One more dumb question

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jkeithrussell

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Last newbie question (for today):

I'm having trouble getting the holes straight when drilling blanks. I've tried speeding up the drill speed and slowing it down, but I'm still getting holes that are off-center coming out of the bottom end. I'm using a nearly new brad point bit and using wood like brazilian cherry, lacewood, etc. I'm also using a centering vice. I'm sure there is something obvious I'm overlooking...

Very cool forum. I've been studying pictures and taking notes all afternoon. You guys make some dang nice pens.
 
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Russianwolf

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1) use a small square and make sure that the table on the press is actually 90 degrees to the bit in several direction (could be perfect in one aspect but not in the perpendicular aspect)
2) check the quill for run out/wobble. Some cheap presses can deflect in the head so the bit isn't traveling in the same line as when no pressure is on.
3) Get a better vise. Not all vises are created equal.
4) switch to drilling on the lathe. although not necessary on all blanks, most feel that they can get much closer to a perfectly centered hole on the lathe. It comes in very true when working on some of the laminated blanks. I think we've all agreed to making the misdrilling of one of Eagle's blanks a felony now.
 

VisExp

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I'm assuming you are using a drill press to drill your holes. If so, I'm guessing that your drill press table is not at 90 degrees to the travel of the drill bit. An easy way to check that the table is perpendicular in all axis is to chuck a piece of coat hanger in the drill chuck. Turn it 90 degrees so it is horizontal, then turn it back another 90 degrees so that it is just touching the table. Rotate the chuck by hand and as the tip of the coat hanger scribes a circle you will easily see where the table is high or low.
 

marcruby

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Wow! I never thought of that. A heck of a lot easier than my crazy process with squares and levels.

Thanks!

Marc

I'm assuming you are using a drill press to drill your holes. If so, I'm guessing that your drill press table is not at 90 degrees to the travel of the drill bit. An easy way to check that the table is perpendicular in all axis is to chuck a piece of coat hanger in the drill chuck. Turn it 90 degrees so it is horizontal, then turn it back another 90 degrees so that it is just touching the table. Rotate the chuck by hand and as the tip of the coat hanger scribes a circle you will easily see where the table is high or low.
 

fiferb

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Is the drill bit getting hot when you drill? If so, it may have a tendency to flex and follow the grain. This may also be the case if it is longer than necessary.
 

jkeithrussell

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The table is square.

I'm not getting this problem on every blank -- maybe half. Usually on the denser woods.

I'm not sure how to answer the question about the drill speed. Yes, it sometimes gets hot and smokes. With the denser woods, I've found that the hole is more often straight at higher drill speeds. I know that's against conventional wisdom, but I use a higher drill speed and just work slower. Is there a reference guide or chart that shows the recommended drill speeds?

The drill bit I'm using is just a standard 7mm brad point. Maybe I should upgrade to a carbide tip?

Thanks again for the info.
 

leehljp

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I didn't read anywhere if your vice is clamped down. If it is moving 1/16 or 1/8 of an inch, that could be part of the problem. If the grain is not totally straight (and sometimes that doesn't matter) is is quite common for bit deflection.

1. Sharp bits and 2. clamped down holder and a 3. a good holder that doesn't allow wiggles as the bit tries to deflect in the grain.

AS Mike said - try the lathe for drilling. On fine, expensive and most segmented blanks, I use the lathe to drill, but on normal ones, I use a 'blank' vise.
 
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