Drilling Polycarbonate Router Plate

[Matthew Bobek]

So, I just received a new router plate for my router table. It's from Eagle America and is the clear, polycarbonate version. My questions are: How do I properly countersink the screw holes? What type of drill bit or countersink should I use for this operation? And what is the best way to drill the 1/2" hole for the winder (I have the 2 1/4 hp triton)? And one more thing, where are the best places to drill the holes for the starter pin, as far as distance from the bit is concerned? My first major project is going to be a run of adirondack chairs, and that's a lot of templates Thank you as always.

[george wilson]

I advise grinding a vertical face on the cutting edge of the drill. I'd use a single cutting edge countersink,probably grind a vertical face on it too.

Be careful that the plastic doesn't get too hot and start to melt. You can get into trouble fast. The vertical cutting edges keep the drill from grabbing when it breaks through,spinning the plastic,or pulling it right up towards the chuck. Also prevents popping the plastic when drilling holes near edges,especially acrylic.

[Keith Westfall]

Use a step drill for the ones you can. It will chamfer both sides easily and quickly. Then a countersink will do the ones that need doing - use a slow speed to avoid heating/melting.

[Chip Lindley]

Mark each hole location by scribing an "X" precisely at it's center. Lightly center-punch each location to start the bit. Drilling would best be done with a drill press at slow speed. Accurate holes are best started with a small bit, working up to final size. Clamp the plate to the DP table once the hole is located. Change bits without moving the work, until the hole is completed. Change to a countersink with the hole still located on center.

[Robert Reece]

I use these countersinks on my polycarb plates:

http://www.woodcraft.com/Family/2005...ks/videos.aspx

They work well.

[Tom Esh]

Are you sure you want to countersink for this? I'd suggest counterbores instead (oversized) and through holes (also oversized) for round / oval head machine screws. That way should you decide to use an insert for guide bushings, you can fine tune the router position so a bit will be exactly centered in the bushing.

[george wilson]

You really do need to grind the drills as I said. Drilling a succession of holes with a normal drill is going to just make it even easier for the drill to grab.

Those "zero flute" countersinks were not what I was describing. I use a countersink with a big wide single flute,giving 1 cutting edge. They will also give much more clearance than the o flute,and will not overheat.