Learned Something New Last Night

[TwoCatsPens]

Just when I thought I had found every way to mess up making a pen, I found a new way to make a mess of it.

I thought I'd knock out a quick acrylic cigar just cuz I wanted something to keep my hands busy. Thought that "eggplant with gold" is what I want.

I do all my drilling on the lathe, use a center drill to set my starting hole, center hole done and perfect as always.

Grab the 10 mm, into the tailstock and start to ease it in. CHATTER CHIPSS CRACKS !!! Death and Destruction.

The bit had skated sideway on the spinning blank, and was trying to drill an "Eccentric Hole". Now I know that eccentric turning is all the rage these days, but trust me, it doesn't work for drilling. Blank was ruined, between all the shatter on the inside and and the huge hogged out hole, no way it was usable.

I Figured that I'd see what was going on, so I flipped the blank around and just eased the bit into the other end (I had only drilled partway into the first end). It immediately skated off to the right.

Now I saw the problem. I have a brad point bit, and somehow the 'brad' part of the the bit had broken off. Without the brad, there was nothing to anchor the bit as it entered the blank, and the torque on the outer cutting edges was enough to walk the bit sideways.

Not sure how it lost the brad, don't recall ever dropping it, or perhaps it just failed. After all, i've only had it for 2-3 years and done a mess of pens and other things.

So, anybody else manage to mess one up this way, or have the same problem?

Steve

 

[Pjohnson]

Interesting issues - I thought I read in a post that some folks were using standard drill bits, as opposed to brad point. This makes the case that brad points are needed.

 

[Ambidex]

Never had that happen...makes me want to check my bp bits before I drill...thanks for the heads-up..

 

[walshjp17]

Hmmmm .... with acrylics, I do not use brad points. I do hold the chuck with a modicum of force to make sure it enters the pilot hole true and does not move in the tail stock. I only loosen the grip after the drill gets about 1/2" into the blank (but I still hold onto the chuck).

 

[Dan Masshardt]

That's a long time to use that bit. I vote that it served well enough.

I use brad points for acrylics without any probs.

I'll prob use less golf then as I want to start sharpening bits but otherwise find that they work well.

 

[InvisibleMan]

Interesting issues - I thought I read in a post that some folks were using standard drill bits, as opposed to brad point. This makes the case that brad points are needed.

the point will certainly be needed for brad points, but brad points are not needed for acrylics. They work fine for me on acrylics, but are most useful for wood as far as I understand.

A good split point regular bit is what I've found to be best for acrylics.

 

[Paul in OKC]

Never used brad point bits, myself. My first thought is if you use a center drill, why the bp. Plus with the center drilled hole, there is no 'meat' there for the point to start in anyway, so the flutes are going to hit first. I wouldn't think a center drill would be needed for a bp drill. Just my 2 crumbs.