gpar

How do you drill holes for the screws in the props.
I use to have a hard time trying to align holes in the prop and holes in the crankshaft, ending up enlarging the prop holes to fit the screws.
Any tips ?

Digger44

My Feedback: (4)

Using the prop drill guide for the motor is probably the safest bet.

BaldEagel

If you have a drill press, you could use the washer at the front of the prop to guide the holes, put a big bolt in the centre and when you have drilled the first hole put a bolt through this to keep alignement for the rest of the holes. The best way is with a drill alignement jig as previous post.

Mike

C185Pilot

My Feedback: (25)

Make sure to drill the back side of the prop with preferably a drill jig. Drilling the back side assures that when the screws emerge from the prop they are perfectly aligned with the threaded holes in the drive washer. If drilled from the front, the drill will wander slightly making it more difficult to align the screws with the holes...even with a drill press.

Tired Old Man

My Feedback: (1)

Some pretty good advice form everyone that provided it. Use it all and everything should go just about perfectly.

coronabob

My Feedback: (10)

I use the round bubble-in-liquid guide on my cordless drill. I place the prop on a piece of wood on a flat floor. As I drill, I center the bubble and do not apply too much pressure. Pull the bit out several times during drilling to clear out the clogging. Minimal friction, medium speed are all that needed.

rajul

My Feedback: (58)

I use a PSP drill jig that clamps onto the prop hub so that it does not shift while drilling. You'll first have to determine what is the proper drill jig and drill size. The largest drill that will fit in the jig is the one to use. For instance in a DA100, the right drill size is 5.2mm. Turn the engine on to compression and then place the prop where you feel comfortable. I put mine at about 1 oclock. One trick to drilling the props is this.

Use a drill press if possible for accuracy. Place the jig in the prop, and drill one of the holes all the way though, being careful not to break out the back side of the prop. Now drill all the other holes about half way through. Take the jig off and put it on the other side of the prop, using the shank end of the drill bit as an alignment pin by putting it through the jig and the fully drilled hole, then tightening the PSP jig. Drill through the prop untill you find the other holes that you started. This way, you do not get any break out on one side of the prop, and the holes are nice and clean. Use a "pecking" fashion when drilling. This means drill about 1/4 inch or less, then back out the drill and let it clear the chips. Make sure the drill doesn't get too hot because it will toughen the wood.