Drilling Help

[Growley]

I just spent the last hour researching this and can't find the answer. I'm using a metal lathe for drilling. More often than not when I'm drilling my smoke hole the drill bit (for the lack of a better word) "dances" around center. I typically chuck the block, face it off and then drill. I've tried pilot holes, different speeds, drilling with the tail stock locked down, drilling with it loose and pushing in by hand instead of cranking it in. I've even tried different and brand new bits.

8 out of 10 times it seems to not go in center. If it weren't for those 2 out of 10 times I'd think my tailstock was off center, but ever so often it goes in perfect. The other thing I find odd is that I seem to have no trouble using the same tail stock to drill the bowl. They drill out very nice.

What are your thoughts?

[Jos]

Hi Growley,

start with a countersink bit, and afterwards your drill bit will center all alone.

Regards, Jens

[Growley]

Thanks Jens, I'll try that.

[caskwith]

Drilling the airway always involves a long thin drill bit, these will flex far to much to drill an accurate hole without proper preparation. I drill my airways like this:

1. 4mm centre drill (http://en.wikipedia.org/wiki/File:Cente ... 123456.jpg)
2. 4mm Stub (machine) length drill bit.
3. 4mm Jobber drill bit.
4. 6" 'long series' 4mm drill bit.
5. if necessary I also have a 10" 4mm drill for extra long shanks.

It sounds a lot of hassle but I keep all the bits well organised and it takes just a metter of minutes to drill a straight centred airway and most of that time is clearing chips.

[Sasquatch]

I never, ever, drill the airway on the lathe. I can't think of a single pipe design where the airway and the mortise are at the same angle, and I find re-adjusting the thing in the chuck much trickier than to do in a vise, with precision, because I can use a tri-square to parallel-up to the lines I have on the block. So I just make a mark while I have the thing on the lathe, just tap the center of the mortise. Then I take the thing to the drill press, line it up how I want, and run the bit down into the starter-hole I did on the lathe, so I get the position in the mortise that I want, but the angle is dictated by how the pipe is designed.

It's so much faster and easier to clear the chips and get a true cut on the drill press than the lathe, that I just don't use the lathe for that particular application. YMMV

[Growley]

I never, ever, drill the airway on the lathe. I can't think of a single pipe design where the airway and the mortise are at the same angle,..

Sas, Now I'm confused...not that I wasn't before So far I've basically only done straight pipes. Aren't they the exact case where the air hole and mortise line up, or am I missing something really important?

[andrew]

I just spent the last hour researching this and can't find the answer. I'm using a metal lathe for drilling. More often than not when I'm drilling my smoke hole the drill bit (for the lack of a better word) "dances" around center. I typically chuck the block, face it off and then drill. I've tried pilot holes, different speeds, drilling with the tail stock locked down, drilling with it loose and pushing in by hand instead of cranking it in. I've even tried different and brand new bits.

8 out of 10 times it seems to not go in center. If it weren't for those 2 out of 10 times I'd think my tailstock was off center, but ever so often it goes in perfect. The other thing I find odd is that I seem to have no trouble using the same tail stock to drill the bowl. They drill out very nice.

What are your thoughts?

What brand of drill bits are you using? Another question: how long a bit are you using? Are they jobber length, center cutting, etc?

[andrew]

I never, ever, drill the airway on the lathe. I can't think of a single pipe design where the airway and the mortise are at the same angle,..

Sas, Now I'm confused...not that I wasn't before So far I've basically only done straight pipes. Aren't they the exact case where the air hole and mortise line up, or am I missing something really important?

Just about the entire bent category (which is filled with people and pipes) involves drilling the airway at a different angle than the mortise.

Like this:



The blue is airway, yellow is mortise.

They are supposed to meet, but the angle is changed. Take a look at some Peterson pipes if you want to see some extreme examples of this.

[Growley]

Yes, I totally get what you're saying for the bents. I'm working on one right now and understand the concept you diagramed. Thanks. I was just concerned that I wasn't doing my straight pipes right.

[RadDavis]

Yes, I totally get what you're saying for the bents. I'm working on one right now and understand the concept you diagramed. Thanks. I was just concerned that I wasn't doing my straight pipes right.

You're doing them right, Brian. Sas is doing it all wrong, because he's from Canadia. They do things different in Canadia.

I drill my first airway hole with a 2 inch long bit. It will wobble a lot less. Go into the wood slowly, giving it time to center properly. Once that's drilled (about an inch or so deep), I switch to the long bit and peck drill the remainder by pushing the tail stock into it by hand, drilling about 1/4 inch at time, pull it out, clear chips, and repeat until I'm done.

Then spin it and drill the chamber down to the smoke hole.

Then remount the block and drill the mortise.

Rad

[SimeonTurner]

I can't think of a single pipe design where the airway and the mortise are at the same angle

Sas, have you been smoking that Canadian Green Tabaccy again? :p

Any straight pipe I make can drill mortise and draught hole on the same line. Bents, never, but straights, almost always.

I wonder if the curvature of the Earth up there in the frozen North makes things harder...hmmm...I may try and commission a 12 week study from MM to investigate.

[Sasquatch]

I drill the airway just a couple degrees upward on a straight pipe. This allows greater flexibility on shaping the bottom of the bowl without having thin/hot spots. The chamber placement is probably 1/8" higher this way, and it allows for all kinds of graceful curves on the bottom of the pipe. I think Thad Johnstone gave me the idea.

I wouldn't expect mass-producers like Rad or Simeon to understand this kind of finesse. But my art demands no cutting of corners, no cheats. Also, they probably spend less than 50 hours cutting the airway, so it's not as good as mine.

[Sasquatch]

Any straight pipe I make can drill mortise and draught hole on the same line.

"Can" does not imply "ought".

[Growley]

Thanks for the tips guys...and the comic relief. It think I'll try both the short pre-drill as Rad mentions, and the countersink idea Jens mentioned. Sas, I see where you're coming from and may add that into my mix as I get a little better.

Caskwith, with that attention to detail, your air holes must be as smooth and straight as a crystal tube when you're done!

Once again, thanks for the ideas. I'm excited to try them.

[Growley]

Andrew,
I'm using Black and Decker gold looking drill bits. They're the common set you buy to have around the house. There one thing I didn't think about when I got all my tools because I already had them. Will it make a big difference if I get better bits?

....oh man, go easy on me for that one. That just sounded like such a novice question. Oh well, the question fits the maker I guess.

[Sasquatch]

The biggest difference in drill bits is how well they are sharpened. Both sides of the flute, both cutters, should be crisply sharp and absolutely identical. IMHO the best bits are made so that there is basically NO connection between the flutes, no common area, but two seperate little knives. I'll go take a picture because this is important.

[Sasquatch]

I strongly prefer bits that are cut like the one on the left - two totally seperate and well defined cutters. The one on the right is just not as able to bite quickly because the shared plane of the cutting surfaces is basically unable to do work.

So I look for bits that are cut a) like this and b) real well. Good sharpening pretty much means good bits, and the cheapy sets where you get 120 bits for 30 bucks are always rotten.

GOOD bits, like Vikings, old DeWalt sets... stuff where you are paying a couple bucks per bit, will cut a lot better.

[Sasquatch]

And NO, I don't use a pink lighter when I smoke a pipe. That's, uh... er, the wife's. Yeah.

[Growley]

I see what you're saying. Thanks for posting the pic. I'll have to look closer at my bits and see what I've got.

[wdteipen]

Like Sas, I put a slight upward slant on my airways on straight pipes too. I like to face off the block so the drill hits a flat surface. I then use my parting tool to put a center divot to get the bit started in the right spot. After that I advance slowly and clear the chips often with a 6" HSS bit. The other key to keeping it centered is to advance slightly then pause to let the bit center itself.