Tail Wheel Bolt

Time: 1 Hour

I had bought the Bogi Bar tow bar from Flyboy Accessories a while back and was going to get the machined tail wheel bolt as well. It was back ordered as flyboy’s has several custom machines parts and it was backlogged in the que to be made. It finally made the air and I ordered one as soon as they were in stock. This bolt incorporates two lugs that the Bogi Bar fits perfectly on and prevents that chance of it slipping off and gives a solid feel. I jacked up the tail and remember the stock bolt and replaced it with the new one from Flyboys. I had to tweet the cotter pin a little to get it to lay flush so it didn’t stick up proud of the lug so the tow bar would slide on. I love the look and how clean it is.

Brake Fluid

Time: 1 Hour

I had on my list of things to get done to add brake fluid to my brake system. I have read several blogs and watched a couple of videos on what was the neat way to accomplish this task. I decided I would try the method that pushes fluid from the lowest point up. So the idea is to use a small pump sprayer to push brake fluid from the bleed nipple on the caliper up through the brake lines and finally into to master cylinder. I went to Lowes and bought the sprayer and some 3/8″ clear hose that has a 1/4″ ID. I cut a two foot piece of the 3/8″ hose. I safety wires it to the nozzle on the sprayer. The other end I attached a spall piece of 1/4″ plastic line that was left over from my pitot static line. I safety wired those together. This is all to prevent leaks in the hose system as you add the fluid. The 1/4″ fits on the bleed nipple tightly and works well to prevent leaking. Once I pushed the hose on the nipple I turned it a 1/4 turn which opens it. With the sprayer pumped up I pushed the trigger allowing the fluid to flow through the hose, the caliper, the brake lines and into the master cylinder. I pumped enough to file it and push any air out. Once full I closed the nipple and removed the spray hose. With a firm push on the brake peddle I checked the firmness and made sure it functioned properly by spinning the wheel as it was jacked up off the ground and applied brake pressure stopping the wheel. Both sides worked well and I only found one small leak and that was due to a loose fitting. The pictures are for show and you want to pump all the air out of the sprayer lines so you don’t introduce more air into the lines. This process took only minutes to accomplish with this sprayer setup.

Baffle Sealing

Time: 4 Hours

One last step that I needed to do on the baffles is to seal up any gaps in the baffles where they meet to engine. The idea is you need to imagine a molecule of air and you want the molecule to cool the engine. That molecule needs to travel past the cooling fins of the cylinders to me the most efficient. If there are other spaces that the molecule can go then that reduces the effectiveness of the cooling properties. So to force as many of those molecules around the fins you need to close any other escape paths for them. One area that had a very large gap was on the right side of the forward baffle. I think it would have been tough to fill it with just RTV so I made a filler strip out of .025″ sheet. Once I had it to the shape I needed I drilled, deburred, primed and painted it to match. Most of the areas that need seal are pretty obvious to see for the not-so-obvious areas I used a light shining up from the underside of the engine to identify them. I used a grey colored RTV sealant, think caulking for environments that get hot and have contact with oils/fuels. It seals well and creates a good bond however can be removed when needed. It’s messy and hard to get it to look good but it is needed to properly cool the engine. I bought a couple large tubes that fit in a caulking gun to make it easier to apply. A couple areas that were too hard to access with the nozzle on the tube so I used a piece of 1/4″ plastic hose that was extra brake line stock attached to the nozzle to help get to those. I was able to use a wet finger to smooth some of the areas but others it was just too tight to get a finger on the seal. They aren’t beautiful but the will accomplish the task. I’m glad I was able to find a color that didn’t stick out like the red RTV that most planes use and would really be an eyesore.

I have a few areas that I want to clean up a little once they cure all the way. In the mean time I went ahead and cleaned all the baffle seals for the top of the baffles and installed them.

Overall I’m happy with how the baffles turned out. I think they will provide good cooling but will have to wait until I’m flying to confirm that.

Fresh Air

Time: 0 Hours

I did pull the RV out of the hangar to clean and sweep the floor from all the winter dust. While it was out I snapped a few photos for you to enjoy…yes those are shoes under the left wing! My son and new private pilot, Chandler, is sitting in the RV making engine noises.

Trim Tab Hinge Pin

Time: 1 Hour

The last month or so has been slow in the hangar as I have been working a lot at United as well as working projects on the new house. I have been keeping a “punch” list of tasks that needs to be done for projects over the last couple of years. These items didn’t need to be done at that time and it was better for them to remain undone to make the remaining projects easier. One of those items was the trim tab hinge pin. I had originally put a temporary pin in that was shorter and without any bends in it to make it easy to remove the tab as I built the tail. Today I moved on to bend and create a permanent pin and a way to secure it. Van’s would have you just put a bend and safety wire it to a small hole in the small spare of the elevator. I wanted to do something a little nicer. I wanted to use a piece of hinge with its eyelet and create a tab to put a screw through. I made some measurements and came up with a plan. I would drill out the two rivers on that spare and put a #8 nutplate there utilizing the bottom river hole. I would drill another rivet hole for the second rivet in the nutplate and enlarge the top original rivet hole for the screw. I made some test bends in a scrap pin and came up with the perfect setup. I then reproduced the shape on a new pin. I then shaped a piece of hinge so that it had one eyelet and drilled a #19 hole in it for the screw. I dimpled the bottom hole in the nutplate and countersunk the spar for the top rivet. I did it this way since the single sided nutplate is pretty tight to try to dimple both holes. Once I had both rivet holes finished and the hole for the screw done and cleaned up I riveted the nutplate in place. I then cleaned up the shape of the hinge tab and bent the tip of the pin so that the tab could not fall off. I put the parts back together and slid the pin in place securing it with a #8 screw. Turned out really nice and clean. It’s little details like this that make the build fun, most people will never see this but it makes me happy knowing I spent the extra time to make it clean and functional.