Drilling success

[blodal]

I recently blew out 4 nice blanks on Baron cap pieces. I had just purchased a set of DeWalt Pilot Point bits. When the bit penetrated the end of the blank it grabbed and blew out the blank.

I know there are several techniques for eliminating this, but I decided to post this for the benefit of other newbies like me.

I read somewhere that you can cut the blank about 3/4 in. longer than normal and not drill all of the way through the end of the blank. This applies to the larger size pens. Then you cut off the excess and have a perfectly drilled blank. This worked perfect for me on 2 blanks a couple of nights ago.

Also, I reviewed my definition of "slow" when drilling. I had been taking small bites with the bit and clearing the flutes. I realized that I was probably going too fast and forcing the bit with each segment. I slowed down (not the drill motor speed)stopped forcing the bit, and let the bit do the work. It took longer to drill it, but I still have the blank.

It is frustrating to ruin some top quality blanks. Hope this helps!

 

[JimGo]

I keep having to be reminded of the "little bites, with light pressure on the drill press arm" rule as well. Thankfully, my $3-5 acrylic blanks are always willing to remind me.

 

[Dario]

Originally posted by blodal
<br />I recently blew out 4 nice blanks on Baron cap pieces. I had just purchased a set of DeWalt Pilot Point bits. When the bit penetrated the end of the blank it grabbed and blew out the blank.

GOOD POST!

Had this exact thing happen to me once [] now I am wondering if it is due to the Dewalt Pilot bits. Hmmm

Here is my list:

1. Drill from the other side (with a smaller bit in case there is drift from the other end). Just deep enough to establish the outer outline of the bit.

2. Make sure the vise holds the blank tight enough so the bit cannot just snag the blank up.

3. Use longer blank (when possible)

4. Apply CA on the exit end to minimize blow out.

5. Support the blank bottom (bit exit end) to minimize blow out.

6. Start point is very critical so "kiss" the blank with the bit as little as possible at entry until a nice dimple (guide) is created.

7. Slow is better than fast

8. Use sharp bits

9. Clear the hole/bit of debris as often as possibble.

10. Smoke is a bad sign [].

 

[sptfr43]

I have had the same problem. what I do now is to drill in steps starting with a bit for a slimline and work up using every other ( skip one bit) bit in my drill index until reaching the size needed. it takes a little longer but saves my blanks.

 

[Jim in Oakville]

Originally posted by Dario
<br />

Originally posted by blodal
<br />I recently blew out 4 nice blanks on Baron cap pieces. I had just purchased a set of DeWalt Pilot Point bits. When the bit penetrated the end of the blank it grabbed and blew out the blank.

GOOD POST!

Had this exact thing happen to me once [] now I am wondering if it is due to the Dewalt Pilot bits. Hmmm

Here is my list:

1. Drill from the other side (with a smaller bit in case there is drift from the other end). Just deep enough to establish the outer outline of the bit.

2. Make sure the vise holds the blank tight enough so the bit cannot just snag the blank up.

3. Use longer blank (when possible)

4. Apply CA on the exit end to minimize blow out.

5. Support the blank bottom (bit exit end) to minimize blow out.

6. Start point is very critical so "kiss" the blank with the bit as little as possible at entry until a nice dimple (guide) is created.

7. Slow is better than fast

8. Use sharp bits

9. Clear the hole/bit of debris as often as possibble.

10. Smoke is a bad sign [].

One other item, I add sometimes depending on the end of the blank is to CA glue on a "cut off" piece to the end if a blank to support the forces of the drill as it exits the face as well, CA on the end grain works well as Dario mentioned.

 

[blodal]

[/quote]

GOOD POST!

Had this exact thing happen to me once [] now I am wondering if it is due to the Dewalt Pilot bits. Hmmm



Where ever it was that I read about the long blank, did not mention any specific bit. The article said it could happen with larger bits.

 

[penbros]

i think that it is the bit because i do dowel joints with the dewalt pilot point and i have a 650 rpm drill and the drill bit grabs the wood and the grab keeps the drill from spinning

i think u should use brad point bits[]

the bros

 

[bonefish]

I have had it to happen with both types of bits. Gluing a small piece to the end of the blank sounds like a good idea.

On another post, I wrote that I support the end with a piece of scrap wood, so that the end of the bit has some support when it exits. I think the gluing a small piece to the end is much better.

The best way of all is to not drill all the way through.

Recently, I drilled a pilot hole with the 7 m/m drill, then went to the larger drill, for a Cigar pen.

The pilot hole went okay, but when I started the larger drill, it grabbed and went half way through the blank before I could stop it. The larger drill wasn't a brad point.

The blank didn't explode, then, but as I continued to drill, it did.

The grabbing must have weakened the blank.

Bonefish

 

[Jerryconn]

I have had only one blank "blow up" on me. I really believe that people get in too big a hurry when drilling. I set the depth stop so that I know when I am getting near the bottom and just before the bit will break through I bring the bit out clear the flutes then really lighten up on the pressure. I have not had a blowout since.

P.S. fingers crossed []

 

[penbros]

im withjerrycon
whats da big problem ive only had one "blow up" and it was myvery first pen. i always use brad points, its hard(for u guys)to admit that piolt point or any other drill bit will grab on to the wood all the with all its might! just use bradpoint.

why dont u use them?
because they wander? big deal

BTW i just drill all the way through in 1/4 inch intervals
and it turns out fine. heck even my brother drills straight through in 1 shot and it turns out perfectly fine

 

[Rifleman1776]

This is more an issue of type of material than size of pen. What Dario said is right on. I emphasize, slow drill speed, clear chips often and use brad points.

 

[JimQ]

Most drill bits are not intended to ream out smaller holes. They may or may not follow the original hole.

JimQ

 

[johncrane]

I use brad point bits. When im drilling put a small tray under the drill. using a squirt bottle fill it with water and squirt water into helps keep the drill cool and the blank cool. From JC down under.

 

[JimQ]

Instead of using water which can be a sudden temperature shock possibly cracking the blank, use compressed air. Second benefit, it helps to remove the chips.

JimQ

 

[johncrane]

IF you start with water. I found the drill doesnt get hot using gentle pressure.and constantly removing the drill and spraying water in the blanks I only use water when turning Acrylics I dont think it would work on timber. using compressed air you would would have to very carefull of your eyes and have to run a air compressor. hope this helps from JC down under.

 

[Dario]

You can avoid heat without adding water. Slow down the drill speed, clear the debris often, use sharp bits.

Using water (even just on acrylics) can form a bad habit. Before you know it, others will be using it on wood too.

Besides water near your DP (or any other power equipment) can't be good. Not all bits are stainless...and definitely most DP table, post, etc. aren't.

 

[johncrane]

the easiest way I have found to remove heat during drilling is to use water it acts as a coolant/lubricant.it stops airbourne dust and increases the life of your drill bit just squirt enough water so the chips come out as a slurry. do not let the drill bit run dry.and back out the drill bit freqently.because this technique is so efective I will never go back to dry drilling . it ain't bad for me don't have to keep stoping and Im onto the a lot quicker.just my way not a bad habit give it a go you might like it. JC DOWN UNDER