Any suggestions when you DON'T own a lathe ? Of course I need to drill the hole along the diameter and come out on the center of the opposite side of the sphere. I hope this is clear.
For my $$$ I have always used 1/8" as the first size where I can start expecting a fairly true, non wandering hole, so I think finding, or making a base so your sphere is locked into a position where it can't roll away, so something with a like depression. Then if you have a drill press start drilling. IF you only have a hand held drill, then your problem for "straight" increases. Anything you can use to hold the drill straight will be helpful.
I have the Rockler drill guide, pretty good, but really costy. There are many on the market, you are looking for heavier build quality to increase it's ability to hold at a set angle, and offer you the best chance to drill straight.
Start watching this video at/around 2:45 mark to see a quick way to make a base for holding your sphere shape still.
I'd file a small flat on one side, put the flat side down and file another flat on top - Can be smaller than the drill bit, but gives you a good spot to start and makes it easy to find the two opposite sides. Use an awl to make a starter hole, then drill half way + a little bit from one side, finish off the hole from the other. You've got a lot more tolerance for error if you meet in the middle, and can also clean up the join with a file if need be (if you have a small enough file at least).
Very interesting. I think this just might to the trick if I can find a big drill bit for a 2" ball. I have some big drill bits but there are paddle bits and masonry bits. I have to check through some of my old stash.
Clamp a piece of timber to your drill press, lock the table... use the relief hole method (if you don't already do it) to cut a circle that the ball can sit in without bottoming out on the table top. The quill should be perfectly centered on the circle (unless you used an oval circle cutter) ... place the ball in the circle and drill a perpendicular hole... just don't forget to replace the holesaw drill bit with your chosen gauge bit (and the holesaw may also inflict some minor damage to the ball if you forget to change... and it'd be a bugger to hold still)...
If your first cut is too short... Take the second cut from the longer end... LBD
I thought about that after words. All I need is the rim of the correct size and a slab so the ball does not bottom out. It will work and I have a 2 in hole saw .. somewhere?
The LBD has a great solution. You don't need a 2" diameter hole saw, just one that is almost as big (1-1/2" will do) Clamp the board to your DP so it doesn't move. This will cradle the ball and if your board didn't move, swapping out the hole saw for the 1/8" bit will keep it centered.
