18-Canopy/FHC
Chapter 18 Canopy
Forward Hinge Canopy: Plans for install are shown first, then actual install is shown at the end of this chapter. In late August, I added a lot of pics on the install at the end of this chapter and I am doing a layup list.
(doubleclick images for larger view, and narrative follows each set)
This is a "split rotation canopy" system. The forward half of the turtleback rotates to the right side, and the Plexi-section is a FHC off of F-28. The key to a dual hinge system is an alignment of the two hinges. This is done with the temporary use of 1/4" metal rods and a "hinge board" (glassed foam of course) connected to a canopy base. Thanks to the builders that posted on the Cozybuilders group, about the FHC idea. The drawings are accurate to scale. Print them off and take 1/4th inch square paper and redraw to make the parts or as a starting point for what you want to do. A printed off copy is NOT to at the plans scale. The top of the hinges are 1/2 inch from the outer surface of the fuselage exterior to give the best rotation geometry. See the home page pic #4 for a foam mockup to test the rotation. I completed the FHC main glassing and I got about 50 degrees of rotation before binding occured, and that is the limit of extention of the gas springs.
CHANGES that are made in this work.
1. Replace the alignment pins with AN3 bolts to allow for more room on the FWD of F-28 and add reinforcement to F-28.
2. As result of the first change, I must have a removable canard cover. I made my canard cover one piece from just above the access door in the nose to the cut line for the FHC. (full access to the FHC hinges is allowed and they can be just under the skin)
3. Place spacers and set pins on the TB and cut the fwd section off and make the drip rail. Most of what is shown in the pics is only possible with a removable TB forward section.
4. Make a rigid base for the canopy that provides the support for the Plex-canopy and with the base including an extention between the hinges.
5. Add more shoulder room without using a "Texas size plexi-canopy".
The plans version of the canopy is an exoskeleton type support system. The urethane (blue/tan) foam is made rigid on the exterior, with some hard points added at various locations. The side hinge setup works with that. The FHC needs a different support setup. A dual hinge articulation works best with a rigid support. I made a "fork" shape rigid base and connected that to a ring support on the aft of the Plexi-canopy in order to get this type support. If your going to have the more rigid base, then the support on the forward side of F-28 really becomes a 'must do".
PLEASE NOTE.
The plans show the F-28 at 3.25 inch high. I added to the top of my F-28 to give 1.5 inches above the level of the longerons as per Newsletter #36.
That notice is to make F-28 four inches in height. Since the plans do not show this, I have redrawn my pencil drawings to show this change. Please overlook the use of "old school" pencil drawings. The scale on the graph paper drawings is the same as the plans. I will just use the paper template to cut out the parts and install. I used paper templates to test the rotation of the hinge/canopy design. 09-04-2010 Rewrite You will need to install the reinforcement pad onto the two F-28 bracket assemblies and the two canopy bracket assemblies. Mark the holes for the brackets to the reinforcement pads and drill for the Tee nuts to slip into the opposite side of the pad. Tape the hinge bracket with masking tape, and punch the holes out for the bolts and install the bolts through the pad into the Tee nuts (base side away from the bracket. Put wax onto the ends of each Tee nut. For the F-28 install, just trim out the inset on the aft side down to the forward side glass and add flox to the pad and seat it into the floxed recession WITH the guide rod in position. Clamp the assemblies in place and let cure. After cure uninstall the brackets from the pads and use a sharpie to outline the bolt holes in the reinforcement pad. Place wax into the holes and do the four ply UND over the aft of F-28. You must be able to see the sharpie outlines through the layup. After cure, dremel out the bolt holes and reinstall the F-28 side of the FCH assembly with the AN4 bolts instead of the guide rod. You already should have added the 4 ply UND layup and stiffener to the forward side of F-28. The canopy side of the hinges has become a simple process with the use of the hinge board. I attached some temporary supports on the inboard sides of the longerons to hold the hinge board Hard Point Material (called 15 ply BID, but I did 16 ply -8 BID & 8 UND) 1. Canopy side hinge pads 4"X4" (two) 2. F-28 side hinge pads 2.75"X4" (two) 3. Gas spring/handle pads 1.5"X6" (two) 4. Rotary draw latch pads 1"X2.5" (six) 5. Piano hinge pads 1.5"X2" (six -three canopy side and three fuselage side) Supply List for FHC ITEM Supplier QUANTITY 2024 Alum-0.25 thick (12"X12") AS 1 1/4"-20 bolts-3/4" long Lowe's 36 1/4" lock and flat washers Lowe's 36-50 1/4"-20 X 5/16" Tee nuts Home Depot 36 AN3-10A bolt(canopy hinge side) Aircraft Spruce 6 MS21042-3 nut Aircraft Spruce 6 AN970-3 washer AS 12 AN4-10A bolt AS 4 MS21042-4 nut AS 4 AN970-3 washer(drilled to 1/4") AS 4 (The F-28 hinge points have room enough for just the plain flat washers from Lowe's) SPD-GSEL-5300-20(pound force)Service Plus Dist. 2 SPD-GSEL-5300-20 (for TB section) 1 BR-12553 bracket SPD 3 (one for TB, 2 for FHC) BR-10684 bracket SPD 3 (one for TB, 2 for FHC) K-3 draw latch (low profile) Southco 2 (for TB section) K-2 draw latch Southco 2 (for FHC) 15 ply BID Hard point material (make up a piece 14 inches X 14 inches) see the list above *I'll probably use some UND scrap pieces for some of the layers, but sandwiched and in different orientations in the BID layers. 18-FHC-3 These locks are going to be installed in the junction point of the fairings where the FHC meets the forward end of the side hinged turtleback section. The left and right locks will secure the canopy on the ground. I will use the K-2 and K-3 rotary draw latches to secure and seal both the FHC and the TB section, during flight. The check list for emergency landing will include unlatching the two FHC rotary latches. I hope that I never have to do that. Canopy start with the turtleback Now, I will explain why the canopy install varies from the plans. The idea of cutting the canopy later is not needed. If you attach spacers (a couple of tongue blades duct taped down on the longerons in two places each side on the forward of the cut section) and then drill through the turtleback lip into the longerons and place finishing nails to reposition, then you take off the turtleback and make the internal supports including the roll over support. Then you reposition the turtleback with the "pins" and make the cut. Once you make the cut, then you can easily do the layups on the forward side of the firewall to support the engine. You can retest the engine mount position and place the FW forward aluminum hardpoints for the engine mount and even drill the 1/8 tap holes for the engine mount. The pictures show this change, so if you go the plans way, then my work will not be of much help. August of 2010 The paragraph above makes the case for a TB install and waiting for the plexi-canopy and canopy base install. I have finished the FHC and it really helped out on the work for me, to have the ability to remove the forward portion of the TB and reposition it as needed. 05-01-2010 The recent postings on deep stall have brought up a lot of good information. I am sure that the second scoop will have some effect on flight. It should be a small effect, but that is to be determined and measured in the testing phase. I will place a mounting in the nose, just aft of the brake fluid reservoir, for one of the batteries to be mounted for one or two person flight, so that I keep the CG to the forward side of the "envelope". The rear CG is a factor in the deep stall. The incidence of the canard is the other major factor for deep stall. I checked the incidence. I added some bulkhead scrap material where the hinge will secure. Later, I changed to a FHC and made the TB portion to hinge off piano hinges that are at the outboard edge of the fairing, so this reinforcement is too far inboard. The rotation point for the piano hinges needs to be closer to the edge of the outer surface to prevent pinching. The round objects in the corners are the bottom side of the drink holders. This whole support collumn is going to undergo a transformation. I will add to it like DeFord's setup. That is connected headrest and hidden gas springs, and ditch the auto headrest. The next picture shows the interior of the TB(turtleback). The closer part is the aft of the TB and that is where the scoop recesses. I placed a 7 ply UND that is 4 inches wide from left to right. At a point directly above the forward edge of the CS, I placed some ribbing for two purposes. It is there that I will attach the secondary firewall. It is more about hiding the batteries and adding sound protection. I will use this as an attachment point for a control for use of the air taken in by the scoop. I will cover that in chapter 23 later. The next thing is the short ribbing that is one inch forward of the future cut line. Last of all, there is the roll support at the forward end of the TB, where the gas spring is to attach (see 18-15 of plans). All of this glassing was done with ease on the work table. I also did the micro work around the windows at this point. After this was done, I repositioned the TB and prepared for the internal drip rail and then the cutting of the TB. Internal drip rail The first picture shows the back end of the forward piece of the turtleback. I trimmed out some of the honeycomb cardboard material with a dremel bur and cut off about 1/2 inch of the inner surface. I matched that distance with the lip to be added on the forward side of the aft section (see next picture). I cut a strip of the yellow foam (1/4th inch thick and the flexible kind) and placed it under the BID strip to wedge it up close to the outer glass surface. I floxed it in and taped the BID strip over and placed the forward section over this to match up the surfaces. Let cure. Glass the bottom side of the foam. Take out some foam and ficro the edge and round the edges to prevent head injuries. The last picture shows this. The back side of the forward section has some micro placed forward of the outer lip to allow support of the inner edge. Go back to the first picture and makes sense. When I add the upper strake fairings, I will add an exit at the bottom of the drip rail for water. This drip rail will not work for nose down parking and I will need a cover for that situation. Upper FW layups T-1 to T-10 T-1 is the first 5 ply BID layup on the lower side of the CS to FW (fig 27) T-2 is the 5 ply BID on the aft of the FW spanning the CS to FW (fig 27) T-3 is a 5 ply BID that laps over the top edge of the firewall onto the back edge of the TB T-4 is a 5 ply BID that spans the side of the TB down on to the fuselage side (aft of the cut point of the TB as per fig 27) T-5 is a 5 ply BID reinforcement on the outside corner of the FW as per fig 30 of pg. 18.5. T-6 is a 5 ply BID that spans the lower inside of the TB onto the longerons and slightly below (fig 27) T-7 is a 5 ply BID at the inside of FW to CS corner as per fig 27. T-8 is a 5 ply BID at the upper forward corner of the FW onto the TB as per fig 27. T-9 is an 8 ply BID over the forward FW hardpoints as per fig 31 of 18.5 (place the aluminum engine reinf. as per fig. 32) T-10 will be done after I position the upper pulleys for the rudder cables. The two pics are of the panel that is above the CS. I used a block of 2 inch thick blue foam and carved in head rest on one side and recesses for the two batteries on the aft side. Forward Hinge Canopy Things to change from the plans way once you choose the FHC (see the list at the start of this chapter) Finally, the Install of the FHC Layup list: (labels of FHC-#) FHC-1: (top of "hinge board") 3 ply BID and UND over full surface FHC-2: (fwd side of F-28) 4 ply UND extending 1-2 inches onto the exterior of the fuselage FHC-3: (F-28 stiffener) 2 ply BID over the glassed parts and 2 ply BID strips as needed to attach to F-28 FHC-4: (aft side of F-28) 4 ply UND, AFTER insertion of the hinge 15 ply hinge hardpoints for the hinges FHC-5: (bottom side of "hinge board") 3 ply BID and UND, after the insertion of the hardpoints for the canopy side of the hinge FHC-6: (bottom side of canopy base-aft of hinge board) 2 ply BID 08-06-2010 Work steps performed 1.Reinforced F-28 2. make upper fairing foam shapes 3. shape and trim plexi canopy (F-28 reinforcement) Sometimes, if you change one thing, then the whole install changes. Bernard Siu's site showed the alignment pin being replaced by an AN3 bolt. So, in chapter 12, I show the insertion of a Tee nut into the forward side of the longeron at F-28 and then I covered the Tee nut and the forward side of F-28 with a 4 ply UND layup extending onto the exterior of the fuselage outboard of the longerons. Pic#1: I came back and removed the alignment pin and did the AN#3 install and the 4 ply UND layup. The canard will now install with a more forward path of insertion. This trial fit is of a 30 inch long and 1.5 inch wide piece. I found that a piece that was 2.0 inch wide was marginal for room and so I backed it back to 1.5 inch. This piece extends past the hinge hard point areas that will be inserted on the aft side of F-28. Pic #2: I marked and numbered all of the pieces. The middle three triangle supports are equally spaced, so that the next layup pieces are easy to cut and add. The next layup will be a 4 ply UND layup. I made it three inches wide and cut two inch long strips (floxed all corners) and placed them in the middle three top sections. On the lower side, I place about six pieces. I buttered the part that seats in the lower side corner, with thick, but not dry flox to hold it in place. Right after the placement, I used 3M masking tape (2 inch wide) and both "peel plied" and held it up. Same for the top. Remember to only use the smooth finishing nails (none with old flox on them). Pic #3: The triangle corner brace aft of F-28 is trial fitted, but it will not be placed until after the hinge hard points are installed and also after the 4 Ply UND layup is placed on the aft of F-28. 18-FHC-1 18-FHC-2 18-FHC-3 18-FHC-4 18-FHC-5 18-FHC-7 18-FHC-8 18-FHC-9
18-1
The first drawings posted have been replaced with this one, because of some improvements made as I did the install of the hinges. Most importantly, I added a cross piece, aka hinge board, between the two canopy side hinges. I also lowered the aft side of the hinge to allow this hinge board to connect to the "base" of the canopy and place most of the support there. It worked out well. I really recommend it.
Pic #1:
F-28 has a brace added. See later pics.
Point A is the rotation point and it is 3/4th inch forward of F-28 and 1.25 inches below the top skin and point A is 1/4th inch sized for an AN4 bolt
The bracket for the F-28 side of the hinge is 2.75 inches tall and 1.5 inches wide.
The bracket for the canopy side is 3.5 by 1.5 and the AN4 hole is drilled first, but the AN3 holes are not drilled until the exact angle for the hinge to bracket to hinge board is set (see Pic#2).
"@" This is a 15 ply BID pad. Another one is in F-28. Not shown in the drawing is the use of Tee nuts to attach the bracket to the hard point pad.
"*" "hinge board" See layup list for that info. The bottom of this support is flush with the top of the longeron. I tapered the top surface as it appoached the longerons. This support stopped short of the longerons also.
"%" This is the cut line, between the canard cover and the FHC. That gives full access to the hinges and aft of the IP area. The FHC side of the cut has a recessed area like the area forward of the rudders on the winglets, to allow the forward lip (aft edge of the canard cover) to rotate into that recess. Water problems are covered with the custom secondary cover that conforms to the bottom of the FHC (see later pic).
"?" Since the canard cover stops at the cut line, I need to have an attachment point further aft. Tee nuts are placed into the top of F-28 (but not over the hinges).
Here is a very short description of the brackets. The F-28 brackets are 2.75 inches long and the canopy side hinges are 3.5 inches long, made from 1.5 X 1.5 angle 2024T3 aluminum (see list).
The hinge is 2024 aluminum 1/4th inch thick. The drawing will render a template, when redrawn and cutout.
Pic #2: I jumped ahead to a pic of the hinges installed on F-28 (I used the steel rod for that part to get the alignment). This shows the use of mustard on the waxed tops of the Tee nuts. I added bracing under the hinges and set the "hinge board" on top of this to see where to cut out for the hard point to be installed on the bottom side of the "hinge board". I cut out the recess, placed the board back in position and with thick flox and masking tape around the sides to set the position.
Pic #3: The heart of the FHC.
Pic #4: The base of the canopy view has lot of info. The base of the canopy has most of the layups and hardpoints.
"V" Piano hinges (two-each 6") placed at the outer edge of the fairing for the TB
"?" K-2 rotary latch hardpoints and steel catch plates (placement is fwd 6" more)
http://www.southco.com/class/k2-k3-k4-k5-rotary-draw-latches-7427.html?ctid=80
"%" secondary pull knobs and hardpoints (see pic #3 of 18-FHC-4 below for main handle)
"#" Hardpoints for gas springs (compressed length=12", extended length=20")
"~" 4 ply UND strip on the top side of base (the bottom side of the base has the UND placed to the outboard of the hinge)
"+" A one inch lip past the edge of the longerons
"@" "Hinge board" from longeron to longeron- placed flush with the top of the longeron. This is bonded to the rest of the base.
"*" Canopy hinge hardpoint installed on lower side of hinge board (see 18-1 pics)
"$" hinge
The blue section is the aft part of the canard cover.
18-2
Hinge Brackets
Pic #1: Cut four brackets at 2.75" and four at 3.5".
The F-28 brackets have the 1/4th inch hole for the AN4 bolt (and the temp. use of the steel rod)
The canopy brackets also have the 1/4th inch hole, but three more holes for AN3 bolts. The AN3 holes are drilled just before the install of the hinge assembly onto the "hinge board", as seen in 18-1, pic #2 above.
The base of the bracket is secured to the hardpoint with 1/4th inch diameter bolts to Tee nuts. The Tee nuts are not threaded for AN4 bolts (for that size), so I used Lowe's bolts. There are 32 bolts holding the brackets, so there is no compromise on strength. The Tee nuts are a major help in the FHC install.
Pic #2: The AN4 bolt is not placed yet. The mustard gets the mark on the matching bracket to help on alignment of the two.
Flox install of hinge pads:
The size is 9.5" by 18.5". Here is the list.
(also 1" by 8" times two for the adjustable seat backs for chapter 24 work)
2024T3 Angle alum (1.5" X 1.5"-12") AS 3
Since I was going to cut a new turtleback, I wanted to simulate the installed engine configuration. This mock up shows where the air intake will be. The fourth picture shows the mock position of the air filter. The air will flow down into the rounded filter chamber and exit upward out of the filter directly to the air intake for the engine. Moisture will be vented out of the bottom of the air filter "loop". The last picture shows the 1.25 inch cutoff of the turtleback. I did not cut off the turtleback at the scoop area, so that the scoop will extend past the FW. The windows are roughly outlined here and the future cut line is marked. I did not repeat the window placement pictures that other sites show.
In the first picture, the cutout turtleback piece was turned over to make the bottom of the scoop. The second picture shows how that when you raise the turtleback, then the FW has to be added to, on the top. Before I cut the FW for the scoop, I made a cardboard template of the firewall and placed the scoop floor onto it and precut on the cardboard. When I was satisfied with the results, then I did the scoop cutout on the FW. At this point, I have already drilled the "tap points" and placed finishing nails throught the lip of the TB. Look at later pictures to see how the lip was added to for the one inch height increase. The height increase is on the full length of the turtleback.
The featherlite turtleback finish is so smooth. I plan to slightly sand for bond and prime directly to the surface. So, the idea of an external drip rail was not very appealing. I made an internal drip rail. If you make the internal bracing on the turtleback to maintain contour with temp changes then this internal drip rail will seal, dependably. In the third picture, I covered the cut line with masking tape. Next, I laid out a 4 ply BID strip. The next picture shows the BID strip before trimming. After the BID strip was made, then I drilled four test holes (1/8th inch size) along the cut line and then cut the turtleback.
I added these pics to show some of the layups that are not shown on the other FW aft picture.
18-FHC-6
