Empennage

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=100 BGCOLOR="#CCCCFF" TEXT="#080000" bgproperties="fixed" background="05b00640egdysm.jpg"> <div> <FONT SIZE="2" COLOR="#000066" FACE="Arial" ><I><B>Steve Kiblinger, .. Builder of a Milholland Better Half 2 cylinder VW and Legal Eagle Ultralight Airplane</B></I></FONT><FONT SIZE="5" COLOR="#000099" FACE="Arial" ><B> </B></FONT><B>    |     </B><A HREF="index.htm" TARGET="_top" TITLE="Steve Kiblinger, .. Builder of a Milholl"><U><B>Home</B></U></A></div> <div> <A HREF="tools.htm" TARGET="_top" TITLE="Tools"><U>Tools</U></A>   |   <B>Empennage</B>   |   <A HREF="fuselage.htm" TARGET="_top" TITLE="Fuselage"><U>Fuselage</U></A>   |   <A HREF="disk_brakes_.htm" TARGET="_top" TITLE="Disk Brakes?"><U>Disk Brakes?</U></A>   |   <A HREF="glue.htm" TARGET="_top" TITLE="Glue"><U>Glue</U></A>   |   <A HREF="wingspars.htm" TARGET="_top" TITLE="WingSpars"><U>WingSpars</U></A>   |   <A HREF="wings.htm" TARGET="_top" TITLE="Wings"><U>Wings</U></A>   |   <A HREF="ailerons.htm" TARGET="_top" TITLE="Ailerons"><U>Ailerons</U></A>   |   <A HREF="id31.htm" TARGET="_top" TITLE="WingsHow2"><U>WingsHow2</U></A>   |   <A HREF="id62.htm" TARGET="_top" TITLE="WingStruts"><U>WingStruts</U></A>   |   <A HREF="id40.htm" TARGET="_top" TITLE="Covering"><U>Covering</U></A>   |   <A HREF="whatdoesitweigh_.htm" TARGET="_top" TITLE="WhatDoesItWeigh?"><U>WhatDoesItWeigh?</U></A>   |   <A HREF="stanswood.htm" TARGET="_top" TITLE="StansWood"><U>StansWood</U></A>   |   <A HREF="brucesengine.htm" TARGET="_top" TITLE="BrucesEngine"><U>BrucesEngine</U></A>   |   <A HREF="gastank.htm" TARGET="_top" TITLE="GasTank"><U>GasTank</U></A>   |   <A HREF="suppliers.htm" TARGET="_top" TITLE="Suppliers"><U>Suppliers</U></A>   |   <A HREF="flying.htm" TARGET="_top" TITLE="Flying"><U>Flying</U></A>   |   <A HREF="eagler_s_nest_s.htm" TARGET="_top" TITLE="Eagler(s)Nests"><U>Eagler(s)Nest's</U></A>   |   <A HREF="id63.htm" TARGET="_top" TITLE="Builder(s)Gallery"><U>Builder(s)Gallery</U></A>   |   <A HREF="id70.htm" TARGET="_top" TITLE="LeonardThisWeek"><U>LeonardThisWeek</U></A>   |   <A HREF="contact_us.htm" TARGET="_top" TITLE="Contact Us"><U>Contact Us</U></A>   |   <A HREF="id82.htm" TARGET="_top" TITLE="John Bolding"><U>John Bolding</U></A></div> <bR> <bR> <div> </div> </td> </tr><tr> <td valign="top" width=200 BGCOLOR="#0099FF" TEXT="#F7F7FF"> <div> <B>Empennage construction</B></div> <div> <B><IMG SRC="092a0da0.jpg" border=0 width="160" height="218" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <DIV ALIGN="LEFT"></DIV> <div> <B> <a href="HTMLobj-147/emp1.jpg"><u>Click for large picture.</u> </a>  </B></div> </td> <td valign="top" height=380 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <I>Empennage</I></div> <div> <B>May 3, 2002</B> - We made the first flight today... The plane flew beautifully... We had not complied with Leonard's empennage bracing change and cut the flying short when the fin showed signs of flutter on the leading edge in the absence of the parallel brace cable... <I><B>THE PARALLEL CABLE BRACING IS NOW MANDATORY...</B></I></div> <div> ----------------------------------------------------------------------------------------------------------------</div> <div> <B>August 9, 2002 - Builders & Flyers:</B></div> <bR> <div> <B>Extracted from Double Eagle Drawing Sheet 24:</B></div> <bR> <div> <B>Please note that the next picture is a Double Eagle drawing which is provided for methodology and materials reference only... Leonard will get out the necessary changes to LEU drawings 1 & 3... Now the changes:</B></div> <bR> <div> <B>1) Notice the parallel cable brace wire holes and the additional rib placement between same... Unseen inside the wire hole gussets is an alum bushing JB welded </B><FONT SIZE="3" COLOR="#00BF00" FACE="Arial" ><B><U>or gusset hole swaged in place</U></B></FONT><B> to backup the cable attachment clips on the outside...</B></div> <bR> <div> <B>2) The front tube is 1/2 inch dia and has been always 1/2 inch on the prototype LEU...  I have a 3/8 inch tube per the LEU sheet 1 plan and it is unsafe!... Ron Cola used a 5/8 inch tube and Randy Maynard put on parallel cable braces after the first flight... I have the parallel braces on now and still see more vibration back there than I want...</B></div> <bR> <div> <B>3) Notice the bottom rib is a 1/2 inch tube... A bent up sheet metal rib is not strong enough here... My doubled (nested ribs) still bent up when the fabric tightened... </B><FONT SIZE="3" COLOR="#00BF00" FACE="Arial" ><B><U>The best mod is an add'l rib from the first leading edge gusset down to the mid point of the bottom rib...</U></B></FONT></div> <bR> <div> <B>4) The under drawing remark (Bend gussets around smaller tube) is a much needed technique to achieve a strong empennage and was first reported by Joe Maynard (building partner in the first plans built LEU)... Say your gusset is for a 3/4 inch tube then the next size smaller tube is 5/8 inches and that is what the gussets will be formed around by squeezing down in a vice with smooth jaws... With spring back in the gusset it will still snap onto the 3/4 inch tube and really lay down close to the rib... One place this is really critical is on the elevators where I see my hand formed gussets flexing if I lift the elevator from the rear spar as you see many pilots do in a walk around inspection...</B></div> <bR> <div> <B>5) The made hinge material is a real improvement and should be adopted by all... It gets rid of the tailpost eyebolt too - Leonard just uses the small tube from pieces 20-21 to weld directly onto the tailpost...</B></div> <bR> <div> <B> </B><FONT SIZE="2" COLOR="#AAAAAA" FACE="Arial" ><I><B><IMG SRC="336140f0.gif" border=0 width="20" height="15" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></I></FONT><B> July 02, 2013:</B></div> <bR> <div> <B>There is time in service with rearward facing VID's and more power being developed from the engines to motivate three Flyer's "Sam Buchanan XL, Joe Spencer LE and myself LE" to advise we have switched the leading edge tube on the fin to </B><I><B><U>.035 wall 1/2" 4130 steel tube</U></B></I><B> - we consider this to be a mandatory change for flyer's...</B></div> <bR> <bR> <DIV ALIGN="LEFT"></DIV> <div> <B><IMG SRC="425f49b0.jpg" border=0 width="500" height="667" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <div> <B><IMG SRC="331f3880.jpg" border=0 width="499" height="392" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <div> <B> <a href="HTMLobj-861/leufinL.jpg"><u>(Click) for full size drawing</u> </a>  </B></div> <bR> <div> <B>We consider these changes mandatory...</B></div> <bR> <div> <B>--------------------------------------------------------------------------------</B></div> <bR> <div> We drew the Empennage parts full size on the building table. Then we bent and cut the tubing according to the full scale drawings. We put sand in the 5/8 tubing to prevent collapsing at the bends and made blocks that had the proper bending radius on them to assist in the bending effort.</div> <bR> <div> The formed tubes were fastened on the drawings and to the table with 3/4" x  3/4" x 4" blocks that were secured with #6 1-5/8" drywall screws. We made 50 of these scrap oak flooring blocks which were used throughout the project.</div> <bR> <div> The gussets were drawn by folding a rectangle of craft paper in half and then sliding it up to the fold centered on the perimeter tube of the joint. The shape of the gusset was sketched with a Sharpie pen on the top surface. The paper was then removed and cut to shape with scissors... The resulting pattern was opened and traced with the Sharpie pen onto the .020 2024-T3 material and cut with aviation snips. Patterns were numbered and saved for the stabilizer and elevator opposing segments. </div> <bR> <div> The gussets were slipped onto the joints and the riveting sequence was performed first on the top side and then the bottom after removal from the table pattern stations.</div> <bR> <div> We had to adapt the plans location of some ribs and the placement of the hinges. These changes will become apparent when the plans are drawn full scale and compared to dimensions given on the plans. We made the ribs from measurements taken on the full scale drawings.</div> <bR> <DIV ALIGN="LEFT"></DIV> <div> <IMG SRC="09ff4250.jpg" border=0 width="500" height="293" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <div> The method of fitting the hinges on the rudder is seen below... I wanted the hinge pivots rotating around the same point vertically... The eye bolt was installed first and the other hinges adjusted to it... The little jig above the wood clamp is useful and notice that a metal clamp was also used to cinch things down... The elevator hinges were held with a block flush to the tube on one side to assure the same pivot point... The tubes were blocked apart with pieces of 1/2 inch plywood... These controls rotate smoothly! No bind or tube distortion... Those are penny's brazed on threaded rod in the wood clamps! - borrowed from Stan... I welded my fuselage construction pivot on the future site of the rudder eye bolt tube hole...</div> <bR> <DIV ALIGN="LEFT"></DIV> <div> <IMG SRC="1d5e0e00.jpg" border=0 width="480" height="480" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <bR> <div> <IMG SRC="1d6e0e00.jpg" border=0 width="480" height="480" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <bR> <div> Don't mount the hinges on top of the tubes as shown below!... This will create an eccentric motion by the elevator and cause the control cables to go from slack to tight fore to aft control stick...  Mount the hinges with the pivot centered top to bottom of the tube... </div> <bR> <div> <IMG SRC="0eb1c950.jpg" border=0 width="540" height="405" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <bR> <div> <IMG SRC="0ed1c950.jpg" border=0 width="540" height="405" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <div> <B>The much discussed eyebolt...</B></div> <div> <IMG SRC="1b91c950.jpg" border=0 width="540" height="405" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> </td> </tr></table></body>