Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

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.

Model Airplane News - RC Airplane News | Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

Model Airplane News - RC Airplane News | Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

 

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.

Model Airplane News - RC Airplane News | Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

 

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.

Model Airplane News - RC Airplane News | Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

 

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.

Model Airplane News - RC Airplane News | Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

 

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.

Model Airplane News - RC Airplane News | Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

 

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.

Model Airplane News - RC Airplane News | Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

 Model Airplane News - RC Airplane News | Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

 

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.
Model Airplane News - RC Airplane News | Scale 3-Blade propellers — Building a Ziroli Static Scale Kit — Part 3

Well, that it for this time. There’s still more work to be done. Come back to see the added detailing and painting.

Stay tuned.

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/

 

Updated: July 15, 2015 — 3:56 PM
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