Drilled off center!

[Woodchipper]

I drilled two synthetic (have no idea what they are) blanks a few days ago; the holes started in the center of the blank. Exit hole was off center. Drilled as low speed and slowly ran the bit into the blank. Drilled on drill press instead of lathe. Took extra pains to make sure the blank was 90 degrees to the bit. Hmm. TIA

 

[bugradx2]

Put a long bit in your drill press and see if it's perpendicular to your table. After you check that slowly rotate the drill chuck and see if it moves away from square. It could be that you have a wobble in your press someplace.

Mine has a wobble so I drill everything on my lathe. I've not wanted to upgrade my drill press just yet.

 

[Woodchipper]

No wobble with the DP. Just got in a hurry and didn't put the pen jaws on the chuck. I can see why many woodturners have a sackful of chucks. I would like to have a couple that are dedicated to one function...one for drilling pen blanks, for instance.

 

[Mortalis]

No wobble with the DP. Just got in a hurry and didn't put the pen jaws on the chuck. I can see why many woodturners have a sackful of chucks. I would like to have a couple that are dedicated to one function...one for drilling pen blanks, for instance.

Yeah, many woodturners either get them (chucks) from suppliers for free or they have a small fortune hanging on their walls. I got my third one a few weeks ago (paid out of pocket) and still want one more. Notice I didnt say 'need' one more. I changed jaws many times on the one or two I had. Now with three I have the basics covered.
I have a pen jaw chuck (less than $60 on ebay) that threads onto the spindle and works a charm for drilling blanks. A lot easier than changing jaw sets.

 

[Woodchipper]

I think I counted about a dozen in one video. I have a HF cordless screwdriver with an adapter and hex bit. Only take a couple of minutes to change jaws. Not a production turner but I do work on a few pens at a time in an "assembly line" mode.

 

[NGLJ]

Since you have to turn a square blank round at some point, I pre-round all of my blanks between centers, and drill using a collet chuck on the lathe. In fact I pre-round them in batches, usually immediately after obtaining them. If you have made any kitless pens you will know the absolute importance of "perfect" drilling. I now apply that experience to all blank drilling regardless of the use of the drilled blank. I never drill straight through to avoid the possibility of blowout on exit. I drill from one end to just past half way, and then from the other end using a smaller bit than the final size. After this, I drill all of the way through using gradually increasing bit sizes. Of course, this is more effort and time, but I have never had a drilling failure following this routine.

 

[Dieseldoc]

So here is what I do to correct the off center drilled blank. Cut blank, mount on lathe turn between centers to round. Take round blank and install in COLLET chuck in lathe, use center drill, then drill to correct size with a SHARP bit on lathe.
his has correct all of my off center drilling.
Drill press , jaw chuck or blank holder is no longer used in my shop.

 

[Woodchipper]

Never had a blowout on exiting. Did have one blank shatter when the bit was lowered in the DP. As I said, got lazy and didn't set up the chuck with the pen jaws.
Turning to round...wood or synthetics (my generic term) blanks?

 

[NGLJ]

Forgot to mention that I use a centering bit before starting to drill like Charlie. I have had the odd occasion where drilling straight through has caused a problem on exit, but not with wood. So out of an abundance of caution I never do.