Do you use the optional prop drill guide available from Desert Aircraft ( $25. ), or have you been successful at drilling those 4 holes accurately using another method ?

Ed

Yes, I use a drill guide. Mine is made by PSP Mfg and was a freebie when I bought my DA-50 from Troy Built Models. ($22 regular price)

Stan

I use a drill press so a guide is not required. The prop washer will do. Without a drill press a drill guide is mandatory and still not always satisfactory.

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I'll never lie to ya.

I prefer to use a drill guide and a drill press. DA or PSP MFG, either one works the same. But with any drill guide I still always need to re-drill the holes a few times to get the bolts to go in smoothly...i.e. no side loading. I don't like any resistance to the bolts threading in or you're asking for them to be sheared off from side load.

I have used the prop washer to mark holes and drill on the drill press. That worked just fine. It's better to mark the holes while the prop and prop washer are on the prop shaft for better accuracy.

I used to drill my props with a handheld drill and didn't always have a drill-guide. The results were hit and miss at best of times. [:@]

You can get a drill press for quite cheap from a lot of hardware stores. They don't have to be the professional ones. All you really need is the ability to properly level the base where you place the prop.
I bought a drill press from a discount hardware store locally to me for AUD$89 from memory. Managed to stuff up one prop regardless - probably got cocky with the new drill press!

" Without a drill press a drill guide is mandatory and still not always satisfactory."

I think that after reading this statement, the big question for me is, what is the best way to square up that table with the drill bit, and properly use a drill guide, so that it is perfectly accurate every time ? ? ?

I have very good luck with the drill guide in a drill press. Note that you drill from the back side of the prop in order for the best alignment with the threaded holes in the hub. Any 'wandering' of the drill still allows for the bolts to engage the hub accurately. I used to fuss and drill three of the holes 3/4 of the way through and the final hole all the way through to use as a pilot for the other side to minimize breakout. Really has not been necesary. The important thing is drilling from the back side.

Stan

Finally somebody explained that clearly. Thanks. I get it now. Makes sense.

Drill from the backside for the first pass. Drill slowly with light pressure to minimize deflecting the drill bit as it passes through the hub. As you drill each hole, drop a acrew into the hole that will pass at least 3/4 of the way through the prop to assure that your jig or prop washer does not slip out of place. Flip the prop over and again drill ...slowly...from the front. Once that's done flip it over on it's back and re-drill the holes one size number oversize. You don't want any pre-loading on the prop bolts The best fit is a drop through to the hub and engaging the holes with no interference with the holes.

Hardware stores used to sell a little contraption that could be mounted on a hand drill to act a little like a drill press. They helped keep the drill motor a lot straighter than most do by hand. If you're going to be using a hand drill, make a little wood jig on the table that will hold the prop and prevent it from moving around. Two pieces of 1x2 nailed to the table just far enough apart to set the prop hub between will do. You'll need to have both hands available for the drill motor and the prop drill jig to maintain as vertical a drill position as possible,

Worst case with a wood or carbon prop is that you might end up plugging a hole with a tight fitting wood dowel and have to start over. Don't worry, the hub integrity will be fine if you have to do this as long as the wood dowel is a tight friction fit with a little ca wicked over it from both sides to permanently secure it.

IF you do go with a cheap drill press ( as I did ), then all you need to do is spend some time making sure the press work surface is aligned properly with the drill as it moves through the prop.

I still use a drill guide, but that has issues for me as I need a proper drill press vice. Any way, since getting a press I haven't "wasted" a prop.

Then again, I'm not the most resourceful or creative among my peers.