Getting back to the scratch-built Hub assemblyfor the static scale Hamilton Standard 3-blade propeller, I turned some pieces of 1/8 inch plexiglass sheet to use as the front and back plates for the hub. Cutting off the corners of the square parts helps speed the turning process. I also turned a smaller, 1-inch diameter one to double the back cover. Turning them requires a ¼ inch hole drilled in them so a bolt and nut can be slipped through them and tightened and then chucked in the lathe. Turning them makes the plexiglass discs very true, much better looking than if I had cut them with a bandsaw and sanded them round.
While assemblying the major parts of the hub, I used a dowel (to the right) as a guide for gluing the discs onto the hub assembly. I used thin and medium ZAP CA glue to glue all the parts together.
The Ziroli kit also comes with a resin cast hub nose-piece cap. My scale documentation showed then nose piece being a little narrower in diameter so I needed to turn it down a little on the lathe.
I drilled a hole in the back of the part and tack glued a length of brass tubing in it so I could chuck it in the lathe.
The cast resin part is very good material and it machines and cuts easily. I reduced the nose piece about 1/8-inch in diameter, (1/16-inch cut depth,) leaving the raised lip ahown here at its base. The cast resin can be sanded and actually smoothed to a polished surface before painting for a metal smooth finish. While I was at it, I also cut a flat spot on the front of the nose piece and drilled a small hole in the hub for an attachment bolt head. This center attachment bolt is a very important detail for the static scale propeller to look real.
To flesh out the hub, I cut some 1/8-inch basswood sheet to make the hub webs between the blade sockets. I then glued them in place with thin CA centering them between each of the blade sockets.
To form the fillets on the hub to make the whole assembly look like a cast aluminum part, I used Squadron White putty that’s intended for scale plastic models. It sands well and builds up nicely and dries quickly! I applied one layer and let dry. The next step will be to sand it smooth and then apply a second and final layer of putty. I will be using red glazing putty for the final coat as it dries to a harder, smoother finish and will require less sanding.
Well, that it for this time. There’s still more work to be done. Come back to see the added detailing and painting.
To see part 4, click the link: https://www.modelairplanenews.com/scale-3-blade-propellers-%e2%80%94-building-a-ziroli-static-scale-kit-%e2%80%94-part-4/