

  

 What i have never understood, is why the cockpit module spar pin bushings are not vertical slots, because when the wings are flexing under G, the lift pins take the fuse lift loads,  and the spar flexing (under positive G) actually force the  spar pins _downard_  against the cockpit module....obviously totally counter-productive.

 

 

 Pete 

 A239

 

 On Aug 10, 2019, at 5:29 PM, Bud Yerly <budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

 

 

  	  Quote: 	
		       

Fred, 

Back before my time when mod 52 was done for the GW increase.  The classic had two 3/8 pins originally.  Mod 52 uses the ½ inch pins and a spar strap . 

  

As the wings pull forward under load, the fuselage would flex so they put in the cross bar and the new sockets. 

  

Then the concern was that the starboard wing spar could become dislodged from the socket and interfere with controls.  The quick fix was to hold in the spar tip with a pip pin.  The port wing was figured would stay put, and the spar strap  would prevent flexing of the spar. 

  

That is all I know.  Andy would have the particulars on the detailed history.  It sort of all makes sense.  

  

Best Regards, 

Bud Yerly 

  

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com) <owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com)> on behalf of Fred Klein <freddythek10(at)gmail.com (freddythek10(at)gmail.com)>

 Sent: Thursday, August 8, 2019 1:29:43 AM

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

 Subject: Re: Reaming of spar and CM bushes  

 

 Bud…you mention the use of the SouthCo pip pin on the port side and the Allen bolt pin on starboard.  

 Do you know the reason for using different types of pins here?

  

 Is there any downside to using SouthCo pip pins both port and starboard?…seems I’ve heard that some builders have done so.

  

 Fred   	  Quote: 	
		   On Aug 7, 2019, at 8:35 PM, Bud Yerly <budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

     

  The SouthCo pip pin is nominally .4985 inches.

  The Allen bolt pin for the starboard side is .497 to .495.

Duncan McFadyean

Joined: 18 Jan 2011
Posts: 219

Posted: Sun Aug 11, 2019 12:20 am Post subject: Reaming of spar and CM bushes

That analysis assumes the fuselage structure to be inelastic and utterly unyielding, whilst the spar is privaleged to flex.



All of the vertical loads going in to the lift pins have to pass through the fus structure too, which will yield to a greater or lesser extent.



Duncan Mcf.

 	  Quote: 	
		  On 10 August 2019 at 22:47 Pete <peterz(at)zutrasoft.com> wrote: 

 

 



What i have never understood, is why the cockpit module spar pin bushings are not vertical slots, because when the wings are flexing under G, the lift pins take the fuse lift loads,  and the spar flexing (under positive G) actually force the spar pins _downard_  against the cockpit module....obviously totally counter-productive.

Pete 

A239



On Aug 10, 2019, at 5:29 PM, Bud Yerly < budyerly(at)msn.com (budyerly(at)msn.com)> wrote: 

 



 	  Quote: 	
		  

Fred,

Back before my time when mod 52 was done for the GW increase.  The classic had two 3/8 pins originally.  Mod 52 uses the ½ inch pins and a spar strap .

 

As the wings pull forward under load, the fuselage would flex so they put in the cross bar and the new sockets.

 

Then the concern was that the starboard wing spar could become dislodged from the socket and interfere with controls.  The quick fix was to hold in the spar tip with a pip pin.  The port wing was figured would stay put, and the spar strap would prevent flexing of the spar.

 

That is all I know.  Andy would have the particulars on the detailed history.  It sort of all makes sense.

 

Best Regards,

Bud Yerly

 

Sent from  Mail for Windows 10

 

From: owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com) <owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com)> on behalf of Fred Klein <freddythek10(at)gmail.com (freddythek10(at)gmail.com)>

 Sent: Thursday, August 8, 2019 1:29:43 AM

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

 Subject: Re: Reaming of spar and CM bushes 



Bud…you mention the use of the SouthCo pip pin on the port side and the Allen bolt pin on starboard.



Do you know the reason for using different types of pins here?

Is there any downside to using SouthCo pip pins both port and starboard?…seems I’ve heard that some builders have done so.

Fred 



 	  Quote: 	
		  On Aug 7, 2019, at 8:35 PM, Bud Yerly < budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

The SouthCo pip pin is nominally .4985 inches.

The Allen bolt pin for the starboard side is .497 to .495.

Duncan McFadyean

Joined: 18 Jan 2011
Posts: 219

Posted: Sun Aug 11, 2019 12:32 am Post subject: Reaming of spar and CM bushes

I would add that in level flight at 1g, my spar pins are as easy to rotate in their holes as when sat on the ground.



DMcF.

 	  Quote: 	
		  On 11 August 2019 at 09:19 D McFadyean <ami-mcfadyean(at)talktalk.net> wrote: 

 



That analysis assumes the fuselage structure to be inelastic and utterly unyielding, whilst the spar is privaleged to flex.



All of the vertical loads going in to the lift pins have to pass through the fus structure too, which will yield to a greater or lesser extent.



Duncan Mcf.

 	  Quote: 	
		  On 10 August 2019 at 22:47 Pete <peterz(at)zutrasoft.com> wrote: 

 

  



What i have never understood, is why the cockpit module spar pin bushings are not vertical slots, because when the wings are flexing under G, the lift pins take the fuse lift loads,  and the spar flexing (under positive G) actually force the spar pins _downard_  against the cockpit module....obviously totally counter-productive.

Pete 

A239



On Aug 10, 2019, at 5:29 PM, Bud Yerly < budyerly(at)msn.com (budyerly(at)msn.com)> wrote: 

 



 	  Quote: 	
		  

Fred,

Back before my time when mod 52 was done for the GW increase.  The classic had two 3/8 pins originally.  Mod 52 uses the ½ inch pins and a spar strap .

 

As the wings pull forward under load, the fuselage would flex so they put in the cross bar and the new sockets.

 

Then the concern was that the starboard wing spar could become dislodged from the socket and interfere with controls.  The quick fix was to hold in the spar tip with a pip pin.  The port wing was figured would stay put, and the spar strap would prevent flexing of the spar.

 

That is all I know.  Andy would have the particulars on the detailed history.  It sort of all makes sense.

 

Best Regards,

Bud Yerly

 

Sent from  Mail for Windows 10

 

From: owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com) <owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com)> on behalf of Fred Klein <freddythek10(at)gmail.com (freddythek10(at)gmail.com)>

 Sent: Thursday, August 8, 2019 1:29:43 AM

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

 Subject: Re: Reaming of spar and CM bushes 



Bud…you mention the use of the SouthCo pip pin on the port side and the Allen bolt pin on starboard.



Do you know the reason for using different types of pins here?

Is there any downside to using SouthCo pip pins both port and starboard?…seems I’ve heard that some builders have done so.

Fred 



 	  Quote: 	
		  On Aug 7, 2019, at 8:35 PM, Bud Yerly < budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

The SouthCo pip pin is nominally .4985 inches.

The Allen bolt pin for the starboard side is .497 to .495.

budyerly(at)msn.com
Guest

Posted: Sun Aug 11, 2019 11:05 am Post subject: Reaming of spar and CM bushes

Last word of mine on reaming and rigging: 

Thanks to my friend Pete Jeffers, and others asking me to clear up and answer a couple more things on rigging issues and errors and of course to address the use of a starboard pip pin point I failed to comment on and the obligatory legal  protection comments on rigging: 

  

In the manual, the rigging of the wings to the fuselage is about as clear as some of my quips.  There are many nicknames for spar cups (buckets), lift sockets or wing sockets, and spar bushings ( or cockpit sockets as I sometimes call them),  don’t be confused.  Read the manual carefully and note that the fit of the wings to each other and then to the cockpit module is somewhat difficult to get right.  In the old Classic, we rigged the wings and cockpit module together on the floor in a vertical  position to get the wings and fuselage bushings all in a line.  I used zero tolerance bolts to do my wing bush alignment and assure the bushes in the wing and fuselage were perfectly aligned.  Then I put the module in the lower “canoe” (but not using crates  and beer cases) and of course it flexed and I had a devil of a time figuring out what I did wrong and why my zero tolerance bolts would no longer fit all three bushes as they did on the floor.  I also noted the port wing was against the fuselage side rather  than an even fuselage to wing gap. I didn’t screw up, fiberglass moves, the cockpit module is not always straight, in any direction, and I learned that some minor fiberglass clearance issues in the wing spar hole, wing root length and slip fit tolerances were  necessary for a plane that could be rigged easily on a daily basis (I was so naïve. ) .  In the XS kit, we rig with the cockpit module glued in the fuselage and still have alignment woes (surprise).  For those of you doing outdoor rigging, due to shop or hangar  limitations, it is difficult to get this procedure precise.  Doing both wings at once during failing daylight on a sloped drive way or a soggy yard complicates the rig further.  (I don’t even use the dummy spar so don’t ask.)  Either way, the wings should  rig out of the fuselage easily and a reamer is nothing more than a cleaning tool for swarf or to get a proper slip fit.  Proper jigs and holding fixtures were essential for me to get things straight in my shop.  In my experience, and most of yours, the short  wing spar bushings are glued and aligned well.  However, when fixing the cockpit module SO1 spar bushings, some epoxy may weep in the hole, there may be contact errors between the fuselage and wings that must be adjusted to properly align these cockpit SO1  spar bushings.  Initially the epoxy is what must be cleaned.  I have gotten stock from Europa of the ½ inch pip pins that measured exactly .5 inches.  No amount of grease can fix a .5 pin into a .5 bush pin to socket fit.  Minor factory building errors and  tight tolerances required reaming of the spar bush port side just to put the wings together initially using the ½ inch pin rather than the sloppy bolt used in rigging outside the aircraft.  In my work experience, the bolts fit easier because they are slightly  undersized rather than the pip pin as I stated before.  In this case, reaming was necessary to get the pin to fit the three bushings aligned with these bolts to allow more of a slip fit or I would break the pip pin head off eventually.  As Pete said so well:   “Difficulty in subsequent assembly has always been shown to be caused by misalignment somewhere. Reamers can possibly be used to remove paint/resin etc. but not to make things fit in the wrong position.”   

  

As I said, if your wing to fuselage spar pin alignment bushes are out of alignment, use a drift to ascertain where the error is and fix that.  If a square end of a 3/32 or ¼ inch drift or punch hits  an edge, and will not pass, you have a bush that is out of alignment.  Find out why.  If a drift does not hang up around the hole but one can still feel the various bush joints, a taper pin should align those bushes.  That is why I use a taper pin for the  alignment and rigging process.  Once the starboard taper pin rigging aid is in, the port pair of bushes need to be checked and if there is a significant alignment problem that prevents a drift from passing at any one point without hitting an edge, you have  a problem.  Fix it.  If they are aligned, then the other pin “should” fit without undo pounding, vice grips and effort.  Should I have only interference, I do ream the hole if it is only an interference problem.  This provides a smooth round triple bushing  hole for the pin to fit snugly in without the pin being grooved by the slightly skewed bushes.  Remember, the reamer is to clearance a hole, not to fix a construction error.  The final test is if both wings are supported to relieve pressure on the spar cups,  each pin should be stiff, but rotate by hand.  With all the pins in, you know you went too far if you grab the wingtip and shake for and aft, up and down and the wings rattle badly, then you need to put in new bushes.  If done properly, the final rig at the  field, even after being disassembled for quite some time due to maintenance, will rig with little effort and be secure and slop free.  If your wings are really tight now, it will loosen with age and pin and bush wear, but with age our strength fails also.   I find it a tie, so I ream to allow the pins to rotate and slide firmly but without the need for hammers and pliers.  I use no more than a bit of grease to prevent corrosion and aid in the slip fit.   

  

To appease my lawyers: 

The Europa does not use two ½ inch pips because only the port side pip pin is necessary structurally.  Normally the starboard pin is shortened to just clear of the spar as it can interfere with the  aileron quick disconnect.  The starboard wing lift sockets on the side of the fuselage keep the starboard root side spar from moving aft or allowing the port wing spar tip to force the starboard spar to move anywhere.  Therefore a starboard pip pin would do  nothing for you structurally except create an interference problem.  The port pip pin retains the starboard spar from deflecting aft under load.  Hence we install the pip pin to the port side, then washer it up to allow the pip pin retaining balls to just  lock the spar cup, with hardened washer, and the spar tip securely in place.  Under bending loads the port pip pin prevents the spar from creeping aft and interfering with the aileron quick disconnects and linkage.  Please follow the instructions and don’t  leave the taper pin you made for a rigging aid, installed for flight operations, this taper pin is a rigging aid only to align the port wing and seat the lift sockets and squeeze the wing gap seals if they expanded.  Rig the starboard wing by pulling the starboard  taper pin out to clear the cup.  Insert the starboard wing, and have the starboard wing supported by a stand or your burley assistant, then insert the taper pin fully in the starboard side to seat the starboard wing.  Insert your port pip pin at this time.   In the event things are still too tight to seat the port pip pin, consider using two taper pins. If you did your job right, a slight tap of the port pip pin with your palm will drive your port pin easily without bruising your hand.  Washer up your pip pin  as required to allow the balls to lock out and hold on the hardened washer on the spar cup firmly to prevent the starboard spar from creeping aft to interfere with the aileron belcrank.   Only allow a fraction of an inch movement of the pin in and out after  rig. 

  

The lift sockets on the side of the fuselage should not be reamed for the lift pins.  Keep these nice and tight, but quality control of the finish on these pins and lift sockets may have been poor  and there may be ridges on the stainless pin.  Buffing the pins on a buffing wheel is perfectly fine, don’t grind on them.  Sharp edges on the wing lift socket face in the machining  process can mar the lift pins when rigging, and a slight chamfer of these  can prevent pin marring and aid rigging.   

  

Ok, ‘nuf said on that.  Lawyers are satisfied. 

  

My thanks to Pete, Fred and others who had further questions we discussed off line with further hints to aid those of you building or those who have never built and are trying to understand why things  are like they are. 

  

Best Regards, 

Bud Yerly 

  

  

  

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com <owner-europa-list-server(at)matronics.com> on behalf of Bud Yerly <budyerly(at)msn.com>

 Sent: Saturday, August 10, 2019 10:21:37 PM

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

 Subject: RE: Reaming of spar and CM bushes  

 

     

On first glance one would see it that way. 

  

The lift pins on the aircraft side (like most gliders) take all the lifting load so the wing spars don’t really bend much and the wing spar pins are in fact set properly to do their one and only job, absorb the bending shear load of the  two spars.  The force of the non bending spars put little force on the cockpit module (in theory).  I suppose one could take out the cockpit sockets and in a perfect positive load the spar pins would have no effect on the cockpit module.  However, as you intuitively  figured out, the spars have to be attached to the cockpit/fuselage to keep the wings from shifting laterally, as well as aft bending and forward bending and of course how the heck could we rig the wings without the cockpit module pins and sockets... 

  

We killed this horse some years ago and somehow all of us engineering types figured out John Bewley got it right when doing the original structural analysis when the prototype was built.  His testament is there are no ADs on his structural  work.  His rework of the glider wing spar (Mod78) makes that wing a brute.  No need for a spar strap for sure. 

  

  

Best Regards, 

Bud Yerly 

  

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com <owner-europa-list-server(at)matronics.com> on behalf of Pete <peterz(at)zutrasoft.com>

 Sent: Saturday, August 10, 2019 5:47:37 PM

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

 Subject: Re: Reaming of spar and CM bushes  

 

  

 What i have never understood, is why the cockpit module spar pin bushings are not vertical slots, because when the wings are flexing under G, the lift pins take the fuse lift loads,  and the spar flexing (under positive G) actually force the  spar pins _downard_  against the cockpit module....obviously totally counter-productive.

 

 

 Pete 

 A239

 

 On Aug 10, 2019, at 5:29 PM, Bud Yerly <budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

 

 

  	  Quote: 	
		       

Fred, 

Back before my time when mod 52 was done for the GW increase.  The classic had two 3/8 pins originally.  Mod 52 uses the ½ inch pins and a spar strap . 

  

As the wings pull forward under load, the fuselage would flex so they put in the cross bar and the new sockets. 

  

Then the concern was that the starboard wing spar could become dislodged from the socket and interfere with controls.  The quick fix was to hold in the spar tip with a pip pin.  The port wing was figured would stay put, and the spar strap  would prevent flexing of the spar. 

  

That is all I know.  Andy would have the particulars on the detailed history.  It sort of all makes sense.  

  

Best Regards, 

Bud Yerly 

  

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com) <owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com)> on behalf of Fred Klein <freddythek10(at)gmail.com (freddythek10(at)gmail.com)>

 Sent: Thursday, August 8, 2019 1:29:43 AM

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

 Subject: Re: Reaming of spar and CM bushes  

 

 Bud…you mention the use of the SouthCo pip pin on the port side and the Allen bolt pin on starboard.  

 Do you know the reason for using different types of pins here?

  

 Is there any downside to using SouthCo pip pins both port and starboard?…seems I’ve heard that some builders have done so.

  

 Fred   	  Quote: 	
		   On Aug 7, 2019, at 8:35 PM, Bud Yerly <budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

     

  The SouthCo pip pin is nominally .4985 inches.

  The Allen bolt pin for the starboard side is .497 to .495.

wdaniell.longport(at)gmai
Guest

Posted: Mon Aug 12, 2019 1:38 pm Post subject: Reaming of spar and CM bushes

You rotated the pins in flight?!!Â  Yikes!

It kinda makes sense but ....

William Daniell



LONGPORT



On Sun, Aug 11, 2019 at 4:35 AM D McFadyean <ami-mcfadyean(at)talktalk.net (ami-mcfadyean(at)talktalk.net)> wrote:



 	  Quote: 	
		         

I would add that in level flight at 1g,Â my spar pins are as easy to rotate in their holes as when sat on the ground.



DMcF.

 	  Quote: 	
		  On 11 August 2019 at 09:19 D McFadyean <ami-mcfadyean(at)talktalk.net (ami-mcfadyean(at)talktalk.net)> wrote: 

 



That analysis assumes the fuselage structure to be inelastic andÂ utterly unyielding, whilst the spar isÂ privaleged to flex.



All of the vertical loads going in to the lift pins have to pass through the fus structure too, which will yield to a greater or lesser extent.



Duncan Mcf.

 	  Quote: 	
		  On 10 August 2019 at 22:47 Pete <peterz(at)zutrasoft.com (peterz(at)zutrasoft.com)> wrote: 

 

Â  



What i have never understood, is why the cockpit module spar pin bushings are not vertical slots, because when the wings are flexing under G, the lift pins take the fuse lift loads, Â and the spar flexing (under positive G) actually force the spar pins _downard_ Â against the cockpit module....obviously totally counter-productive.

PeteÂ 

A239



On Aug 10, 2019, at 5:29 PM, Bud Yerly < budyerly(at)msn.com (budyerly(at)msn.com)> wrote: 

 



 	  Quote: 	
		  

Fred,

Back before my time when mod 52 was done for the GW increase.Â  The classic had two 3/8 pins originally.Â  Mod 52 uses the Â½ inch pins and a spar strap .

Â 

As the wings pull forward under load, the fuselage would flex so they put in the cross bar and the new sockets.

Â 

Then the concern was that the starboard wing spar could become dislodged from the socket and interfere with controls.Â  The quick fix was to hold in the spar tip with a pip pin.Â  The port wing was figured would stay put, and the spar strap would prevent flexing of the spar.

Â 

That is all I know.Â  Andy would have the particulars on the detailed history.Â  It sort of all makes sense.

Â 

Best Regards,

Bud Yerly

Â 

Sent from  Mail for Windows 10

Â 

From: owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com) <owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com)> on behalf of Fred Klein <freddythek10(at)gmail.com (freddythek10(at)gmail.com)>

 Sent: Thursday, August 8, 2019 1:29:43 AM

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

 Subject: Re: Reaming of spar and CM bushesÂ 



Budâ€¦you mention the use of the SouthCo pip pin on the port side and the Allen bolt pin on starboard.



Do you know the reason for using different types of pins here?

Is there any downside to using SouthCo pip pins both port and starboard?â€¦seems Iâ€™ve heard that some builders have done so.

Fred 



 	  Quote: 	
		  On Aug 7, 2019, at 8:35 PM, Bud Yerly < budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

The SouthCo pip pin is nominally .4985 inches.

The Allen bolt pin for the starboard side is .497 to .495. Â 

	


	
	




Â  	




Â

n7188u

Joined: 15 Nov 2015
Posts: 404

Posted: Mon Aug 12, 2019 1:39 pm Post subject: Re: Reaming of spar and CM bushes

I installed my wings around 3 months ago. In my case, maybe luck, I had no need for reaming or do I need tapered pins to install the wings now. I need to clarify that as the former owner of a couple fo gliders I have plenty of experience assembling the wings on these kind of planes so I have a feel for moving wings and wiggling them to achieve proper alignment before I drive the pins in. I use saw horses when installing the wings.  In the case of my Europa, minute adjustments of the wings (up, down, fwd and aft) will result in either perfectly aligned bushings or pins that will not go in. I don't force if the pins don't go in, I re-adjust the wings and try again. But I do know my pins will go in easely if things are set properly so I just adjust until pins go in.



The reason I attribute the proper bushing alignment in my plane is that I didn't follow the manual when it came to cockpit module bushing installation. I waited until the wings where being fitted to the fuselage. Not easy to do and required some custom made tools to make it happen. I am not advocating not following the manual but I found that the way the manual told you to bond these bushings so early in the build and then expect them to align at the end made no sense. My wings mated perfectly when rigged outside the airplane so I figured that all I had to do was make sure those CM bushings were not out of alignment at the end. 



BTW, I used a bubble level used for leveling machine shop machines which are ridiculously accurate for setting the wings incidence (what fun did I have, it drove me crazy!!). Also, and this may be contrary to some advice, I was more concerned about incidence than sweep. That doesn't mean I didn't got sweep very close, but I didn't force the wings to have perfect sweep (I think I got within .05" - .1"). My reasoning here was that if you force the wings to have a perfect sweep before setting the lift pins, when taken apart they will never want to go in smooth and easy again. So my rule during lift pin setup was to not force the wings fore and aft too much so as to prevent throwing the spar bushings out of alignment.



If interested, go to my build site (https://myeaa.org/?myproject&proj=7S3RojQBL&cat=wings&listcat=) and scroll down until you find the entry about bonding the CM bushings. The entries in this log are not intended to be assembly instructions so I don't know how clear it will be. If you have questions ask but I would never override anything Bud instructs (he has been my mentor for this build and an invaluable resource). I still have to fly this plane to find out if these stuff I did will result in a nice flying plane so don't trust anything I say 



Chris

budyerly(at)msn.com
Guest

Posted: Mon Aug 12, 2019 4:38 pm Post subject: Reaming of spar and CM bushes

Just put saw horses under your wings like you did when you rigged it initially.  It works. 

  

I just can’t figure out how I can twist around in my cockpit without unstrapping to check it in flight!  That would be a heck of an accident report. 

  

Bud 

  

Sent from  Mail for Windows 10 

  

  From: owner-europa-list-server(at)matronics.com <owner-europa-list-server(at)matronics.com> on behalf of William Daniell <wdaniell.longport(at)gmail.com>

 Sent: Monday, August 12, 2019 5:41:02 PM

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

 Subject: Re: Reaming of spar and CM bushes  

 

   You rotated the pins in flight?!!  Yikes!

 It kinda makes sense but ....

      William Daniell

 

 LONGPORT

 

 

 

 

 

 

 

  On Sun, Aug 11, 2019 at 4:35 AM D McFadyean <ami-mcfadyean(at)talktalk.net (ami-mcfadyean(at)talktalk.net)> wrote:

 

  	  Quote: 	
		     

I would add that in level flight at 1g, my spar pins are as easy to rotate in their holes as when sat on the ground.

  



  

DMcF.

   	  Quote: 	
		  On 11 August 2019 at 09:19 D McFadyean <ami-mcfadyean(at)talktalk.net (ami-mcfadyean(at)talktalk.net)> wrote: 

 

 

That analysis assumes the fuselage structure to be inelastic and utterly unyielding, whilst the spar is privaleged to flex.

  

All of the vertical loads going in to the lift pins have to pass through the fus structure too, which will yield to a greater or lesser extent.

  



  

Duncan Mcf.

   	  Quote: 	
		  On 10 August 2019 at 22:47 Pete <peterz(at)zutrasoft.com (peterz(at)zutrasoft.com)> wrote: 

 

   

 

 What i have never understood, is why the cockpit module spar pin bushings are not vertical slots, because when the wings are flexing under G, the lift pins take the fuse lift loads,  and the spar flexing (under positive G) actually force the  spar pins _downard_  against the cockpit module....obviously totally counter-productive.

 

 

 Pete 

 A239

 

 On Aug 10, 2019, at 5:29 PM, Bud Yerly <  budyerly(at)msn.com (budyerly(at)msn.com)> wrote: 

 

 

  	  Quote: 	
		     

Fred, 

Back before my time when mod 52 was done for the GW increase.  The classic had two 3/8 pins originally.  Mod 52 uses the ½ inch pins and a spar strap . 

  

As the wings pull forward under load, the fuselage would flex so they put in the cross bar and the new sockets. 

  

Then the concern was that the starboard wing spar could become dislodged from the socket and interfere with controls.  The quick fix was to hold in the spar tip with a pip pin.  The  port wing was figured would stay put, and the spar strap would prevent flexing of the spar. 

  

That is all I know.  Andy would have the particulars on the detailed history.  It sort of all makes sense. 

  

Best Regards, 

Bud Yerly 

  

Sent from Mail for Windows 10 

  

   From: owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com) <owner-europa-list-server(at)matronics.com (owner-europa-list-server(at)matronics.com)> on behalf of Fred Klein <freddythek10(at)gmail.com (freddythek10(at)gmail.com)>

 Sent: Thursday, August 8, 2019 1:29:43 AM

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

 Subject: Re: Reaming of spar and CM bushes  

 

 Bud…you mention the use of the SouthCo pip pin on the port side and the Allen bolt pin on starboard. 

 

 Do you know the reason for using different types of pins here?

 

 

 Is there any downside to using SouthCo pip pins both port and starboard?…seems I’ve heard that some builders have done so.

 

 

 Fred 

 

  	  Quote: 	
		   On Aug 7, 2019, at 8:35 PM, Bud Yerly <  budyerly(at)msn.com (budyerly(at)msn.com)> wrote:

   

 

 The SouthCo pip pin is nominally .4985 inches.

 The Allen bolt pin for the starboard side is .497 to .495.

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