Skip to main content

Fuselage Sides

 Once the tail surfaces were done and I decided to pursue widening the fuselage to 38" I could clear the jig blocks from the table and paint over the lines for the tail. I then laid out all the dimensions for the fuselage side onto the fresh white paint.

It's worth noting here that the plans give views of the top, bottom, and side of the fuselage, as if you are looking straight at the side. However, the sides angle back in space, so if you were to flatten that side out to lay on the table, it will actually be longer than the dimensions given on the drawing. In drafting, flattening out a panel like that is referred to as "developing". Widening the fuselage by almost 5" also changes the length of the side, so the developed side is actually 1.5" longer than shown in the side view. I drew up the developed side in CAD and used the dimensions from CAD to lay out on the table.

The dimensions given on the drawing are to tubing centerlines and need to be offset to show where the jig blocks will go, like with the tail surfaces . I made some little metal spacers the width of my tubing to make marking these offsets easier.

The long pieces of tubing that will make up the top and bottom of each side are called "longerons." The upper longeron is easy, it's just a straight piece, but the lower one needs to be bent in two places. This one done by placing the tubing on the table with a block at the first bend, then the tubing was heated with a torch and gently coaxed until it matched the angle I needed. That section could then get held in place with more jig blocks and the next bend was made in the same way. Both longerons were left long so I had some room to adjust things if I had to. While I had the torch out and jig blocks in the right places, it made sense to bend up the second longeron for the other side.

The longerons were dropped into the jig and then I could start cutting tubing to fit between them. Once again CAD helped out. I could measure the angle between the tubes in CAD and then print out a template at that angle to mark the notch in the tubing. I used https://www.blocklayer.com/pipe-notcheng.aspx to develop the templates. I could walk through the whole tubing notching process, but I'm sure other people have done it better.

Once everything was fitted for one side, I numbered each tube, pulled it out, and made a second one for the other side.

Once I had tubes made for both sides I tack-welded one side, hung it on the side of the table, laid out side two, and tack-welded it. The fuselage can go 3D now!




Labels:

Comments

Post a Comment

Popular posts from this blog

Drag wires

Progress on the airplane has been very limited as of late. It has, however, been made. After a long episode of researching and calculating I have found drag wires.   Not the drag wires the plans call for, but still. The plans want 1050 alloy steel wire to be threaded with a #6-40 thread and retained with what are essentially spoke-nipples from motorcycles wheels. The aircraft rated nipples are about $7 each and I need 24 of them. Spoke nipples are 20 to 50 cents each. We'll, I wasn't going to spend $170 on bolts, but $12 seemed reasonable, so I ordered a bunch of spoke nipples. I had intended to match the thread of the nipples with my drag wire stock, but they are just irregular enough that I couldn't find a thread that matched and it seemed like sending wires out to have the correct thread rolled on wouldn't be worth the effort. So, despite having bought my spoke nipples, I abandoned the idea of using them. Enter the Baby Great Lakes. I researched drag wires and alt...
2 comments
Read more

Where to start?

So, where does one start when building an airplane?   The answer changes from person to person. The kernel of inspiration to build an airplane was there, as I mentioned in the last post, from the time and effort it took to build the Spirit. But what plane? I looked at the trusty Pietenpol, but the size of the cockpits and the useful load left me wanting for something more. I looked at the Double Eagle and the Airbike, but my girlfriend didn't like how open they were. Finally, I made a list of what I thought I wanted in an airplane, reproduced here.  -High wing monoplane (biplanes mean building 4 wings)  -Taildragger w/tailwheel  -Fabric wings and stab.  -Aluminum tube or wood construction, maybe steel  -Inexpensive to build  -Inexpensive to operate  -Single carb engine.  -Aircooled?  -Two seats  -Mostly enclosed cockpit (not a breezy)  -minimal systems  -AOA/reserve lift guage  -Amphibious a plus ...
2 comments
Read more

Fittings. How fitting.

  Not much has happened on the Ace this year. The winter was long and spring has been very cold, so I spent a long time waiting for the garage to warm up. Now that there's a little heat down there I've been making some headway on the next step of my wing build: fittings. I copied the parts off the plans into CAD and then printed them onto cardstock to use as patterns when laying fittings out on the steel stock.    First I tackled the brackets that will hold the pulleys for the aileron cables. I have a lot of extra material in case I had to remake these. The next step was to bend up my fittings. There is one fitting that mounts to the forward side of the strut which gets bent to a 90° angle. The fitting which mounts to the aft side of the spar gets bent at about an 85° angle. I forget the exact number, but don't feel like looking it up at the moment. Next I cut out the aileron control horns. My Harbor Freight porta-band chucked into my vice works well for cutting th...
Post a Comment
Read more