Was the hole drilled trough already to allow the web to pass ?

I work up on drills - not every size but plenty. If important
I might use number, fraction, letter, metric and do a fine cut
at the last.

Remember the center of the drill mostly pushes with a turn.
the outside has the surface length to turn. Without a center hole
the center of the drill has to cut or mush out to be cut the core
as wide as the web diameter.

Martin

Martin H. Eastburn
@ home at Lions' Lair with our computer lionslair at consolidated dot net
"Our Republic and the Press will Rise or Fall Together": Joseph Pulitzer
TSRA: Endowed; NRA LOH & Patron Member, Golden Eagle, Patriot's Medal.
NRA Second Amendment Task Force Charter Charter Founder
IHMSA and NRA Metallic Silhouette maker & member. http://lufkinced.com/

On 6/20/2010 11:55 AM, Jon Danniken wrote:
I was doing some drilling with my drill press yesterday, using an MT2 shank
25/32" bit @ 300RPM (and plenty of cutting fluid). It was just for
experimenting, as I have never used a bit that large before, and wanted to
see how my new press would handle it.

Everything went well, except that the front (idler pulley to spindle pulley)
v-belt (size M-25) would slip the idler pulley (spindle would stop) if I
applied too much pressure. This meant that I had to peck at it, which isn't
what I am looking to do.

So, as this is a used press, I considered getting a new belt, but it is hard
locating an M-25 belt, especially locally, and even online (couldn't find
one at mcmaster carr) From what I can tell, the M refers to the large width
being 10mm, and the 25 refers to a 25" circumference. Would a 3/8" (9.52mm)
belt work in this application?

What I would like is a belt that was less prone to slipping when I drill
large-ish holes (13/16" is the size I will be doing a lot of in the near
future). Would a cogged belt be a good solution for this? Any other
less-slippy belt suggestions?

Thanks,

Jon