Hi,

Ok ive beeing using a set bran prop for a while now with no probles, i had to pick up a Black Masterscrew type as the others had run out, but this doesnt fit the shaft ???? is it just a simple case of drilling the whole on the prop bigger to fit ???

Thx

Yes, but you have to make sure it's bored as accurately as possible.

You can get prop reamers from a hobby shop, or use a drill.

Once you have enlarged the hole, it's a good idea to re-balance the prop to make sure any error in concentricity is accounted for.

-David C.

Yes. If the hole is too small, make it bigger.

David's got you going in the right direction.

Enlarging a prop hole is a "Good News - Bad News" proposition.

Good news - It's easy. You don't even have to be overly careful, because the drill will naturally follow the existing hole.

Bad News - The drill can "Auger" its way into the hole, so be careful that you are holding the prop securely (and - especially with an MA Prop - make sure to hold it with a glove and/or remove the edge flashing so that IF the prop catches and tries to spin, you won't get sliced up)

If you have access to a drill press, this would be a good time to use it.

Quick related question. When you install a prop do you want it to "slide" onto the shaft? When I put one on I normally have to "screw" it onto the shaft. Will that cause problems? I would think I would need to be careful not to get the hole in the prop too big but I am unsure of how tight the prop should fit on the shaft.

Thanks

If you have a drill press it's one way to enlarge the hole. Iwouldn't try it with an ordinary hand held drill motor. The best way if you don't have a drill press is one of the stepped reamers available at most hobby stores. Prop should be a push fit.

I use a hand drill all the time and it works fine. You do have to be careful, and make sure you're holding the drill perpendicular to the prop, and balance it afterwards. I prefer my props to have a snug, "screw on" fit.
Dennis-

The best way is to get a reamer and ream the hole to the proper size.

I use a drill press. It ensures a 90° hole.

Aaaah yes, those wonderful black Master AirScalpels...

When you install a prop you want it as snuggle to the shaft as possible to avoid concentricity problems that can cause vibration. Just not so tight that you will get the piston to go thru the compression stroke.