RCU Forums - View Single Post - Picking a Prop
View Single Post
Old 06-08-2004 | 07:13 PM
  #5  
phread59
Senior Member
 
Joined: Jul 2003
Posts: 1,483
Likes: 0
Received 0 Likes on 0 Posts
From: coal township, PA
Default RE: Picking a Prop

Jett's chart pretty much spells out prop selection. You just need to remember this simple factoid. Pitch=speed, diameter=power. Pitch makes the plane go faster. Diameter (or length of prop) gives you more pulling power. You want a low pitch long prop for what you are asking for. Also to go up and down in prop sizes. You trade 1 for 1. In other words a 10-6, 11-5, 12-4 and so on would have about the same load on your engine. You can go the other way too 10-6, 9-7, 8-8. This is aproximate and is a good guide for experimenting.

I would lastly like to point out that different prop manufactuers props are not the same. Master Airscrew props load an engine differently than APC's. So when experimenting use the same brand and model prop. MAS makes several different series of props and they are all different. And plastic and wood are also different. You will get different loadings there as well.

Basicly pick a brand (I like APC's) and model and stay within their range and you should have no problems.

Mark Shuman

PS: This is for standard engines with standard fuel. Rinning high nitro(20% or more) and using tuned exhausts will change this. They are for more experienced modelers and I will not go into the changes for these applications here. Unless someone wants me to.