9" x 1-1/4" hole drilled on a lathe

[John K Jordan]

Trent Bosch used a gun drill in his hollowing presentation at the symposium. He just used a 3/8"

Did he describe the drill, type, brand, source? Specifically, was it a drill typically used for metal and used on wood without modification or one made for wood?

I've looked for one before but hate to spend the money just to experiment with something that may not work well with wood! Some are pretty expensive.

JKJ

[Marvin Hasenak]

Research "How to make a D style drill bit". It will take you to the world of bagpipes. I tried this years ago for making a flute, my results were mixed but were doable, but I can't imagine making one 1.25" diameter.

[William C Rogers]

Did he describe the drill, type, brand, source? Specifically, was it a drill typically used for metal and used on wood without modification or one made for wood?

I've looked for one before but hate to spend the money just to experiment with something that may not work well with wood! Some are pretty expensive.

JKJ

Trent said it was a 3/8 that he got off eBay for about $30. I don't remember anything about special sharpening. He put a handle on the end with a air quick connect. Didn't take long to make his starter hole.

[Brice Rogers]

Brian, the biggest risk IMHO when drilling a deep hole is that the Forstner will pull out of the extension when you try to back it out. That can be pretty well be mitigated by clearing the chips packing in behind the forstner every inch or so of drilling. I sometimes also squirt in WD40 on a clean hole to reduce the friction (and heat). Just take your time and keep clearing the chips and you should be in good shape.

[William C Rogers]

Brian, the biggest risk IMHO when drilling a deep hole is that the Forstner will pull out of the extension when you try to back it out. That can be pretty well be mitigated by clearing the chips packing in behind the forstner every inch or so of drilling. I sometimes also squirt in WD40 on a clean hole to reduce the friction (and heat). Just take your time and keep clearing the chips and you should be in good shape.

+1 on extension pulling out, don't ask why. When drilling deep I also put some wax on the bit

[John K Jordan]

Brian, the biggest risk IMHO when drilling a deep hole is that the Forstner will pull out of the extension when you try to back it out. That can be pretty well be mitigated by clearing the chips packing in behind the forstner every inch or so of drilling. I sometimes also squirt in WD40 on a clean hole to reduce the friction (and heat). Just take your time and keep clearing the chips and you should be in good shape.

Maybe try the compressed air method I mentioned. I use a long nozzle on the air gun which extends part way into the hole. I started using this method years ago and it keeps the chips clear and reduces friction. It may help with the extension problem you mention.

Although, my extensions have set screws to hold the bit.

JKJ

[Michael Schneider]

https://youtu.be/bPqZz-PDa4A. Take a peek at the 59 minute mark. Trent describes how hw converts a metal working gun drill for wood turning use.


Edit: fixed typo in tme mark, thanks JKJ
Michael

[John K Jordan]

https://youtu.be/bPqZz-PDa4A. Take a peek at the one hour 59 minute mark. Trent describes how hw converts a metal working gun drill for wood turning use.
Michael

I watched this (fast forwarded through most, actually), nice. Good ideas there.

In case someone else looks for the gun drill part I found it at the 59 minute mark instead of the 1:59 (which was the end of the video.)

JKJ

[Brian Kent]

Thank you everyone. I look forward to studying these responses when I am done with a work trip. I am leaning toward drilling instead of cutting and routing. I can see 2 basic options - adding strong extenders or a long-enough rod, or starting from both ends. Either way, I plan to leave as much material as possible on the sides, so that when the hole is drilled, I can turn between centers and get an even wall thickness.

[Brice Rogers]

I have had a couple of forstner bits pull out of the extender. I just had a lightbulb flash in my brain. The next time I do this (besides clearing the chips very frequently and maybe using a lube), I'm going to grind a "flat" on the forstner that lines up with the tightening screw. That would tend to minimize the bit pulling out.

[Dick Strauss]

Brice, take it one step further. Drill a small hole using your set screw holes as guides. Then enlarge the holes so that they are slightly larger than the set screw diameter. Once you do this there will be no chance of the bit pulling loose unless you missed the holes when tightening the set screws or the set screws vibrated loose!

[Brian Kent]

I ordered a long 3/4" drill bit for a starter hole to remove some material, a 1-1/4" forstner and a 6" extender. I have smaller forstners to step up in size if needed, and I know to start a 1/2" deep hole at final size to guide the forstner.


I do not have a source of compressed air to clear as I go.
I have never tried auger bits with lathe drilling, so I have no confident opinion on them.

[David Metzman]

I guess you are done but you could order on Amazon:
Century Drill and Tool 38112 12-Inch Ship Auger Drill Bit Extension, 3/8-Inch (about $17) - I have it and it works fine and also order a bit on Amazon as well.