Drill press

Welcome to the group @Girlyharleygirl !

The more info that you can give the better the advice will be.
(type of stone, shape of stone, what hammer drill and bits you have now, etc.)

I have one of those hand-drill stands shown above that I have been trying to give away, but no takers.
Even the local used tool store didn't want it; no market.
(I used it as a bottle-capper when I made my own beer, but that hobby has gone by the wayside)

-brino
 
I'm thinking hammer drilling might be too violent for your rocks and might crack them. I would use carbide tipped drills and/or those coring drills that were mentioned earlier
-Mark
 
Based on my stone and glass drilling experience, diamond core bits are cheap and jaw droppingly effective in a drill press. Surprisingly fast, very clean hole. If you need to go deep, break off the core with a screwdriver and keep going. Far, far better than hammer drilling!
Btw, with some practice you can hand drill with these cutters, but starting is a bit tricky.

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extropic said:
A hammer drill (HD) is the way to go. One aid might be to construct a vertical guide for the HD. I'm imagining re-purposing a drill press by removing the head and using the base, table and post, then rig up something to mount and guide the HD.


It's important to have a solid base under your rock. Imagine trying to use the HD with the rock sitting on a mattress. The hammering would produce a lot of bouncing and not much "hole".

I'm also not understanding why you're starting with 3/16" and then multiple increments up to 7/16". Is the HD too wimpy? Will the rock break if you use 7/16" to start?
extropic said:
A hammer drill (HD) is the way to go. One aid might be to construct a vertical guide for the HD. I'm imagining re-purposing a drill press by removing the head and using the base, table and post, then rig up something to mount and guide the HD.

It's important to have a solid base under your rock. Imagine trying to use the HD with the rock sitting on a mattress. The hammering would produce a lot of bouncing and not much "hole".

I'm also not understanding why you're starting with 3/16" and then multiple increments up to 7/16". Is the HD too wimpy? Will the rock break if you use 7/16" to start?
Click to expand...
Surprisingly starting with the 3/16” and moving up in sizes is much easier. Starting with the 7/16” takes much more “braun“ and wear/burns out the bit extremely fast.
Click to expand...
 
For starters what exactly do you have now?
Have you tried it starting with the 7/16 bit?
It is hard to recommend an upgrade when we do not know where we are starting from or where we need to go.
 
Flyinfool said:
For starters what exactly do you have now?
Have you tried it starting with the 7/16 bit?
It is hard to recommend an upgrade when we do not know where we are starting from or where we need to go.
Click to expand...
Sure that makes total sense. I have a Dewalt hammer drill DW 505. I have started with the 7/16 bit and have found that it takes quite a bit more braun and burn thru the bits very quickly.
 

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That should be enough drill to get the job done. How fast are you spinning the bit? High or low range?

I like that idea, I may have to try it to.
Now to find some rocks and a SS rod..........
 
Flyinfool said:
That should be enough drill to get the job done. How fast are you spinning the bit? High or low range?

I like that idea, I may have to try it to.
Now to find some rocks and a SS rod..........
Click to expand...
The specs on the drill has the max rotations per minute 2700 rpm, and the beats per minute ( I think for the hammer part) as max of 46000 bpm - and I definitely max it out. Maybe a stronger hammer drill??
The rods you can get at ace or Home Depot :0)
 
An old way to drill through hard materials like stone and glass is to use a sacrificial "bit" plus grinding grit, like the kind used when tumbling rocks. Make a dam out of clay around the hole-to-be, add grit + water and use a brass tube of the right diameter as your bit. This will create a lot of mud so you will have to periodically wash out the hole, (a turkey baster should work nicely for this). To see if the sides of your dam are high enough, just put water in the dam first and turn the drill press on. The spinning action of the tube will fling the water away from the center so the level _will_ go up when the tube is spinning. If taking this approach you do want to use a drill press so you are grinding the same area at all times. A "pecking" action will be needed to refresh the grinding medium in the hole.

As the tube wears, it just drops down a little so you can keep on drilling. The grit sort of embeds in the relatively-soft brass so the combination can cut much harder material. While diamond grinding powders would work quite well, you'd go through a lot since you will need to periodically wash out the stone mud.

This method will be slow. But that's the price you pay for being cheap (and I freely admit to that affliction) :big grin:.

Awhile back I experimented with this approach to grind very small holes in silicon. For that, I used a solid brass rod and and soldered on a dab of solder on the end to form the grinding tip & flattened the end with some sandpaper. Then I forced the tip down into a pile of diamond grit, to embed diamonds in the soft solder. It worked, but I was just making ~1mm diameter holes, about 100 microns deep -- quite a difference from what you want to do!

BTW, when the "drill" first penetrates the stone all the water + grit + mud will trickle out -- unless you put some tape or a layer of clay on the bottom side to act as a flexible seal. Depending on how clean the hole needs to be, you probably could just knock out the remaining stone (but of course the edges won't be cleanly cut). A hammer drill will bust out the bottom of your hole anyway so it likely isn't a deal killer, eh?

Good Luck!
 
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