How to cut perfect with hands on plasma cutter

admin

I got a fairly new plasma cutter and still cutting nameplates and stuff but I would like to cut real nice straight and swirls without having to grind/buff after my plasma cuts. Any suggestions. Cardboard, Wood? any old pics using a template? Thanks.Tubing/Square RollerPipe BenderO/A SetupLincoln 175 HDLincoln AC 225Hypertherm Powermax 30
Reply:you need to ask JimColt as he is the Hypertherm expert.   you should be drag cutting with the tip right on the metal... just like OA welding though, you need a clean tip and good diffuser and electrode to get a clean cut.   On my ESAB the tip makes all the difference in the world when it comes to cutting.   I have found that drag cutting does not work well on dirty metal as its hard to keep a steady speed.  Hit the surface with a flap disk or sanding disk first if the metal is dirty or rusted then try drag cutting.The SmartA$$ answer is "Lots of Practice and a steady hand"Oh the Dross or Slag should come off real easy with a chipping hammer if u are cutting right.  I use a pair of Tile Nippers too for hard to reach areas.Last edited by soutthpaw; 04-13-2011 at 11:53 PM.Tiger Sales:  AHP Distributor    www.tigersalesco.comAHP200x; AHP 160ST; MM350P,  Spoolmatic 30A; Everlast PowerTig 185; Thermal Dynamics 60i plasma.  For Sale:  Cobra Mig 250 w/ Push-pull gun.  Lincoln Wirematic 250
Reply:For me, the key to cutting a perfect straight line is using a straight edge guide clamped to the work.Circles on the other hand is a bit different. You can purchase a kit that will enable you to cut perfect circles, straight edges and bevels if your willing to spend the $$.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:CNC plasma does an excelent job.  A good cut  usually means having your settings right as well as your travel speed and moving consistantly. If you crank up the amps you need to move faster to get a nice cut. Very much like when you run O/A. Too slow a speed at higher amps and you will get a ragged edge and more dross. You may find turning DOWN the amps will let you run slower and give you a better cut especially with curves and complicated shapes..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:CNC is in my future however, for artistic pieces I use a stencil. Spray paint around the stencil, then remove the stencil and cut out what is not painted.Still takes a fast-moving, steady hand.Last edited by zbounce; 04-14-2011 at 02:42 AM.Reason: Adding text
Reply:nmwelder,It kind of depends on which power level and model of plasma cutter you are using.....some are designed to work well with drag cutting and template cutting, some do not.Rule of thumb: if the torch is not shielded (exposed nozzle) you can generally drag with it at under 40 amps....there will be a little bit of arcing between the nozzle (tip) and the plate, and shorter consumable life, but it will work. With the Hypertherm shielded torches you can drag cut at any power level....the front of the torch stays cooler and you can use almost anything as a template.It is also nice to have different amperage nozzles....a 30 amp nozzle operating at 20 to 30 amps works better for intricate hand cutting (bettercut quality at slow speeds) than a 60 amp nozzle (designed for thick plate...or extremely high speed on thin sheet).Jim Colt Originally Posted by nmwelderI got a fairly new plasma cutter and still cutting nameplates and stuff but I would like to cut real nice straight and swirls without having to grind/buff after my plasma cuts. Any suggestions. Cardboard, Wood? any old pics using a template? Thanks.
Reply:nmwelder,The human hand can only move so fast and still be precise.  Because of this, lower amps, tends to make better cuts on thin material.  Too many amps and not enough cut speed will result in excess dross (slag) and possible warping of the material.  jimcolt is right about matching the nozlle to the current you are cutting at.  For example, if you take a 90 amp machine and turn it down to 30 amps to cut sheet metal, you should put a 30/40 amp nozzle in the torch.  This will tighten up the arc and the tighter the arc, the better the cut.  I know the ESAB machines with the PT-31XL torches make excellent drag cuts using any material.  Good plasma cutters should not arc over onto the guide even if it's a conductive material.Larger plasma cutters that will not allow you to touch the tip to the material usually have an optional stand-off guide that can be used for guide cutting on thicker plate.Once you have the equipment set-up properly, make sure your air suplly is sufficient and "dry"!!!  Moisture in the air will eat consumables.  From there, just practice moving at a consistant speed while keep the torch perpendicular to the plate and you should get great cuts.Hope this helps.Welding is my hobby, I just happen to get paid for it!
Reply:I appreciate all the replies. Practice and more practice.Tubing/Square RollerPipe BenderO/A SetupLincoln 175 HDLincoln AC 225Hypertherm Powermax 30
Reply:No coffee on cut-day........200amp Air Liquide MIG, Hypertherm Plasma, Harris torches, Optrel helmet, Makita angle grinders, Pre-China Delta chop saw and belt sander, Miller leathers, shop made jigs etc, North- welders backpack.
Reply:Originally Posted by nmwelderI appreciate all the replies. Practice and more practice.
Reply:Originally Posted by bert the welderNo coffee on cut-day........
Reply:Originally Posted by bert the welderNo coffee on cut-day........