Introduction to Plasma Cutting

hey guys welcome back to well comm so today we're going to talk about the basics of plasma arc cutting so we're gonna go over all the consumables you know how to tell when they're bad what types of consumables you use we're gonna go over the settings for the machine we're gonna cut some different types of materials so the first thing we want to talk about is what is plasma okay plasma is the fourth state of matter so you have solid liquid gas right that's three states of matter everybody's familiar with and then plasma it's just a superheated column of gas so lightning is considered a plasma the plasma column is a forty thousand degree Fahrenheit heat so within this system we're going to use a transferred arc system meaning we have to have a workpiece clamp we have to have a torch there's going to be an electrical circuit electricity is gonna flow through that circuit and we're going to be able to cut any material that's electrically conductive so it doesn't matter steel stainless aluminum doesn't care as long as it's electrically conductive we can cut with it whereas with oxy acetylene it has to contain iron right because oxy acetylene is a chemical reaction it's basically an accelerated rusting process so it's limited to items that contain iron so you can't cut non-ferrous items like aluminum or stainless steel chromium nickel anything like that so there's a lot of advantages with cutting with plasma cutting for instance we have a smaller heat affected zone because we don't have to preheat we'll run them 40,000 or 40,000 degrees Fahrenheit plasma column so we're gonna cut through that piece of material a lot faster some of the limitations with it it's not as portable as the the oxy acetylene kit you know I can pick that up I can put on top of a building no problem it's a self-contained unit with plasma arc cutting I have to have a power source and I have to have air whether it's a compressed gas and a cylinder or shop air so today for our demonstration we're gonna go ahead and use shop air that's probably what most of you have at your disposal we have a Hypertherm power max 105 now some of the settings that we're gonna use they're not gonna be the same for what you have at home I don't know what you have at home so I can't recommend what amperage is you're gonna cut on the the amount of air pressure that's going to go through there we're gonna show you how our system works and I'm gonna refer you back to your user manual to find out your cutting speeds and your air pressures that go in your machine because I don't want to recommend something and then you overcharge it with the air so let's go ahead get start we'll talk about the machine we're gonna go ahead hook everything up we're gonna build our torch then we're going to make some cuts so the first thing we're going to do is plug in the air so we have 100 psi coming into the system on this system specifically this is 135 psi max so we're gonna make sure we don't exceed that this machine is actually pretty cool because it actually regulates the air pressure coming in off the amperage that's going to be put out your machine may vary slightly so make sure you check your user manual for the air pressure settings as well as your amperage settings for the type of equipment that you have at the house first thing we're gonna do is this plug in the air hose very simple now in here we have a filter you want to have like an air dryer filter all that good stuff in place because if you start getting moisture in your lines it's going to come out in your torch and you're going to burn up your consumables a lot faster so if you notice that you've you're pretty proficient at the cutting process but you keep burning up your consumables it's probably because you have moisture in your lines so hook up an air dryer they make little attachments that go on the back end that'll kind of help prevent some of that stuff from getting in your lines next thing let's go ahead and take a look at the front of the machine and we'll start setting up the accessories the attachments that go with it so the first thing we're gonna hook up is our workpiece clamp it's not a ground clamp we split hairs get technical about it it's just a workpiece clamp because plasma cutting is dc- meaning that when i hook the workpiece clamp up i'm actually hooking up to the positive cool thing about this is you can't screw it up so I can't put it on the wrong polarity I can't put it on reverse polarity even if I wanted to because the attachment points they're completely different the torch is going to plug into this hole and the workpiece clamps is gonna plug into here so you can't screw that up right even a welder can't mess it up alright so let's talk about all the consumables that go in here the first thing if you notice on top of most machines or on the side you're going to have a little diagram with part numbers and descriptions of what everything is that's just gonna make it a lot easier for you to order so the first thing is the swirl ring swirl ring is actually going to direct our air down to down through the torch and it's going to create a counterclockwise direction for the plasma column to follow so it's just going to make it a nice cylindrical shape of the arc right here's our electrode electrode are typically made out of tungsten or hafnium you can tell when they start getting bad because you're gonna develop a deep pit in here anything after a depth of about one millimeter that's about time to throw the consumable out but if you're less than one millimeter or you know the equivalent of 1/32 it's still good so don't throw these away until until you reach that depth that's just gonna slide in here like that this is our nozzle now note there's this nozzle is 105 amp for our system make sure you have the correct nozzle that you you intend to use when you're cutting because if I ran like a 45 or 65 in here and I ran 105 amps on my machine I'm gonna burn this nozzle up now nozzles they kind of get whenever this this hole up here starts getting elliptical or has a circle and air dented damaged cut up burn up it's time to change that out this is something you don't want to make contact with your material okay you should stand this off roughly eighth of an inch from your material we're gonna cover that when we get into cutting but make sure that this doesn't make contact with whatever material cut you're cutting because it's going to tear that orifice up once that orifice is all messed up your cut quality is gonna go downhill really quick all these pieces go in here just like this you really can't mess this up if you do the torch won't work you'll get an error code on every machine I've worked with if these aren't in place if something's missing this torch will not fire because it has different safety measures in here I have a retaining cap right here this is just gonna hold everything together and then we'll take our shield and put that over top of here now this is a drag shield notice it's got like a crown on top of it I'll be able to put this right up against the material and won't have any issues with that notice there's little airports around here not like where airplanes fly out of but there's little ports where the air comes out and that's gonna keep on my consumable shielded as I'm cutting I'll slide this over top of here lock this down and again this I'll be able to make contact with the material it's gonna stand off a distance that's going to keep that nozzle protected on the inside of the torch so depending on the thickness of the material you're going to cut you're going to swap out your consume so you have like 45 65 85 105 amp consumables today we're going to be using 105 amp consumables just because that's what we have on hand we're gonna cut a variety material thickness we'll be able to do that all based off of 105 amps unlike welding where I need specific amperage for different thicknesses of material my amperage is gonna stay constant depending on the type of consoles that I put in there the only thing that's gonna really change in my travel speed so if I have ticker material I'm gonna cut slower thinner material I'm gonna cut a lot faster and I'll show you how that works when we get ready to cut in the material so now that we're plugged in we're gonna go ahead and turn this on I prefer to plug the machine in after I've got everything hooked up to it's my personal preference I think it's a lot safer that way so we're at 63 amps right now you can go ahead and crank it up to 105 because I have 105 amp consumables in here now you'll notice that I have a selector switch over here the first one is it's got like little spaces in it that's for cutting expanded metal so if you have perforated material expanded metal anything like that this is going to be the appropriate setting if I have solid material like I'm cutting lines or shapes out of solid stock or a flat plate I'm gonna go ahead and use this setting here if I'm going to do couching or anything like that I'm going to move to this last one you can kind of see it's at an angle and then the last one here is just a trigger lock kind of like 2 T or 40 on your foot pedals and finger switches on your TIG torch is very similar I pull the trigger and let off that pilot arc is gonna stay lit until I pull that trigger again and then let it go if you're doing long runs that's great that's probably where you would use that long runs on material anything like that I'm gonna go ahead and set it here for solid material and we'll hop on over here and we're gonna go over some of the consumables one more time just to kind of explain and then we'll do some cutting okay so let's go ahead and talk some worn out consumables first so this right here is our electrode see how we have this big divot in here that's that's bad that's not what you want so anytime it exceeds about 1/32 or one millimeter you want to go ahead and throw this out now here's a nozzle that's seen better days okay so it's kind of well-worn the orifice the cutting orifice in here is kind of waller doubt yeah that's a word Waller once it's tore up like that it's it's a good practice good idea to swap both of these out at the same time the manufacturer recommends that any time you swap out your nozzle go ahead and swap out that electrode and vice versa it's a drag shield I don't know what happened to it just laying around the shop looks like it's seen better days got some melted areas in here it would be a good time to go ahead and swap this out as well remember that it's okay if this piece makes contact with the material it's not part of the electrical system so you can make contact with the material that's exactly what it's designed for to keep that standoff distance the appropriate amount away from the material while you're cutting but it's probably a good time to go ahead and swap this guy out so let's go ahead and talk PPE real quick because you know with any job that we're gonna do safety is always first we're dry garments so welding jacket welding caps always a plus safety glasses as we discussed in our last video I prefer to use a welding hood just for the simple fact that I'm gonna deal with 105 amps here so infrared glasses while they're great these are awesome for oxy acetylene cutting this is not something I would use if I was going to be doing plasma arc cutting anything probably above 40 or 50 amps so because we're using 105 amps I'm gonna go ahead and use the shade 9 on my welding hood and then we're also gonna make sure that we wear leather gloves again stay away from the synthetic fibers because they're they're gonna melt come on a melt they're gonna melt your hand you're just gonna have a bad day something with a little bit of dexterity because on here we have a safety switch you want to be able to get your finger up underneath there so a big gaudy pair of arc welding gloves Paulie aren't the best things to use I'm gonna reference my manual here it says for 105 amp consumables which we have in the machine right now mild steel I'm gonna cut some 3/8 plate it tells me I need to run about 94 amp or I'm sorry 94 inches per minute so how do I get this is something you have to do visually so if you're cutting too fast you're gonna notice all your sparks are shooting out away from you or in the opposite direction that you're cutting at a pretty steep angle you want them to come out slightly prob about a 10 to 15 degree angle from the bottom if they're coming out straight down you're cutting too okay I know that sounds counterintuitive you're gonna count two or you're gonna cut two slow you're gonna have a much wider curve which is the area the kerf is the material loss due to the cutting process doesn't matter if it's a skill saw the table saw plasma cutting oxy-fuel that's what that kerf is so that's that's the width we're gonna be taken out of the material so you want to make sure your cutting on the appropriate side of the line or on the line and understand the width of your kerf but if I cut too slow I'm gonna have a much wider kerf I'm gonna have a lot more dross on the bottom of my plate that I'm gonna have to clean off later I don't want to deal with that I want to try to make this as less labor-intensive as possible so we'll show you three cuts we'll do a too fast too slow and then a just right kind of like Goldilocks I'm gonna get rid of the paper because plasma cutting we can shoot sparks up to forty feet so I'll try not to cut towards the cameraman over there you also want to check the surrounding area especially if you're in a small garage or shop you've got gas cans laying around lawnmowers hanging out over there move that stuff out of the way or move your cutting operation to a different area like I said these sparks can travel up to 40 feet so don't cut in enclosed spaces while we're on the topic of safety fume extraction is a must so we're gonna go ahead and we're gonna set up a vent over top of this to when we're cutting you don't want to breathe this stuff in especially we get into the stainless and the aluminum because stainless says contains hexavalent chromium anytime we cut grind or weld on that you want to make sure you have a respirator or at the source fume extraction same thing with aluminum this stuff's just nasty to breathe in you don't want to do that so set up the fume extraction if you're in your garage set up a fan if not you know set up the operation outside just make sure you're not doing it over a bunch of dried leaves and grass and stuff like that what I want to do now is I'm just gonna measure from the the outside of my orifice or the outside of my drag shield to the inside of my orifice and it's about 3/16 of an inch so I'm gonna offset a piece of just flat bar or you know just a little piece of sheet metal 3/16 of an inch from the line that I intend to cut so that I mean that's kind of how you can keep everything nice and straight where you're cutting and fabricating just you know set that little offset this is 3/16 yours is probably gonna be different same thing if I have a stand off guide I would actually measure from the outside of that stand off guide to this Center the orifice on the torch that way when I cut that I get you know nice clean consistent cut marks and my accuracy is going to greatly improve versus trying to do this freehand went ahead and hooked up the workpiece clamp because you want the the electrical circuit to be the path least resistance right so because we're using the electoral system to do this so notice that the workpiece clamp is on the side that's going to remain on the table I don't want to put it on the piece that I'm cutting off because once I cut that piece off it falls with the workpiece clamp I could become myself the path least resistance okay this is a high frequency system I don't want to get shocked with it so keep the workpiece clamp on the material not the part that's gonna fall off try to keep yourself out of the electrical out of the electrical circuit don't put yourself in that in that situation I could hook it to the table but like I said path least resistance so closer I get into the material the better cut quality I'm gonna get better ease of use more efficient I'm gonna be with it so alright so the first one we're gonna go ahead we're gonna cut this one too slow I'm gonna go ahead and shut up and I'm gonna start cutting nice when you start right here on the end of the material pull the trigger and like I said I'm gonna cut too slow so the spark should come straight down if you can notice the travel speed is uh you know since we're going so slow it's kind of difficult to control the quartz because I have material building up on the top of the plate as well as on the bottom and that's just causing the this drag silver stick just a little bit we'll go ahead and flip it over here when we're done we'll show you the bottom all right so you can see that I've got plenty of drops built up here on the bottom it'll be easy to take off with the the chip hammer but you can see the cut quality is just crap I've got a severe bevel on there just because took way too long to cut that piece right that's kind of what we wanted to show you that's why your cut quality is gonna look like if you go too slow remember one of the advantages of plasma art cutting is the ability to travel much faster alright so now we're gonna go ahead we're gonna so I'm gonna set this back up we're going to show you two fast all right that was too fast you just kind of see how the plasma coming through there was scraping off the bottom 20 further away from me like I said you want about a 10 to 15 degree tilt away from you as you're pulling it towards you or away from the other direction of the cut so I'm gonna go ahead and cut one last piece and this should be right about the appropriate speed and you just kind of have to judge it you know as you're cutting through all right so let's go ahead and take it take a look at the samples we cut so got this first one was too slow disregard this piece right here that was completely human error but the rest of you can kind of see the cut quality on here not to mention the fact that it's it's pretty eighth up as far as the bevel okay so that's the cut line is or the cut was too slow this one here the cut was too fast although this it looks pretty clean it's not bad there's not a lot of dross on the bottom over here there's a little bit but nothing you know we can't hit with a wire wheel or a chip and hammer but let's take a look at that bevel right so we've got a pretty decent bevel on there I'd like to have a 90 degree cut you know if I was cutting a piece for you know depend on what I was cutting right and this one was just right okay a little bit of excess of dross on the back here but the cut quality as far as the the bevel is much better much closer to a 90 degree angle on this one so and a lot of this stuff I mean we're kind of nitpicking I mean you can clean that up with a grinder we just want to show you the difference so you can identify you know what's going on with your cutting if you're too fast too slow of your speeds just about right and it's gonna vary on different thicknesses of material remember go back to you use your user manual and check the cutting speeds for each thickness and type of material you're working on it's gonna be completely different if I was working on something like stainless steel all of my my travel speeds are gonna completely change for the dependent on the thickness and the type of material that I'm working on the same thing with aluminum or any other type of material so that's how you cut in a straight line let's go ahead and move on to cutting different shapes out now depending on if you want to keep the shape you're cutting out or you just want to cut a hole in something so for instance I'm gonna cut a circle if I want the circle plate that I'm gonna keep I'm gonna cut in a different direction than if I'm cutting a hole in the plate okay so because the plasma column comes out counter clockwise I'm just like kind of like a router have you ever used a wood router I'm gonna cut opposite of the direction that it's cutting out so it's always going to have your cleanest edge to the right hand side of the plasma column so the first thing we're going to do is I'm going to cut a hole in the plate okay so the piece that comes out of the middle I don't care about it I want the clean-cut quality to be on the plate not the piece that's falling out of it in addition to that depending on what type of template that you're using remember we have a just on this one my personal torch beside yours is gonna be a little bit different I have a three sixteenths offset okay so whatever that is I'm gonna have to double that for a circle so the diameter so I'm gonna once I get done with this I should have a hole that's 3/8 less than the template that I have right here so before before I make that rotated cut because I'm piercing through a plate starting out here on the edge is fine but because I'm piercing through a plate if I try to punch straight down especially on thicker material that material is gonna jump back up it's gonna clog up my nozzle or burn it tear it up it's just going to destroy the consumables so what you want to do I'm gonna start off roughly at a 45 degree angle I'll pull that trigger sparks are gonna fly that way so you want to be you know cognizant what's over in that area I'll rotate that up to a 90 degree and then I can go about my business and cut that piece out so any time you're doing a Pierce cut start off roughly a 45 degree angle pull the trigger rotate up into it okay the hole right here on the plate which is what I wanted has a much greater cut quality so it has almost a 90 degree vertical up and down to cut quality so it doesn't taper in however the piece that we cut out does have a noticeable taper to it so you can see that you know that's the piece that I want to just to discard this is the piece that I wanted to keep the cut quality is on the plate now we're going to go ahead I'm going to do the same thing I'm going to cut an outside circle so I'm going to cut outside of this template and what I want to do is I want to keep the the piece that's gonna fall out so I'm going to start outside of the area I'm going to do another Pierce cut and then I'll go ahead and I will cut that counter clockwise keeping the piece that I want to the right hand side of that pilot arc once I do that the piece that falls out should have these this straight edges on there and then the the plate that we're cutting out of that's the one that's going to have the beveled edges all right so as you can see got better cut quality on the piece that got cut out versus the the piece that we cut it out of there's a much larger bevel on the peat on the material we cut it out of then there is on the piece that we actually wanted to keep you can also tell that I need a little bit more practice because I've been getting spoiled by using the CNC cutter all the time so it's about time I go back to the basics as well and do some do some freehand cutting and some cutting with templates and guides alright guys hope you found this video educational and informative hopefully it helps you out along your journey whether you're in school and the shop new to fabrication seasoned welder that just hasn't had much experience with plasma cutting that's pretty much it until next time make your well better than your last

Channel: Weld.com

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Keywords: plasma cutting, welding, weld.com, mig monday, tig time, how to weld, learn how to weld, plasma cutter, how to use a plasma cutter, plasma cutters, using a plasma cutter, plasma cutter how it works, plasma cutting basics, plasma cutting for beginners, plasma cutting tips and tricks, plasma cutting 101, plasma cutting machine, plasma cutting stainless steel, plasma cutting art, plasma cutting metal, plasma cutting aluminum explosion, Plasma cutting projects

Id: ZcGPeM6A3G0

Length: 21min 12sec (1272 seconds)

Published: Wed Sep 18 2019