Plasma Cutter - Why do I keep breaking my ceramic cup?

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I purchased a China cutter off Ebay and have been using it for only a day. So far I have broken two of the ceramic cups. What am I doing wrong? I am resting the gun on the metal while I cut instead of leaving some air space (I don't have a very steady hand) and I am wondering if that is what is killing my cups. Thanks in advance for any help you can give me.Yes, I am a noob posting his first question. Thanks!
Reply:I think wet air makes the cups explode when it turns to steam. Are you using a drier?DavidReal world weldin.  When I grow up I want to be a tig weldor.
Reply:Yes, I'm using a dryer.
Reply:1) Do NOT start the arc without cutting or gouging, it shortens the nozzle and electrode life. 2) Set correct air pressure for your unit, probably between 50-70 psi. 3) Make sure your air is clean and dry. Make sure you don't have an oil lubricator in line of your air supply. 4) Maintain a 90 degree angle to work piece when cutting. 5) Sparks should pass through the work piece and out the bottom when cutting. 6) If sparks flare back from the cutting surface, this is an indication that travel speed is too fast or amperage is too low. 7) When doing extended (non-shielded) cutting, maintain an 1/8" between electrode and work piece. 8) Do NOT put pressure on drag shield when cutting. Slide shield along cutting surface for proper cutting results. 9) PULLING rather than pushing the torch makes for easier cutting. I think a few of those should help. John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:One more thing - when installing the new cup, make sure you just barely snug it on (not even finger tight), if you try to tighten it even a little, when the heat hits it, it will break.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Thanks for all the tips! Yes, I have the cups screwed on as tight as I can get them by hand - oops.Cutting or gouging? Do you mean so I have bare metal or do I need a hole all the way through the metal?
Reply:Don't 'dry fire' the gun.The life of the consumables is controlled by several factors. 'Starts' is one of the variables.Most CAM software will not only give you inches of cut, but the number of 'starts'.  Thats important to know for billing purposes.'Starts' are initial piercings.  If you cut a circle in one continuous cut, it will take one 'start'.  Don't waste your consumables with unnecessary trigger activation.
Reply:Gouging is when you're trying to remove a weld with the plasma. You tilt the torch at a 45 and move along the weld.edit - as Dano said, another term could be "dry firing the torch". Make sure you're near the metal or about to cut the metal.Last edited by MicroZone; 11-28-2007 at 11:17 PM.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Originally Posted by rmcelweeI purchased a China cutter  Thanks!
Reply:Originally Posted by WANNAWELDMaybe this is the answer
Reply:Originally Posted by WANNAWELDMaybe this is the answer
Reply:RM - glad to hear your plasma is working for you. Keep on with the project, looks good...a Miata trailer for a Miata race car?Last edited by MicroZone; 11-30-2007 at 11:57 AM.John -  fabricator extraordinaire, car nut!-  bleeding Miller blue! http://www.weldfabzone.com
Reply:Nah, the race car has been stripped to the point that I wouldn't want to attach a tow hitch to it. This will be strictly for carrying luggage, beer, etc for vacation.
Reply:rmc... what model cutter did you get? I have a few myself (bought before I even had a clue) but haven't really bothered to use them. Did you cut that whole body with just your plasma?If it did that I say I break them out of their boxes and start using them.
Reply:Originally Posted by yellowrmc... what model cutter did you get? I have a few myself (bought before I even had a clue) but haven't really bothered to use them. Did you cut that whole body with just your plasma?If it did that I say I break them out of their boxes and start using them.
Reply:china says it all
Reply:Originally Posted by ed macchina says it all
Reply:Originally Posted by rmcelweeYes, I have been chastised many times about my $200 Harbor Freight Mig and a $300 Ebay Plasma cutter. Both are 220V and are just fine for what I use them for. I would not be welding/cutting right now if I had to spend $1500 per unit so I am very thankful for the cheap units. In any event, I cut quite a bit yesterday and didn't break any cups. I was very careful not to touch the electrode or cup to the metal and did my best to maintain a 90 degree angle. You can see the project I am working on here:http://www.lightweightmiata.com/trailer/trailer.htm
Reply:Originally Posted by William McCormick JrDo you have a metal attachment that keeps the head off the work,
Reply:I never was able to find the cutter you have. The seller no longer has any listed. Was it one of the Cut(30/40/50) series cutters?I have a Cut40 and Cut50 but like I said I have never used either.
Reply:Originally Posted by rmcelweeNope, it was operator error. I haven't broken a cup in the last 5 times I've used it.
Reply:Originally Posted by yellowI never was able to find the cutter you have. The seller no longer has any listed. Was it one of the Cut(30/40/50) series cutters?I have a Cut40 and Cut50 but like I said I have never used either.
Reply:nice project
Reply:Wow I have to say I have not seen that color scheme before. Looks to be a Cut40.
Reply:The chinese units are very non forgiving.. I don't have a steady enough hand to use it.  My TD doesn't care how you use it.  It just likes to cut ..  I am building a nice jig for the chinese unit though.  Maybe I can atleast salvage it for something.Originally Posted by Jeep07The chinese units are very non forgiving.. I don't have a steady enough hand to use it.  My TD doesn't care how you use it.  It just likes to cut ..  I am building a nice jig for the chinese unit though.  Maybe I can atleast salvage it for something.