LandingGear

<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" ><B>Steve Kiblinger, .. Builder of a Milholland Better Half 2 cylinder VW and Legal Eagle Ultralight Airplane</B></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><B> </B><A HREF="fuselage.htm" TARGET="_top" TITLE="Fuselage"><U><B> Fuselage</B></U></A></div> <div> <B>LandingGear     </B></div> <div> </div> </td> </tr><tr> <td valign="top" width=200 BGCOLOR="#0000BF" TEXT="#F7F7FF"> <bR> </td> <td valign="top" height=380 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> <I>LandingGear     </I></div> <div> <A HREF="#latest_news_1" TITLE="LandingGear "><U><B>Click and goto the latest gear & brake news...</B></U></A></div> <bR> <div> <B>The landing gear generates questions and this is what we have learned...</B></div> <bR> <div> <B>o Leonard specifies the gear to be made of .049 wall tubing...</B></div> <bR> <div> <B>o The entire gear pictured below weighs 15 pounds...</B></div> <bR> <div> <B>o Some builders use 3/4 tube from the axle to the fus sta 2 fitting -  a good idea... .095 wall tube for the 5/8" axles would also be prudent... </B><A HREF="id69.htm" TARGET="_top" TITLE="Gallery2"><U><B>Click here for another flyer's repair...</B></U></A></div> <bR> <div> <B>o We changed the compression strut because it was bottoming out - lengthened the 3/4 strut tube from 6.5 inches to 7.5 inches - increased the slot in the strut tube in the direction of the wheel from 1 inch to 1.25 inches plus - discarded the valve springs and got die springs that measure 3 inches long, 3/4 inch ID and press 650 inch pounds...</B></div> <bR> <DIV ALIGN="LEFT"></DIV> <div> <B><IMG SRC="21730a40.jpg" border=0 width="560" height="420" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <div> <B>It is March 27, 2002</B><FONT SIZE="3" COLOR="#000000" FACE="Arial" ><B> and we are modifying the landing gear after taxiing over a sandbag with the  left main wheel and collapsed the right gear brace tube that goes to station 2 and also bent the axle tube... The gear was displaying 2" of negative camber on the 650 IP strut springs (very hard to turn the plane with negative camber) ... These are the changes:</B></FONT></div> <bR> <div> <B>1) We fish mouthed a 3/4" tube and welded it over the 5/8" brace tube stubs for the station 2 gear braces...</B></div> <bR> <div> <B>2) The axle was straightened and a 1/2" tube pushed inside both 5/8" axles - the left axle was showing bending stress too...</B></div> <bR> <div> <B>3) We replaced the 650 IP strut springs with 1000 IP springs PN </B> <B>9295K84 (3 1/2 x 1 1/2 x 3/4 bore) from McMaster-Carr, Atlanta, Ga. Tel 404-346-7000... We preloaded the strut springs 1/4" or 250 pounds...</B></div> <bR> <div> <B>We found a no brakes plane too difficult to handle on a hillside strip and are mounting 4.5" band brakes from </B><A HREF="http://www.tracyobrien.com/showcat.asp?id=9" TARGET="_top" TITLE="http://www.tracyobrien.com/showcat.asp?i"><U><B>Tracy OBrien</B></U></A><B>... We have (ACS)  American Cycle Systems, Inc.  Z-Mag wheels and it looks like we'll make a big 1/8" 2024-T3 alum (very wide area) washer that just fits inside the drum and close to the wheel hub... 5 (3/16") bolts will go thru the very wide area washer/drum/ 3/4" bushing with a washer on both sides of the wheel spoke web... A simple metal plate will be formed to fit on the axle brace cluster that holds/anchors the brake band in place... Both brake cables will split from one grip on the control stick - the wheels spokes are too fragile for differential braking...</B><FONT SIZE="3" COLOR="#00FF00" FACE="Arial" ><B> </B></FONT></div> <bR> <bR> <div> <B>Roman Wasilewski, o</B><B>ur aviation mentor and aeronautical engineer, is very skeptical about the durability of the wheel spokes under the additional load of the brake drum... We have recently learned from ACS (distributor of our wheel) that the wheel should have only have up to 45 pounds of tire pressure - the tire casing has 65 pounds stamped on it so you probably should check out what tire pressure your (wheels) are rated for... We are going to initially fly the plane at Ocotillo Wells, Ca dry lake without brakes...</B></div> <bR> <div> <B>It is June 24, 2002 - </B></div> <div> <B>The (ACS) American Cycle Systems Z-Mag wheels have started to fail at the inner hub where our inner split nylon bearing seats... We have replaced the wheels with </B><A HREF="http://www.leadingedge-airfoils.com" TARGET="_top" TITLE="http://www.leadingedge-airfoils.com"><U><B>LEAF</B></U></A><B> Tuff Special wheels that have the sealed ball bearings... This wheel is different at the hub (spokes and rim look identical) so we are back at square one with designing a brake system...</B></div> <bR> <div> <B>Summary: We advocate using 3/4" brace tubes from the axle up to Fus Sta 2 and 5/8" .095 wall axle tubes... We are developing a brake system that our aviation mentor is frowning about... The 1000 IP springs with 1/4" pre-load just start to compress with the empty aircraft weight on the gear... If you want the compression to start at gross pre-load 1/2" - make a fixture to hold the strut assembly for welding the pre-load to avoid a shop accident... (The plane finally feels right on the gear now!)... We used Moly-Graphite grease on the strut rod prior to assembly after seeing all the galling and rust when we disassembled the unit for the spring change... The clevis pins wear rapidly so inspect often!...</B></div> <bR> <DIV ALIGN="LEFT"></DIV> <div> <B>Here's a picture of the 3/4 station 2 tubes and the brake drum lined up in the proposed location...</B></div> <bR> <div> <B><IMG SRC="31d30eb0.jpg" border=0 width="560" height="747" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <div> <B>Don't use bolts anywhere in the strut assembly - use clevis pins in the 3 connecting locations per Leonard for better weight and </B><FONT SIZE="3" COLOR="#FF0000" FACE="Arial" ><B>wear</B></FONT><B> characteristics... The black springs are the 650 IP units - they weighed 7 OZ's and the new springs under 9 OZ's - powdercoated too!...</B></div> <div> <B> </B></div> <div> <B><IMG SRC="31e30a40.jpg" border=0 width="560" height="420" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <div> <B>The brake parts below weigh 1 pound 6 ounces (times 2)... With a single control grip on the stick this system weighs less than 5 pounds... The cost is under $100...</B></div> <bR> <bR> <div> <B><IMG SRC="31f309e0.jpg" border=0 width="560" height="670" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <div>  <A NAME="latest_news_1"><IMG BORDER="0" SRC="1x1.gif" HEIGHT="1" ALIGN="bottom" WIDTH="1" HSPACE="0" VSPACE="0" ></A><B>It's October 26, 2002</B></div> <bR> <div> <B>We have put a 4" shank from a grade 8 1/2" bolt inside the 5/8" axle tubes with 2" of the bolt in the cluster and the rest outboard into the wheel mounting area... Holes were drilled in the cluster area axle tube and rosette welds run into the inner bolt material... The 1/2" .049 tube axle reinforcement had bent during the Copperstate cross country flight on the left gear (the tube was not mounted to the outer axle with rosette welds - just pushed in)...</B></div> <bR> <div> <B>In the picture series below we show how we mounted the </B><A HREF="http://www.mtbreview.com/reviews/disc_brake_system/product_78912.shtml" TARGET="_top" TITLE="http://www.mtbreview.com/reviews/disc_br"><U><B>Formula Activa</B></U></A><B> mechanical disk brakes to the LEAF Tuff Special wheels mentioned above... The brakes are 2 rear units purchased from </B><A HREF="http://www.jensonusa.com" TARGET="_top" TITLE="http://www.jensonusa.com"><U><B>Jenson USA</B></U></A><B>... Jenson is no longer showing these items and I've found </B><A HREF="http://www.thorusa.com/formula.htm" TARGET="_top" TITLE="http://www.thorusa.com/formula.htm"><U><B>a site stocking them</B></U></A><B> at a higher price...</B></div> <bR> <div> <B>The LEAF Tuff Special 20" wheel I purchased has thru slots in the hub area that I pass AN3 bolts thru side to side with a 1/8" 2024-T3 large area crush washer on the outside and a 3/8" thick 2024-T3 adapter plate to anchor the 5 thru bolts and pickup the 6 screws from the brake disk... The machining (CNC) on these parts was done by the </B><A HREF="http://www.thebugpatch.com" TARGET="_top" TITLE="http://www.thebugpatch.com"><U><B>BugPatch</B></U></A><B>... The caliper mounts were made from .050 4130 plate and folded on a metal brake... The mounting on each side is different because there is no right / left version of the bike rear brake caliper... The pattern for the angles included below is not to scale ( an ACAD .pdf file is in the works)... The angles are initially mounted with the disk and caliper in place and held with clamps - tack welded - then the unit disassembled for finish welding... These attachments are  v e r y  light weight and the vertical mounting on the left may need a back brace depending upon future service experience... </B></div> <bR> <div> <B>The hand grip is a light weight and inexpensive bike unit - there are many to chose from... The bike control grips are all intended to mount on a 7/8" pipe... We cut our 1" control stick tube and bolted a 7/8" tube inside with the same bolt that holds the brake cable terminator... The red rubber grip shown is a standard bike accessory... The cable terminator is a 3/8 x 1.5 x 1.5" 2024-T3 block that has a milled 1" mill radius cut in it that makes it lie down tight to the 1" stick tube... A 3/16" bolt hole drilled right thru the center of the block attaches the block to the front of the 1" stick stub and captures the nested 7/8" top stick discussed above... 2 vertical #30 drill holes are centered thru the 3/8" dimension of the block and located 1/2" on either side of the block </B><B>vertical </B><B>center line... Use a #2 drill for a countersink in the #30 holes at the bottom of the block for the cable sheath ends coming up from the 2 brake calipers... We bought two 44" fabricated performance bike brake cable assemblies and one tandem bike brake cable... One of the 44" cables is not used... The other 44" cable is cut down to go from the brake handle to the half hard stainless steel hanger on a 1" pulley... One of two required screw type cable ends is used to attach the short grip cable to the  pulley hanger... We used a lock spring for the cable cover sheath between the pulley hanger and the grip... The long tandem bike cable is anchored to a caliper - threaded up thru the 44" cable sheath and thru the block and over the 1" pulley... Then back down thru the other side of the block and thru the other 44" cable sheath to the second brake caliper... Fasten the cable after length adjustment with the other screw type cable end...</B></div> <bR> <div> <B>Adjust the brake calipers to one notch open from a caliper to disk contact...  These brakes are powerful and will hold the LEU during a full power runup... Use lightly when taxiing or landing... The system has slowed the LEU quickly without a side to side pull - it feels so good when the plane slows as you gently squeeze the brake grip... The entire brake system weighs less than 4 pounds...</B></div> <DIV ALIGN="LEFT"></DIV> <div> <B><IMG SRC="37930a40.jpg" border=0 width="560" height="420" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <div> <B><IMG SRC="38730a40.jpg" border=0 width="560" height="420" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <DIV ALIGN="LEFT"></DIV> <div> <B><IMG SRC="37d30a40.jpg" border=0 width="560" height="420" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <div> <B>The fabricated brake caliper mounting angles...</B></div> <div> <B><IMG SRC="38530770.jpg" border=0 width="560" height="631" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <div> <B><IMG SRC="37f90150.jpg" border=0 width="400" height="533" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <div> <B><IMG SRC="38130a40.jpg" border=0 width="560" height="420" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <bR> <bR> </td> </tr></table></body>