Hello all,
I'm about to cg balance my ARF .46 Phoenix Extra 300 with a O.S. .55 engine. The recommended prop from O.S. is a 12-6/7 or a 13-6/7. I weighed the props and there's a almost a 1/2oz (.4oz) difference between the 12" and 13" I'm not sure which prop I'll end up using but I'm thinking of using the 12" to at least break in the engine then I could try the 13". Is this difference in weight a concern when you balance a plane for the first time? Since switching props would have a effect on CG. Any input would be appreciated.
Thanks in advance for you help.
Pat

I have never worried about the weight difference between props and it hasn't got me into trouble so far...I guess it must make a difference though...You are starting out with the lightest prop so you won't get your self into trouble when you switch to a prop that's a tiny bit heavier . If you were flying a aircraft that was already tail heavy and you went to a lighter prop I could see where that might cause a problem...

I've never worried about it. I do a static balance before the maiden to make sure the plane will be flyable. After that it I always redistribute the weight to get the plane balanced in the air and fly the way I want it to.

Balance your plane with the lighter prop. once the engine is broken in and you go to the heavier prop you won't notice any real difference in the balance. 1/2 oz on the nose won't make much the plane nose heavy to where there would be a dramatic affect.

Tom

Thank you for all your replies, I'll balance with the lighter one.

Have you flown with this engine? I think the 13-6/7 is too much for it, 13/4, 13/5 max. I think you would be happier with the 12/6 or 12/7.IMO

Hi Steve,
No, I have never flown this prop with the O.S. 55. For now I'm going with the 12/6. The O.S. manual has the 13" and 12" as recommended prop sizes.

Ditto !

I am just finishing up a Great Planes Revolver 59 with an OS .55AX. Will be running 11/8 prop.

Personally, I would go to Master Air Screw propeller site and check out their recommendations of props for your size engine.

I also agree with the 12/6 prop . Be sure to balance the prop before you use it. The bigger diameter prop will cause havoc if not balanced properly.

Frank

Im Balancing My Plane per specs of 70mm or 2 3/4" behind trailing edge And They Say a Little Nose Heavy Is Ok but wheres the line on a little iv balanced mine with level bubble off the horizonal stab running with the fuse and iv got a 1 1/4 inch drop in plane from the point of level to nose Measuring from a fixed point on plane from both level to free standing is 1 1/4 inch drop is this ok or do i need to back some weight off nose a little  the Plane is A Super Decathlon .46 By Pheonix

NOTE That The Fixed Measure Point WasAt Rear Of fuse Just In Front Of The Stablizers so measurement will be greater than if Measured at front of plane the drop indicicated in level bubble was bubble just left outside the the marks

Just Checked The 1 1/4 Drop Was Measured 20 inch Back From Pivot Point

Just balance it where the tail doesn't drop at all...remember this....extremely nose heavy may be difficult to fly...a tail heavy plane will probably crash!!

Tom

Dang Must Have Been tired when i post last 2 postI hadplane balanced with 1 1/4 inch drop in nose but iv backed that back off to1/2 inch drop it should be good there