D.I.Y. Electrical Discharge Machining - First Runs of home made machine

I designed this from watching KZbin videos and reading a paper I found online with a google search, (which now seems to be hidden behind a paywall). My machine sort of works, needs some tweaking, but this is literally all within the first hour of it ever being turned on with a probe & fluid attached. And it's my first ever attempt at EDM.
I'm hoping, if I can get it working properly, to do a series detailing its full workings.
Its based on cheap eBay power supplies, motor-run capacitors, big sweaty power resistors and an arduino mega controlling a stepper motor.
The 4-line LCD is a SAINSMART I2C unit using the FMALPARTIDA Library to drive it.
Full schematics & arduino code WILL be provided in and with following videos, once it's at least working properly.
What fun!

[@dingolovethrob]

Okay folks, I've been somewhat preoccupied doing other stuff, but in response to several requests here's a link to a googledrive zip file containing the arduino sketch & a PNG of the schematic. It's all very simple stuff really, not much there at all, but I hope it's of help. drive.google.com/drive/folders/1_gUA86CwqRCjitwhPA-qMTarSMNEgztc?usp=sharing

[@OperationAllOut]

Waiting for the schematic and code

[@klausbrinck2137]

Hallo, I like your design, but after studying the provided plans, I still have some quick questions: 1. Your "fet-switch", what does it consist of? Simply a fet, or also a fet-driver-circuit? (which fet maybe?) 2. Is the 80µf-capacitor still needed, when you switch over to "pwm", or is then simply the current used, that´s coming directly from the psu? 3. What´s in your "potential divider network"? is it simply a potential-divider made out of 2 resistors (so that you feed "Analog-Input-0" with 5v or less)? 4. How is your up/down-joystick made? I couldn´t locate it anywhere on the machine´s interface/front-panel... Is it a 2-position-switch somehow? Thanks á priori for every answer, even if to a single of the above topics, it would help a lot, believe me. I don´t have the posibility to experiment, so, I try hard to find a secure design, and I am a bit disappointed by what I´ve found... I learnt even a bit of electronics cause of my search, but there´s either not enough infos for the simple designs (code´s missing or circuitry is missing), or the designs are far too complicated for me (not to build, but to deeply comprehend and troubleshoot if necessary)... Aside to the few "black boxes" mentioned in my questions, it´s the most complete circuitry of a simple, but real-working machine I´ve seen till now (and not an idealized circuitry that just displayss the principle, but is no real circuitry), and I have looked into dozens of them...!!! Thanks again

[@user-vr5lf1st7j]

Suuuuper

[@250smacks]

Is there a shopping list somewhere? I understand how it cuts as im familiar with doing a little ECM but this is a whole other animal.

[@neozman]

17:18 hehe that laughter :P:P

[@DutchPhlogiston]

6:00 looks like a lot of electrolysis is occurring. That is not desirable. Are you using deionised water?

[@nirmalakhatri9667]

great job could you share more detail of how do you have controlled current of spark

[@dingolovethrob]

First, let me say, I'm no expert at any of this, I'm playing with this for a hobby, these are just my opinions. Others may know better than me. So: The current is rather poorly controlled as there is no specific current control mechanism as such. The peak current depends upon the resistance of the circuit during discharge and the peak voltage. The circuit consists of the PSU charging the capacitors through the current limiting resistors, and that charges them to 48volts nominal. So that sets the maximum peak voltage. As I understand it, when the capacitors are discharged by the breakdown of the dielectric and the subsequent spark, the current is limited only by the internal resistance of the capacitors, the parasitic resistance of the wiring, & electrode, the resistance of the plasma arc and any inductance in the circuit. If the gap is large then the voltage is high and you probably get a high current, but if the gap is small, the breakdown will happen at a smaller voltage, and so the caps won't charge up to as high a voltage before the next spark, so the peak voltage will be lower and the current will be lower too. Thats probably why it burns so unevenly at the moment. Current depends heavily upon the behaviour of the servo and that's still very poorly written at the moment... - Its still early days yet. I have lots of ideas to try out.

[@nirmalakhatri9667]

@@dingolovethrob please share your mail Id so I can share my content over this machine

[@dingolovethrob]

I don't normally share email addresses widely, as programs scrape email addresses to use on spam lists. but I have set up the address [e-mail] for this purpose. If it gets spammed then I'll be closing it immediately.

[@nirmalakhatri9667]

@@dingolovethrob do you have checked your mail id

[@joesmoe71]

How dangerous are the voltages involved here? Is it something that could kill you if you accidentally touched it?

[@dingolovethrob]

48 volts is right on the edge of what is considered "safe" , in fact in the EU I think it may be classed as a hazardous voltage, depending on which legislation you read. I won't play with anything over 48 volts while drinking beer & messing about in a shed, so that's why I chose that. It's probably just about safe, but I avoid touching it anyway. Many EDM machines use much higher voltages but I didn't want to risk it. Getting shocked or killed is not fun. If anyone else says it's safe then let them give themselves shocks.

[@Ferraday]

I’m glad that the creator is very cautious, but the way an EDM is setup, there is a very low chance of getting shocked, and I would go up as high as 400v on a setup like this (keep in mind I don’t know the optimal circuitry or voltage for edm). People make handheld 200-800 volt coilgun rifles, in which you’re directly next to a giant handheld chunk of charged wire

[@Spark-Hole]

DC not as dangerous as AC, Your flesh act like a capacitor, AC current can pass easily, and AC when said 110V it means peak at 156V.

[@ovnprojects2640]

Hi, why did you chose to do RC type instead of the other options? I have played around with "PWM"/pulse type of EDM. If you have trouble with aluminium whit copper wire as electrodes you could use steel and graphite as electrode it makes testing easier.

[@dingolovethrob]

Hi ! I saw that others had made RC type machines and they seemed to be very simple to make, and then found a paper online that detailed enough about the operational principles to have a go at designing one myself. I've bought some brass to play with for electrodes, but haven't tried graphite or steel yet. I had some big brushes from industrial motors in a box somewhere, if I can find those then they may be good as electrodes...

[@user-mm9tt2gx9x]

Ст-45 возьми сталь 45 каленую до 50hrc