Motorized Electric Discharge Machine
Principles of drilling
The [MH20M] motorized EDM has been designed to drill the tiny holes in any conducting gasketmaterial that the diamond anvil cells (DAC) operation requires.
Fast drilling, high hole shape quality, high accuracy in centering and very easy operation make the [MH20M] the best tool to prepare the gaskets used in high pressure physics.
Using different diameter wires (50µm, 80µm,125µm, 150µm, 200µm, 250µm, 300µm, 380µm) the hole diameter can be continuously varied from 60µm to 450µm by controlling the electrode voltage.
A needle is used for drilling from 20µm to 100µm.
A non motorized version of the MH20M (ref MH20), may also be ordered.
A motorized module MOTO1 can be added latter to upgrade the MH20 to the MH20M.
Principles of drilling. (Spark Erosion with wire)
An electrode at high voltage spark erodes a metallic gasket immersed into a dielectric liquid (e.g. light oil). The electrode is fixed.
The gasket holder is set on the vertical micro translation stage and moves up during the operation.
• Drilling diameter : from 20µm to 500µm.
• Centring accuracy : < 5µm.
• Drills in any conducting material : Stainless steel, rhenium
• Easy to operate
• Fast drilling : dia. 40µm /minute for a dia. 200µm hole in a stainless
• Possibility to change the polarisation and to tune both the
voltage and the current : to optimise drilling performances as a
function of gasket material, thickness and hole diameter.
• Centering microscope (x 400)
• Observation microscope (x 40)
• Motorized drilling : the voltage between the electrode and the
gasket feeds back to control the movement of the vertical table.
• Weight : 12 kg; Size : 19 cm wide., 33 cm deep., 42 cm high.
Before drilling, the centering of gasket is done by the micro metric XY stage (the rotating head has to be rotated by 90° into the
The adjustable electrode holder makes it very easy to install and adjust new electrodes.
NOTE : Manual drilling is also possible with the motorized MH20M.
Visualisation during the drilling
pre-drilling and alignment
Finished drilling & cylindrical
Checking the hole
Rotating head rotates 90 °
to change from centering visualisation position to drilling.
EDM Accessories & spares
Using different diameter wires the hole diameter can be continuously varied from 60μm to 530μm by controlling the electrode voltage.
A needle is used for drilling from 10μm to 50μm.
List of Type II electrodes :
Electrode Needle radius 2µm.
Electrode Ø 50µm - 80µm - 100µm - 125µm -
150µm - 200µm - 250µm - 300µm - 380µm - 500µm
The abrasive toolshave been designed in order to facilitate the repair (with emery-cloth) of used and worn MH20 spark- eroder electrodes.
The quality of repair does not depend on the dexterity of the user.
There is no risk of destroying ( bending or folding ) the tungsten part of the electrode.
Electrode set :
The tungsten top of the electrode is guided in a Ø500μm hole.
Top of the needle :
The electrode is always perpendicular to emery cloth.
Erosion of electrode :
About 10 to 20 seconds to repair an electrode.