Monday, November 16, 2009
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More Information on Fine Hole EDM Drilli... »
I have written here in the past about EDM fine hole
drilling, but I have some update info that is very interesting. Makino recently
did some testing for a customer who needed a 0.007-0.008" (0.177mm - 0.203mm)
diameter hole drilled through 0.75" (19.05mm) of CPM material. That's a
Length-to-Diameter ratio (L:D) of 125:1. Some will say "That's impossible, it
can't be done.". However, Makino Application Engineers were able to produce
this very thing on the Edge2 Fine Hole machine. Using a 0.006" (0.15mm)
diameter copper pipe and a tooling set-up that allows 90 degree incremental part
indexing, they were able to produce a 0.0075" (0.1905mm) diameter hole through
0.75" (19.05mm) of CPM-M4. Here's a picture of the block of material with a
piece of 0.004" (0.101mm) wire running through it, and magnified view of the
hole itself. The hole, drilled from both sides to meet in the middle, took 30
minutes. When the part was cut open with WEDM to inspect the middle of the part
where the 2 holes met, there was no visible line or mismatch at the meeting
point.