Taper on cut edge

  1. Brad93

    Brad93 M J B Engineering

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    It’s soul destroying. These aren’t cheap toys and when you’ve got a job that you need it for, it’s a pain in the ****.

    we will get away with it for this one.
     
  2. MattH

    MattH Member

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    Agreed.

    I’ve actually come to the conclusion that I’m never going to be happy with the plasma table for what I want to do (lots of detail 2mm Ms). Just way to much post op clean up.

    Possibly be committing to 2tons of China’s best on Monday (watch this space).
     
  3. Fraserb

    Fraserb Forum Supporter

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    When I next cut something like this out I'll get a picture/video of the clean up but I reckon on 2-3 minutes to clean one of these up, done in 2mm steel.
    IMG_20200625_202610.jpg
     
  4. Hood

    Hood If it walks like a duck....

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    I have never really had much cleanup to do on mild steel, stainless is different, it often has small dross particles and the edge itself needs cleaned as it is oxidised. Aluminium is usually pretty good as well, should have taken some close up pics of the 10mm 5083 I have just done today but here is a zoomed in image.

    ScreenHunter 784.jpg
     
  5. mtt.tr

    mtt.tr Member

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    Essex England
    Can you not make a cut in the y axis adjust torch to remove taper

    Do the same in the x axis?
     
  6. henry Kadzielski Member

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    865
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    Australia Wollongong
    My two cents worth.
    Cutting components for my cnc upgrade (10mm 5083), I just used the old consumables from cutting steel. Two sides 'huge taper' other sides straight. Checked the nozzle and found slight erosion in one part of the nozzle, so nozzle changed, result much much better, but still taper and top dross. When the plasma stopped due to worn electrode and electrode was changed, top dross disappeared, almost no bottom dross as well. Just a note @Brad I have also applied some 'O' ring lube around the 'O' ring that seals the air from escaping from the nozzle holder (note that I am using the Hyamp torch). You need to make sure that the electrode is moving freely and straight in it's holder and the nozzle is flat and square in the bottom of the nozzle holder. I clean out mating surfaces when doing consumable changes. Still have to say what @Hood is getting seems to be very very good, also if he is getting that without fiddling then it is even better:(. I am running very much behind my upgrade so am going to produce more of my components my self (dxf files on monday 20mm 5083). I will take some vids and photos and we will see how that goes
     
  7. Hood

    Hood If it walks like a duck....

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    The only messing I ever really do is tweak the arc voltage on the THC. For example I will set the THC voltage to what I think it will be but then watch the height as it starts to cut and wind the THC dial up or down to get the height I want. With the Trafimet I found 2-3mm was a good height no matter material type and thickness and it seems to be similar for the Jasic.
     
  8. Brad93

    Brad93 M J B Engineering

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    What a laser?
     
  9. MattH

    MattH Member

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    3,894
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    1000w of fibery goodness!
     
  10. henry Kadzielski Member

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    865
    Location:
    Australia Wollongong
    Just did some 20mm 5083 (new pieces for the cnc upgrade) have some pics, but forgot to do a vid. Came out quite OK very little taper, better than expected. Haven't dome 20mm for quite some time. Have more to do tomorrow so will take a vid and post photos as well.
     
    Brad93 and Hood like this.
  11. Brad93

    Brad93 M J B Engineering

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    I’ve cut some 1.5mm and some 3mm today and had pretty good results.

    still got dross and taper on 6mm. I think it’s something to do with the 45A consumable.
     
  12. Hood

    Hood If it walks like a duck....

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    Do you use different current settings and different consumables for different thicknesses?
     
  13. Brad93

    Brad93 M J B Engineering

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    Yes different consumables for different thicknesses.
     
  14. Brad93

    Brad93 M J B Engineering

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    Fine cut consumables up to 3mm, 45A nozzle up to 6mm, 65A nozzles up to 15mm.
     
  15. Hood

    Hood If it walks like a duck....

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    mmmm ok, I don't fart about with that crap myself. Crank the plasma to max, have max consumables on and let it rip.
    Obviously if you wanted to do really fine stuff with minimum kerf width then you would have to lower currents and use nozzles with smaller holes but... well I haven't had the need yet, suppose it depends on what size of work you want to do.

    The only thing that may limit the max current/consumables method is your max axis speed. Mine is 20m/min and nothing is going to be anywhere that fast at 80 amps, even 1mm will likely only be around 8-10m/min material dependant.
     
  16. henry Kadzielski Member

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    Exactly that. When doing direction changes the gantry shakes the table and that is with the setup that I have now. With the much bigger gantry that I will be having this can only get worse. From the Hypertherm book 'use the lowest amps / nozzle' for the material that you are cutting. This helps with taper, well so the book says. I try to use the book setting as much as possible for the cutting that I do, and only vary the torch voltage for the cut distance. Mostly that has been OK, short of consumable issues (erroded nozzles and worn electrodes). But I have to admit the 20mm went better than expected. I will post some pics and possibly a vid later today
     
  17. henry Kadzielski Member

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    865
    Location:
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    Vid as promised cutting 20mm 5083.


    Quality not the best on this vid, was better off the phone. One thing I did notice, have cut a bit of 20mm 5083 and these pieces had started to get taper on opposite ends, adjasent ends were straight. Initially when I cut the first piece (about 600 by 400) there was virtually no taper, so happy with that, but not too many pieces later taper was getting significant. The oriface size was also getting bigger after a few meters at 125amps.

    plasma 026.jpg

    This is the plate straight of the plasma no dressing, bottom dross max about 1mm, very easily taken off with a flap disc and virtually no taper.

    plasma 027.jpg

    There is some bottom dross where the slats for the bed are, however apart from that, well at least I thought that's pretty good. Didn't seem to last too long. The nozzle seemed to erode far too quickly, can't say the piercing has something to do with that. Book cut height is supposed to be 4.6mm at 125 amps 170v, I dropped it back to 167v, which according to the Z axis was 3.8mm cut height. With that cut height there was no way of any tripups from top dross on the plate:thumbup:
     
  18. Brad93

    Brad93 M J B Engineering

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    You’ll find at 125A is when you need to be looking at high definition water cooled torches because the consumable life isn’t going to be great.
     
  19. Hood

    Hood If it walks like a duck....

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    Look pretty good Henry, that is the kind of finish I used to get with the TecArc, a quick single pass with the flap disc and it was smooth and clean ready for welding. Like you I got minimal dross and only when running over the table bars.
    The Jasic however is in another league, you can actually distinguish cut lines on it as you would in steel. As said I have no idea if it is the Jasic itself, the refrigerant dryer or a combination of both but here is what the 10mm looks like, I have not done any cleaning up of tht part yet.

    ScreenHunter 80.jpg
     
  20. dannyp Member

    some usefull information here :) been playing with plasma at work quite a bit recently all fun and games as no one really knows how to use it and theres no manuals or anything so its a bit like driveing by feel.

    we are running a 2nd hand 2.4x1.2 tabel didnt have a plasma for it for ages last year boss man got a 45A hypertherm for it, it proved the tabel worked and that it chuld do what we wanted it also proved that a 45A wasent enough to do what we wanted, finally had an upgrade to a hypertherm powermax 105 its a lot more intresting to play with now as it can do usefull things, with agri stuff 3mm is as thin as it goes really most of what we do is 6,10,12 mm
     
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