Hi all,
I need to mill a dozen slots in about 40 1 mm PCB panels.
The slots are 1.2mm wide and about 20mm in length. The slots are full depth of the PCB. The panels are around 160mm x 120mm.
I’m planning to use a 1.2mm burr style mill. I also have access to 1mm 2 flute slot mills. Both are carbide.
Has anyone had experience with this type of milling? I’m particularly interested in the speeds and feeds to use. As I’ve seen conflicting advice.
Also I plan to make a fixture to hold the PCBs as the position of the slot is critical.
The panel has four 1.5mm diameter locating holes on the panel. One option is to use 2 1.5mm dowel pins on diagonal holes to locate the PCB, then clamp it with a couple of strap clamps. I can’t find the dowel pins from a supplier that can provide them quickly, but I can be used the shafts from some 1.5mm drill bits. I also have some 1.5mm spring steel that I can use in a pinch. This method allows me to stack a number of PCBs if I’m game. ????
The other option is to cut a relief into the fixture that is made out of Corian. The relief would be 0.8mm deep to allow for the strap clamps.
I’m not sure which way to go. I leaning towards the first method with the locating pins. One reason is that I can sandwich the board to be cut under a cut one if the top edge of the cut is not clean.
I can try both fixture methods if necessary but am mostly concerned with the speeds and feeds along with the depth of cut as the cutters are quite easy to snap. Also I plan to use air to cool the bit and remove the swarf.
Any advice is welcome.
Cheers
Peter.