what is high aspect ratio in drilling the slot in micro edm?

Question

first time i asked about edm and in second time i asked about micro edm...................i think thre is a difference in em and micro edm aspect ratio..............and in particular there must be difference between high aspect ratio of slotting and high aspect ratio of drilling... i am asking this time specifically............

Answer 1

Aspect ratio is length to width.
Drilling and milling are different operations with little in common.
Whats the question?

Answer 2

The problem in electric discharge machining is tool wear. The eroded debris has to be flushed out of the spark zone. If the circulatory system is not properly designed, there is a possibility of greater side machining (Over cut). The problem is aggravated when machining small dimension holes.

Since over cut is independent of the l/b ratio one finds that slots with a small width and large length get more distorted than a large width/ large length slot. Generally this is not an issue if the minimum width is more than 2 to 3 mm.

Fine hole drilling poses its own problem of over cut. Deep, fine holes tend to give trouble.