Posts Tagged Plans
So after about a year since my last post… where did that time go! I thought I’d get back onto the B-17 build. I’ve started to build the wings up for the main reason that the plans don’t include a template for 3 parts called WSP1,2 and 3. these fit into the fuselage and join the two wings together. Now its easy to approximate the shape of these parts as you can use the corresponding fuselage templates, however what there is no guide for is how far into the root of the wing to extend these parts or indeed what or how to set the dihedral of the wings. Hence time to build the wings, set the dihedral and get the parts built.
Anyways enough rambling here’s a shot of the first wing coming together.
Looking around several websites seems that the dihedral needs to be set around th 4-5 degrees mark. The side view drawing roughly shows the spar positions in relation to the fuselage so it shouldn’t be too difficult to set correctly. More progress soon.
Now have all of the fuselage formers cut out. Just got to notch out where the longerons fit. So thought i’d test fit all the formers to the 3/16″ crutch. Still a lot of work to be done before it can all be glued together permanently. The photo only shows formers 1 thru 14 in place. I’ve still to cut the crutch notches out for the remaining 5 formers before attaching them.
I’ve started thinking about how best to attach the wings to the fuselage for easy transportation. The original plan has the wing as a single piece construction removable by unbolting the wing from the fuselage via the bomb bay.However looking at the diagrams, there seems to be longerons spanning the length of the bomb bay, which would make it impossible to remove the wing. I’m currently thinking of making this a 2 piece wing joined to the fuselage using carbon fibre spars bolted via the bomb bay.
The last couple of days have been spent tracing out and cutting the fuselage formers. The plans called for a mix of 1/8″ ply and 1/8″ balsa to be used. However the widest sheet of balsa i can get anywhere is 4″. This is not wide enough for the formers, I’ve.taken the decision to change this to lite-ply. Although this will make the fuselage slightly heavier it should be pretty negligible. At the current pace I should have all of the formers completed in the next couple of days.
I’ve been thinking about building the fuselage on some form of jig to ensure straightness. My current thoughts are to use some 4″ blocks of wood with spacing controlled by a dowel or metal screw rod. This would maintain squareness of formers, and then just pin the centre crutch to the blocks to keep horizontal squareness. Anyway I’ll continue to play with this idea and post up a picture if it works out.
Made a conscious effort to start on a new build that i have been pondering for a while. I’ve had a copy of the plans for a few months and just finished a trial build of a Lockheed Vega. This build is of a 78″ wingspan B-17G WW2 bomber, named the Bit o’ Lace. The plans were created by Walter Oetzell, but there’s not much information of other builds from these plans on the internet.
Here’s a quick picture of the side view of the aircraft pinned up on the wall currently for inspiration, apologies for the Stuka shadow!!
The plans are missing some key information which the builder needs to take into account. Firstly 3 wing spars that hold the wings to the fuselage have no template on the plans so must be created by the builder. Secondly there is no mention of the required dihedral for the wings, although from a few internet searches this seems to be between 4-6 degrees.
The first task on the list is to start marking out the formers and wing ribs onto Ply and balsa sheets ready to be cut. As i don’t own a cnc machine these will all be cut by hand using an electric scroll saw. I’m using a different method of putting the templates on to the wood this time. Previously i’ve photocopied off the plan and glued the templates to the wood with lo-tack spray glue. I’ve come a cross a couple of issues with this, namely the template not sticking properly, as well as glue overspray. This time im going a little more old school using a set of compasses and tracing paper. We’ll see how successful this is as we go!