Drilling Techniques

[beck3906]

I have several high-dollar blanks I'm about to drill and prepare to turn...things like Jeff Powell blanks and Curtis's Worthless Wood and cactus blanks. Most of these blanks wil be used for Jr Gent sized pens.

When drilling, would you suggest drilling a small pilot hole and then the full-size hole? Or do you go for the gusto and drill the full-sized hole ?first?

I don't want to ruin these blanks as ther's too much invested.

Thanks for any suggestions.

 

[Lenny]

Some like to drill with the small drill first then enlarge it with the big drill.

I prefer to drill on the lathe using my PSI collet chuck. If the drill I'm going to use is a brad point, I will just use it from the begining. If it is a regular (135 degree ?) I like to use a center drill to help insure it get started completly centered. I usually just drill with the finished sized bit in one step, stopping before breaking through the other side, then cutting the blank back to the hole.
http://content.penturners.org/articles/2009/lathedrilling.pdf
From the Library... http://content.penturners.org/articles/2009/lathedrilling.pdf

On youtube .. http://www.youtube.com/watch?v=Z1suUVIQpfQ&feature=channel

 

[Mr Vic]

Tried a slightly new technique on a tru-stone blank last week. The pen was a navigator with two different diameters. Instead of cutting two extra long blanks, I just drilled the first (smaller) diameter to the tube length plus a tad bit (1/16 - 1/8"). Cut to correct tube length and then drilled/cut the larger diameter. Doing it this way I had a lot less waste then I usually have with drilling after cutting. I use the blocks for finials and center bands and the savings gives me a couple extra centerbands.

 

[ed4copies]

By far the biggest issue is a SHARP drill bit.

Then comes control of the bit and the blank.

An aggressive bit can try to "grab" the blank--if it succeeds, too great a "cut" is made and the blank is likely to break. SAFEST method--turn the blank round, you will then see the pattern and can adjust your "center" if needed to keep your pattern centered. Then, when you are happy with the "turned pattern", get the blank to one diameter, put it in a collet chuck and drill.

Neither your tailstock with the drill bit, nor your collet chuck are going to allow the blank to move, so you are unlikely to have an "unpleasant event".

Even then, if you see the cut is yielding "ribbons" rather than "sawdust", life is GOOD!!! With sawdust, consider a trip to your Drill Doctor!!

Hope this helps--I just did one last week---turned out GREAT, but my first estimate would not have been as "Neat"--acceptable, but not GREAT!!

 

[wforge]

I generally use a Beall collett chuck and start with a center drill. Using this method I have had no blow outs or off center holes.

 

[BKelley]

I like to use a brad point drill in wood and plastics. I use these in a drill press that has NO wobble and runs 99.9 per cent true. Speed depends on the material that I'm drilling. I back off every little bit to clear shavings/chips. Sharp drills are a must.

 

[KenV]

1. Eagle (rip) said it well -- "drill to the center of the pattern not the center of the blank". sometimes but not always they will be the same.

2. Very sharp bits that are not overly agressive - I like the 118 vs 135 degree angle and go for split point bits when I can. Machinists are taught to start with a punch and use a center bit to start for best precision. While not required with wood and plastics, it is a good practice, especially with drilling materials of mixed density. Clear the flutes frequently as heat is your enemy.

3. The lathe offers better precision all day every day vs a drill press. Drill presses are great for high volume and lower precision. Yes there are high precision drill presses, but you do not find them in the garage shop. And the lathe is a more labor intensive slower process with less failures when you use consistent processes such as Ed Brown suggests.

take your time and think through what your steps will be -- even write them down.