I had this issue before but I can't for the life of me figure out how I fixed it last time this is to hold an Arduino board down, needs 4 3mm holes and 4 5mm holes, for some reason sketchucam is generating double holes for the 3mm holes, right now the bit is set at 3.175 but I tried to make the holes 3.5 and still getting 2 holes, I'm sure it's simple....LOL Bob
if a line intersects the purple 'here is a hole' line in the plunge hole symbol, then you will get 2 holes, because each 'begin' end of those purple lines creates a hole, an intersecting line auto splits the line into 2 parts = 2 begins = 2 holes. this is why all plunge holes are created as groups, and this does help, but there are still cases where an intersecting line will create an extra hole. so, you want 3mm holes but you set the bit to 3.175, this made the symbol 3.175mm diameter. if you have already drawn 3mm circles where you wanted holes, those would intersect with the hole symbol and create an extra hole. instead of drawing circles where you want holes, rather just place a construction point to mark the center.
Thank you David that makes sense... I'm sure I'm not the only that has had problems and you will have helped me and future others!! thanks Bob