CAD out of the box™
Sheet metal add-ons for AutoCAD, GStarCAD, ZwCAD and BricsCAD
  • Which CAD platforms does LITIO 2 work within?
    LITIO 2.0 sheet metal works in the following CAD platforms and versions:
    • AutoCAD: ALL versions (including R2021);
      ALL 20XX versions, starting with R 2000 (and Mechanical Desktop 200X); only Windows versions.
      Warning: Litio 2 DOES NOT run in Academic, Lite, nor LT versions.

    • GStarCAD: ALL versions, starting with 2016; only Windows versions.
      Warning: LITIO 2 was not tested with GStarCAD Standard nor earlier versions.

    • ZwCAD: ALL versions, starting with 2018. Only Windows versions.
      Warning: LITIO 2 was not tested with earlier versions.

    • BricsCAD: ALL versions, starting with 2018 onwards (BricsCAD 2018 and newer). EVEN in BricsCAD Lite (BricsCAD's 2D Drafting mode; Litio2 will also draw the 3D folded patterns). Only Windows versions.
      Warning: LITIO 2 was not tested with earlier BricsCAD versions.

    TIP: Please check LITIO 2.0 compatibility with your CAD system (feel free to run the TRIAL mode).
  • After clicking "OK" in the "Settings" dialog, LITIO2 crashes and it does not keep configuration changes.
  • LITIO2 does not keep configuration changes in a new drawing session.
  • This problem arises when the user has not the required permissions and/or privileges to access or modify files in your CAD's SUPPORT folder (since all LITIO software need to modify the respective configuration file, litio2.cfg; other files may also need to be accessed).
    To solve this problem, you need to be logged-in as an administrator, and/or, you need to get the necessary permissions or privileges: right click the folder, properties, security tab, give permissions. (If not, when making configuration [settings] changes, they will not have any effect, and Litio add-ons may might crash).
    You can also watch the following explanatory video.

  • Dialog images are not clear
    Check your right add-on and CAD platform:
    • Litio 2.0 - All CAD platforms: Got to the SETTINGS dialog of your LITIO add-on, and choose the color of your choice.
      For additional details, check the Installation and Running FAQ and look at the embedded video.

  • Does LITIO2 dimension the parts/the graphs?
    • LITIO 2 Sheet metal: Our own sheet metal experience shows that dimensioning of sheet metal developments is often superfluous. The common use is to use the files to a CAM (laser, plasma, automatic punching, etc.) cutting machine , or to a cutting provider without any dimensions. They (or you, if you have these machines) just cut the parts by pasting the figures into the CNC cutting machines.
      The other option is to plot the developments 1 to 1 (1 drawing unit = 1 inch or 1 mm) and to use the printouts as templates to cut the sheet metal patterns.
      The very irregular shapes of some kinds of developments [rectangle to round, intersections, Ys, etc.] makes dimensioning almost useless. (You would need lots of dimensions to define the figure shape).

  • English or metric units: LITIO2 is not showing the units I want
    How it selects the display format of the values in the input boxes?
    Is 3'-6 the same thing as 3'-6", 3'6 or 3.5'?

    After starting, LITIO2 reads the values of certain CAD system variables in the current drawing session (e.g., MEASUREMENT, LUNITS, LUPREC, etc.), to automatically set the units to be used. (Refer to your AutoCAD user manual for further information about these system variables).
    Please note, it may happen, you think you are using Metric units in your CAD platform, when you are actually using Imperial units.
    Check the following video.

    If English units are used in the current drawing session (MEASUREMENT = 0), all inputs will be in feet and inches. If metric (MEASUREMENT = 1), inputs are in millimetres. After the input of each value, LITIO2 verifies the validity of its input format. For example, if the input has invalid characters, LITIO2 will show a zero value (0").
    English units:
    If unit mode is either of one of the following: Scientific (Lunits=1), Decimal (Lunits=2) or Engineering (feet and decimal inches; Lunits=3), the input would be shown in the Engineering (feet and decimal inches) mode (Lunits=3).
    If the units mode is either Architectural (feet and fractional inches; Lunits=4) or Fractional (Lunits=5), the input would be shown in the Architectural (feet and fractional inches) mode.
    The number of decimal places or the denominator for fractional inches is set by the system variable LUPREC.
    The following are examples of typical inputs and how are they shown in the input box.

    If UNITMODE = 0, the hyphen (-) separates feet and inches.
    If UNITMODE = 1, the hyphen (-) separates inches and fractional inches.
    (1) The value of AutoCAD system variable LUPREC is important in this case. The input value is rounded to the nearest fraction available [here x/16"].
    (2) The input has invalid characters (e.g., the word feet). LITIO2 shows a zero value (0").
  • LITIO2 shows the following: "Problem while trying to load GEOMCAL.
    Please try to start the program again."
    and crashes


    LITIO2 software uses some AutoCAD built-in features to run. One of these is the Geocal or AutoCAD's calculator.

    In certain AutoCAD versions, LITIO2 loads the GEOMCAL in the current drawing session. But, in some AutoCAD versions you need to manually load the calculator (a good way to do this is to set an autoload for the calculator).

    To load the calculator manually, just type:


    in AutoCAD's coomand line (and press enter). This loads the calculator and a prompt appears asking for a math expresion. You can type something like:


    or anything of the like. In this case, you get the result: 16.

    The calculator is loaded and after that LITIO softwares should run fine.
  • I have generated ruled surfaces with the RULESURF CAD command. Can LITIO2 unfold such surfaces?
    Anyway, there are some considerations about ruled surfaces, which are not all developable. [That is: you can "unfold" them, but such a "development" (to call it in some way) would not match your object perfectly, and you would have difficulties during bending or rolling; e.g.: helical augers, which are not developable].
    A ruled surface is defined as a surface generated by the motion of a line called generator or ruling.
    Developable surfaces are a special class of ruled surfaces that can be developed or unfolded onto a plane without stretching or tearing.
    For example, in shipbuilding, doubly curved plates are manufactured by roller and line heating processes, while in HVAC, dust extraction, conveying systems, and piping industries, etc., the singly curved plates (developable surface) are manufactured by roller (linear bending) only.
    Developable surfaces are ruled surfaces for which the tangent plane is constant along each ruling. Cylinders and cones are the simplest, trivial developable surfaces. Cylinders are surfaces generated by a line as it moves, parallel to itself, along a curve. Cones are generated by a line, which passes through a fixed point P and moves along a curve.
    The following statements are the equivalent necessary and sufficient conditions for a surface to be developable:
    • Gaussian curvature is zero [that is, the line, which generates the surface by its motion (generator or ruling), is a straight line]; and
    • The normal vectors on a developable surface along the ruling are parallel; or
    • Developable surfaces possess the same tangent plane at all points of the same generator.

    In general, there are infinite possible ruled surfaces that can be generated between two closed curves. And only one of these would be developable. The problem is, then, to find THE developable one. [See examples in the following figure].



      Hugo Beirao da Veiga
      Developable Surfaces
      Journal of Mathematical Fluid Mechanics XX (2004) 1-9
      Birkhauser Verlag, Basel, 2004

      M. M. Lipschutz
      Theory and Problems of Differential Geometry
      Schaum's Outline Series
      McGraw-Hill, 1969

      Dr. K. H. Ko
      Prof. N. M. Patrikalakis
      Computational Geometry
      Massachusetts Institute of Technology, 2003

      M. J. Mancewicz and W. H. Frey
      Developable surfaces: Properties, representations and methods of design
      R&D Publication 7637
      General Motors, 1992

  • Why do you encourage registered users and TRIAL users to add a link to your site?
    we very much appreciate your back-links, but not only this. We also appreciate your mentions of LITIO.SI software in engineering and architecture blogs, and in your professional social media (e.g., Linked-in).
    This is related with the shareware concept. Shareware developers let you try out a program for free, so that you may evaluate it. If you like the program and have a use for it, then you are obligated to purchase the REGISTERED VERSION. The idea of Shareware is to let useful programs spread through the industry by word of mouth, and the Internet.
    This marketing technique allows its authors to offer programs at very modest prices.
    Continuing to use the SHAREWARE VERSION of the program after evaluation and not purchasing the REGISTERED VERSION is an infringement of the LICENSE AGREEMENT. You are free to distribute the TRAIL version of the program, providing you do not charge a fee nor supply any upgrade information nor upgrade KEYS and/or files.