PDP 8 panels. Feedback

rod rodsmallwood52 at btinternet.com
Tue Oct 27 04:08:16 CDT 2015

    Yes clamp it down. I have a pillar drill and that has a table that 
the workpiece can be clamped to.
This means they are at right angles to each other. So the drill bit 
works as designed.
Sharpen or replace drill bits if they get worn.
Next start small and work up in drill size. There are tables for speed, 
feed, size of drill and type of material.
As my old school metalwork master would say "more speed less feed".
Whilst you may not be able to judge feed rate because it involves time. 
Slower feed is better.


On 27/10/15 06:59, steven at malikoff.com 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.
>> --Chuck
> Agree with Chuck, a moderate drilling speed is better, you do _not_ want
> to melt your way through, you want to cut.
> And my advice, sadly learnt and forgotten quite a few times, always after
> drilling a critical part:
>                     **** CLAMP THE JOB DOWN! ****
> If you think you can hold the Perspex with your fingers, you can't and
> your nice panel piece suddenly catches, climbs up the drill bit in a flash
> and is wrecked before you can say something nice like 'Oh golly I do wish
> I had clamped it down!' or words (not) to that effect.
> For clamps I suggest those newfangled ratchet clamps. I bought some a few years
> ago and they are the best thing ever. These things ar esuperior to the
> average old-fashioned G-clamp in almost every way, except for when massive
> pressure is required. (search  'crescent connect clamp' on eBay, the 12" ones
> are excellent). And like G-clamps, you can never have enough of these, get
> some different sizes.
> Steve.

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