Can't drill a straight hole?

[routerman]

[Han]

routerman wrote in news:de14af63-50c0-402c-97a8- [e-mail]:

gives errors not enough storage to complete operation

[Doug Miller]

That would be a problem on your PC, not with the website.

[Han]

[e-mail] (Doug Miller) wrote in news:iko6n0$6gt$ [e-mail]:

That's why itried several times, even just the base url, with and without www. No luck. I then took a shower. I didn't turn off my laptop, and kept FF running. Just tried again. No problem accessing.

No idea what gremlins there were nor where they were.

Just FYI. .

[John]

Another quick note: if you mark the wood with a center punch (I'm guessing an 'ice pick' is some sort of center punch), and you clamp the piece of wood to the table, then if the mark is not EXACTLY under the center of the drill, then it will pull the drill bit to the side which results in an angled hole. This is especially true for hard woods like maple, and long, thin drill bits.

There are a couple ways around this. First is to not clamp the piece to the table, and slowly lower the bit to the wood until it touches. This results in the bit pulling the wood towards the center, and you get less of an angle. The next is to clamp the wood let the drill bit spin when it's just touching the notch. Let it spin there for ten seconds or so. This way, if it's not exactly aligned, the drill bit will be able to cut the notch to a position closer to dead center.

When you think you have the notch centered, raise the drill bit, and then, looking very carefully from the side, lower the drill bit slowly. If the end of the drill bit shifts when it touches the wood, your notch is not centered. Repeat the steps above until it's centered. Only apply pressure on the drill press once the hole is exactly centered.

Even if you don't use a center punch, you should be careful when drilling the first 1/2mm to ensure the drill bit tip doesn't wander.

John

[Father Haskell]

Would an Enco vernier count as a cite? Mine shows the butt end of a 1/2" bit to read 0.005" narrower than the working end.

[Father Haskell]

Same reason all handsaws are either set or taper ground.

[-MIKE-]

I'm guessing there may be one type of specialty bit that is as you describe. I'm certainly no expert, but every drill bit I've ever used, save tapered wood bits, are the same exact diameter for the entire length of cutting surface.

I suspect your "bits are generally tapered a few thou" statement is grossly inaccurate.

[Edward Hennessey]

Same reason all handsaws are either set or taper ground.

FH:

Again, my understanding departs. If you are using a worn drill bit for measurement, because most abrasion will occur at the tip, it would reason that the wear pattern would progressively erode the diameter from the tip towards the terminus of the cutting surface preceeding the shank. A new, quality, regular twist drill used in machining operations should have a uniform width along its cutting length short of the shank.

How could you simply drill a straight, shallow hole if the drill bit tip were tapered? How could you drill a blind hole for an even interference fit along its length if the drill bit had the described taper? There are second operations to deal with these problems, but why would be a drill bit be designed to necessitate them?

Handsaws are very different animals in many respects. Some have a taper grind for blade clearance plus minimized binding and a reduced tooth set which makes for a cleaner cut along with less binding. Importantly and differently from power drilling apparatus, they have a comparitively feeble human unsteadily driving them, not a reliable motor delivering continuous performance in a fixed line to a cooled tool.

I'd be happy to hear your position on drill taper was endorsed on rcm by machinists with specialty knowledge superior to mine. It is always good to learn something new to lighten the load of my ignorance.

Regards,

Edward Hennessey

[Jeff Gorman]

"John" wrote

To supplement a very useful posting, when drilling metal, I've realised that the centre punch needs to be accurately ground so that it makes a perfect conical indentation with the centre of the cone dead central with the circular outline of the dent.

If otherwise, the drill or the job will be slightly deflected as the drill starts to cut.

Jeff

[Larry W]

Edward, I agree with you about drill bits not normally being tapered, however, I believe the poster who asserted that meant that the taper was such that the diameter was smaller at the shank end, not the cutting end.

[Leon]

Drill a pilot hole before using a cheap bit. Chuck in a steel rod instead of a drill bit to test for square -- bits are usually tapered a few thou to prevent binding, and a longer rod gives you a better reading than a short bit. Test the rod for straightness by rolling it.

Can't say I agree here, roll a standard drill bit on a flat surface, does it roll in a circle or arc? Mine don't. If your hole ends up being wider than the shank of the bit the cutting tip the bit is improperly sharpened or bent.

[Leon]

Same reason all handsaws are either set or taper ground.

If the bit tapered back from the tip chip evacuation would jam and burn the insides of the hole.

[Leon]

Use the proper bit for drilling a deep hole. That's the tip. What you want is either a Forstner bit or a good quality Brad Point bit. Don't use a spade or regular twist bit. Pen makers deal with this all the time but use quality bits suited for drilling deep straight holes.

[Leon]

Would an Enco vernier count as a cite? Mine shows the butt end of a 1/2" bit to read 0.005" narrower than the working end.

On a "brand new" never used drill bit? Bits do wear.

[Edward Hennessey]

LW:

Well, Larry, maybe I misread it. I know that there are, in fact, taper-shank drill bits. But my impression that we were talking about the working length of the tool got a spur from the reference to the working portion of handsaws.

Regards,

Edward Hennessey

[Larry W]

Well, a good quality hand saw IS thicker at the cutting edge compared to the spine.

[Edward Hennessey]

LW:

I agree with you as the quote from a post above went:

Handsaws are very different animals in many respects. Some have a taper grind for blade clearance plus minimized binding and a reduced tooth set which makes for a cleaner cut along with less binding.

Yet there are hand saws which are an exception to this rule, which was remarked.

Bought a Bosch flush-cut saw the other day. That's an interesting item, though fairly limited in application.

Regards,

Edward Hennessey

[Edward Hennessey]

Leon:

Here's a readable page:

to work and regards,

Edward Hennessey

[-MIKE-]

No. You checked one bit. You didn't state a policy by bit manufacturers or manufacturing standard for making bits tapered.

So it's smaller at the end that gets put in the chuck and bigger at the cutting tip? That would make sense. Now you have me thinking.

So where's the good Father Haskell to clarify?