I just purchased Palmer plans for an 87" C-130H. It calls for 4x.25 engines, which I will mostly likely make OS .25 LA's. I am trying with zero success to find 4-blade propellers to use with the .25's. I understand that the 4-blades are inefficient, but I would only be concerned if that really affected it's ability to fly. Has anyone built a 4 engine plane with these motors and 4-blade props? I'd really hate to use 2-blades...

Woodsymatt,


I too have ordered the 132" Herc from Plamer but have not yet started const. I plan on using 4 RCV-90's turning 4 blade carbon fiber props 14x10 or so. the manufactour is designing them now and he will have to cut them down a bit to acc. for all that blade area of the Hamilton Standard. i'll include a couple of links. Sorry no pics yet. I didn't really ans. ur question but just to let you know that i'm having to custom make my own props. good luck. maybe try Zingerprops.

http://www.propellers.us/prop1a.jpg
http://www.propellers.us/prop1.jpg
http://www.propellers.us/prop.jpg
http://www.zingerpropeller.com/4_bladed_propeller.htm

Grinder.

Thanks for the links. I have actually been to Zinger's site and saw that very page. I have read that if you use a 3-blade prop over a 2-blade that you need to reduce the diameter by an inch. The .25's use a 9x6 typically, so that would imply a 3-blade 8x6. I wonder if the 10x4 that zinger makes would be usable. By thrust alone, the 10x4 makes less thrust than a 9x6. What do you think?

I forgot to mention that I really like the designs for your custom props. Do you mind if ask how much they run?

sounds like it makes sense but, I don't know, i'm not an prop guru. maybe you can find that info elsewhere on RCU.


As far as cost goes for the props i don't know yet but it will be substancial as he is custom deigning them for me. Normally he makes fullsize woods props on his cnc table. All i wanted is to be able to show up at the field and not have to change from static to flying props. but none were available with the sqaure blade design.

Grinder.

WoodsyMatt:

I use 8x6 three blade props on my 25 engines, they will just pull 9x6 three bladers. A 10x4 three blade prop will be a similar load, but on the plane you're talking about they would probably work acceptably, since they will unload more as the airspeed comes up.

Bill.

WoodsyMatt,

I dont know bout the whole 4 blade prop thing. I know my Uncle Dave was looking into getting 4bladed props for 130 but couldnt find any he liked. I know he used the two blade for flying and pulled them off and put 4 bladed on for static compitition.

I know his 130 flew great on the 25 la's w/ 2 bladed props.