PDP 8 panels. Feedback

Paul Koning paulkoning at comcast.net
Tue Oct 27 12:07:35 CDT 2015

> On Oct 27, 2015, at 12:33 PM, Jon Elson <elson at pico-systems.com> wrote:
> On 10/26/2015 11:38 PM, Chuck Guzis wrote:
>> On 10/26/2015 08:54 PM, wulfman wrote:
>>> 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
> 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.)

I would think a counterbore would work better, because it doesn't cut on the sides, only on the bottom.


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