Want to Purchase a Plasma Cutter

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Need a little help on purchasing a 50A Plasma Cutter (cutting up to ¼”).  I have never used one and getting ready to purchase my first.My question is?I need to stay in the $500 range if possible.  Would like to know if any one has purchased and happy with your in this price range?What brand?Are you able to get tips at local shops?Any recommendations would be appreciated. Thanks Randy
Reply:Originally Posted by randyaI need to stay in the $500 range if possible.
Reply:Watch Craigslist and buy a used major brand 25 to 30 Amp plasma.....you will find one in the $500 range....you will get good performance and will be able to buy parts and service for many years. The brands to look for:  Hypertherm, Thermal Dynamics, Miller, Hobart, Lincoln and Esab....Your local welding supply house can service and supply consumables and parts for major units like these. I would recomend a Hypertherm Powermax380, Powermax30 or Powermax 600, 800 or 900....all excellent units.Jim
Reply:Originally Posted by NomandThat's Chinese... Longevity, Everlast, Giantech... All represented here on this site.... There are some other Chinese brands - wan't make a difference I guess...Consumables - seems like eBay the cheapest... The same - Chinese...And it is not for machine, but for torch or torch type - there are not too many... Most of them compatible with big brands...Again - MOSFET / IGBT - IGBT more expensive... But very little burns compared to MOSFET...Consider your compressor if it can work with plasma at all... Needs filter too... I have M26...
Reply:welcome save up and get one made in usalets see your smoker in making one
Reply:Thanks for all the input.  I spent time during the weekend reading reviews on different Plasma Cutter’s.  I mainly deal with 1/8” and 3/16” so I ended up getting the Horbart AirForce 250ci (USA).  Got it from the Tractor Supply Co and picked up the extended 4 yr service contact.  The manager gave me a 10% off so got it for $719.99 + $129 for the service contract totaling $905.23 out the door. The reviews were very good!  I liked the size and built in air compress was a nice feature to me.  Got it home and tested it on a ¼” piece and worked great.  Now I’m getting ready to start work on my 250 gal smoker project.Thanks again to all,Randy
Reply:There's a reason that MOSFET's are calledMetal Oxide Semiconductor, FIRE emitting transistor.The correct name is Metal Oxide Semiconductor Field Effect Transistor.
Reply:...Razer...very good...I did, and still do a bit of electronics stuff....most people have no clue what MOSFET is, but it sounds impressive....I worked on stuff back in the 1970's and early 80's...machine tool ball-screw drives....before MOSFET's were SCR's....pretty crude stuff compared to now days....so do you know what SCR's are named for...I know, but do you?  Hypertherm and Thermal Dynamics....good stuff....buy their consumables too....they'll last awhile....clean, dry air is important...and piercing is really hard on the nozzles too....I'd suggest starting from edge, drill a pilot hole, or if you can't, start the pierce at an angle to the plate..after burning through...go to 90 degree angleDougspair
Reply:oooh oooh, I know that one! Do I get a Prize ?   Silicon-Controlled rectifiers where every wheres in the army communications vans I used to repair.  You think the MOSFETsgo POP??  Don't know how many times some dumb operator tried to get out of the field by zapping these!
Reply:Well, fuzzykjun beat me to it, but yea.It's a normal diode rectifier that does not forward conduct until triggered at which point it will conduct in the forward direction until the current falls below the threshold needed to keep it conducting.I do not know why mosfets blow so spectacularly when over-currented.Are scr's spectacular?  What do you call them?I blew a little D-PAK SMD IGBT one time, but it only smoked.  It did manage to unsolder itself though.I've seen plastic cased 1N4007's explode when connected in forward bias across a 12v battery, but there was no fire.
Reply:You guys may be talking about different devices...MOSFET and IGBT both have nothing to do neither with SCR nor with rectifier...MOSFET and IGBT are transistors...I think you are talking about thyristor, jargoned triac... Although may look like diode or transistor - has completely different principals...
Reply:SCR's were used for output current control on welding and plasma power supplies.....that is why they are being discussed along with FET's (or MOSFET's) and IGBT's...and the like. SCR's were actually very reliable...however they have dramatically slower on/off switching capability....as compared to transistors....so cannot control the current as accurately.Hypertherm used to have SCR power supplies that provided up to 750 amps of DC power for high current plasma cutting applications. Today these same power levels are switched using IGBT (insulated gat bipolar transistors).Jim Colt