1. The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
FP7 - Research for the Benefit of SMEs
Development of a next generation Micro-ECM sinking machine for the Automotive,
Aerospace, & medical device sectors.
€1.2 million in Funding
Dr. David Tormey

2. Project Overview
ObjecUve
• To develop a new generaUon of μECM
machine with nanosecond pulsing capability
and soWware simulaUon modelling of the
process
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

3. TransnaUonal CollaboraUon
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

4. Partners
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
No Partner Type Country
1 IT Sligo RTD/ Co‐Ord Ireland
2 Vox‐Power SME Ireland
3 Brunel University RTD United Kingdom
4 CDAMC RTD Ireland
5 Sonplas SME Germany
6 Vrije Universiteit
Brussel
RTD Belgium
7 Elsyca SME Belgium

5. Brunel
CDAMC Sonplas
Process development
+
Demonstrator
VUB Elsyca
SimulaUon
SoWware
IT Sligo Vox‐Power
PSU
Power Supply Unit
µECM
Process
Customizing Process
ProducUon Machine
concept
Customer
Partner relaUonships

6. Process Advantages
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
• Reduce the costs per part through
• Shorter cycle Ume
• No tool wear
• Less down Ume (tool replacement)
• Improved machining accuracy
• Roundness
• Repeatability ‐ No need for dressing of electrode
• PosiUoning of cathode
• Improved surface quality
• Roughness (Rt0.1µm)
• Individual hole shape possibiliUes

7. AutomoUve fuel injecUon systems
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

8. Requirements
• Product – e.g. Diesel InjecUon nozzle
• Requirements
– Micro Holes
– 100μm diameter
– 1 mm thick cross secUon
– < 10 second drilling cycle Ume
– Shape control (k‐factor control)
– Flow tolerance requirements ± 1 % Cpk 1.33
– Costs savings over the EDM process
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

9. Project Workpackages
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
WP No. Title Ac7vity Lead Partner
WP1 Project Management MGT ITSligo
WP2 Power Supply Development RTD VOX‐Power
WP3 ECM simulaUon soWware RTD Elsyca
WP4 Design, Test & Validate micro‐ECM RTD CDAMC
WP5 Build demonstrator prototype micro‐ECM machine DEM Sonplas
WP6 DisseminaUon‐ExploitaUon‐Knowledge transfer RTD Sonplas

10. WP2 ‐ Power Supply Development
• Typical PSU characteris7cs
 Uses a pulsing stage fed through a filter to provide DC
voltage to a load.
 Current PSU technology switches at 200kHz to 1MHz.
 Current PSU technology uses silicon Mosfet switches.
• uECM applica7on characteris7cs
 Requires pulsed voltage without filtering.
 Switching frequencies up to 50MHz.
 AlternaUve switch technology required.
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

11. Technical challenges
• Custom circuit required to generate 50MHz
PWM control signal
• Power switches must be extremely fast
switching <3nS, and must have very low
capacitance
• Accurate measurement of circuit parameters
will be difficult at 50MHz
• High frequency pulsed current will require
very low circuit parasiUc inductance
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

12. Power Supply: Requirements
• IT Sligo & Vox Power have developed a PSU
that:
– Provides a width modulated pulse train up to a
frequency of 45 MHz
– Provides a pulse current amplitude up to 20 Amps
– Provides process feedback
– Communicates with system controller
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

13. Power Supply: ParasiUcs
• At 45 MHz normal cabling has significant
impedance characterisUcs
• Therefore
– Traces and cabling must be kept to a minimum
– Pulse generaUon must be located as near as
possible to the tool
– Process gap model must be accounted for
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

14. Power Supply: Pulse GeneraUon
• Dual stage digital control
• Dead band and synchronizaUon ensure pulse
shape and Uming
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

15. Power Supply: Parameter Control
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
• DigiUzed & analogue parameter feedback
• Adjustable parameter limits

16. Assessment of current status
• Progress made
 Load characterised
 Spice SimulaUons completed
 Power switch technology idenUfied and evaluated
 PWM control circuit designed and verified
 uC selected and soWware under development
 1st pass prototype hardware
• Issues idenUfied
 IniUal tests show that controlling parasiUc elements is extremely
difficult
 Probable that mulUple PCB iteraUons will be required to opUmise.
 Delivering clean pulses to the inter electrode gap will require a lot
of design effort
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

17. WP3‐ ECM SimulaUon: DL capacity
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
• Effect of the double layer capacity

18. SimulaUon: Tool InsulaUon
• Effect of tool insulaUon
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
18
versus
AcUve Insulated

19. SimulaUon: Slew Rate
• Effect of slew rate
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
19
toff ton tslew tslew
18 V/ns
T x 3.1
0.45 V/ns 0.225 V/ns
T x 1.7
T

20. SimulaUon: Gap Size
• Effect of gap size
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
20
t/sic/A02E-074E-07-0.001-0.000500.00050.001
t/sif/A02E-074E-0700.00020.00040.0006

21. WP 4 ‐ Test Bench Design

22. Test and Validate Test Bench

23. Test Rig results: Electrolytes
• Sodium Nitrate (NaNO3) – Best
• Sodium Chloride (NaCl) – Good
• Phosphoric Acid (H3PO4) – Poor
• Increased concentraUon increases MRR but
reduces localisaUon.
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1

24. Test Rig Results: Machined Hole
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1
• Increasing pulse
duty cycle increased
MRR
• Decreasing duty
increased
localisaUon

25. Demonstrator Design
FiltraUon
system
Electrolyte
control
system

26. µECM- Developed ECM Demonstrator

27. µECM- Developed ECM Demonstrator

28. Summary: Work Achieved
• Modelling of IEG
• Development of simulaUons and soWware
based around model
• Development of ECM PSU
• Development of test rig and validaUon of
model by test
• Ongoing design and development of a
demonstrator machine
The research leading to these results has received funding from the European Union
Seventh Framework Programme (FP7/2007‐2013) under grant agreement № 262072,
µECM – Micro ECM for SMEs, Research for the benefit of SMEs FP7‐SME‐2010‐1