propellers and spinners

[steven]

Hi,
With all that's going on now, I had some free time and I just built the series 400 Spitfire and it came out pretty well. Last built a model 30 years ago. The only part that I'm not happy with is the spinner. I bought a 3 blade propeller and I cut slots in the spinner to get it to fit over the propeller. However, there's a large gap between the cowl and the spinner and propeller/spinner assembly wobbles again the cowl (because the piece on which the propeller rests is curved. Does anyone have any suggestions? I hope I described the problem accurately.
Thanks,
Steve

[heywooood]

It sounds like your 3-bladed prop needs a backer disc. I don’t have any photo’s of my P-40 build related to the prop assembly but the prop, spinner, and backing disc make for a 3 part assembly. The disc face holds the prop blades and is then capped by the spinner. The disc diameter should fit just inside of the spinner. You can trace the outline of your spinner onto a piece of sheet balsa 1/8” thick or a piece of sheet birch ply 1/32” thick at least but then you’ll want to laminate that to a disc of 1/16” thick balsa. The reason is you want that prop backing disc to be 1/8” thick at least so it can easily be glued into the spinner. So run your prop shaft into the fuse hopefully into a small block of balsa behind the nose of the cowling..and glue it in. Then glue your prop to the backing disc with a hole in the center of both disc and prop. Then cut the prop shaft with about 1/8” protruding past the prop center and use a disc of 1/32” birch ply cut with a common hole punch - just drill a hole in the center of that small disc and slide it onto the prop shaft to capture the prop. A drop of super glue on the outside of that shaft/disc will hold the prop - then attach the spinner over the top. You should have a spinning prop that is as tight as you want it to be to the airplane

[steven]

Thanks for the detailed info-- very much appreciated. Will try it out.

[steven]

I followed some of your advice, and I glued the propeller to a backing piece of balsa. Then, I cut out holes for the prop blades in the spinner and glued the spinner to the backing balsa. The prop shaft runs through a hole in the backing balsa and is glued to the propeller. Now the spinner is tight against the cowl and it spins. Not super freely, but that's ok for a static model. I'm happy with how it turned out. Thanks for the advice.

spinner close up.jpg

front shot.jpg

[heywooood]

Excellent! Nice looking model. Yes the tighter your prop is to the airplane the less effectively it will spin - but with a display model it’s ok and best that the prop can rotate a bit so that if it is bumped the blades wont break and the plane wont be flipped onto the ground..at least - that’s why I prefer they can spin or turn on my models