Building The EMG-6 (27-41-00) Rudder Assembly (LD)

welcome back to another episode of building the EMG 6 in this episode we’re going to assemble the low drag rudder assembly the estimated build time for the low drag rudder assembly is from 2 to 4 hours the rudder assembly components are manufactured using a CNC match drilled system this ensures a proper fit easy assembly and minimizes construction time in the previous episode of building the EMG 6 we assembled the rudder spar sub assembly we did this by inserting three inserts into the spar positioning them and riveting the rudder hinge net plates in place to hold these inserts the construction procedures assumed that you have completed these steps or have purchased the preassembled rudder spark to get started we need to have an overview of what we’re going to be working with the part numbering sequence in the aircraft uses a version of the 88 code the first two digits in the numbering code system identify the primary segment of the aircraft in this case 27 indicates that this is part of the flight control system the second two digits indicate in the part number in system the primary sub assembly in this case 41 is the code for the low drag rudder assembly the remaining digits identify the individual parts within that sub assembly so let’s go over each part individually so you get an idea of the makeup of the individual parts within the sub assembly – 10 is the rudder spar – 50 is rib number 1 located at the bottom of the rudder – 51 is the number-one rib support which ties the two legs of rib number one together forming a box structure – 65 is the trailing edge – 53 is rib number two on the left side and rib number 54 is the number two rib on the right side all of them remaining ribs aft of the spar are made up of both a right and a left side that are riveted together – 55 is rib number 2 support which forms a box structure for the control horn – attached to the rudder assembly – 20 is the right and left rudder control horn assembly which will be bolted to the frame after covering – 56 is rib number 3 left – 57 is rib number 3 right – 58 rib number 4 left – 59 at rib number 4 right – 60 is rib number 5 left and – 61 is rib number 5 right – 76 is the leading edge sheet metal with multiple lightning holes in it – 72 is rib number 6 which is the rib for the leading edge top and – 73 is rib number seven which is the rib for the leading edge bottom within the wood the spar sub assembly we have a few more components there are three each of the ms-20 1 0 7 8 – 4 nylock nut plate and then we have 3a + 9 16 – 4 16 quarter-inch washers and a + 43 B – 20 a.i bolts and these are the eye bolts that form the hinges for the rudder assembly the rudder spar assembly includes the – 10 rudder spar and then – 12 the rudder mid support – 13 is the rudder spar lower support and – 14 is the rudder spar upper support and last but not least we have – 77 which is the leading edge spar now that we have an overview of the rudder assembly let’s talk about a few builders notes there will be multiple drawings that you will want to reference all of which are available in the builders database under chapter 27 – 41 all of the components in the rudder kit have an identification label which identifies the part number which includes a sub assembly for which each part belongs to in addition there is a picture of the particular component on each label most of these labels are placed in a manner so that they’re easy

to remove from the component in many cases the label will simply come off when the plastic is removed from the sheet metal you may find it helpful to stick the labels to the workbench as you remove each one as they also provide a visual picture of each part number that may be helpful and identifying the parts as the labels have been removed ribs two through five consists of two piece ribs both left and right in order to help with the orientation and identification of each rib after the labels have been removed there’s a coating system built into each rib each rib has an identifier on the forward side of the rib that identifies the rib number by the number of holes that are drilled into the aluminum for example rib number three has three holes and rib number four has four holes and so on in addition the ribs that are located on the right side of the rudder facing forward have all of the identification holes drilled at an angle whereas the ribs on the left side of the rudder have all of the rib identification holes drilled parallel with the rib before we can begin assembly we need to do one more modification to the rudder spar because the radius of the Bend on number six rib there is an interference between rib number six and the top of the rudder spar we simply need to provide a small amount of clearance by filing or sanding off the outside edges of the rudder spar a radius or a chamfer of just over an eighth of an inch will provide plenty of clearance once you’ve removed this material deeper the end of the spar now that this is complete we are ready to begin the assembly process we’re going to start the process of assembling the rudder starting with the very top rib this is rib number five and work our way down to the bottom which is rib number one we will start with rib number five working the process completely and then we’ll duplicate the process for the remaining four ribs first we will remove the plastic material from each side of the rib sheetmetal piece you can simply grab the edge with your fingernail peel it back a little bit get it started and then with a nice even pull you can get the plastic off relatively easily then we’ll need to do the other half of the rib number six once this is complete the next step is to deep butter each one of the pieces in their entirety there’s many different methods for deburring and you can refer to the deburring video if you need a different digital help with these procedures once we have both the right and left side of the ribs deeper we can click them together to form a single rib as shown here now utilizing our spar with the nut plates oriented towards the aft portion we can click on the ribbon place using two 1/8 inch click OHS on either side to position the rib correctly we now have the tip rib rib number 5 completed and installed it is now time to join rib number 6 to the rudder spar and rib number 6 completing the upper rib portion of the rudder assembly once again we deeper the edges and the holes of rub rib number 6 before installation and then we will use to click o’s to join rib number 6 to rib number 5 on the top of the rib and then to click o’s to attach rib number 6 to the top portion of the rudders bar now that we’ve completed rib number 5 we’re simply going to duplicate the entire process for rib number 4 we will identify the proper part number for each rib remove the plastic and then deeper both the

edges and the rivet holes next we can either assemble the rib completely and then click o it on to the spar or we can do as we’re doing in this section here and we’re doing one half of the rib at a time and then once both rib halves are a click o to the spar we can rivet the two rib halves together next we’ll proceed on to rib number three and then on to rib number two using the same basic procedures for rib number two we will proceed the same as we have for rib number five four and number three but we have an additional component to add to this rib assembly rib number two has a sephora rib that bridges the two legs of the rib together to form a structural box that the rudder control horn assembly will attach to we will take the number two ribs support and prep it for installation and then click oh it in place next we will install the rudder control horn on to the forward spar and the rib number two we will be drilling the spar holes with a 3/16 inch drill bit and then the first two holes in rib number two in the final assembly we will be attaching the rudder control horn with four and three bolts but for now we’ll simply use three sixteenths inch click OHS to hold it in place the rudder control horn will be installed permanently after the rudder assembly has been covered with fabric rib number one is a little bit different than the rest of the ribs as it is a single piece rib that is already pre bent into the final shape the procedures are however very similar to the rest of the ribs remove the plastic and then Bieber both the edges and the holes and the rip on rib number one there is an alignment tab that is used for the manufacturing process to position the rib correctly in the CNC press break during the bending process this tab is intended to be cut off before you can install it onto this bar simply take a pair of sheet metal here and drop the tab on the inboard end there is an additional tab on the outboard end however this end does not need to be trimmed once you’ve got the tab off you should use a file to smooth and deeper the area where you’ve cut it next we will install the rib number one on this bar using to

click OHS on either side rip number one just like rib number two has an internal support rib that ties the two sides of the rib together deeper and Cliquot this in place as shown in the drawings now that we have all of the ribs after the main spar installed we’re ready to install the trailing edge you will want to remove the plastic from the trailing edge and remember that there’s also plastic on the inside and you might as well go ahead and remove it now so that it’s not floating around after the airplanes been built you’ll want to trim the lower section of the trail image material so that it matches the profile of number-one rib you can mark it and then cut it with a bandsaw hacksaw or even just sand or file it to the proper profile next we’re going to insert the trailing edge material in between each of the rib mounting sections start by measuring to ensure that the trailing edge is the proper distance away from each of the aft sections of each rib to ensure that it’s parallel with the rib tabs notice that there is a difference from the right side to the left side on the distance of the ribs to the trailing edge the reason for this is to offset the rivets so that they don’t interfere with each other now site down the length of the trailing edge to ensure that it’s centered on the rest of the rudder ribbed structure then drill and Cliquot the trailing edge to the number one rib on both sides then proceed to rib number five and drill and click oh that ensuring that it is also centered during this process next you could drill one rivet hole in each of the remaining rib tabs on either side of the rudder simultaneously ensuring that the rudder trailing edge has no twist and is properly centered when we began the installation of the trailing edge we aligned it with rib number one this leaves us a little portion of trailing edge material sticking out past the top of rib number five this will need to be marked cut and trimmed to fit flush with the profile of the top rib the last rib that we have to install is rib number seven this is the leading edge lower rib and we’ll use the same procedures that we did for all the other ribs just simply deeper and then go ahead and install it it should be installed with the flanges facing upward we now need to prepare the leading edge for installation onto the rest of the rudder assembly once again we will deeper the edges the Lightning holes and the rivet holes next we’ll prepare the leading edge spar by deburring it once we have the leading edge spar deep bird we will need to click o it in place we will need to have a click oh about

every third to fourth rivet hole now it’s finally time that we get to start installing some rivets we could use a hand pop rivet gun especially on something as small as this rudder assembly because it has a relatively limited number of rivets but if you’ve got a bigger job ahead it’s nicer to have a pneumatic rivet gun to work with we’re going to be installing leading edge spar with eighth inch aluminum pop rivets and these will be part number BSP four – to install all of the pop rivets between the Kliq O’s insuring that you have good pressure to close up the gap between the two pieces of sheet metal once you have filled all the holes between the click O’s remove the remaining clecos and install the rest of the rivets and the remaining holes next we want to trim the manufacturing tabs from both ends of the lean inch skin trim off the tabs using a pair of tin snips then using a file smooth out and beber the rest of the leading edge next we will want to remove all of the rivets that hold the ribs in place where the leading edge skin will be attached you can go ahead and remove enough rib number seven from the leading edge as well and position it into the lower portion of bleeding-edge skin and Cliquot it in place once again place the clecos every three to four rivets facing now position the leading inch skin in place and secure it to the spar ensuring that you have at least a couple of rivets in each one of the ribbed locations align and drill any remaining holes in both rib number six and rib number seven and secure them with qlik OHS as well next we can start riveting the leading edge skin to the structure once again we will be using BSP 4-2 aluminum top rivets in most of the locations where the leading edge skin goes through another single layer of aluminum the areas that will not receive these rivets or anywhere where the skinned ribs and spars are joined together we will use stainless steel rivets in these areas after we’ve completed the other steps in the construction once we’ve installed all the rivets remove the remaining click O’s except those at the rib locations and install the remaining aluminum pop rivets on occasion you may run across the location where rivet holes are not aligned perfect and you may need to simply run a drill through to clean up the hole use a number 30 drill bit next we will move on to the trailing

edge and install the BSP 4-2 aluminum pop rivets into the rivet hole locations remaining with one click o during the installation process then remove the remaining click O’s and install rivets in those holes now that we have installed all the aluminum pop rivets it’s time to proceed on to the installation of the remaining pop rivets at each one of the rip locations the stresses are higher and require stainless steel pop rivets we will be using CCP 4 – 2 or 4 – 4 stainless steel protruding head pop rivets depending on the thickness of the materials being joined together refer to the drawings if you’re unsure about which holes require which stainless steel pop rivets we will begin by joining the rib halves together using CCP 4 – 2 rivets in the areas close to the spar you may need to use a hand rivet pop rivet gun in order to get enough clearance to access the rivet right next to the spar the rivets located where rib number five and six are joined together and the rib spar locations will require CCP for – for rivets remove one or two rivets at a time leaving at least one click on each rib during the installation process to ensure proper alignment we will proceed on to the remaining ribs and install stainless steel pop rivets in these locations on the sides of the rib there are rivet holes used to attach the fabric to the structure these will not receive it rivets except for rib number one and number two at the forward locations where the rift support rib is located and there’s an extra set of rivet holes there is consistent spacing for the fabric attachment holes with an additional rivet hole placed between this spacings you may want to refer the drawings for proper placement of each of these rivets we have now finished the construction of the rudder assembly and are ready to proceed to the covering process remember that the control horns will not be installed permanently until after the entire rudder has been covered the final weight of the entire rudder assembly should weigh less than five pounds if you enjoy watching these videos

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