"THINGS THAT FLOAT"
creations by David Bosworth and friends
To the right shows the fan with the stainless leading edge tape applied and we are ready to install the fan on the hovercraft. I don't care for the stainless tape much, I always seem to reach for the band-aids when I use it! but the other plastic tapes I have found cost more money than it takes me to build a prop in the first place and the erosion repair is really quite simple.
To the left I have taken the same 7/8" stainless steel shaft that I use on the balancer and inserted it through the split taper bushing and propeller mounting hub assembly and into the center bore on the fan. This makes certain the hub is centered. The prop mounting bolts are protruding out the bottom of the hub face just a hair, I rap the top of the bolts with a hammer and this will mark the propper location to drill the bolt holes through the fan.
On this page we will show various stages of the carving process I use for making wood and epoxy glass reenforced thrust propellers and the lift fans for hovercraft. If you want to jump on in and join the fun! all you need is to get your prop plan templates and instruction book from Universal Hovercraft this is where you will get your demensions and working lines.
Above we are glueing up the prop blanks for both a 36 and a 42 propeller. Clamps are 2x4 and 1/2inch allthread.
Above left are the makings of a 26/14 lift fan. The blade on the left has the leading edge and airfoil shaped, on the right it has only been flattened. The blades being only two pieces of wood thick allowed us to make the blades as two units and assemble later, this sped up the process alot because we could use the bandsaw on the blades instead of doing it all by hand with the backsaw and chisel. I will add at this point that you can do all the meat removal with a powerful disc sander or chainsaw, I choose the bandsaw method because it makes alot less dust and I scrap less parts when things move a little slower!.
On the left we are test fitting the disc with the blade sets before glueing. There is a hole dead center of the blades and one in each disc, these were put there for layout and now make the assembly almost fool proof. Above right the two props are ready for the rounding of the airfoil and final blending of the hub and blade area, then a quick trip to the balancer before glassing.
Above we are working on the bottom or back of the prop, we have marked the working lines for the hub area, trailing edge, leading edge and airfoil and removed most of the meat with a bandsaw, at this point I make a series of kerf cuts between the lines with my backsaw to act as a depth indicator whilst chiseling and sanding on the surface. The idea here is to create a flat surface between the working lines, the tailing edge will define the blade twist.
More to come of course!
Propeller set for the UH-12T4
