Thanks for the recent article and pictures about drilling cork rings - using a lathe to spin the cork and a fixed drill to bore the hole.

I have used the lathe for years, and have always used the lathe to drill hole into something round that I wanted centered.

I don't know why I haven't used the lathe before for doing the cork drilling. So simple, slick, dead on accurate etc. etc. etc.

Wonderful idea that works very well and it is something that I should have been doing for the last years.

This method is far superiro to the use of a drill press, since it is a guarentee that your hole will always be centered in the cork. That isn't true for a drill press.

If you happen to get a cork ring or other ring that is a bit larger or smaller, the latch chuck will self center the ring, and you will be set with a centered hole.
The drill press is all right, as long as the drill jig is setup and the rings are always exactly the same size.

Take care
Roger

If your lathe chuck jaws are deep enough to allow it, you can often bore the rings 2-up, which cuts the overall time required by half.

And... put a piece of tape on the drill bit to mark the depth required. You don't want to run an expensive drill bit into the back of the chuck.

............

I drill the wood inserts that I include in my cork grips on the lathe prior to assembly. This way I can drill them at 3/8 or 7/16 before I glue them together with the cork. I do this with my reel seats as well. I drill them to 3/8 prior to turning them. It's a lot easier than trying to drill them out afterwards, and no risk of splitting or chipping the wood.

Thanks Roger,
What type of bit do you like to use?

Jeff

Jeff,
The fosner bit is nice if you happen to have one the right size.
Otherwise I use a conventional machinest bit that I have modified.
I will take a standard machinest bit, and face it off flush on my disk sander. i.e. I take all of the cutting edge off the bit. I also take all of the point off the bit.
Then, I put sharp edges back on the cutting edges of the bit, with a very flat edge - and nearly no point. i.e. I make the bit essentially flat on the end.
The result of this is that the bit becomes much more of a shaving bit - as opposed to a chunking bit - as happens with using a standard machinest drill on cork.
The idea of facing off the drill is to make the bit much less effective and allow the bit to only take very small bites of the cork as it spins. This results in a very clean cut, with no chunking of the cork.

I use the same type bit, if I want to drill rubber or eva. Very very clean cut.

Take care
Roger

Since I always glue up rings on a threaded rod and then transfer to a mandrel for turning/shaping, that seems like an awful lot of work for nothing. I have a benchtop drill press and I use a Flex coat pilot drill (usually a 3/8) and just turn it on grab a ring, push it up the bit and chuck it in a bin and do up as many as I want/need Probably take less than 5 seconds. If it's off a few mm, it doesn't really matter at all since after I glue them up and clamp them on threaded rod, I put the cured grip on a mandrel and turn/sand/shape on the lathe. If you use a lathe tool, the grip HAS to be perfectly concentric to the hole, no matter if it was a little off when you started. Subsequent reaming will give a nice interior surface for mounting to the blank. I use that same method with burl, foam, EVA and it works very well

Mike (Southgate, MI)
If I don't want to, I don't have to and nobody can make me (except my wife) cuz I'm RETIRED!!

Mike,
I hear what you're saying about simply feeding the cork against the turning bit. I'm more interested in knowing how to avoid tearing a jagged hole when the bit emerges from the cork. BTW, I don't have a drill press so may try the lathe method.

Jeff

Jeff, If I get that, I just flip the ring and go through from the other side! I got the drill press from Harbor freight for $39

Mike (Southgate, MI)
If I don't want to, I don't have to and nobody can make me (except my wife) cuz I'm RETIRED!!

I use a sharp regular bit in a drill press, take it slowly, let the ring spin a little as the drill contacts it to allow it to center, and have no problems with concentricity (that subsequent turning on a mandril won't fix) and no noticeable chunking on the drill's exit from the cork. I am using burl. I use 7/16 threaded rod for the mandril, turn the handles in the drill press (I have a 7/16 bore ball bearing mounted in a piece of wood that I clamp to the drill press bed to give me a stable setup when turning using the drill press.) Using 7/16 means that I have less hand reaming to do-you can use whatever diameter makes sense for the butt size of the rod you are building.

I'm sure a lathe would work better, but this method with the drill press is pretty good.

Mick