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Kagi's F.A.Q.s like the following:
- Cash or check payment: Which currencies are accepted?
- How can I pay by check, cash, money order, or PAYPAL?
- How do I place a purchase order at Kagi?
- What if I need help with placing my Kagi order?
- Why do you encourage registered users and users during evaluation to add a link to your site?
This is related to the shareware concept. Shareware developers let you try out a program,
free of change, 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, Bulletin Board Systems (BBS's)
and the Internet. This marketing technique reduces the high cost of advertising and allows
its authors to offer programs at very modest prices.
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- Due to the type of fittings and thickness I usually work with, I need to add to all my developments a sheet excess to fold the seems. The standard OFFSET command does not help me (as you suggest in the manual), because I need different offset distances on each development side.
There is a program feature not documented in the user manual, to draw the 2D contours in four parts and not as a single object (This option is not available for all objects).
To activate this option, in the current drawing session, after loading the program, type the following in AutoCAD's command prompt:
(setq aell:litio:dw2dc4 T)¿
(The symbol "¿ " of the crooked arrow means the "ENTER" key).
The 2D contours draw afterwards will be in four parts (not a single object). So you would be able to offset each side of the 2D contour with a different offset. Afterwards you should close the figure with line entities (see figure).
To draw the following contours in one piece again, type the following in AutoCAD's command prompt:
(setq aell:litio:dw2dc4 nil)¿
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- 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).
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- 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] has the following limitations:
* Thickness limitations (see page 22 in user manual)
* No input of offset values available. Thus, offset X: and Offset Y: (where applicable) are disabled [grey].
Thus, with the evaluation [DEMO] version you would only be able to make centred [not offset] objects, nor pipes intersecting cones at an angle of 90°, neither bifurcations of parallel ends.
Also conical bifurcations are not available.
Please see also the following list for the objects available in DEMO:
1 Cone: Available
2 Offset cone: Available; without offset
3 Round to round - Bifurcation: Not available
4 Rectangle to round: Available
5 Rectangle to round - Offset: Available; without offset
6 Bifurcation - Rectangle to round: Not available
7 Rectangle to Rectangle - Hopper: Available; without offset
8 Rounded rectangle to rounded rectangle: Available; without offset
9 Bifurcation - Rounded rectangle to rounded rectangle: Not available
10 Cone to Cylinder - Bend : Available
11 Cone to Cylinder - Bifurcation: Not available
12 Bend - Cylinders: Available
13 Cone to Cone - Bend: Available
14 Cone to Cone - Bifurcation: Not available
15 Bifurcation - Cylinders: Available
16 Cylinder to cone - Bend: Available
17 Cylinder to cone - Bifurcation: Not available
18 Bend - Cylinders: Available
19 Inlet on Cone: Available
20 Inlet on Cone: Available
21 Branch - Cylinders: Available
22 Intersection - Cone with round duct - 90°: Not available
23 Intersection - Cone with round duct - angle: Available; without offset
24 Reserved
25 Intersection - Cone with rectangular duct - 90°: Not available
26 Intersection - Cone with rectangular duct - angle: Available; without offset
27 Reserved
28 Cut Cylinder: Available
29 Cut Cylinder - Rounded rectangle: Available
30 Rectangular duct - Bend: Available
31 Rounded rectangle to rounded rectangle - cut: Available; without offset
32 Rectangle to Rectangle - Hopper - Cut: Available; without offset
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- 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.
|
INPUT |
Engineering
(feet and decimal inches) |
Architectural
(feet and fractional inches) |
|
UNITMODE=0 |
UNITMODE=1 |
UNITMODE=0 |
UNITMODE=1 |
|
31' 2 |
31'-2" |
31'2" |
31'-2" |
31'2" |
|
86' 7.0732" |
86'-7.0732" |
86'7.0732" |
86'-7 1/16" (1) |
86'7-1/16" (1) |
|
86' 7 1/16 |
86'-7.0625" |
86'7.0625" |
86'-7 1/16" |
86'7-1/16" |
|
455.087 |
37'-11.087" |
37'11.087" |
37'-11 1/16" (1) |
37'11-1/16"(1) |
|
46' 7 7/128 |
46'-7.0547" |
46'7.0547" |
46'-7 1/16" (1) |
46'7-1/16" (1) |
|
46 feet 7 7/128 inch. |
0" (2) |
0" (2) |
0" (2) |
0" (2) |
Notes:
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").
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- 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.
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- I have generated ruled surfaces with the "RULESURF" AutoCAD command. Can your program unfold such surfaces?
The current version of LITIO cannot develop 3D MESHES generated by the user. We have made a small program that can do that, but it is still not a part of the current version. Our aim is to add it in a future version.
Note: We have provided, upon request, some specific software routines to some special customers (who have purchased two or more licences). Some of these routines, which are still experimental, include 3D-surface unfolders, helical auger developments, nonparallel cones, nonparallel square to round transitions, etc.
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].
Bibliography
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
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- Can LITIO layout patterns for intersection of cylinders of different diameters (i.e. intersection of 8"
diameter with 24" diameter at 45 angle)? And how about intersecting cylinders of different diameters
offset form centerline?
That would be a pattern like # 21 Branch - Cylinders (as seen on page 19 of user manual), but with
branch diameter D, smaller than main diameter D1. To make such a pattern, #23 Intersection - Cone
with round duct - angle (as seen on page 19 of user manual) should be used.
The input should be as follows (using the figures of the question):
D1 = D2 = 24"
D = 8"
A = 45
And input the desired OFF Y, if offset of centerline. Demo version does not allow to input offset
values.
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- Dialogue images are somewhat small, and it is difficult to see parameter dimensions.
Dialogue image size is optimized for a screen size of 800 x 600 pixels. For a 1024 x 768 screen, dialogue images might look rather small, so feel free to edit litio.dcl following parameters, as follows (make a copy and rename it, e.g. litio-old.dcl, to respore old values if you want or need):
bigdialimag : image {
aspect_ratio = 0.65 ;
color = -15 ;
key = "timage" ;
width = 60 ;
}
Change width = 60 to 80 or 100 or more. That would change dialogue image size.
Warning: You have to be careful, not to set a too big number and to respect DCL sintax.
If not, dialogues may not appear on screen, hanging up the program, and
making and error message to appear.
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- Dialogue images lines are not visible enough. They are white and dialogue image background is grey.
In some AutoCAD versions these lines are better seen when changing background colour to white. This may be somewhat tiring for your eyes, and users may prefer to use a black background. In such case, if lines are not visible enough, you can use a new image file (litio.slb) with black lines.
Download it and replace your existing litio.slb with this one.
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- 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\Drawing4_1_1_6962.sv$ ...
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.
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- 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.
Download DEMO of this new version [600 KB]. Registered users who have this compatibility problem can get this new version 1.2 for free.
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- Does LITIO V. 1.3 work in AutoCAD 2008?
Yes. Third-party applications for AutoCAD 2004/2005/2006 based on Visual LISP or AutoLISP are also compatible with AutoCAD 2008. [Extracted from: AutoCAD 2008 Questions & Answers: www.autodesk.com/autocad ]
Many registered users have migrated to AutoCAD 2008, and some new users have AutoCAD 2008, and they run LITIO successfully.
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