The reason for the change in hole size is to increase vacuum (of course). The customer is contemplating a change to a "stiffer" material, (polypro) and they think they will need the increase in vacuum. As for the number of holes, this is spread out over several sets of tools.
The drilling has to take place from the mold surface side, these are deep tools with .25 holes drilled in from the back and the .016 breaking in to connect the vacuum to the source.
I like the dremel idea, I am going to do some experiments and see how they go. On new tooling I use the sensitive spring loaded chucks, which work well. But these are mounted in a b.port type mill, and using this system means I am would be constantly realigning the mold tool with the spindle. I have my doubts as to whether I can do that or not, (or if it is even worth it). |