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Building Tips and technical articles. => 1/2 A building. => Topic started by: Robert W on October 22, 2009, 06:08:48 AM

Title: PAW80 Prop
Post by: Robert W on October 22, 2009, 06:08:48 AM

I did a quick search and could find any prop recommendations for the PAW80. I finally acquired one and would like to hear what has been working for those who have flown then in 1/2A sport stunt.

Robert

Title: Re: PAW80 Prop
Post by: Ralph Wenzel (d) on October 22, 2009, 09:18:32 AM

Depending on your application (and especially on the weight of the plane), you and the P.A.W. 80 will probably be happiest with something in the 6-4 to 7-5 range. If you use APC's, please sand off the razor edges of the LE and TE!

Mine like Dr. Diesel's "Olde English Blend" fuel; Aerodyne is also good. I have some RedMax, too, but haven't tried it. A gallon of this stuff goes a l-o-n-n-g way!

Title: Re: PAW80 Prop
Post by: Robert W on October 22, 2009, 04:26:58 PM

Thanks Ralph

I just got through running it with a 7X3 rev-up on the bench using the redmax blend. The little motor showed 12K on the tach, does this sound about right? My experience with Diesel's is very limited, but I am having fun learning how to run them. I will probably built model with a built up wing around 230 in^2 to Carry the weight.

Title: Re: PAW80 Prop
Post by: Larry Renger on October 23, 2009, 12:14:39 AM

Your rpm seem just about right.  I don't know what happened to my earlier reply, but my recommendation is a minimum 6x4, generally a 7x3 or 7x4 or the Tornado 6x4 3-blade prop.

Title: Re: PAW80 Prop
Post by: Graham Collins on October 23, 2009, 10:15:40 AM

My preferred prop on my PAW 80 has been the MA 7x3 or Graupner 7x3.  However, I don't have the engine currently mounted a plane but the when I get around to using it again I will trying some of the APC offerings in the between 6 and 7 inch diameter range. These props I seem to recall are aimed the racing crowd and some have a alot of pitch. However, the lower pitch ones may just work better on a given airframe than a 6x4 or 7x3 - testing will tell.

The Paw 80 is a wonderful little engine. Mine hand starts readily but I tend to use my small 1/2a starter instead.  Don't believe the old wives tale of never using a starter on a diesel. Balderdash I say!  If you go into it with a clear thought of what you are doing you won't damage the engine any more than you can damage a glow engine by over priming (and providing the same kind of hydraulic lock which won't necessarily stop the starter but will bend the rod).

cheers, Graham in Ottawa Canada.