Battery Mount/ Armrest Mod’s

Time: 8 Hours

Today I wanted to finish it the battery mount addition. I had the marks made on the mount support angles and I put the mount back into position to double check the marks were on target. Once I was satisfied I took the mount sides off so it was just the angles and the mount base bolted to them. This gave me room to take the whole structure to the drill press and drill the holes. I started with a #30 hole on al 8 holes. I then took the structure back to the fuselage and placed it into the correct position. I used the holes I just drilled as a guide and drilled down thru them and the fuselage structure underneath. I then moved the mount back to the drill press and enlarged the holes to 3/16″ with my reamer for the AN3 bolts that I will use. I grabbed the reamer and drilled the fuselage structure from the bottom up. Once I had those holes drilled I used my 3/16″ clecko’s to hold a -3 nutplate in place under the fuselage. I then used them as guides to drill a #40 hole up thru the nutplate and fuselage for the rivet attach holes. The two aft nutplates are one wing ones where the 2 rivets are on one side of the screw hole rather than one on each side.

In between those tasks I started the painting of the aft side skins, just the forward end, just aft of the second bulkhead gets paint as it is the rear baggage area.

I moved on to the countersinking of the angles of the gear tower and firewall where the nutplates will get riveted. I dimpled the 4 nutplate holes that are in the skin center.

Riveting all those holes took me 2 hours as it was a difficult place to rivet. I ended up using my tungsten bar on the flush side with a lot of downward pressure and my back rivet set from underneath. It worked pretty good except the aft inboard nutplate. I had a heck of a time getting them to sit and they are raised a slight bit. Won’t be a big deal as they are secure and the mount will cover them up. One mod I decided to do last night was to create a pocket of sorts in the right arm rest structure. Below the middle armrest between the two vertical bulkheads normally is just left open. Others have placed a piece of sheet metal around 4″ tall from the floor up to create a pocket between that sheet and the side skin and between the two bulkheads. To finish the look off I decided to add a small sheet filler from the armrest above this area going down towards the floor. You can see this top piece in the next photo.

I used my new 18″ metal brake to bend a 1/4″ 90° inward bend on this piece to give it some rigidity. I then used a piece of .040″ sheet to create the bottom piece and clamped it into place.

Once I was happy with the size and shape removed the hole armrest structure as one piece and laid out 3 holes on each side, using one existing hole. I then removed the bottom sheet and drilled the 5 holes to a #19 hole for #8 screws. I replace the whole structure back into place on the fuselage and placed the new pocket sheet in place and clamped it. That allowed me to match drill the new sheet with the holes I just drilled in the bulkheads.

The pocket sheet will have 6 nutplates on it that will secure it to the bulkheads. I will be able to bend the sheet slightly to remove it once the outside skin is riveted in place. I will also trim up the bottom as needed to get a good fit with the floor. While I was working on all this I also started the priming/riveting/painting of the battery mount support structure.

One last task I worked in today was to position a USB outlet that I got from Stein Air. My plan is to have a Ram Mount for an iPad/iPad Mini/iPhone on the right side of the rear roll bar as that will be right in front of the passenger. I wanted a power source close to that spot which would be the armrest aft bulkhead. So is mocked up that area with the cockpit rail in place to see how low I could go without the wires being seen thru the lightening holes in the roll bar supports bracket.

I clamps the USB to the area to see how it looked.

Once I was happy with the spot I marked it with a sharpie and removed that bulkhead to make the cuts.

I used the drill press to drill a couple holes followed by several small files get the opening just right. I clamped the USB back in place and marked for one of the screw holes and drill it to a #30. Once screwed into place I marked the second hole and drilled it. I attached the USB back to the bulkhead after rebuilding the structure on the fuselage to see how it looked.

Another very productive day in the Hangar and feel pretty good about the items I got done. I also touched up some primer on the aft tail bulkheads that got scratched during the initial fitting. That’s where I called it a night and cleaned up the shop so I could pull the truck in as there is a chance of freezing rain/snow tonight here in Chicago.

More Painting & Fabricating

Time: 8 Hours

Like yesterday today I worked on more priming/painting with some fabricating work in between. I had breakfast with the guys this morning and they stopped by to see my work and grade me! Good news is that they gave me the thumbs up on my overall work and Glenn looked at my battery mount and said it looked good. I had also asked him some other questions about my Andair fuel valve and its placement and that’s where I started today and figured I would work on the battery mount later since all I need to do is drill for the attach bolts. Before that started I grabbed one of the mid side skins and cleaned it so I could start the priming on it.

The fuel valve has 3 positions, left tank, right tank and off. The goal is to have the “off” position located in the aft or pointing towards the back of the aircraft. This would have the left pointing 45° to the left of center line and the right pointing 45° to the right. I also wanted to have the center post of the valve to be located on spot of the measurements of my buddies.

So I first sat down and did some thinking on how I wanted it to be attached to the mid side console. I decided that I would use 3/4″ x 3/4″ angle stretched between the inboard brace and the outboard mid longeron. In between those I would lay a piece of sheet that the valve would be screwed to. You have to worry about the thickness of the materials that you use as there is a cover plate that has the labeling on and it can only be 1/8″ max above the valve body. So my first goal was to find some scrap sheet that was close to the same thickness of the mid brace. I ran out to the airport as they have a scrap bin that they put old and new scraps in and was able to find a matching piece that was big enough. I used the template that Andair sends and made the required holes.

I then cut that sheet a little larger than I needed so that I could make the final size cuts later after the support angles were in place. I placed the angles where they were close and made some measurements from forward to aft. Once I had that measurements I was able to drill some #30 holes for thru the brace/longeron and the angles. On the outboard holes I enlarged them to a #19 for #8 screws. I made some likes on the angles and braces so I could be sure to line them up again. Then I removed the angles and added a single sided nutplate to the outboard ends.

The inboard ends I will leave at the #30 size until the skins and longerons are riveted for good as it will probably move the location of everything slightly. I can enlarge the holes then and if there is any misalignment it will be corrected with the larger drill bit. I then countersunk the 2 larger holes on the outboard ends for flush screws. Now I could screw those ends tight and clecko the inboard ends.

Now I had my forward to aft measurement all set I could now slide the plate inboard or outboard to get that measurement. Once I had that all set I marked and drilled 4 #30 holes in those spots. I then enlarged those to a #19 for the same flush screws.

I could now remove all the parts and drill for the 4 #8 nutplates that would be used to hold the plate on the angles. I countersunk the rivet holes for those nutplates and used the pneumatic squeezer to rivet them in place.

Now I could put everything back in place and clecko the valve in position.

That stuff took me hours to figure out and make al the fabrication, again I may not be as quick as others but it turned out perfect. In between all that work I finished priming and painting both the left and right mid skins, I picked those only because they were on top of the pile of skins I had waiting. I will keep those in my spare bedroom to help cure in the warm house for a few days.

I removed the battery mount and made some measurements for the 8 bolt holes, 4 on each side, for the work tomorrow.

Another great weekend in the Hangar and I always feel really good after spending so much time getting to work on the plane. I cleaned up shop and called it a night.

Priming & Fabricating

Time: 8 Hours

Today was the start of priming and painting process of the fuselage parts. I started with the bottom skin as well as the two side skins of the aft fuselage. I cleaned the skins and then massed off the areas with tape and painters paper so that I could prime. On the bottom skin I primed the area in the rear baggage compartment as well as a 3/4″ strip at the aft end where it overlaps the other skin.

In between primer coats I started working on the battery mount. As with any other fabrication I do it takes a lot of mental calculations and paperwork to get it right. The battery mount was no different. My plan is to use 3/4″ angle between the firewall lower angle in the gear tower forward angle. This will give me two good attach points besides attaching to the bottom forward skin. I made some measurements and calculations so that the two angles would not hit already installed rivets on either of the two support angles. Once I had those measurements I cut my ankles and set them in place, from there I took the base plate of the battery mount to see how the layout would work. From there I clamped some smaller pieces of angle upside down in the opposite direction of the other angles.

Once I thought I had a good layout I traced the outer edge of the base on the angles. I then removed everything to make the cuts and layout the rivets with my new layout tool.

I used the band saw to trim the ends and the 3M wheel to shape them. The drill press made pretty quick work of drilling and then match drilling the matching angle.

I placed the two brackets back in the battery compartment and laid the base on top. I took some measurements and centered the base so that it all lined up with the underlying angles. I then clamped it in place with four spring clamps. With the brackets and bass back on my workbench I center the battery on top of them and added the two sides with clamps so that I had a tight fit and it was centered. In this position I now had two holes for the base and two holes for the sides that went through the base giving me for total holes per side. I’ve been marked and you to center punch for each of the four holes on both sides and used the drillpress to drill these holes to a #19. I then used my 3/16″ reamer to final size each hole. I cleaned up each hole and put it all back together using AN3-5 bolts and nyloc nuts.

I have not drilled the 4 holes that will attach the angles to the firewall and gear tower as my friend Glenn is going to stop by tomorrow morning after breakfast to look at it for me and make sure my idea is sound. My plan is to have the 2 end bolts, AN3’s, and 2 middle bolts, AN3’s, that will go through the bottom skin giving me 8 total bolts for the battery mount. My concern was while flying inverted and any negative G’s would put a large load in this area as the battery weighs 15lbs. Hopefully he will give me a thumbs up in this setup. In between the fabrication I fished up the aft side skin priming, hitting the area that’s visible in the baggage area and the bottom 3/4″ where it overlaps the bottom skin.

I also got the 2 forward bottom longerons primed. One other item I worked on was to add a 2″ pass thru duct to the seat ribs. If you remember the wing build you install a NACA vent to the bottom of the wing. This scoops up air and delivers it to the passenger vent that sits along side the control stick so the passenger has airflow on hot days. To connect the scoop to the vent you use 2″ tubing and run it from the wing thru a hole in the side skin/seat ribs to the vent. Apparently there is a problem with air seeping around the hole which the tubing goes thru during cold flying allowing cold air to enter the cockpit when you don’t want it. So some have added this 2″ duct to so this area is all sealed up and prevents this. Unfortunately I drilled this hole per the plans which makes it too big for the new flange I bought. So I cut some sheet and drilled a new 2 1/16″ hole in it. I then match drilled the flange to the rib and then to the new sheet I cut. This covered the larger hole and gave me a more appropriate hole. I will ProSeal this fill and flange to the inside of the rib giving a tight seal.

While I was finishing up that work I started the painting of the lower longerons. I gave each of them 3 coats and will let them cure for a few days before installing them. Tomorrow I will get to priming the other 4 skins and start the painting as well. I have a lot of parts that need priming and painting and will keep me busy for some time.

Dimpling Done

Time: 8 Hours

Today’s task was to finish up the few items that still needed deburring. I then moved on to the big task of dimpling all those holes on the skins. First up I laid out the skins with the plans next to them so that I could mark out the holes that don’t need dimpling with a red marker. That took a little while as there are a bunch of different symbols that tell you what style rivet as well as the length. After I laid out all the holes and their marks I needed to do 2 tasks first. The first was to edge roll on all of the skins. The forward side skins needed the aft edge rolled. The mid side skins needed the aft edge rolled. The aft edge of the bottom skins also needed rolled. This process puts a slight bend in the skin so that when the two skins are riveted the top skin will pull tight and make a tight seal.

The second task was to scuff the insides of the skins that would be visible in the cockpit and rear baggage area. So I masked off the areas and used my small orbital sander with 3M scotch-brite pads which made quick work of it. I also scuffed up the bottom 3/4″ edge of the aft side skin where it will over lap the aft bottom skin. The forward and mid skins got the entire surface scuffed since they will be seen.

I then grabbed the pneumatic squeezer and the DRDT dimpling machine and several dies. I had #8 screw holes, #6 screw holes, 1/8″ and 3/32″ holes to dimple. There was one spot in the mid fuselage bottom skins at the aft end that needed dimpling but they overlap each other and needed to be countersunk instead.

From there I hit every hole with one of the required dies and dimpling tool. It took a while and I used the workbench for some and but the DRDT on the floor for the long aft side skins.

So that was a great 8 hours in the Hangar and got a lot of work done although you may not see it. The skins are now ready for primer and paint. I will start that this weekend and will prep all the other parts for the same. I’m getting so close to assembling the fuselage for the last and final time!

Deburring & Dimpling

Time: 6 Hours

Now that all the substructure has been final drilled to match the skins all the hikes need to be deburred. The plans have you start with all 6 skin panels, 2 forward, 2 mid and 2 aft skins. That’s a lot of holes to debur since you have to do both the inside and the outside parts of each hole. So with a fully charged electric debur tool I went to work. Not to much to show with this process so I didn’t take any photos. I ran the battery dead before I got halfway done so I had to move on a little while it charged up. The forward skins have 2 reference tabs at the bottom for fitting and they need to be trimmed off at this point.

I also received a few goodies in the mail this week. First up is my Andair fuel valve. These are precision made valves that really make the stock valve that Van’s sends look pretty bad. A lot of builders go this route and there is a lot of documentation showing great installs of this valve.

I also got a gift certificate from the best girl friend ever to Cleveland tools which I used to but a rivet spacer that allows me to evenly space rivet holes when I freestyle build.

The other thing I got was a tail light adapter that will get riveted to the lower part of the rudder and make maintenance easier down the road.

Another item that was delivered was my battery hold down. I want to install the battery in the forward baggage lower area based in my buddy Glenn’s experience with it in the same place. I wanted a sleek yet strong mount that would allow easy battery replacement. Here is what I came up with and will make an attachment plan later this week.

I finished up the deburring of the skins and all other items called out in the plans. I then moved on to the dimpling process. There are a lot of areas that get dimples and some that don’t. I used tape to mask the holes that I don’t want to dimple, these are mainly ones that line up with the longerons as they were countersunk.

I made sure to scuff the items before dimpling them to make it easier later for priming. Not a lot of pictures today but a lot of work done. Another good day in the Hangar.