Brass tube drilling.

[Haydo]

I have just drilled a 5/8" hole through 40mm of glass. I used 120g silicon carbide grain in the process. The job got done but am feeling my technique or slurry mix may have slowed the job. This is the old style of doing it and wanted to use this system before outlaying on a more expensive set up with water chucks etc. I have the spindle speed set at 480RPM. Was hoping some with experience in this type of cold working could shed some light. I didn't time it, but it felt like a fair chunk of my life slipped by. The other tube is one inch diameter, and both of these will be used to bore holes into bubble blocks that I muck around with when time and tooling permit. Is it just a case of raising and lowering the tube while cutting, keeping an eye on temp? peace, haydo

[Tom White]

Unless your drill press is a whole lot larger than mine the first snag I see is fitting the 1 inch brass tube into the drill press chuck. I would need to fabricate a plug that would fit inside the 1" tubing on one end and fit the drill press chuck on the other end. Here in Texas, USA I would go to a good hardware store and purchase a 1" tungsten carbide hole saw with the grit electroplated onto the 1" end and with a suitable sized shaft to fit the drill press chuck on the other end. Not really sure what you have available in the line of grit tipped hole saws in your location.

Best wishes,
Tom in Texas

[Haydo]

Thanks Tom, good idea. These brass tubes are what was once used extensively in the past. They come with a square drive and shank that slip into the tube. Cheap enough for now. Have just finished an inch bore through a 45mm section of glass last night. Do a bit, walk away, do some more. My problem is even though I'm getting the job done, is my set up and technique correct? I'm careful to flush job and cool down several times. Yet I'm still thinking if i could be doing it quicker. The brass is apparently better for cleaner holes because the grit gets caught up in the brass. If things speed up for this one direction I'm taking I'll invest in set up that His Glassworks sell and get a quality drill press designed for accuracy. I am liking the idea of using silicon carbide grit because I could most likely experiment with other ways to achieve holes. Gets tricky when the plug from drilling is a little shorter than the height of bubble, truly have to believe in what goes up must come down. peace, haydo

[Kevin Midgley]

Diamond tools were invented for a reason.
A water feed chuck and a 16mm water feed diamond drill bit can be found online delivered to you for about $75Aus or less.
Your time has to be worth more than that.
Note I will not list the source as I don't want to be blamed for something not working for you.
Quality from the source has in the past had a wide range of excellence and non excellence.
The source also seemed to have a maximum water feed drill bit size of 16mm.
Dry drilling for a nano second can destroy the diamonds.
Might need a slower drilling speed.

[Tom White]

Sounds like an old glazing setup. Yes, brass tends to embed silicon carbide grains into itself better than steel. Cast iron flat laps were equipped with an abrasive grain and water feed which dripped both onto the lap surface slowly. Something like that might could be set up on your drill press if you choose to continue using loose grit abrasives.

Best wishes,
Tom in Texas

[Haydo]

Cheers fellas. Hope to go shopping again soon. Feels like Christmas when packages are coming in from all over.
peace, haydo