I cut the main wing struts a bit over length, with the expectation that I’ll have to fit the struts on each plane. There are 8 struts that hold the top wing on – it doesn’t have any connection directly to the fuselage. I used store bought 3/16” dowels for the struts. I cut the rear two body-to-top-wing struts at 1-3/8” and the forward two body-to-top-wing struts at 1-1/2”. I cut the two vertical lower-to-upper-wing struts (the center struts) at 3-1/2” and the other four struts to 3-7/8”. I cut 5 sets of these for the 5 planes I’ve got in progress.
The only remaining item to fabricate is the propeller.
I used a strip of the 1/4” poplar, ripped to about 9/16” (the width isn’t terribly important but the propeller can’t be so long that it hits the “ground” when the plane is sitting). I cut the propellers to 5-7/8” long.
The first operation I did was to drill the hole for the peg that holds the propeller to the body. My plan involves running the propeller through the router so it’s easier to drill the hole before the routing operation (at least in my mind).
Because I had 5 of them to do and they’d all be cut to the same length (using a stop in my miter saw), I set up a stop on the drill press. The pegs are 7/32” and because I wanted the propeller to spin freely, I used a 15/64” drill bit.
Note that the material under the work piece serves 2 purposes: 1) helps prevent tear-out without chewing up the drill press table insert; and 2) elevates the work piece so I can turn the drill press quill handles – without the additional height the handles hit the drill press table fence.
Next, I routed a “blade” shape into the propellers on my router table. I used a 45 degree chamfer bit with a bearing. I elevated the bit as far as I could so the bearing would just catch the top edge of the work piece, cutting as much profile as possible. Next, I adjusted the router table fence so it was in line with the bearing (I pull the fence forward a bit, place a straight edge against the fence, then move the fence back until the straight edge hits the bearing).
I adjusted the gap in the fence so it cleared the bit but left as small of a gap as possible. It would probably be a good idea to use a sacrificial fence but, well, I didn’t. I didn’t seem to get any tear out in the poplar.
Next, I clamped a stop to the left fence so that the cut ends less than half way from the end. This will allow me to make the same length cut on each of the four passes.
Here’s a wider view of the setup:
Then, using push sticks for safety (I play guitar in addition to woodworking and don’t want to loose a finger tip), I made the first pass. From there it’s just a matter of repeating the same cut on all four edges accessible using this set-up. Here’s a view of the end profile:
The final step is to trim the ends. They could be rounded but I chose to cut some angles at the ends. I set my miter saw to a 22.5 degree cut (it doesn’t really matter what the angle is – my saw has a stop there and I just chose to use it). I snuck up on the cut so that it was keeping the full length (I almost left the propellers with a flat at the end) and set up a stop on the saw so I could do all of the pieces the same.
And here’s a shot of all 5 of the finished propellers (I already wiped some Danish oil on the one on the right):
Next it’s the finishing and assembly…
-- Randy Morter, Phoenix, AZ