Date: Wed, 15 Feb 1995 02:27:58 -0500 From: Ewestland@aol.com Subject: Winglet Chapter 20, step #4 is alot of work, unless you enjoy sanding, in which case you picked the perfect project :-) ! Sanding through the micro down to the glass ( the 2 inch deep "high stress area") has taken me a couple of evenings. I would suggest to those of you that have not skinned your wings or winglets yet to lay out the area that needs to be sanded in step 4 before applying the glass. Then put down a layer of the thin peel ply (to avoid a joggle) that Alexander sells over the foam, much like you do on the trailing edge of the wings/canard. Even if you do not sand a slight recess into the foam prior to glassing, the very minor bump is in an area that receives several more layers of glass. Then once you get to step 4, you just cut into the foam and remove the peel ply. One more suggestion : when I cut the end of the wing for the winglet in step 3, I positioned the winglet, traced it and the sawed 1/16" SHORT of the line so that when I bondoed it, I had something to set the winglet on other than the block in figure 11. Later, I filed off the last 1/16" and rounded the corners for the inside BID layup. Go ahead and cut right on the line when you cut the spar cap as it takes some time to file. A question for those of you that have done your winglets. In the second paragraph of step 4, it says, "Extend 2 of the 8 plies aft to the winglet trailing edge". Should this read WING T.E.? I see no purpose for a 2-ply BID layup between the upper and lower winglet/rudder joint. Did you do this and if so, did you extend the 1/2" flox corner to the trailing edge of the upper winglet? Also, any tips on positioning the lower winglet? Thanks, Eric Date: Thu, 16 Feb 1995 19:17:34 -0500 From: SidLloyd@aol.com Subject: Re: Winglet > Also, any tips on positioning the lower winglet? Well, it might be too late for you. What I did was attach the lower winglet to the upper winglet prior to mounting. I then notched out the lower piece and after the upper winglet was mounted, I reattached the lower piece that I cut out. This created a perfect alignment of the upper and lower winglets and I don't know why Nat doesn't do it like this. I got this tip from Jeff Russell (AeroCad) and it works great. Sid Date: Fri, 17 Feb 1995 00:55:56 -0500 From: Danky01@aol.com Subject: winglet Today Eric wrote about the winglet attach in chap 20 step 4 >A question for those of you that have done your winglets. In the second >paragraph of step 4, it says, "Extend 2 of the 8 plies aft to the winglet >trailing edge". Should this read WING T.E.? I see no purpose for a 2-ply >BID layup between the upper and lower winglet/rudder joint. Did you do this >and if so, did you extend the 1/2" flox corner to the trailing edge of the >upper winglet? Also, any tips on positioning the lower winglet? Well I hate to admit this Eric but I did the step 4 on both of my wings last week and I did not catch that sentence. I read the thing but I THOUGHT that it said "wing" not winglet. After reading your note I went back are read it again, your are right it does say "winglet". I agree with you thats what it says, but I too see no purpose in a 2 ply layup here. Did I do this wrong or is this a typo??? Kyle Date: Mon, 27 Feb 1995 08:11:49 -0500 From: SidLloyd@aol.com Subject: Winglet option If you haven't done your winglets yet, try this. Attach the bottom winglet to the upper winglet and then skin the entire assembly. When you mount the winglet to the wing, you will need to cut out a chunk of the lower winglet, using the template int the plans, and cut straight down from just behind the wing TE. Leave the bottom rear section of the lower winglet attached to the upper winglet. Then do the attachment layups. You can now carve the skinned chunk you cut out to fit over the outboard layups and when you attach it, you can use the still attached rear lower winglet section as a guide to achieve excellent allignment. I also went with the internal bellhorn mods which require shifting the rudder cable toward the rear before you skin your wings. Jeff Russell at AeroCad has the plans for this. Sid Date: Sat, 4 Mar 1995 23:16:01 -0500 From: Ewestland@aol.com Subject: RUDDER HINGES Fellows, I have a question for those of you that have installed your rudders. The plans call for pop rivets on the rudder side of each hinge, but I would swear that I have never noticed these pop rivets on any finished plane. Did you use them and if so, did you use the flush-head type or the regular pop rivets and micro over them? It seems to me that sanding around these rivets would be a real pain. Please advise. Thanks, Eric Date: Wed, 8 Mar 1995 20:21:58 -0500 From: Ewestland@aol.com Subject: Progress Report Fellows, An update for those of you interested and those of you that were kind enough to answer questions along the way. Well, I finally am finished with my first wing. I have had the basic wings done for a while and have recently focused on the winglet, rudder and aileron. Last night I mounted the rudder and it works just fine. As you may remember, I had some concerns after I cut out the rudder - the long dimension on the rudder had a 4 degree bend in it towards the outside because of the alignment of the lower winglet at this point. This did not jive with the lowest hinge location at the bottom of the rudder. I decided to move the hinge to the point above the lower/upper winglet joint (I reinforced to the bottom) and while there is contact at the bottom-most outside corner of the rudder when fully deflected, it works out just fine. Ron Kidd suggested to me that I add a layer of carbon fiber BID cloth at the hinge reinforcement areas which I did. He had experienced a little paint cracking at the hinges because of the flexing. After adding the carbon, it won't be flexing - that stuff is tough! I also used the regular head pop rivets. They seemed to work fine, but it still seems strange to me that you would need to add that much fill to cover them up. Oh well.... A question : On the rudder, you use a 4" spring which you cut from a longer piece. This leaves you with a spring with no connecting eyes on the end. I tried bending some - not a chance there, so I heated up the ends which made it bend easy, but it looks like it weakened it as well. Any ideas? Eric Date: Mon, 27 Mar 1995 20:16:51 -0500 From: Ewestland@aol.com Subject: Winglet tips My students are quietly working right now, so I thought I would use this time to pass on a couple of tips for those that have not mounted their winglets yet. I have now done both and learned something each time. What I learned may be obvious to some, but it never is obvious to me - I always seem to start with the hard way and eventually discover an easier way, so, here are a few pointers: 1) when carving out the triangular foam area for the inside layups, it really helps to have a light below the wing shinning up through the glass so you can be sure all the micro is sanded away. 2) in the winglet, where you micro in the com antenna coax, DO NOT micro the lowest 3.5 " at the leading edge as you will need to dig all this out later for the layups. 3) on my first winglet, I made large triangular foam wedges to flox in place. On the second one, I just cut out a bunch 2" wide and put them in one at a time. It went easier this way. 4) I completed both 8 ply inner ribs, peel-plied them and put block A in the next day so as to avoid any chance of exotherm. I also kept the shop cold and carefully used a hair dryer to assist the epoxy wetting out. 5) When I cut off the end of the wing for the winglet, I left a couple of small "tabs" for the winglet to sit on while I lined everything up for bondo. I filed the tabs away later. Hope this helps. Eric Date: Mon, 10 Apr 1995 14:31:15 -0400 From: Ewestland@aol.com Subject: BSCQ-43 Pop Rivets I called Wicks today, then ACS, then Alexander trying to get 40 BSCQ flush- head pop rivets for my rudders and they can no longer get them. Does anyone have 40 extra they would like to sell or have a suggestion for an alternate source? Thanks, Eric