27 Oct
2015
27 Oct
'15
9:33 a.m.
On 10/26/2015 11:38 PM, Chuck Guzis wrote:
On 10/26/2015 08:54 PM, wulfman wrote:
The ultimate way to drill holes in Plexi is with an end
mill. It can make a slight chipping when it punches through
the back, so you either need a backstop material or lighten
up the feed a bit just before it goes through. (This of
course requires a center-cutting end mill, I prefer 4-flute
for this.)
Even better than just plunging an end mill is to use a CNC
mill and a cutter smaller than the required hole diameter.
You use a pocket boring routine, set up for "climb milling"
and after working through the material in several depth
steps just less then the desired diameter, does a finish
pass at full depth to bring it to final hole size. This
takes longer to describe than it actually takes the machine
to perform, and leaves beautiful holes.
Jon
To effectively drill in plastics you need to run
the
drill press on
the highest speed you can and use a freshly sharpened
drill bit.
If this is Perspex/Plexiglas, I've had great results with
a good sharp Forstner bit in my drill press at medium (say
750 RPM) speed and a not-too aggressive feed.. No
melting, just lots of crumbly shavings. I've done this
with sizes down to about 1/4", but no smaller. When
you're almost through the material, turn it over and
complete the hole from the back side. Very clean edges,
with no chips at all