AboutKen Myers Expertise I can answer beginning, advanced and expert questions about electrically
powered R/C model aircraft, and many questions about R/C model aircraft of
all types, except helicopters. I`ve been building, flying and designing R/C
model aircraft for 40 years.
Experience I have been building and flying radio controlled model aircraft since 1960. I'm the president of the Electric Flyers Only, Inc., located in southeasten Michigan. I'm a past president of the National Electric Aircraft Council. I'm vice-president of the Midwest R/C Society. I was president and main founder of the UFO (Union Lake Flying Organization). I've built and flown most types of model aircraft except helicopters.
Expert: Ken Myers Date: 6/1/2008 Subject: Propellor choice for a hovercraft
Question Hello, I'm currently in the design stage of an RC hovercraft, which will be using a .40 plane engine for both thrust and lift. My question is about the propellor choice, something around 10x6.5 seems to be suggested, but what is the physical size of this propellor? If it is, as I'm guessing, 10" in diametre is there any way I can reduce this, for example by using a 3 (or more) blade prop? Does the fact that the prop will be in a cowling make any difference to prop selection? I would like to keep the prop as small as possible to fit it in the hull, otherwise a rescaling of the model will be required.
Many thanks,
David
Answer Hi David,
Yes, in a propeller described as 10x6.5, the diameter is 10 inches and the pitch is 6.5 inches. For a hovercraft, you'll want to use a fairly "flat" pitch like a 10x4, 9x3.5, 8x3, etc. You might also want to consider multi-blade props like 3 or even 4 blade, but they are much harder to come by. A .40 size glow engine usually doesn't swing less than a 9" diameter 3-blade, but you MIGHT get away with an 8-inch diameter 3-blade. Go to http://www.towerhobbies.com and search for props. They will have a large selection and show you what is available. You can order from them or go to your local hobby shop, once you know what is available.
Good luck with your project.
