A New Hope Workbench
The fuselage and wing of the Pietenpol Air Camper are large assemblies that have to be assembled on a large, flat surface. Many builders use the ground (e.g. a flat concrete slab) or join a couple of separate workbenches together. My ground slab isn’t flat and occasionally gets wet – hence, it wasn’t an option for me. Whilst I do have a couple of matching workbenches – one of them was in poor condition and the two together are not quite long enough for the fuselage. Hence, I set about constructing a new workbench that would allow me to lay out the entire fuselage. I had a spot in mind for the workbench underneath the house, however, this spot has a drain – hence, the workbench would be required to span over the drain. I set about creating a rough design of the workbench using Fusion 360.
The length of the long fuselage Pietenpol (there are short fuselage versions used for other engines) is approx 173″ in length. Therefore, I set about making a workbench of about 4800 mm long so that there was some extra space on each end. The large span of the workbench was going to require very expensive, large sections of timber to get the requisite stiffness. Hence, I settled on a truss design using inexpensive smaller sections. The main unknown in the design was how much the timber would creep – causing sagging of the work surface. I figured I could add a simple center prop if it was really needed later on.
I purchased the timber required from my local Bunnings and laid out the basic side trusses. Everything was attached with screws to allow for future modification and breakdown.
The two side trusses are connected by a cross member at each node in the top and bottom chords. A diagonal haunch brace was used to keep the legs square and provide some resistance to racking. The design allows for two levels of dedicated timber storage between the trusses. The top surface was clad in 18 mm MDF sheets – this proved to be a mistake as a wet summer caused the MDF to develop mould. I later replaced the MDF with melamine sheets which seem to resist moisture better. The finished workbench will provide an excellent surface on which I can lay out the entire horizontal stab or fuselage.
