drilling profile rails

[routercnc]

Hi Reefy,

I've just finished drilling and tapping my rail mounting holes in the frame, but this is BEFORE the frame is assembled and the epoxy added.

My plan is that when everything is assembled in place, moat made, etc I will put long bolts into the holes covered in grease. After the pour, when things are nearly set I'll take them out.

The epoxy will not stick to them and the threads will be clear. I can then lay the rails down and bolt them in place. This method means you can drill the frame on a normal pillar drill.



I used my cnc machine to spot drill mark the holes:


But as yours is not ready yet you can use transfer punches to mark through the rail and into the frame (with the rail clamped in the right place and aligned parallel to the other one). Select the right diameter transfer punch which just about fits in the hole in the rail, and tap with a hammer. The pointed tip will create a centre mark on the frame below: