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  • Need schooling on plasma cutting

    Hi everyone,
    In just a couple days and under 3 dozen cuts, I've had to replace the tip twice now. It was cutting just fine, and then I hung up on something barely there, and then it all started. The sparks started spraying out all over and now the tip is ruined. It's now spraying out strange. Is this normal to go through them like this? I'm pretty sure I either pulled up a bit or something. What am I doing wrong? I'm starting the cut just outside the edge of the metal, and then following the line by dragging the tip across the steel. Is this wise? 2 tips in 2 days, this isn't going well.

    IT doesn't seem to be the elecrtrode, it's the actual cap that now has an elongated hole in it along with metal stuck to it.

    Please help me figure this out!!!!
    Thanks.
    --Bob
    millr210, 125cf tank C-25w/.030 wire. spdgls 9002x. Jet 5x6 bndsw, HF chopsaw, 4.5 and 9 inch grindrs. .

  • #2
    Holy mackerel.

    What kind of POS plasma cutter is that? (Just wanted to know so I could stay clear).

    If my plasma cut like that, it'd be in the dumpster before the sun went down.

    Looks like you could make a cleaner cut with a hammer and a cold chisel.
    SundownIII

    Syncrowave 250DX, Tigrunner
    Dynasty 200 DX w/CM 3
    MM 251 w/30 A SG
    HH 187 Mig
    XMT 304 w/714D Feeder & Optima Pulser
    Dialarc 250 w/HF 15-1
    Hypertherm PM 1250 Plasma
    Victor, Harris, and Smith O/A
    PC Dry Cut Saw and (just added) Wilton (7x12) BS
    Mil Mod 6370-21 Metal Cut Saw
    More grinders than hands (Makita & Dewalt)
    Grizzly 6"x48" Belt Sander
    Access to full fab shop w/CNC Plasma & Waterjet
    Gas mixers (Smith(2) and Thermco)
    Miller BWE and BWE Dig

    Comment


    • #3
      As I started reading, I was going to ask how dry your compressed air was, but I think you have much bigger problems...

      What is the RATED capacity of your unit, and how thick is that steel? I don't want the sever rating, I want the quality cut rating.

      Comment


      • #4
        Yeah, brand, capacity, workpiece - all good information.

        BTW, you might want to reconsider the cutting over a plastic trash can.

        Dave
        Still building my new old truck - see the progress!
        http://www.ford-trucks.com/forums/65...-coe-idea.html
        http://www.hobartwelders.com/weldtal...ad.php?t=27017

        Square Wave TIG 200 - Woot!
        MM180
        SP125+

        Comment


        • #5
          Bob,

          Blowback is a problem; when you lose the cut and the molten metal blows back up into the tip, you'll get damage like that. Also run a tip like that with about 1/8" standoff, dragging that tip will give you trouble. Finally, moisture in the air is a killer - the little regulator/water trap that's undoubtedly on the back of that machine is just about useless; you're going to need to set up some decent air drying capacity. Hotfoot talked a little about this in your other thread I think. Especially if you're using a small compressor that's having to work hard and get really hot to keep up with your air demand.

          And to everyone who's ragging on Bob, he's got a machine I wouldn't have personally chosen, but from reading his other thread I believe the biggest problem right now is that he's new to plasma cutting and he's still working through the operator learning curve, too.
          Last edited by Zrexxer; 12-20-2008, 04:12 PM.
          Trailblazer 302 * Millermatic 212 * Syncrowave 180SD * X-Treme 12VS Feeder * Spoolmate 3035
          Thermal Dynamics Cutmaster 52 Plasma * Lincoln 175 MIG

          Victor Superrange II * Victor Journeyman

          Hobart HH 125EZ


          Comment


          • #6
            I've got a riland cut40. It does a great job, it cuts very smoothly. Until I screw up the tip. I've been dragging it on the steel, with a small pieces of 1/8" steel for templates. I'm dragging the copper tip around the template. It cuts so smoothly it's incredible. Here's what's happening. Let's say I'm cutting a slot. I start it just a bit off the steel, near the middle of my template not actually touching the template. it penetrates in an instant. I then move slightly to the side to come into contact with the template, and zip around the template to cut my slot. Works great up until I go past the spot where I punched through initially. At that spot there's just a bit of crud from the start of the cut. I hit that with the tip, and my tip sometimes hangs up, then jumps ahead when I finally get passed it. When I do, the tip skipped a bit, and came off the steel a bit. So now I have this hole where I paused/got stuck, and a part that I didn't cut through completely. Then I go back over it, but now it's all bumpy and cruddy, and it's hard to cut it cleanly through.

            I'm wondering about settings, my air compressor is at about 70 psi, the small regulator in back of the plasma is at about half way up, and the amperage in front of the unit is set at 33. Do I need to set it higher/lower? There has been no water collected in the plasma regulator thing, so I think I've got pretty dry air.
            I guess what I'm wondering is what settings should I use for 1/8 thick steel, and what settings should I use for 1/4 steel.

            When I have a new tip, outside edge, and it cuts like it's butter. Attached photos are of the drops from the garbage can.

            Oh, and I agree cutting over the plastic garbage can is bad... What you don't see in the picture is I filled it with snow about 1/2 way. Not great, but it's got to do in a pinch until I get fully set up.

            Thanks everyone for your help! This takes a bit getting used to , but it is an awesome machine. I'll post more pics later.

            --Bob
            millr210, 125cf tank C-25w/.030 wire. spdgls 9002x. Jet 5x6 bndsw, HF chopsaw, 4.5 and 9 inch grindrs. .

            Comment


            • #7
              Originally posted by Bob S2 View Post
              There has been no water collected in the plasma regulator thing, so I think I've got pretty dry air.
              You've got a flaw in your reasoning there. If you haven't got any other drying capacity on your air supply, there is moisture in the air. The reason there isn't any trapped moisture in the regulator bowl is because the "water trap" they supply with these things is next to useless. It doesn't work to any degree necessary for plasma cutting.
              Trailblazer 302 * Millermatic 212 * Syncrowave 180SD * X-Treme 12VS Feeder * Spoolmate 3035
              Thermal Dynamics Cutmaster 52 Plasma * Lincoln 175 MIG

              Victor Superrange II * Victor Journeyman

              Hobart HH 125EZ


              Comment


              • #8
                I've done cleaner cuts with a SHOTGUN!!

                I had a problem with mu Riland Cut40 that was traced to the inner electrode having worked loose. Unscrew the parts, tighten all up.

                Put a new tip on, that blob of metal on the one in the picture, although decorative, is making it useless.

                Never use a conductive edge (like your steel one) against the tip as a guide or template . When you do so, you are shorting out the tip. (that may be your problem!).

                I drag my tip all the time with no problems, although holding it about 1/4" off or so can give cleaner cuts.

                Double check your ground connections...at the machine, and on the piece, icluding the wire at the clamp.

                You air MUST be completely dry. Use a blow nozzle and blast some air against a concrete floor, if you have one. No puddle should form. No droplets.

                My unit continues to do very well, and, if you can't get the problem solved, give the guys at Riland USA a call (holidays may make it tough). they are knowledgeable and helpful.
                "Good Enough Never Is"

                Comment


                • #9
                  It's on my 'to do' list to pick up one of the motorgard filters. Thanks for that advice. I was hoping to skate by that problem during the winter months when the cold air can hold much less water than when it's 90* and humid.

                  So, I'm going to replace just the tip, not the electrode which seems fine. I'll see how that goes. I'll even try to hold off the steel a bit and see how that works.
                  --Bob
                  millr210, 125cf tank C-25w/.030 wire. spdgls 9002x. Jet 5x6 bndsw, HF chopsaw, 4.5 and 9 inch grindrs. .

                  Comment


                  • #10
                    Bob,

                    When doing your pierce cut (initial cut), don't try to hold a slight standoff and go "straight in". Place the tip on the surface at a slight angle when you initiate the arc. When cutting starts, rotate the tip to a 90 deg angle.

                    Your piercing technique may be blowing slag back into the tip.
                    SundownIII

                    Syncrowave 250DX, Tigrunner
                    Dynasty 200 DX w/CM 3
                    MM 251 w/30 A SG
                    HH 187 Mig
                    XMT 304 w/714D Feeder & Optima Pulser
                    Dialarc 250 w/HF 15-1
                    Hypertherm PM 1250 Plasma
                    Victor, Harris, and Smith O/A
                    PC Dry Cut Saw and (just added) Wilton (7x12) BS
                    Mil Mod 6370-21 Metal Cut Saw
                    More grinders than hands (Makita & Dewalt)
                    Grizzly 6"x48" Belt Sander
                    Access to full fab shop w/CNC Plasma & Waterjet
                    Gas mixers (Smith(2) and Thermco)
                    Miller BWE and BWE Dig

                    Comment


                    • #11
                      Be sure you have completely drained the tank on your air compressor, as well! Also, the Cut 40 has a small water trap glass bowl on the rear,where the air line enters. That little bowl has a drain on it, make sure the bowl is dry and empty...if its not, you MUST dry your air supply before proceeding! Do not reply on that as a water trap, it is more of an "indicator" that water is getting through.
                      "Good Enough Never Is"

                      Comment


                      • #12
                        Hi Hotfoot,
                        With all the cutting I've done so far, I have no water whatsoever in the glass trap. It's once again cutting great with the 1/8". I think the first time I screwed up the tip I was trying to cut 1/4 thick steel, and had the settings too low. I think I had stuff blow back up onto the torch as a result.

                        I know you have the same cutter. What settings do you use for 1/8 and 1/4? What air pressure do you use?

                        I'm going to make some wood templates for the slots today. We'll see how that goes.
                        --Bob
                        millr210, 125cf tank C-25w/.030 wire. spdgls 9002x. Jet 5x6 bndsw, HF chopsaw, 4.5 and 9 inch grindrs. .

                        Comment


                        • #13
                          1/8" I probably use about 30, and on 1/4" about 35 or 40...it all depends on how it goes. I tend to hold the torch off and (critical) positively at a right angle to the work on 1/4". I run 80 psi on my air. My water trap is 25' of iron pipe up to the ceiling from the compressor, along the top of the wall, then down to the outlet, with a one foot 'down tube' with ball valve at each end as a water trap...but very little, if any, water seems to get past my cheapo HF water separator/regulator combo (the big blue one)...(which has really crappy threads, which Goop cement seals well)...plus Drain that tank!! I have an $8.00 auto drain on mine (HF), but have to let my tank go down to zero before it opens. It then snaps shut at 20 psi. I only "zero it down" about every two weeks.
                          I keep meaning to rig a Schrader valve from a truck wheel with a simple foot pedal, so I can blow some moisture out each time I crank it up....saves the wear and tear and electricity of drawing down and building the pressure back up.
                          Last edited by Hotfoot; 12-21-2008, 10:40 AM.
                          "Good Enough Never Is"

                          Comment


                          • #14
                            Thanks hotfoot. What number do you run on the regulator attached to the plasma cutter in back? Do you change it depending on the cut, or do you just set it once and leave it?
                            --Bob
                            millr210, 125cf tank C-25w/.030 wire. spdgls 9002x. Jet 5x6 bndsw, HF chopsaw, 4.5 and 9 inch grindrs. .

                            Comment


                            • #15
                              Originally posted by Hotfoot View Post
                              Never use a conductive edge (like your steel one) against the tip as a guide or template . When you do so, you are shorting out the tip. (that may be your problem!).

                              I drag my tip all the time with no problems, although holding it about 1/4" off or so can give cleaner cuts.
                              Ummm, dragging the tip (regular, standoff) shorts it as well. Wallowing out your tip, wrecking the electrode, and damaging the machine (over ~30A).

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