---------------------------------------------------------- Europa-List Digest Archive --- Total Messages Posted Mon 12/21/20: 3 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:26 AM - Re: Re: Spar Strap (Jeff B) 2. 08:45 AM - Re: Spar Strap (jglazener) 3. 07:16 PM - Re: Re: Spar Strap (Bud Yerly) ________________________________ Message 1 _____________________________________ Time: 07:26:54 AM PST US Subject: Re: Europa-List: Re: Spar Strap From: Jeff B Jeroen, In the grand scheme of things, what's another 5 or 6 months? Take the time to make sure your baby is 100%. You want to be confident when the pucker factor sets in on first flight. Just me two cents worth. Jeff N55XS "Hate can be a destructive thing, especially when it clouds one's judgment" -JB On 12/20/2020 4:42 AM, jglazener wrote: > > Thanks everybody for all the useful information and particularly Bud for once again coming to the rescue with really good instructions. When are you going to bundle and publish these? > I take to heart the point about getting it finished properly. I haven't cut corners so far and agree this is probably not the best place to start. I will give the styrofoam idea a try- as soon as they will allow me into a shop to buy some... . Winter here is everything epoxy and I don't like: cool and very damp so I am sure that will make the difference between ending up with a strong part or a soggy mess. > > -------- > Jeroen > > http://www.europaowners.org/main.php?g2_itemId=44165 > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=499749#499749 > > > > > > > > > ________________________________ Message 2 _____________________________________ Time: 08:45:39 AM PST US Subject: Europa-List: Re: Spar Strap From: "jglazener" Hello Bud, just make sure I understand everything correctly, you say the spars should be vertical, rather than the wings vertical which the manual seems to suggest. That would certainly make setting the wings up on simple sawhorses a lot easier. Rgds, Jeroen budyerly@msn.com wrote: > Just my two cents. > The spar strap prevents the spars from doing two things. > Bending back and impacting the aileron cross connect, twisting or separating. > > As many have found on the original Classic, the spar cups took abuse. Some of that due to poor security of the starboard tip by the 3/8 inch pin. Some from the twisting of the spars under load, and some due to poor technique on installation and rigging. > > With the GW increase testing, enlarging the pin to allow a pip pin to securely hold the spars firmly from creeping aft was a very thoughtful idea. The spar strap really keeps the spars from bending which they do under load. Remember, the XS short wing spar has no bid around it for a shear web, so the roves are good in vertical bending but not so great in twisting or bowing. > > So belts and suspenders. Either enlarge the thickness of the spars with shear webbing as in the glider wing, or retain them seems to be the dilemma. They chose simple, a spar strap. > > I would always install a spar strap. It aids rigging if built right with some clearance, reduces pressure on the spar cup during rigging, assists in keeping the spars safely put under high G pullouts. > > Take the time and do it right. If you don't do it in construction, it may never get done. In testing, if a situation requires a quick pull out, the added spar strap fixation may become a factor. I try never to cut corners. Anything worth doing is worth doing right. > > Technique: > Support the wings and spars so the spars are exactly vertical, each wing is at the same incidence and the spar pins rotate easily. This is important to ensure the strap is going to be properly aligned and not just slightly askew. NEVER clamp the spars together to get alignment. > > Wrap the starboard spar with blue painters tape then the release tape to give you a few thousands more room for rigging and more importantly derigging during construction. > > Make the upper curved inlet as shown but do the same on the lower on the starboard side of the cup layup to ease rigging. I make my spar strap "ramp" about 1/4 inch larger than depicted as well as the strap to allow nice clean trimming. > Make your glass wrap as shown in the manual. > Wrap peel ply around your glass to prevent sagging and use some release tape to hold the peel ply from sagging if necessary. > > In cold climates: > Try to find a shop that may let you do the work in the warm, but if that is impossible: > Make a box over the spars out of styrofoam and use an incandescent light to keep it warm to cure. > > Once cured, if heat treat is necessary pull apart the wings and heat treat slowly in the garage. > > The spar strap when done properly is an excellent aid in rigging as well. As the starboard spar is inserted, it is aligned with the strap and will slide along the port spar and assist in self alignment. The spars stay properly vertical, assisting the wing tip assistant. If the builder also installs a rigging aid for the spar to slide on and assist in alignment,(keeping the spar from sliding aft) and building a small ramp on the spar root to assist lifting the spar as it hits the cup and thereby aligning the pins to very near their required elevation, even the most clumsy of assistants even without a saw horse or trestle under the wing will be amazed how easy the rig is. > > Best Regards, > Have a great holiday.. Bud Yerly -------- Jeroen http://www.europaowners.org/main.php?g2_itemId=44165 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=499758#499758 ________________________________ Message 3 _____________________________________ Time: 07:16:14 PM PST US From: Bud Yerly Subject: RE: Europa-List: Re: Spar Strap Jeroen, I whacked this out this evening. It is a bit rough but gives a bit more de tail. You can mount the wings vertical like the book or horizontal. It is impera tive that you make sure the wings are at the same angle so the spars are de ad parallel in their vertical orientation. Take a look at the .pdf I'm att aching. I hope it is a bit clearer. It also has a few other things to con sider. Best Regards, Bud Yerly -----Original Message----- From: owner-europa-list-server@matronics.com On Behalf Of jglazener Sent: Monday, December 21, 2020 11:45 AM Subject: Europa-List: Re: Spar Strap Hello Bud, just make sure I understand everything correctly, you say the sp ars should be vertical, rather than the wings vertical which the manual see ms to suggest. That would certainly make setting the wings up on simple saw horses a lot easier. Rgds, Jeroen budyerly@msn.com wrote: > Just my two cents. > The spar strap prevents the spars from doing two things. > Bending back and impacting the aileron cross connect, twisting or separat ing. > > As many have found on the original Classic, the spar cups took abuse. So me of that due to poor security of the starboard tip by the 3/8 inch pin. Some from the twisting of the spars under load, and some due to poor techni que on installation and rigging. > > With the GW increase testing, enlarging the pin to allow a pip pin to sec urely hold the spars firmly from creeping aft was a very thoughtful idea. The spar strap really keeps the spars from bending which they do under load . Remember, the XS short wing spar has no bid around it for a shear web, s o the roves are good in vertical bending but not so great in twisting or bo wing. > > So belts and suspenders. Either enlarge the thickness of the spars with shear webbing as in the glider wing, or retain them seems to be the dilemma . They chose simple, a spar strap. > > I would always install a spar strap. It aids rigging if built right with some clearance, reduces pressure on the spar cup during rigging, assists i n keeping the spars safely put under high G pullouts. > > Take the time and do it right. If you don't do it in construction, it ma y never get done. In testing, if a situation requires a quick pull out, th e added spar strap fixation may become a factor. I try never to cut corner s. Anything worth doing is worth doing right. > > Technique: > Support the wings and spars so the spars are exactly vertical, each wing is at the same incidence and the spar pins rotate easily. This is importan t to ensure the strap is going to be properly aligned and not just slightly askew. NEVER clamp the spars together to get alignment. > > Wrap the starboard spar with blue painters tape then the release tape to give you a few thousands more room for rigging and more importantly deriggi ng during construction. > > Make the upper curved inlet as shown but do the same on the lower on the starboard side of the cup layup to ease rigging. I make my spar strap "ra mp" about 1/4 inch larger than depicted as well as the strap to allow nice clean trimming. > Make your glass wrap as shown in the manual. > Wrap peel ply around your glass to prevent sagging and use some release t ape to hold the peel ply from sagging if necessary. > > In cold climates: > Try to find a shop that may let you do the work in the warm, but if that is impossible: > Make a box over the spars out of styrofoam and use an incandescent light to keep it warm to cure. > > Once cured, if heat treat is necessary pull apart the wings and heat trea t slowly in the garage. > > The spar strap when done properly is an excellent aid in rigging as well. As the starboard spar is inserted, it is aligned with the strap and will slide along the port spar and assist in self alignment. The spars stay pro perly vertical, assisting the wing tip assistant. If the builder also inst alls a rigging aid for the spar to slide on and assist in alignment,(keepin g the spar from sliding aft) and building a small ramp on the spar root to assist lifting the spar as it hits the cup and thereby aligning the pins to very near their required elevation, even the most clumsy of assistants eve n without a saw horse or trestle under the wing will be amazed how easy the rig is. > > Best Regards, > Have a great holiday.. Bud Yerly -------- Jeroen http://www.europaowners.org/main.php?g2_itemId=44165 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=499758#499758 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message europa-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Europa-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/europa-list Browse Digests http://www.matronics.com/digest/europa-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.