Added: 4 years ago
From: cheaphardwarez
Views: 56,112
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  • Bla bla bla diode bla bla ,common bro ?

  • Too much Mac n cheese bro , and u start talking that space talk , remember people are learning Here .weres your junk and that camera is swinging to fast ,we're you goin to the crap room ,

  • ya good idea asshole. just leave a few things out ya no biggy, little johnny just fried mom pop sister and the fucking neiborhood!. if your going to post something at least have your head outa your ass.

  • how about just a schematic...

  • Like i said about your other vid ....i would build one with very clear instructions but probably only if you were standing there to tell me if i am about to kill myself doing something wrong....i must say your understanding of how this works seems to be pretty thorough..keep the vids coming.

  • thanks for the video! I have just finished my build it works fine! Many thanks!

  • Could you make a playlist of your videos in order of relevance to understand exactly what and how you are trying to explain this topic. Would be most appreciated.

  • what is keeping from welding with this?

  • @JOOODYJOOODY The current is limited and the voltage too high, probably you could weld thin stuff that needs 20-30A of current but I'm not sure of the results (probably lots of sputtering, at least) and consuming much more power than required (20A at 240V are around 5kW )

  • Do you know what the voltage over the actual plasma is?

    I would very much like to know this.

  • Nice work there.

  • SupermaxCNC .....Abovegroundminer is a little slow..gay but a little slow .

  • SupermaxCNC... Thanks for convincing me to build one of these machines!

    Perhaps we all could build this with a breaker, a isolation transformer's, Caps,SCR's? (my secret), a reactor and minimal electronic's?

    Maybe Study capacitive reactance and stuff.

    I like this man's video!

    Most people sell plans like this on ebay..

    He give's his plan's for free..

  • you have awesome water resistor there ! :D

  • DO NOT BUILD THIS! IT IS A DEATH TRAP!

    By code and law plasma cutters are required to have their output isolated from mains power. This means that there is a isolation transformer in between the mains and the input rectifier.

    If you were to come in between ground (Lets say kneeling on wet pavement) and the tip it would kill you in a split second. There are NO safeties in this machine.

  • Go home to cry! Cheaphardwarez have done a great gagdet so shut up! And if you can read, it already reads on his info!

  • ok you dork, if you want an isolation transformer on the input then add one to yours. Like the boy says, "If you don't understand the concepts presented here, this project is not for you". As for me, I am not going to put my tongue on the tip of the gun and pull the trigger.

  • Wow, maybe this plasma cutter should be renamed the "Darwin Plasma Cutter". As building it will increase the general intelligence quotient of the population by the users removing themselves from the gene pool.

  • Its the same method used my some large automated industrial cnc setups. Its not for the normal consumer. Even so, there is no measurable voltage from the work to ground, but can still post a life risk if you hold a ground in one hand and hold the work or dig in the tip with the trigger pulled, lol.

    I would not suggest building a project like this if you do not know how to safely handle electricity.

  • I am a service tech for industrial plasma cutting machines and welding equipment. There are no industrial machines built this way.

    Hypertherm makes a better machine than miller.

  • How much for a working model?

  • @cheaphardwarez

    In the video you said to have a HV capacitor across the + and - of the diode bridge to filter out high volt spikes, how important is this, does it really work?

    it wasn't in the schmatic video, and I fried a diode pack,

  • Comment removed

  • @cheaphardwarez

    I am a service tech for those large cnc machines and I have worked on Esab and Hypertherm units up to 400 amps. All of them use transformers.

  • So go to miller and buy your self a cutter.

  • @SupermaxCNC

    It could be made safe if powered with Half-wave rectifier connectred to 3 phase power grid.

    in that case all you need is to maintain correct phase and ground connections.

  • @deltaxcd

    No, that wont work. There is still grounding on three phase. A corner grounded delta has one of the lines tied directly to ground. One 120/208 delta the center of coil of the transformer is tied to ground as well.

  • @SupermaxCNC

    You do not understand me.

    To be safe you need to use HALF WAVE rectifier.

    You connect ground wire to your workpiece.

    and use 3 diodes (one from each phase ), not 6 diodes in full bridge comfiguration, to power plasma cutter head.

  • @deltaxcd

    As the line is not isolated it will have a voltage potential from the torch to earth ground no matter if you use a half wave rectifier or a full wave rectifier. And then what do you plan on using for a work ground? Using a half bridge on delta's three lines leaves you will only earth ground as a return path and to use that would violate NEC.

  • @SupermaxCNC

    There is no isolation in any case even if you use transformer you are grounding one wire by connecting it to your workpiece so if you touch your plasma head you may get electric shock anyway.

    this is why isolation transformer is not required. It just does not do anything.

    Of course this will not pass NEC but it is relatively safe, comparing to full bridge setup which is plain death trap.

  • @deltaxcd

    A half bridge is no safer than a full bridge and you still have not shown a return path for the current from the half bridge.

    An isolation transformer provides considerable protection. Not only to yourself or hapless bystanders but to other equipment and building wiring. With an isolated setup you have one return path, through the work cable. With an unisolated setup you have a return through anything, tables, power tools, even the ground you are standing on.

  • @SupermaxCNC

    No safer? if you use full bridge and connect one wire to your fence or car which you want to weld you may be killed before you will even start you work. any accidental grab to your workpiece will be your last.

    half bridge is only harmful if you fail to connect ground to your workpiece and then touch it with other electrode in that case you will get some shock, but it wont kill you since it is short ,also 110v i relatively harmless if you do not stand in the water.

  • @deltaxcd

    Well, I guess it is safer since it will not work. What do you connect your ground too? If you had a neutral wire with your three phase you could use that but if you are on delta you wont have one and even when you do have Wye often the neutral is not dropped to an outlet. Unless a machine needs 120v internally the neutral is left out.

    110v is anything but harmless. Its the current that kills you, not the voltage. Higher voltage just makes it easier to get through the dry epidermis.

  • @SupermaxCNC

    You do not have neutral wire? I have never seen such case, since where I live we always have neutral wire.

  • @deltaxcd

    There are, in general, only two instances here where you have a neutral wire. That is with 120/208 Wye and 277/480 Wye. And the only time I have seen an outlet that has all 5 wires (3 hots, 1 neutral, 1 ground) is when a machine or piece of equipments specifically needs 120v like some power supplies. But usually the machine designers build a machine to run with only the three hots and use an internal transformer is 120v is needed. This makes machines more compatible for installation.

  • @SupermaxCNC

    It could be made safe if powered with Half-wave rectifier connected to 3 phase power grid.

    in that case all you need is to maintain correct phase and ground connections.

  • Not bad and i agree that you give plenty of information on the subject. More than is required as far as i am concerned. The concept is all that is required and with that well done

  • Im sorry to saiy that you poorly explain that. The directions were confusing. I would highly sugest a longer more descriptive video. that would would make you vido much beter. beacuse what i hear for that video makes absolutely no sense. and i would not sugest that video to anyone. (no offence)

  • You need to watch all the videos and read the info on each video to get to whole picture. Draw it out on paper as the connection points are discussed and if you can connect one component to the next component as this video shows then I would suggest you not ever try to build such a dangerous device!

  • Everything you need IS here on youtube. Really!

  • what if i addignition wil it give bigger spark?

  • ignition? For starting or what?

  • And other question yet, what materials are the electrode and the plasma channel?

  • Tungsten electrode copper tip. A home made torch tip is the same using a modified tig welder using tungsten electrode and machined copper drag tip.

  • Very cool! I am going to build this but I`d like to know what for are the inductors?Thanks!

  • The inductors are 12mH and the value is not so critical unless you do a series resonate circuit.  They serve as part of the filter circuit to made the DC more pure. The more ac wave you have in the output the less smooth the cut will be, unless that ac is very high frequency.

  • @cheaphardwarez 12mH each? With that much you could limit the current on AC side instead of wasting power in the resistor...isn't 38mH the AC equivalent of 12 Ohm at 60Hz? The resistor is cheaper but not in the long run, plus you don't have a water bucket with live wires in it around the shop

  • It is power that generates heat. Faster air through a spark = higher temp. You just have to be able to keep the spark going. You will find that things like spark coils from a car can not arc in that much flowing air. You need lots of current and very high voltage to start the arc.

  • There is a reason that plasma cutters do not step the voltage down. I would think you would need about 4 or more MOTs(at 1200watts) to get the power rating up. As long as you can keep the cutting voltage above 90 at the current level you need then you are fine.

  • hi me again

    i dont know if my design will work so i hope you dont mind if i run over it with you,

    im using a mot transformer to step down the voltage and step up the amperage then i rectifiy this lower voltage and run it past a bypass cap 0.1uf 2000v then a dimmer cap 360uf 400v and lastly a 10 ohm resistor "

    not water type" basically the concept is high amperage dc low voltage

  • The small HV cap I used was to bypass the high voltage(90KV) from the starter keeping it off the diodes which are rated at a much lower voltage.I have heard that you can use MOTs in parallel to make a high voltage plasma cutter. I do not know though. I would rather not have 10KW of high voltage anywhere near me! Good luck! If you do manage to make something that works let me know.

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