RV-12 Canopy Latch Instillation Completed

The section of the plans that covers the instillation of the canopy has by far the most pages devoted to it … 23 actually. Last year there was the introduction of the canopy latch micro switch and at that time a few of the canopy latch parts were slightly modified by Van’s to create more of a positive latch and a -1 was added to the part number.  In addition to the instructions for adding a micro switch, section 34 received an additional seven pages which mostly covers various methods of sealing the canopy at numerous locations. A trip was made to the printer so the changes to the plans and the new additional pages could be printed out and inserted into the instruction book.

One of the modified parts is the C-1205 latch block which is now the C-1205-1 latch block. The latch block will be installed under the roll bar and has a trough which captures the canopy latch. Prior to instillation it requires a little finessing by way of countersinking, taping and drilling. The latch block comes with two holes drilled into it and the builder is to countersink the holes for the head of a #8 screw. Easier said than done because there is a trough cut into the latch block and it interferes with the countersinking bit. I ended up taking apart the countersink cage and placing the center portion into the drill press then SLOWLY countersunk down through the wall of the trough and finally into the hole.

Using the drill press to SLOWLY chew away at the wall of the trough on the C-1205-1 latch block and finally on to countersink the hole for a #8 screw. The countersink cage was disassembled and the center portion was placed into the drill press.

Finished machine countersinking of the C-1205-1 latch block. Because of the white on white it is hard to see but zooming in on the photo one can see the wall adjacent to the rear countersink was carved into a little by the countersink bit.

The second hole in the latch plate is a piece of cake to countersink compared to the first hole adjacent to the wall. After both holes are countersunk, the plans instruct the builder to tap one of the holes in the latch block to 8-32 then use it as an aid for tapping the hole in the roll bar squarely. The instructions say to Cleco the tapped latch block onto the roll bar and screw the tap into the latch block and then tap the hole in the roll bar. The idea here is to make a straight square taping of the roll bar. The second roll bar hole is to be tapped after the holes in the latch block are drilled out to #19. Because the holes in the latch block aligned perfectly with the holes in the roll bar, I deviated from the plans and just tapped both holes in the latch block and clecoed it in position to use as a guide for tapping both holes in the roll bar. After the first hole was tapped to 8-32, a screw was placed in the threaded hole to secure the latch block onto the roll bar so the second hole could be tapped … after both holes were tapped, took it all apart, got rid of the metal burrs, final drilled the latch block to #19 per the plans and screwed the completed C-1205-1 latch block onto the roll bar.

Using the threaded hole in the C-1205-1 latch block as a guide to tap the hole in the roll bar squarely using an 8-32 tap.

(Have to mention here that leaving the rear window out has proven to be a golden decision. Working on the latch assembly and adjusting the micro switch would have been much harder if the window were in place). The final piece necessary to complete the canopy latch assembly is to fabricate the C-1214 latch block. The C-1214 latch block is attached onto the aft face of the F-1231F-1 latch plate and level with the latch plate. I made mine just slightly proud about 1/32" … seemed to be a better fit that way. After positioning the C-1214 latch block is to be match drilled to the F-1231F-1 latch plate.

C-1214 latch block clamped onto the F-1231F-1 latch plate for match drilling.

Match drilling the C-1214 latch block using the holes in the F-1231F-1 latch plate as a drill guide.

After drilling, the left most hole in the C-1214 latch block is countersunk for a flush rivet this countersink is to be made deeper than flush. The C-1214 latch block is to be shaped to conform to the shape of the F-1231F-1 latch plate … the Scotch-Brite wheel was used to adjust the shape as necessary. The C-1214 latch plate was then installed using a CS4-4 rivet and two LP4-4 rivets. Because the micro switch and associated wiring has already been installed, all that was necessary to complete the canopy latch instillation was adjusting the positioning of the micro switch. The switch was adjusted so it just barely activates as the latch handle drops into the trough in the C-1205 latch block.

Completed canopy latch and micro switch instillation.

Temporary Ballast Added To Nose Gear

Bernie came by the hangar shortly after my arrival and having a helping hand available, I decided to not work on the canopy but instead use Bernie’s assistance to bolt the WD-1201 nose gear assembly onto the firewall. This is all in preparation for having the capability to roll the RV-12 outside the hangar for the sanding phase of the upcoming canopy fairing fiberglass work. Prior to rolling the RV-12 around, the nose needs some weight to insure the nose wheel stays on the ground. However, because the nose gear assembly is not yet bolted onto the firewall, adding weight up front pulls the nose gear assembly away from the firewall … not good. Turning ahead to the engine mounting section of the plans reveals the two engine mounting holes in the WD-1201 nose gear assembly are to be drilled out to 3/8" through the firewall. Prior to drilling, an AN3-5 bolt is to be placed into one of the holes and tightened thus keeping the nose gear assembly aligned and tight to the firewall while the other bolt hole is drilled.

The 3/8" drill bit chosen for this task is a DeWalt pilot point drill bit. Because there is already a hole through the firewall and WD-1201 nose gear assembly, the tip on the drill bit will keep the drill bit tracking straight through the existing hole.

 DeWalt 3/8" pilot point drill bit chosen for drilling the nose gear/engine mount holes in the firewall.

A closer look at the tip on the DeWalt 3/8" pilot point drill bit.

With Bernie’s assistance and a little finessing by way of lifting up on the tailcone, the holes in the WD-1201 nose gear assembly and firewall were brought into alignment and the temporary AN3 bolt was inserted and tightened. The other hole was then drilled out to 3/8" and then deburred. After deburring, the proper bolt for this location was inserted and an engine mount vibration isolator is temporarily installed along with a washer and nut to keep the nose gear assembly tight to the firewall so the remaining hole can be drilled.

Bernie about to pull the AN6-27 bolt through the firewall as I push it towards him from inside the cockpit. Note the smaller AN3 bolt holding the position and keeping the nose gear assembly tight to the firewall.

I was able to use a socket on long extensions to get the bolts through the firewall without needing to climb into the cockpit. The same technique was also used for deburring by taping a large deburring bit onto a socket and using the extensions to reach the hole inside the cockpit while standing outside and leaning into the cockpit.

Drilling the remaining hole in the WD-1201 nose gear assembly into the firewall using a 3/8" DeWalt pilot point drill bit.

Until the RV-12 takes to the sky for the first time, it could be considered a land yacht of sorts. And what self respecting yacht owner would not have an anchor for his pride and joy?  So Mike K. loaned me an anchor to help keep the nose wheel anchored to the ground. Decided to make a cantilevered support for the anchor and some additional weights out of two pieces of 1/2" pipe and insert the pipe into the nose gear tubing. The pipe has some duct tape wrapped around it so it will not mar the powder coating on the gear tubing.

Two pieces of pipe … one 9" and the other 18" to hold the 15 pound anchor.

Mike’s 15 pound anchor suspended beyond the front tire offered enough weight to keep the tailcone from hitting the floor.

The 15 pound anchor was likely enough weight … but just to make sure, Bernie brought over a couple of additional weights so they were also added bringing the total to 37 pounds.

Final combination of Mike K.’s anchor and Brenie’s weights … a total of 37 pounds.

A wire was wrapped around the tie down loop on the nose gear and run up to the cantilevered pipe to minimize side to side swing. This can be seen in the above photo. Although a little Rube Goldbergish, the weights will only be needed for a little while until the engine is mounted. Thanks Mike and Bernie for the use of the anchor and weights.

RV-12 Canopy Installed Along With Canopy Latch

Yesterday, finished off reinstalling the left C-1202 canopy skirt and securing the left side of the canopy (for the second time) with the #6 screws Van’s provides. But the extra work was worth it … the flush rivets really complete the look!

Replacing the canopy screws that Jan helped me with over the weekend. Shhh … mums the word. Jan does not need to know her trip to the airport over the weekend to help me was all for not.

Once the canopy was screwed in place, the left C-1202 canopy skirt was riveted onto the WD-1219 canopy frame using flush rivets in the place of LP4-3 rivets. To complete the attachment of the C-1201 canopy onto the canopy frame, the canopy is riveted onto the forward bow of the WD-1219 canopy frame using a special AACQ4-4 rivet which appears to require much less force to set. Of course, riveting the canopy was still a scary proposition not knowing if a crack would suddenly appear in the canopy from the stresses of being riveted onto the canopy frame … especially since the holes in the canopy were machine countersunk for the flush AACQ4-4 rivets used at this location. Happy to report no cracks.

Using the pneumatic rivet puller to rivet the C-1202 canopy skirt onto the WD-1219 canopy frame using flush rivets in the place of LP4-3 pop rivets.

Completed instillation of the C-1202 canopy skirt onto the WD-1219 canopy frame using flush rivets. Did not rivet the canopy handle so there will be the option of paint or powder coat.

Riveting the C-1201 canopy onto the front bow of the WD-1219 canopy frame using the Van’s supplied AACQ4-4 pop rivets.

Whew!!!!!!! No cracks! Completed riveting of C-1201 canopy onto the front bow of the WD-1219 canopy frame. This completes the canopy instillation onto the canopy frame.

With the canopy now a permanent part of the canopy frame, it was time to begin installing the canopy latch and handle. The plans instruct the builder to insert the WD-1218 canopy latch into the hole in the WD-1219 canopy frame and install the washer and C-656 handle. A test is to be made of the ease of rotation … this is one place where a tight fit with drag is very desirable so the latch will not move on its own. At first I thought there was enough drag but think it was caused by some overspray getting into the hole. After a few insertions and greasing of the canopy latch shaft per the plans, the latch began moving quite freely. Van’s solution to induce some drag is to “carefully pinch” the lower portion of the canopy frame tube that the shaft on the latch slides into.  Frankly, it is totally daft to be doing this now … especially at this location. More of my thoughts on that below.

Here is the issue … trying to deform the bottom of the tube is not that easy at this stage of construction (or wise) and if really successful the builder will have a very difficult time inserting the canopy latch into the pinched hole.  Ask how I know. My first attempt was to use a C clamp to deform the hole ... hardly enough room with all the stuff in the way but I was able to deform the hole slightly but not enough, as the clamp would slip off the edge of the tube. Next a slight tap with a large pin punch slightly deformed the end of the hole, but then I was unable to insert the canopy latch’s shaft into the hole … had to tap it down from up above to open up the hole enough so it could be inserted from below … however, the drag was still not enough.

Attempting to use a C clamp to deform the bottom of the canopy frame tube … this worked a little, but did not get the job done.

Then it occurred to me … just flatten the top of the tube a little. Because the handle is installed from below, it makes more sense to deform the top of the tube rather than the bottom of the tube where you need to insert the shaft of the latch handle into the hole. I accomplished this task by taking a hard plastic faced mallet and placing it against the top edge of the tube in the canopy frame and gently hitting the mallet with a dead blow hammer a few times until the edge of the tube deformed inward. The canopy latch was then greased and tapped in from below. This resulted in a nice positive drag. I did place a little blue Loctite on the threads of the screw during final instillation.

Installing the screw that will hold the canopy handle onto the canopy latch … this was during the initial trial fitting.

Completed instillation … canopy latch assembly in the open position.

Completed instillation …. canopy latch assembly in the closed position.

Builder note and tip: As mentioned above, I feel it is totally daft to instruct the builder to deform the bottom end of the canopy frame tube. This is the hole the WD-1218 canopy latch’s tube is going to be inserted INTO … there is little margin for error. Plus, my biggest gripe is all of this should have been done prior to installing the canopy on the canopy frame. My suggestion for fellow builders: Test fit the of the WD-1218 latch handle prior to installing the canopy frame on the RV-12 … and, if necessary, deform the upper end of the canopy frame tube while access is easy. When happy with the drag on the canopy latch (make sure the shaft is greased), remove the latch and install the canopy frame on the RV-12 when the time comes knowing the drag has already been checked and adjusted. There is just no good reason to be attempting to deform the canopy frame’s tube after the canopy is installed.