LITIO - 3D Sheet metal software for AutoCAD
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LITIO - 3D Sheet metal software for AutoCAD

Frequent Asked Questions
Answers to F.A.Q.s
All answers to F.A.Q.s
  • Why do you encourage registered users and users during evaluation to add a link to your site?
    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 reduces the high cost of advertising and allows its authors to offer programs at very modest prices. So, 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 SHAREWARE version of the program, providing you do not charge a fee for the program and do not modify the program or documentation in any way.
  • Does the program dimension the parts?
    Our own sheet metal experience shows that dimensioning of sheet metal developments is often superfluous. The common use is to send DWG files to a CAM (laser, plasma, automatic punching, etc.) cutting provider without any dimension. They (or you, if you have these machines) just cut the parts by pasting the figures into their machines.
    The other option is to plot the developments 1 to 1 (1 drawing unit = 1 inch or 1 mm) and to transfer by hand (marking with a hammer and a sharp-end tool or graver) some points to the sheet (every 10-15 mm approximately, depending on the sheet size and precision required). Afterwards you cut them, also with hand-operated methods. This is useful when a high precision is not the main concern, and the human uncertainty is not significant, and/or if you need to make a part immediately.
    The very irregular shapes of some kinds of developments [rectangle to round, intersections, bifurcations] makes dimensioning almost useless. (You would need lots of dimensions to define the figure shape).
    Perhaps in a future version (depending on user feedback) it could be an interesting upgrade to draw extreme dimensions (just to know sheet metal size needed).
  • The user manual mentions some limitations of the evaluation version, but it is not clear enough. Would you mind making this clearer?
    Evaluation version [Demo] of LITIO 2.0 has the following limitations:
    • DEMO is limited to OFFSET [dtX or dtY] input = 0.0 . If any of them is different to zero, LITIO 2 will draw virtual objects.
    • There are also some patterns that not available in DEMO. LITIO 2 will draw virtual objects [DEMO displays a message in this case].
    These virtual objects are not part of the drawing, and will disappear after a ZOOM, REGEN, REDRAW, PAN, etc.
    The following patterns are drawn in DEMO as virtual objects:
    • Free pattern from two 3D curves
    • 2D Free profile from 2D curve
    • Trim 3D of 2 3D objects
    • Bend - Conical - N parts
    • Bifurcation with intermediate part - Circle
    • Bifurcation - Rectangular [fillet] Cylinder
    • Cone to Cylinder Bifurcation
    • Cone to Cone Bifurcation
    • Cylinder to Cone Bifurcation
    • Trifurcation - Circle to Circle [3 Cones] - Non parallel
    • Trifurcation - Aligned - [3 Cones] - Non parallel
    • Helix - Biconical - 360°
    • Helix - Biconical - Angle
    • Helix Lateral - Conical - 360°
    • Helix Lateral - Conical - Angle

    Thus, the evaluation [DEMO] version allows you to get used with the program and allows you to draw lots of patterns, still not allowing you to have a printout of some.
  • How does the program realise, whether I use English or metric units?
    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 it, the program reads the values of certain AutoCAD 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).
    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, the program verifies the validity of its input format. For example, if the input has invalid characters, the program 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.


    (feet and decimal inches)

    (feet and fractional inches)





    31' 2





    86' 7.0732"



    86'-7 1/16" (1)

    86'7-1/16" (1)

    86' 7 1/16



    86'-7 1/16"





    37'-11 1/16" (1)


    46' 7 7/128



    46'-7 1/16" (1)

    46'7-1/16" (1)

    46 feet 7 7/128 inch.

    0" (2)

    0" (2)

    0" (2)

    0" (2)

    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). The program shows a zero value (0").
  • I do not have a web site.
    We encourage those users (either corporate or personal), who have a web site, to link to us. If you have none, you are encouraged to add the link when you create your web site [if you get one]. By the way, there are lots of sites where you can create web pages for free, even if you do know nothing about html.
  • I have generated ruled surfaces with the "RULESURF" AutoCAD command. Can your program 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; 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].

    Not developable and developable ruled surfaces


      Hugo Beirao da Veiga
      Developable Surfaces
      Journal of Mathematical Fluid Mechanics XX (2004) 1-9
      Birkhäuser 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

  • Sometimes your program draws nothing, stops working with no error message, but AutoCAD shows a message like the following:
    Automatic save to C:\Documents and Settings\ ... \Temp\$ ...

    This may be due to two different reasons:
    • You have set on AutoCAD automatic saving feature, which may interrupt normal running of LITIO. Our suggestion is you set it off.
    • You have installed some other AutoCAD add-on. Some programs may also interfere with LITIO. Our suggestion is you run LITIO with these programs uninstalled.
  • The program shows a message-box "not able to load GEOMCAL. ..." and it exits.
    In some non-English versions of AutoCAD R2006, some compatibility problems have arisen.

    LITIO uses the AutoCAD embedded feature GEOMCAL to make some calculations. AutoDesk has changed the geomcal command syntax in VLisp. Thus, previous versions of LITIO would not work properly in some non-English versions of AutoCAD 2006 (Spanish version has no problems, though!; previous non-English versions of AutoCAD do not have this problem!). LITIO might need to be further customized for some OTHER non-English AutoCAD R2006 versions. If so, please send us an email.
  • The program loads fine, it starts running, it shows the greeting box, but after clicking "OK " in the "Settings" dialogue, it exits and it does not keep configuration changes.
    This problem arises when the user has not the required permissions and/or privileges to access or modify files in the SUPPORT folder (since LITIO2 needs to modify litio2.cfg). The solution is to be logged in as administrator or get the necessary permissions or privileges.
    Another option is to place all LITIO files in an accessible folder, add this folder to the AutoCAD SUPPORT search paths, and place it at the first position of the list, to prevent any conflict.
  • Does LITIO V. 2.0 work in AutoCAD 2015/AutoCAD 2016/AutoCAD 2017?
    Yes. Lots of users run LITIO within AutoCAD 2015/AutoCAD 2016/AutoCAD 2017.

    To run LITIO2 within AutoCAD 2015/AutoCAD 2016/AutoCAD 2017, you need to follow the steps described in the following PDF file.
  • Does LITIO V. 2.0 work in AutoCAD 2013/AutoCAD 2014?
    Yes. Lots of users run LITIO within AutoCAD 2013/AutoCAD 2014.

    To run LITIO2 within AutoCAD 2013/AutoCAD 2014, you need to follow the steps described in the following PDF file.
  • Does LITIO V. 2.0 work in AutoCAD 2011/AutoCAD 2012?
    Yes. Litio (1.x and 2.0) worked troubless in every new appearing AutoCAD version, and lots of users run LITIO within AutoCAD 2011/AutoCAD 2012.

    Please note, that unlike for other AutoCAD versions, as it can be seen on paragraph 3.1 of AUTOCAD 2011 QUESTIONS AND ANSWERS they are not so cathegoric this time.
    Anyway, accoring to third party reports, Litio2 should work OK with a 99% of certainty.

    Anyway, many registered users have migrated to AutoCAD 2011 and AutoCAD 2012, and some new users have AutoCAD 2011 and/or AutoCAD 2012, and they run LITIO successfully.

    We recommend you make a try with the DEMO version. You can download clicking on the following link (download). If you are able to run the DEMO version successfully, you will have no problems with the REGISTERED version.
  • Does LITIO V. 2.0 work in AutoCAD 2010?
    Yes. Third-party applications for AutoCAD 2004/2005/2006 based on Visual LISP or AutoLISP are also compatible with AutoCAD 2010. [Extracted from: AutoCAD 2010 Questions & Answers: ]

    Many registered users have migrated to AutoCAD 2010, and some new users have AutoCAD 2010, and they run LITIO successfully.
  • Does LITIO V. 2.0 work in AutoCAD 2009?
    Yes. Third-party applications for AutoCAD 2004/2005/2006 based on Visual LISP or AutoLISP are also compatible with AutoCAD 2009. [Extracted from: AutoCAD 2009 Questions & Answers: ]

    Many registered users have migrated to AutoCAD 2009, and some new users have AutoCAD 2009, and they run LITIO successfully.
  • When I try to load LITIO V. 2.0 an error like ; error: COM exception: Error while trying to access OLE Register. is shown.
    Perhaps you get an error message [at the COMMAND line] like the following:

      Command: (load "litio2")
      ; error: COM exception: Error while trying to access OLE Register.

      or, in Spanish...
      Command: (load "litio2")
      ; error: COM exception: Error al tener acceso al Registro OLE.

    This seems to happen with certain versions of AutoCAD combined with certain versions of Windows Vista. Just type the same again and it should work... The strange things about VISTA...

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