Jon askes about twist style bits for a yankee style push drill,

* Jon Endres, PE  [2003-Jan-21 15:51 AKST]:
> Also, where can one get new bits for these?  I would like to find 
> twist drill bits rather than the two-flute style.

Flipping through the latest Lee Valley flyer, I noticed they sell them.  
Pretty sure Garrett Wade does too.  (No affiliation, etc.)

I also recall people commenting on why the fluted style is better than 
twist bits.  It's fuzzy in my mind, but I seem to recall something about 
how the fluted style is much less likely to split a very thin piece of 
wood (like for a shaker oval box, for example) than a twist bit, which 
may pull itself into the wood between the fibers before it cuts itself 
an opening.

Chris
-- 
Christopher S. Swingley      University of Alaska Fairbanks
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Hi all,

How do you sharpen the two-flute bits for a Yankee push drill?  I have a few
bits and they all seem to be dull as a bowling ball.

Also, where can one get new bits for these?  I would like to find twist
drill bits rather than the two-flute style.

It's a standard chrome-type Yankee (#41?) if that helps.

Jon Endres, PE
West Mountain Engineering

Jon Endres asks:

> > Also, where can one get new bits for these?  I would like to find
> > twist drill bits rather than the two-flute style.

To which Chris Swingley replies:

> I also recall people commenting on why the fluted style is better than
> twist bits.  It's fuzzy in my mind, but I seem to recall something about
> how the fluted style is much less likely to split a very thin piece of
> wood (like for a shaker oval box, for example) than a twist bit, which
> may pull itself into the wood between the fibers before it cuts itself
> an opening.

This is absolutely the case.  The "pointy" twist bits have a distinct 
disadvantage when working with Shaker box veneers.  The pressure of drilling 
will split the band fingers every time. 

The supposed advantage to the spiral bits is that they don't wander as much 
when you start the hole, but I don't have this problem with the 2-flute 
variety either.

If you are using a push drill for pilot holes and the like, I really don't 
think you'll notice any difference between the two styles of bits.

ralph

Jon asked:
> 
> How do you sharpen the two-flute bits for a Yankee push drill?  I have a few
> bits and they all seem to be dull as a bowling ball.

    Easy as pie.  Pick out the biggest one you have and stare at the
angles of the bevels.  Also take note of how there is a ridge running
perpendicular to the flutes.  Keep these images in your minds eye.  Hold
the bit on a sharpening media (I use a small diamond hone) and hone away
whilst preserving the bevel angle and the ridge.  Do the other side.
Schmear with paraffin.  Put it back in the magazine and take out the
next one.  Repeat, until the last one is sharp.  Bob is your uncle.

>
> Also, where can one get new bits for these?  I would like to find twist
> drill bits rather than the two-flute style.
>

    I just saw the twist type in the Lee Valley catalog.  Something like
$18 for a set of 8.  If you like that sort of thing.  Me, I'm a proud
luddite who prefers the fluted variety, not some new-aged twisted
nonsense.

Regards,
Steve