Chapter 18 – Canopy Latch Hardware
This page covers all the hardware required to secure the canopy (besides hinges & pneumatic canopy strut) after the physical construction of the canopy.
20 August 2016 — During the last week I have been doing some odd & end stuff on the build, much of it stuff I was never able to really put together before since I didn’t have all the pieces parts in the same location.
A note that I’ve had for a while in the middle of my electrical switch diagram states to account for the panel space required by the canopy latch arm that sticks out horizontally into the space near the throttle handle. I became acutely aware of how much space the canopy latch was really taking up when I sat in my buddy Marco’s Long-EZ specifically to note clearances, required reach to cockpit items/switches, and simple ergonomics. It emphasized that the note on my switch diagram truly had merit, and that I must indeed account for this most necessary but intrusive component (pic below is from Jack’s website).
Thus, back at my hacienda, I finally got around to pulling out the EZ-Rotary Canopy Latch kit that I bought from Jack Wilhelmson (eznoselift.com). I first (re-)inventoried all the parts to ensure I hadn’t lost anything over the years. I then did a quick (re-)review of the installation procedures to get a feel of what I was up against. My main current concern was of course the clearance with the instrument panel, and luckily with this setup the bearing block hangs down from underneath the longeron, and not straight out from the panel, thus giving me back the 3-4 square inches that I wouldn’t have been able to use on my instrument panel if I had installed the plans version of the canopy latch.
26 June 2017 — I realized as I was making up a quick sketch of all the GIB controlled electrical components (with the addition of the LED lit fuel site gauges) that I should account for the canopy locking rod & latches. I stumbled upon a discovery that shows yet another faulty assumption on my part, and I’m not sure exactly how I missed it.
The bottom line is that I found that the midpoint canopy latch is supposed to be –as per plans– situated at the front business area of my roll bar. I played around with it for a while, but realized I just had to bite the bullet and will have to move the middle canopy latch about 1.4″ forward. I’ll probably adjust the aft latch a hair forward as well, but at least now I know. Amazing that just this nth order affect took me about an hour to track down (well, technically over 2 years to track down!).
10 January 2018 — I started off this morning reading an email from my buddy Dave in OZ extolling some issues on placing the latch for Jack Wilhelmson’s RL-1 Canopy Rotary Latch system. Dave has too many interfering components, including the left knob on his Garmin GTN650, if he tries to put it in the traditional location just in front of the left side of the instrument panel. Just as a point of note, that was seriously a big primary reason why I went with the GNS480: no left knob except the on/off/vol knob, which is still however my own limiting factor for moving my RL-1 latch up as close to the panel as I’d like.
Well, curiosity got the better of me, so I grabbed my latch and mocked it up… I was aiming for the plans’ ~4″ in my head and mocked it up quickly, realizing immediately after I took the pic below that the longer lever doesn’t reach forward as I have it in the pic, it only just travels between the 7’ish to maybe 1 O’clock position (as I understand it).
I pulled out the installation manual and had in my notes to move the whole canopy latch shebang 1.4″ forward to allow clearance at the rollover assembly and also for the throttle. Dave’s solution looks to be mounting it mid-strake opening, thus turning it into a center controlled latch with the small catches forward and aft of the main latch, where as obviously both are aft on the plans style latch.
Since I can’t really do what Dave is doing (since Dave is building his Long-EZ to fly around the world, he has no fuselage cutouts into the strakes… the fuselage sidewalls are the interior walls of the fuel tanks), my issue becomes one of tight tolerances and clearances.
Although the cardboard cutout I made as positioned below is ~1.4″ inches forward (F.S. 42.6) of the plans’ position (F.S. 44), allowing clearance for the throttle, this position has the short fat rotary latch knob hitting my GNS480 on/off/vol knob. Moving it aft about 0.2″ provides clearance for the knobs, but only gives me about 1/4″ clearance from the outboard top edge of my CURRENT WOT throttle position to the robust, square-edged latch cam I note in the pic above (noted as “#1 issue”).
Thus, I provide Wade’s 3-point plan for eaking out just enough room to make this work:
1. Ensure the rotary latch assembly is driven as far outboard up against the sidewall as possible when mounted to better provide clearance between the latch cam (top pic) and the outboard edge of the throttle handle. BTW, the throttle handle’s outboard edge aligns vertically very closely with the inboard edge of the longeron (if you drew a line or strung a plumb bob and viewed it from top/aft/front), so there is clearance… but I just want more for my poor pinky! Also, regarding the clearance between throttle and canopy latch, the real issue is only during T/O and climbs at WOT.
2. I still need to drop the throttle down when I construct the new throttle lever. With the canopy latch position required to be a hair aft of where I originally wanted it, I may cheat a bit and drive the throttle inboard say 0.1″, and mount it lower (the handle, not the quadrant) the furthest it will go comfortably.
3. There’s approximately a 3/4″ gap between the front of the rotary latch’s smaller fat knob (depicted blue above) and the GNS480 face when the rotary latch is locked and closed. Again, this is approximate of course since I don’t know the exact resting position of this knob, but it is close to what I have shown above. This shorter latch knob will also just barely clear the bottom front edge of the “PWR/VOL” knob. However, since I come in at a slight angle from the right anyway to push the CDI button (XPDR button is inop in my setup), the short fat knob if left alone wouldn’t present a big problem. But by driving the rotary latch assembly as far outboard as possible AND trimming about 1/8″ off the bottom (outboard) of the knob to reduce it’s overall protrusion into my GNS480 op space, I should have zero issues for any 480 button-pushing tasks that may ensue.
12 January 2018 — I started off today discussing a variety of issues via email with my buddy Dave Berenholtz, one of which was parts availability for the canopy latch system. I took the pic below of my Wilhelmson RL-1 rotary canopy latch components to add some clarity to my email and thought I’d include it here.
20 March 2018 — Because of the issues detailed above, over the past couple of weeks I have decided to undertake yet another mod (I know, I know . . .!) and build a new canopy latch based on Mike Bowden’s design since his high horizontally-situated/activated latch works much better for my configuration (read: operating space) than does the rotary latch extending down in front of the left-side panel.
Although based primarily on Mike Bowden’s design, I will combine it with the forward latch catch manipulating features of the mystery Long-EZ that I somehow have a pic of, but have not been able to find who owns it or built it. Coincidentally, as I was compiling a buy list of all the materials I would need to construct this latch, I got a text from Mike Bowden… who graciously provided me a plethora of dimensions that I had asked him for regarding his canopy latch.
17 July 2018 — (Build Note) I curved the outer edges and tops of the last round of foam additions I made for the 2 aft canopy latch hard points on the left side canopy frame. The forward of these 2 hard points was already at the exact width I needed, 1.85″ while the aft hard point needed a little narrowing so I sanded it down to 1.85″ width as well.
I then laid up 2 plies of BID on the forward hardpoint of this pair, canopy latch #3 of 4.
And then also laid up 2 plies of BID on the aft canopy latch hardpoint.
I would like to note that these 2 aft protruding canopy latch hard points (above) are 1 of 2 options that I have for mounting the canopy latch hardware. As per plans, the standard canopy latches will get mounted with bolts running vertically. However, if I find these hardpoints too obtrusive, unsightly or the plans method of latch catch installation too problematic, I reserve the right to shave these off and mount new latches (which I would have to cut out of flat aluminum, see pic below left) which would mount with the hardware installed horizontally (pic below right).
Option #2 is a blatant copy of Mike Beasley’s outstanding work that he did on his canopy, which is pretty close in size & shape to mine (from what I can tell pic wise). I nabbed these pics off Mike’s very informative Long-EZ build site.
One final point of note on my 2 canopy latch options is A) for option #1 I already have all but one set of latch hardware in hand, and B) since these hard points traverse the width of the canopy frame, it’s clearly much easier to lop off the protruding hardpoint section to go with option #2 than it would be to add it later if I wanted to go with option #1.
14 February 2019 — As has been evident many times before in this build, there is often layer upon layer of interdependencies that drive design changes (aka “mods”). This very point became evident after I received my GNS-480 —and after I placed it in just about the only place it could go in my panel— when I realized that my EZ Rotary Canopy Latch from Jack Wilhelmson was just not going to fit. And believe me, for the price I paid and the beauty and quality of Jack’s latch, it was not something I chucked aside in a momentary flight of fancy for something else!
At the time I remembered that both Bill Allen and Mike Bowden had rather unusual canopy latches, somewhat similar in style and appearance, and both of which I had seen at the Rough River fly-ins.
Well, through Alaska Long-EZ builder, Brian Ashton, I was linked up with Mike Bowden… who graciously gave me a very thorough run-down of the dimensions on his canopy latch. These conversations took place almost a year ago.
Well, today I finally got around to plugging in all the known dimensions and extrapolating a few of the others to draw up Mike’s canopy latch in CAD. The one significant mod I made is that I added a triangular pivot plate to the canopy latch arm which will allow a forward reaching pivot arm to manipulate the forward canopy hook. If you’ve seen Mike’s Long-EZ than you know he has no need for one of these since he has a permanently attached windscreen portion on his canopy (like an F-104 Starfighter).
The shot above is a somewhat straight-on view of what you’d see in the cockpit. The one below would be an upward view of the latch from the pilot seat area.
This is an outboard view of the canopy latch, shown with the 4 mounting screws that will secure it in place on the fuselage sidewall.
Here’s another outboard view, but here I’ve highlighted (blue rectangle) the exterior handle part of the canopy latch that will be visible from outside the aircraft.
And a snazzed up version of the canopy latch. As I’ve mentioned over the past few weeks, I plan to machine the majority of these CAD-drawn components using CNC once I get down to North Carolina and settled in. That being said, I should also note that I’ve been quite sick this week, so I’ve been doing some CAD work to pass the time (when I haven’t been passed out!).
17 February 2019 — Today I was able to create a virtual left-side cockpit space in CAD to get a good feel on the mounting location for my canopy latch. By adding in a bit of the upper longeron, front panel and left armrest, I was able to just about pinpoint the dimensional specs for installing the canopy latch.
In short, this canopy latch will work as planned to provide me the clearance I need with both the throttle handle and the instrument panel (specifically the GNS-480 GPS).
With a per-plans-spec sized sidewall now in my “possession,” I was able to do a fair number of machinations to also figure out installing a lock for the canopy handle. Clearly this is, in turn, a lock for the fuselage proper.
I started with a ‘standard’ sized lock but quickly found they were a bit too robust so I went with the “mini” version (1/4″ less in diameter), which seemed to both fit and look better.
Although in rough format, this pic provides an idea of how the external side of the canopy latch handle will look . . . along with the lock.
28 March 2019 — I figured as I went about my duties today I would have “Bob” (my 3D printer) hard at work printing out the components to my Canopy Latch assembly.
As I worked up the canopy latch handle in CAD, I spent a good deal of time —all in vain I might add— to connect the components together in Fusion 360 using its various software generated joints in an attempt to make a working virtual model of the canopy latch to see how it would operate… and if there were any configuration issues. Alas, all for naught as I found out from a good unnamed friend of mine that in Fusion 360: “Joints are a b*tch!” True that!
In addition to seeing how this thing will work mechanically in the real world, as with most of my components I want to be able to actually test the size, fit and configuration in my real plane on the next trip down to my NC hangar.
To be clear, this is just a working mockup that will facilitate flushing out any bugs (hopefully!) so I can tweak the design if required before machining the final canopy latch assembly out of aluminum and phenolic.
With the white PLA filament still loaded in the printer, I started Bob off printing a mockup of the threaded phenolic sleeve that will thread into the center block of the handle assembly to mitigate friction of the aft sliding connecting rod.
I then swapped the PLA filament to blue and began printing the main canopy latch assembly components. Below is the latch assembly’s lower mounting bracket.
Here we have a “so far” progress pic with the lower mounting bracket and “phenolic” connecting rod sleeve insert.
I then 3D printed the upper mounting bracket.
Then came a rather mo-jamma 3D print: mainly since the main handle piece needed supports for the overhanging part of the handle — on the left side in the pics below.
Supports in 3D printing are designed to be removed after the part is completed printing, but serve to support any part that overhangs more than around 45-50°.
Here’s the canopy latch handle with the 3D-printing supports removed.
And a final glamour shot of the canopy latch handle.
A number of 3D printed parts later (2x connecting rods and connecting end cap) and with no real hardware to speak of, I quasi-assembled the Canopy Latch assembly as best possible. I’m very interested to see how this contraption will work once I get some hardware and attach all the parts together!
I had ordered some black PETG filament from Amazon that had not yet arrived, so I picked up some gray PETG from a nearby Micro Center store.
PETG is a filament that combines the ease of printing of the very common PLA filament with the robust strength and heat tolerances of ABS. Actually, PETG is stronger than ABS but just a bit less tolerant of high heat (PETG is stable up to around 80°C). Moreover, with just a few slight parameter tweaks, PETG prints out somewhat normally analogous to PLA, whereas the much more finicky ABS requires an enclosure around the printer to ensure heat retention during the entire printing cycle of the ABS part. Whereas ABS prints are renowned for their nuisance seam splitting and corner lift-ups off the printing bed, PETG can be excessively stringy and have globules all over the part if the print parameters aren’t dialed in correctly.
Thus, armed with this knowledge in hand, I set off to 3D print my first PETG part: the small pivot plate for my Canopy Latch assembly (this pivot plate allows the latch to mechanically manipulate the #1 canopy latch hook that physically sets farther forward in the cabin than the canopy latch handle assembly does).
29 March 2019 — Today I ran down to my local Village Hardware Store to pickup the required hardware to make my canopy latch assembly work. There were still some compromises since I couldn’t find any CS screws shorter than 1/2″ (plus, the countersinks on this latch assembly are set for 100° aircraft screws vs. the standard 82° sold everywhere else).
Besides getting a real sense of its size, the best part of having this physical model of the canopy latch assembly is to actually make it function as designed… to see how all the parts move and work together real world. I have to say, so far I don’t see any binding or snags with the configuration so far.
Of course, how this carries over with actual manipulation of the canopy rods and latch hooks remains to be seen, but so far we’re off to a good start.
Here’s the outboard side of the canopy latch assembly. You can see where the main body will get bolted –via 4x AN3 bolts– to the interior fuselage sidewall. Also, you can see the rectangular portion of the handle (center/left) that will protrude through the aircraft sidewall and will be visible on the exterior of the airplane.
Since the 3D aspects and functioning of the canopy latch assembly is hard to depict simply by mere words and pics alone, I made a quick video to help describe it…. along with some other 3D printed parts that I’ve made for (or related to) the Long-EZ build.
Here’s a shot of the major 3D printed Long-EZ related components or models that I’m currently working on.
7 June 2019 — Today I finally got back on the build a bit by determining where my canopy latch hooks (C2-Ls) will get mounted to the left longeron.
I started by determining the alignment of the canopy latch hook attach points on the canopy side, then marked the associated C2-L AN3 bolt positions on the longeron.
After marking the canopy latch hook attach point locations at the respective Fuselage Stations, I then measured the required 0.6″ down from the top of the longeron at each canopy latch hook attach point and marked a crossline to identify the spot to drill.
I then drilled a small pilot hole at each canopy latch hook attach point location from the interior outboard and then drilled each pilot hole out further to 3/16″ diameter.
From there, I drilled each hole with a 1/2″ drill bit from the outside in to clear out the foam at each hole and create an opening in the glass skin to allow clearance for the AN3 bolt heads.
Now, you may have noticed that I have 4 canopy latch hooks –2 forward and 2 aft of the pilot’s seat– versus the 3 called for in the plans. The reason behind my using 4 canopy latch hooks is simply to keep my significantly oversized canopy nice and secure during flight. Moreover, my rollbar longeron mount messes with the original plan’s location of the middle canopy latch hook and required me to move it forward to avoid the rollbar mount. This left quite a gap between the middle and aft canopy latch hook assemblies, so I added a fourth canopy latch immediately aft of the rollbar mount.
Below are the aft 2 canopy latch hook attach points with the AN3-13A bolts and 2 each AN970-3 washers in place. Since my longeron is about 0.3″ thicker from the front seat aft, I’ll need to increase the length of the aft bolts a bit longer than the current AN3-13As.
And here we have the forward 2 canopy latch hook attach points with the AN3-13A bolts and 2 each AN970-3 washers in place.
Finally, here’s a shot of the very forward canopy latch hook in place at the plan’s position, F.S. 44. Of course, this canopy latch hook is definitely not per plans either since I’m using a very different canopy latch handle than the stock version.
10 June 2019 — Today I again focused mainly on the canopy latches to get them as far along as possible on this NC trip.
I started off by gathering up all the actual C2-L latch hooks, thin washers and standard nuts (to allow for removing the C2-L assemblies when it comes time to paint the longeron) and installing them onto the left longeron.
Here we have the front set of C2-Ls…
And below is a shot of the aft pair of C2-L latch hooks in place. As I mentioned in my last post, I had to swap out the AN3-13A bolts for AN3-15As for the aft two C2-L latch hooks since my longerons are about 0.3″ thicker from the front seat aft. With the bolt swap out the aft C2-L latch hooks, washers and nuts fit spot-on.
With all the C2-Ls in place I then measured the distance between all the latch hooks to determine the required lengths of the connecting tube segments that will link all the C2-L latch hooks together to be actuated simultaneously by the canopy latch handle.
I also took the opportunity to inventory all the parts I have on hand in an attempt to ensure that I have what I need to connect up the canopy latch system… unfortunately I don’t and will have to acquire/make a few parts.
NOTE: Remember my canopy latch setup is a bit different than the stock configuration.
I then got busy assembling the 4 canopy-side C8 latch catches.
11 June 2019 — I started off today in a failed attempt to follow the plans in using Bondo (aka “Builders Bog”) to set the C8 latch plates in place on the canopy hard points. I don’t know if the Bondo was too old or if the C8 surfaces were too smooth and shiny for bonding, but being in transition meant I had no Acetone or accessible mineral spirits to clean up the C8 edges for bonding.
Wanting to get these canopy tasks moving forward, I simply crawled into the cockpit and set the C8s in place one-by-one as I marked where they needed to be attached with a finer-tipped Sharpie. I then held up the C8 to its respective outline, adjusted for the Sharpie line width and then marked the holes for drilling.
I will point out that my C8 install is unlike the plans steps where you Bondo the undrilled C8s to the canopy hard points, then drill through both the attached C8 and canopy hard point in one step, to later then drill out and tap the C8 mounting holes. My install is different since I’m using Jack Wilhelmson’s Canopy Latch Kit which included predrilled and pre-tapped C8 latch pieces.
To ensure my alignment both in drilling the C8 mounting holes correctly spaced and C8 alignment in relationship to the C2-L latch hook –including proper clearance with the longeron– I started each C8 install by drilling one hole, setting the C8 in its proposed spot, climbing into the cockpit to check clearances & alignments, then remarking before drilling the second and final hole.
The C8 mounting placement on the #2 canopy hard point (just forward of roll bar frame) sits just under the actual embedded canopy edge, which leaves me no option to place the mounting screws either on the inside of the frame as I did with the aft two C8 latch plates (#3 & #4) below, nor on the external side of the canopy frame as I did with the very front latch plate (#1) . . . [Sorry, no pics this time of the exterior holes on #1].
I’m not surprised on the improvised method I’ll need to employ for C8 latch plate #2 install, since incorporating mods on an already-modified pseudo-French canopy install is going to call for some unique, out-of-the-box processes to complete.
The #2 C8 latch plate will thus get mounted by pre-mounting threaded pins to the C8 mounting holes and then floxing those pins and the C8 into place inside 2 holes drilled into the canopy hardpoint, much as we do on many other components of the build (elevator hinge plates, baggage pods, etc).
I have to say that I’m very happy with how the canopy hard points worked out for the aft pair of C8 latch plates spacing and configuration-wise.
My improvised method worked fairly well with only a couple minor SNAFUs.
First, with no proper drill bits on hand I stopped off at Harbor Freight and picked up a cheap set of bits. I mean, after all, I’m only drilling through fiberglass and foam. I have to say this was the worst purchase I’ve made at Harbor Freight, having used numerous drill bits from there before. I broke 2-3 drill bits literally within the first few minutes, and unfortunately one of these was in the forward hole on the #3 canopy latch hardpoint.
As frustrating as it is, I’ll have to punt on this #3 C8 install (below) and drill the broken bit out later with a good quality drill bit . . .
In addition, somewhat analogous to the countersunk screws required to attach the canopy frame to the canopy hinges… and my not having the correct lengths on hand when I needed them, so too did I not have all the correct lengths of button head screws required to install the C8 latch plates (again, this is not a standard plans canopy install). As you can see below I improvised with some AN bolts/screws I had on hand as I await the menagerie of button head screws to arrive from ACS.
Beyond some minor logistical and qualitative tool challenges, getting these C8 latch plates’ mounting locations nugged out was a big step. As with most things on this build, doing the initial install in any given area begins the iterative process of flushing out all the further required steps in acquiring correct parts, redos/repairs and prerequisite data collection for subsequent tasks.
Here we have the aft pair of canopy C8 latch plates in place.
And here’s a shot of the #1, #3 and #4 canopy C8 latch plates in place.
25 August 2020 — The other day I used some left over flox to fill in the current front canopy latch hook bolt hole.
Well, today I moved the hole by checking it on the upper latch and then drilling a new hole about 0.2″ aft of the original one.
Of course I had to widen the exterior hole in the glass and foam to get the new bolt installed.
29 August 2020 — The canopy tasks in this posts are from over the past few days… I’ve been doing a ton of measuring, mocking up, testing, tweaking, etc. to dial in the canopy latch system.
First off, to fine tune the positions of the longeron-mounted canopy hooks (C2-L), it made it much easier to move them in unison. Besides the fact that I needed to punch a hole through the upper pilot seatback for the interconnecting canopy latch rod at some point anyway.
After determining and marking the rod through-hole position, as best possible, on both the front side of the pilot seatback…
And the aft side, I then got to drilling.
And was then able to finally connect the back set of latch hooks to the front. Remember, since my canopy is massive, combined with needing to move my center latch hook forward to avoid the roll bar frame, I added another latch hook assembly just aft of the roll bar to make 4 total (vs 3 stock).
A point of note: As I posted on before, I bought Jack Wilhelmson’s canopy latch handle kit with all the required canopy latch parts included. Then my buddy Marco bought a baggy of miscellaneous canopy hardware components at the Rough River auction a couple of years ago. Since he’s been focused on some sweet upgrades to his flying Long-EZ, JT, he gave me the bag to cherry pick some of the parts. I’ve used the bare minimum parts to add the extra latch hook assembly, and some rod pieces… it really helped a ton having those extra bits on hand. Thanks Bro! But not to be outdone in Long-EZ buddy cool points, I’m giving him my Jack Wilhelmson canopy latch for his project bird… it’s a nicely machined latch, but as I’ve pointed out I just can’t use it in my configuration.
Also note that due to the curve of my fuselage + the width of the heating/cooling intake air duct at the aft sidewall/seatback corner, I actually need a dogleg at the #2 canopy latch hook with the canopy latch rod attaching on both sides of the hook.
Here we have the canopy latch rod through-hole on the aft side of the pilot’s seat .
And a shot from above…
With the canopy rod fairly dialed in through the seatback, and after many iterations of spacing between latch hooks and the canopy side C8 latch catches, I went to work installing the oddball of the 4 canopy-side latch brackets: C8 #2.
You see, the configuration of C8 #2 is different from the others since I have no physical way to install a pair of bolts/screws in the topside of the canopy bracket hardpoint to secure the C8 bracket to the underside rail of the canopy frame. Since my canopy frame is much thinner than standard, at this hardpoint the canopy is literally straight above the C8 canopy latch bracket. Thus, no physical bolt clamping pressure can be used to hold this C8 #2 to the canopy.
What to do?
I decided to flox it in place. Although this C8 bracket could be considered extra, I still want it to be as mounted as securely as possible.
I decided to add a middle hardpoint to the C8 since I’d be relying solely on the power of flox to hold this sucker in place. I drilled and tapped a 10-32 hole, then used an AN3 bolt to mount a Cozy Girrrl baggage pod insert to the new center flox hardpoint. On the aft side I used a stainless steel hex head cap screw, a bit longer since there was a good bit of canopy hardpoint meat to drill into there. On the front side I used a shorter bolt because it was closer to the front edge of the canopy hardpoint.
I then rounded the heads of the bolts to keep the bracket insert holes as narrow in diameter as possible.
I then took a deep breath and proceeded to drill the 3 holes into the bottom of the canopy frame into the #2 latch hardpoint.
I’ll point out that besides the adding the extra/middle hardpoint for the baggage pod insert, I also had to trim the aft side of the C8 bracket to avoid hitting the rollover assembly mounting rail… how’s that for planning?!
Improvise, adapt and overcome . . .
I whipped up some flox, tending towards the wet side, and then floxed the #2 C8 assembly to the bottom side of the canopy. I held it in place with Gorilla duct tape, specifically focusing on pulling the tape more taunt on the bottom side to pull the C8 inboard with whatever scant amount of play (not much) was there.
Well, although I had checked countless times in my C8 vs latch hook alignment, Murphy reared his ugly head and after the C8 was installed —super strong as I wanted it!— I just could not get the C8-mounted button head screw AND the latch hook to fit between the inboard frame of the C8 bracket and the longeron. Something seemed to have changed in the spacing/alignment in the mounting process.
Something had to give. Either I try the heat flox and remove C8 floxed inserts method, or try thinking outside the box. I seriously did not want to apply a bunch of heat to the bottom of the canopy frame… so I decided to trim down the thickness of the button head screw head.
So I chucked up the screw in the lathe.
And narrowed the diameter of the head while also greatly reducing its height.
The new (and improved?) C8 canopy bracket hook latch bolt.
I did also do a fair little bit of sanding on the longeron and was able to dial in the barest minimum of clearance to get the canopy closed without the C8 nub scraping the longeron, while also getting the hook to seat on the screw shank freely.
I then turned my sights to the very aft canopy latch hardpoint: #4. I had this C8 bracket installed, but did need wider diameter notches on the top to allow for using AN3 bolts vs the narrower head NAS bolts I had installed originally.
I climbed inside the GIB seat with my trusty Dremel tool and went to work.
And not too much later had the #4 (all the way aft) C8 latch bracket floxed and bolted to the canopy.
I also knocked out the final mounting of C8 bracket #1.
A couple of years ago when I worked on the canopy at the hangar, I didn’t have any of the correct length of screws on hand since my canopy clearly doesn’t match a stock one.
Well, although I had ordered a plethora of button head screws, I ended up using a button head screw + NAS bolt pair for a couple of reasons: the NAS bolt’s length, with a thin washer, was the perfect length (vs button heads) on the aft hole for not having any thread poking out the bottom side of the C8 bracket.
But just as important: button head screws suck for not stripping out when you really torque them… (I really don’t like them). So what I did was torque down the button head screw all the way, with the NAS bolt threads barely engaged in the threaded C8 hole. Once the button head was good to go, I then used a nut-driving “screw”driver to cinch up the NAS screw nice and tight.
Here we have 3 of the 4 C8 brackets installed on the canopy (#1, #2, and #4). As a reminder, I unfortunately broke a drill bit off deep into one of the holes on C8 bracket #3’s mounting hardpoint. It will take some effort and cunning to get that hole cleared to get a bolt mounted in there, so I decided to get the “easier” C8 brackets installed first.
30 August 2020 — I didn’t get a lot of shop time in today. However, what I did do was very significant and a huge milestone for my Long-EZ build. I finally extricated that darn broken drill bit from the forward bolt hole of the #3 canopy C8 bracket hardpoint.
It took nearly an hour total using the Dremel tool with a very tiny ball cutter bit. Almost what a dentist would use for drilling a cavity. Regardless, I finally got it without too much destruction, other than an oversized hole.
I filled the hole with flox and then went about installing C8 #3 using AN3 bolts.
Of course to first get the proper length bolts I had to sit in the back seat with my Dremel tool and carve away the semi-circular, half-moon notches (both in height and circumference). I also had to allow for getting a wrench and/or socket around the bolt heads to tighten them.
In the end, to get the length just right on the bolts I needed to add a thin washer to each one.
Here’s the final product. Not bad!
With this being an oversized, non-plans, one-off canopy I’m very pleased that the hard points have lined up as required this far.