DIY PULSE EDM - Part 3 - Fixing the exploded machine

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My engines

Күн бұрын

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@Viper54K 2 жыл бұрын

Great to see you here again Rolf. I look forward to the next episode.

@tudedude 2 жыл бұрын

I admire your dedication and look forward to the next video.

@edmguru9056 2 жыл бұрын

I don’t know the design of the E.D.M. you’re trying to build but it looks like a pulsed R.C. design and not a true pulse E.D.M. as the burn amps and electrode wear look way too high when using a 25 Ohm output power resistor to your electrode, although you could be using two in parallel for a 12.5 Ohm output so output amps should be either just 2 or 4 at the working voltage (50v) which is not what it looks like in your video. I have found out lately that those types of resistors are a bit “iffy” so I would recommend that you just make your own from nichrome wire which works out cheaper and they also need to be fan cooled by at least a 100cfm fan. It’s actually easy to build a true pulse E.D.M. Take a look at the “Easy Peasy” E.D.M. on my channel that I built a few years ago (and at my latest more complicated build design). I would recommend that you build a custom version of that with maybe 3 or more independent Z axis with multiple electrodes on each all sharing a common multi channel power generator. It would not only look amazing in a video but it would be the fastest way (apart from using a wire E.D.M.) to produce the slots in your engines. If you need any help with your E.D.M. build at any time please let me know.

@myengines2443 2 жыл бұрын

Hi EDMGuru, of course I know your videos, really great work. The EDM is a true pulse machine built after the second book of Ben Fleming. I also built his R/C EDM which works nice but has problems with the slim electrodes. With the heat sink the problem with the resistors is solved. The electrode wear is much better than with the R/C EDM but not optimated (it was the third burn with the pulse EDM) and I also have obviously problems with the OFF time adjust to optimize the wear. A 0.5mm copper electrode vs. 1.4571 stainless steel always causes some wear at least when you can't optimize the ON/OFF timing. I hope I can fix the pulse EDM and find out what killed the IC's and get it to long term endurance running. Many thanks for you help and your great videos. When I know where I need specific help I will ask. Always waiting for new videos of you... Greetings Ralf

@edmguru9056 2 жыл бұрын

@@myengines2443 Hi Ralf, Thank you for your kind words on my E.D.M. builds. I’ve more improvements to come btw. Ok, I’m glad it’s a true pulse machine; it must be the output amps that are set too high for the surface area of the electrode that’s giving the high wear rate. I used to have my own spark erosion business from the seventies to the noughties and did all kinds of work including slots and also I have my own charts for spark gaps, surface finish, different electrode material into different metals, electrode wear rates at different amps and pulse frequency etc so I’ll give you some settings to try when your machine is built if you like. It would be a good idea to stress test those resistors at full power with no lift off timer and at a true plasma burn voltage (working volts) of 40 volts or slightly less for half an hour or so just to be sure as I think you’ll need to fan cool them. Use a larger electrode with a small through hole for flushing, at less than 2 psi and all should be good. Finally, about the slots, do they have to be that specific shape or could they be more like an elongated key hole? Only if they could be larger/ circular at the far end you could get a very small flushing hole in there and by not using your lift timer, shorten your burn time considerably. It’s just a thought. Cheers.

@th600mike3 2 жыл бұрын

@@edmguru9056 I just got my pulse 2.0b board today, have been going through all of your videos and my engine's videos. Amazing wealth of information you have. I really hope you continue to post more and more. I would really like to EDM some internal splines in various pieces of hardened steels... Would you try to use a wire approach? Or would a plunger based electrode be a better idea? I need to rewatch your videos again, this time more closely. I am only going for a half inch depth of cut, most would probably be one inch. So not quite as aggressive as what my engines is doing for his... engines! Also, does the electrode mass or purely the "contact" area matter between the workpiece and the electrode? Both of you guys have great channels. Channels like yours keep me on youtube.

@edmguru9056 2 жыл бұрын

@@th600mike3 It depends on if the internal splines that you wish to spark erode are going to be in a tube/ collar or in a blind hole as to which type of E.D.M. is best to use. Wire E.D.M. requires a through hole for the wire so it would be the best and fastest way to produce a spline in a short tube or collar. It sounds like from your description of the splines that they are to be eroded into a blind hole so a plunge type of E.D.M. is the only option for your task. It’s the surface area which determines the ideal output amps, ideally for low electrode wear aim for 25 amps per square inch of electrode if using a copper electrode but this could easily be doubled if surface finish is not a problem. The ideal way would be to use two electrodes, one being slightly smaller in width at high amps to do the main work of removing metal and then use a finishing electrode at low amps to size the splines and give a good surface finish. The flushing of the electrode is very important also on such a job and should be done by using a through hole in the electrode and at a low (less than 2 psi) pressure. I also should point out that if you plan to build the same machine as my engines, then electrode wear and stability might be a problem as I’ve not seen any good examples of low electrode wear etc. online with that design, but I could be mistaken. I feel that you should research this for yourself first.