The good news is the wing kit leaves the US on the 8th of August. Until it arrives however, there is a number of things that I am trying to get finished off so I can focus on the wings when it gets here.
The horizontal stabiliser and elevator are out for media blasting and finish welding. They needed work as they are just starting to get surface rust just sitting in the garage bare and I want to get some primer on them. Thats what you get with humidity I guess.
I am now riveting the upper wing fuel tank. Should have that finished quite quickly but will wait to have it welded because I need to check the clearances in the wing and particularly underneath the tank to make sure the clearance of the drain/fuel line flanges are acceptable. I will build a drilling template also to locate the holes in the lower surface of the wing.
I am also still completing the second and last butt rib for the upper wing, which is different than a butt rib from the standard wing. This rib is a 1/2″ think rather than the standard 1/4″ and has the compression wood within it.
Finally I have been playing with the cabane struts, having been fortunate to scrounge some streamline tubing from a fellow builder in Canberra. Thanks Lou!!
Whilst I have not posted for a while and I am still waiting on my wing kit, I decided to have a go at some aluminium. In a previous post you saw the outside tank ends, but now onto something a little more substantial – the ribs and tank skin.
The plan is to make the ribs, fold the skin, bead the tank skin, drill and then match drill the ribs. Once I can cleco it together, I will then get the drains, fuel outlet and tank filler welded, before riveting and final welding. The welding and riveting will be in a separate post.
Step 1: The first thing I did was build the rib template to plans and fold the two outside tank ribs. See previous post.
Step 2: Make the four internal ribs. I used the same rib template to ensure the correct size. Then used a large hole cutter to make the holes.
One thing I learnt is make sure the hole cutter is locked and can’t move. I ended up putting a mark on the lock nut to ensure that it wouldn’t unwind and incorrectly enlarge the hole diameter. I learnt this fortunately on some scrap when figuring out how to work it. It un-did and I didn’t get a circle!!
Also note!!!!!!! In this picture above you can see both left facing and right facing ribs. This is not shown on the plans, but I have done that so that I can reach from each side when riveting the ribs to the skin when closing it.
Step 3: Fold the skin around, match drill and cleco close. Test fit drains and filler.
And now….we wait for welding. Will be back for part 2 later.
I have had a go at working with aluminium for the first time. Working out quite well.. Right now I have three ribs mostly completed. Two inner ribs with a relief in the corners and one without the relief which will be on the of the ends for the tank. The relief is not cut in the ends as the corners will get welded.
Last thing to do is final sand the edges and then drill/cut the lightening holes with a flanging to finish. Then it will be onto the tank skin.
Aside Posted on
Ok given my wing kit despatch is now 3 months late, I am running out of things to do. So in order to keep making some progress I have decided to have a go at something new, the top wing centre section fuel tank.
I have ordered the aluminium sheet locally and ordered parts from Aircraft Spruce. I found a bead roller and sheet metal brake online so am fully equipped to do this.
This week I started with making the template/jig for the ribs for the tank. In the picture below the 5/8″ thick template will be used to bend the flange edges over the template. You can see the template sitting on the template for the inside dimensions of the actual spacing between the spars. The tank will be about 40″ wide. If you are building this tank, note that the Steen plans have the incorrect width of this tank on the plans. Re-measure to be sure. I also want to put a capacitive probe in it…these have about 3/4″ on the outside of the tank so you need to make allowance for that spacing. Remember the tank needs to be centred to be balanced too so whatever space you leave on one side, you will need on the other.