Just bought your Tig Welder DXF...

Discussion in 'Tech Support - SignTorch' started by Mike Scott, 8/12/18.

  1. Mike Scott

    Mike Scott member

    Hey, love it, nice work! Only had 7 lines to adjust.

    I run a Mazak laser, and have a small issue with DXF lines being too small. Normally, I buy/download a DXF and have to spend hours readjusting lines to get them to the required lengths. (minimum of .008 inches on a line, .016 on an arc). If it's a single line, by itself, it's no big deal, the RADAN program just says "Hey, skipping this line, you won't miss it".. however, if it's several in succession.. it does odd things, like randomly throw cutlines around, chopping off features.

    Anyway, yours came into AutoCAD at about 8" wide, and blew it up to 34" wide to run it, and it only had like 7 (maybe 8) arcs that were still too short.

    Couple of questions for you..
    Is that a plasma cutter or something that permits lines to be that small?
    I even find 0-length lines on some DXFs.. what on earth would that be for?

    Finally, do you use a tablet to draw with? and a program that will "autocorrect/ignore" small movements? Does such a thing exist? I hate doing artwork and being forced to spend days fixing it.

    Again, completely satisfied with my purchase, and won't hesitate to go for one of your collections next time I need something you've got. Thanks!
     
    RHM963 likes this.
  2. SignTorch

    SignTorch Artist

    Roles:
    • Vinyl CuttingVinyl Cutting, CNC RouterCNC Router, Designer / ArtistDesigner / Artist, Hobby / PersonalHobby / Personal
    Brands:
    • Corel DrawCorel Draw, Adobe PhotoshopAdobe Photoshop, V-Carve ProV-Carve Pro
    Location:
    Vidor, TX
    That is not a machine issue - valid gcode can be infinitely large or small and a valid machine gcode interpreter can (or should) process it correctly and accurately.

    Size limits and zero length motions are software issues - if all software was perfect there would be no problem - but all software is different and imperfect - for this purpose, your software is more imperfect than usual - whereas for typical sheet metal fabrication it may well be more perfect than usual - if something is too short for your software, that does not mean the geometry is invalid, it means the software is limited - no matter what type of machine or cutter is being controlled



    I draw pixels with a tablet, then convert those pixels to vectors with raster to vector software - then I use vector editing software to check and refine the result - then for DXF, I use curve fitting software to arc fit the vectors with lines and arcs

    There is always some error between pixels and vectors and vectors and arcs - error tolerance limits are almost always based on proximity, not length. No software that I know of autocorrects/ignores so-called "small" "movements" - vector graphics are infinitely scalable so whether it is small is a matter of opinion - graphics themselves do not involve motion so there is no such thing as a small motion in an image.

    When you use CAM software to cut the image - it has to offset the path with kerf compensation - so arcs become smaller or larger on inside or outside path segments - at that point, some software may be so specialized and so sophisticated that it can remap excess geometry with simpler geometry within some error tolerance limit - but that would be too special and too sophisticated for typical general purpose graphics and CAM software which most of us use - if it even exists, I don't know

    well, unlike me, that's normal -
     
  3. Mike Scott

    Mike Scott member

    Thanks, yeah, I meant running the program after weeks of work on it, and THEN discovering hidden fatal flaws that I have to spend days tracking down and fixing. That's when I hate it.
    As for "little movements" I meant sketching freehand on the tablet with some sort of tolerance/correction algorithm, to smooth arcs.. straighten lines.. similar to what flash editors used to do (or maybe still do).
     
  4. SignTorch

    SignTorch Artist

    Roles:
    • Vinyl CuttingVinyl Cutting, CNC RouterCNC Router, Designer / ArtistDesigner / Artist, Hobby / PersonalHobby / Personal
    Brands:
    • Corel DrawCorel Draw, Adobe PhotoshopAdobe Photoshop, V-Carve ProV-Carve Pro
    Location:
    Vidor, TX
    sketching freehand is, to me, a raster operation - at that level there are only pixels - no arcs, or lines exist until it is converted to vectors - you can use a larger pen to avoid sharper corners and various other image operations to clean it up before converting to vectors - then it all depends on the raster to vector program as to whether you get clean lines and arc like you want

    it is possible to draw in vectors - but those are typically based on bezier curves which do not form true arcs - and there are drawing aids like from astute graphics for adobe illustrator - but even then it is hard to use general vector graphics software for precision drawing - the flash editor would be like that - although it is primarily for making onscreen display graphics

    the only good way to be super precise is in a CAD program but those are least likely to support freehand operation or real time smoothing/correction capabilities
     
  5. RHM963

    RHM963 Artist

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    Location:
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    I draw in vectors. I have Corel and use the b-spline tool. I convert to raster to make the JPG proof but I never draw in pixels. Some programs have issues with my splines but most can use them as is, a few have to make a few clicks to get them to behave properly.
     
  6. Mike Scott

    Mike Scott member

    Thanks to both of you for the info. I'm trying to decide how to proceed. I'm most familiar with AutoCAD, but it's really not the place to start drawings because of the precision.. I'm looking at inkscape, and like their DXF export, but at the moment I'm concerned about my learning curve.

    Do you happen to know if Inkscape supports Wacom tablets? Been eyeing one of those for AutoCad. I'll check it myself later if y'all aren't sure.
     

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