KELSEY - ALIBRE
Why Alibre?
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ShopBot and Alibre:
Although ShopBot doesn't officially sell or support
Alibre Design software, we've used it in-house
for many years. All ShopBots are modeled and designed in Alibre and
we are big fans of Alibre
specifically and parametric design software in general.
So when Kirk and Connie Kelsey, woodworkers, designers, and
Alibre experts, suggested a web column on using Alibre with a
ShopBot, we thought it was a great idea.
The Kelseys are
longtime contributors to the ShopBot forum and consultants to
many ShopBotters, helping them to finetune their manufacturing
processes and develop new products. They will be using the same
step-by-step approach in this column to show us all how to use
the power of parametric design to become more efficient
ShopBotters. Even though
the full Alibre version is very reasonably priced, the release
of the free
Alibre Xpress version makes it possible for ShopBotters to
try out parametric programming and see if it's a good fit. |
ALIBRE -
PART TO PRODUCTION -
February 2009
The simplest use of any design program is to create a single part and
produce output (such as a DXF file) to allow production of that part.
This article will cut right to the main interest of any CNC owner, how
to create output from your design so that you can get to manufacturing.
Alibre drawing files for this article are
available
here
Create your Part:
We will skip over most of the details on how to draw up your part, and
leave the details on the use of the Part drawing tools for further
articles, and the free tutorial videos available from the Alibre
website:
http://www.alibre.com/training/cd-series.asp. In a nutshell ( from
the tutorials under CD1):
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1.
Create a new Part file using the icons in the Alibre Home
window.
2.
Create a new Sketch on the default XY Plane using Activate 2D
Sketch (upper right).
* Orient the “grain” horizontally and attempt to center
the part about the origin.
* Add Constraints before Dimensions helps retain the shape
of your initial Sketch
3.
Extrude Boss the Sketch to create a solid using the MidPlane
dialog option.
Save your new Part, or
download the example Part. |
Create a Full Size 1:1 Drawing of your Part:
Creating a Drawing at 1:1 scale
will allow Export of a 2D DXF file, from which you can create your
toolpaths using PartWorks or other software:
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1.
File > New > Drawing using a Blank Sheet with drop down
setting of Custom. Input a Width of 96" and a Height of 48" (or
other size to suit your part). The size of the sheet defined is
not relevant, although it should be larger than the dimensions
of the Part. Make sure the Default View Scale is 1.0 : 1.0, or
you will need to change the scale after inserting your part.
Press the OK button. |
| 2. If your
Part file is open, the Design box in the Standard View Creation
dialog will be populated with your part file. If multiple files
are open you will need to use the drop down under the Design
area to select your desired Part. If you have saved your Part
file and closed it, then you can use the Browse... button to
locate and select your Part file.
3. In the
View Selections area, click on the Top and Right view buttons to
unselect them and leave only the Front View selected. If you
created your Part on the default XY plane as suggested, the Face
of your part should be visible in the Front View graphic window
to the left of the View Selections. The buttons around the
graphic allow for different orientations should you create your
parts in another orientation.
4. Make sure
the Scale is again set to 1:1 in the Standard Views Creation
window and press the OK button. |
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5. A light
yellow outline will appear in your new Drawing window to
indicate the location of your part on the material. Just left
click at the default center location where your Part appears, as
it does not matter where your part is located on the Material.
PartWorks and most CNC programs will compensate for the part
location and it does not need to be located in the actual area
where you want it cut out of the material.
If you have a CNC program that
requires the Part in the lower left corner, then you will need
to use a 2D CAD or your CNC program to shift the location of the
part in the DXF file after it has been created. Although, you
can drag the part near the lower left corner as defined by the
blue sheet outline to get close enough for practical purposes.
The blue outline showing the material boundaries is not included
in the exported 2D DXF file. If you failed to provide the
correct 1:1 scale, hover near the part until a red view outline
appears and Right Click with the mouse. Select Scale from the
pop-up menu and set it to 1:1. |
6. Save your Alibre Drawing for possible future use.
If you change the dimensions of your Part file, you can open this
drawing again and it will updated to match your Part file. You can then
Export a new DXF file with the new dimensions and other changes made to
your Part file.
Export the Drawing to DXF format:
File > Export... to open the Export File dialog box and browse to where
you would like to create your new 2D DXF file. Enter a new filename if
the default filename is not adequate. Use the “Save as type” drop down
to select an export format. We generally use AutoCAD 14 DXF as our
output format because it seems to work best with a broad range of
software. Experiment with you software and determine for yourself the
best DXF format to use. You can even Export an AutoCAD DWG format file
if that will work better with you. We normally only use the DWG format
for dimensioned drawings when a customer insist on AutoCAD compatible
output.
 Conclusion:
You may be thinking that
it would be better if you could simply output a 3D DXF file directly
from the Alibre Part file. Well you can by purchasing an add-on program
or by going through SketchUp and exporting to DXF using SketchUp Pro.
However, by creating a Layered 2D DXF using this same Alibre Drawing,
you can get into production faster by having toolpathed your part in
Alibre. Your toolpathing is also associative to changes in the model,
and you will not have to start the toolpathing process all over again
when you make changes to your model.
Additionally, you can use the same Drawing and Model to create similar
parts with different dimensions and the Alibre Drawing toolpathing will
updated to match changes to the model. By creating named layers, you can
simply match up a pre-defined tool within PartWorks (or other software)
with all geometry on that named layer. Look for the article on creating
Layered DXF output.
If you are using PartWorks, you should select the geometry after you
import the DXF file and use Join Vectors to eliminate any gaps between
your geometry. Even though everything is constrained properly in Alibre,
PartWorks does not recognize the closed nature of all geometry exported
from Alibre. But, it is a simple matter to Join Vectors on the imported
DXF file.
| Now that you know how easy it
is to create DXF output and quickly get to cutting parts, you
can relax and learn to use the Alibre Part 2D sketching tools
and other techniques to create more complicated Part designs. |
Why
Alibre? - November
2008
Alibre Design is a full featured CAD “Design” program that
creates 3D watertight solid models from which you can create
Drawings and other output such as 2D DXF files in order to
manufacture parts with CNC equipment. Alibre
includes a full range of design modeling capabilities and does
not require the user to write custom code or purchase utilities
in order to accomplish standard design tasks.
Designing with
Alibre uses techniques very similar to those used in the
manufacture of a piece. This provides a good opportunity to work
through production issues while still in the design stage. We
find it so close in technique to the woodworking process that we
often consider our design process as Virtual Woodworking.
The solid nature
of the modeled parts allows interference checking between parts
and troubleshooting of the entire design before manufacture. A
true graphical representation of the design and all the
individual parts allows a thorough review of the component parts
and the completed assembly. |
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Alibre provides a SketchUp
exporter add-on that allows you to export your Alibre designs
into SketchUp, where you can do Room Layouts, Renderings,
Animations, and Walkthroughs. Alibre Design can model almost
anything you can conceive, and can be used to do custom designs
of furniture as well as cabinetry. No need to wait for a
programmer to add new capabilities to your design software, just
create a 3D model of your design elements and combine them to
construct your latest vision. |
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Constraints add a whole
new design environment where you can easily specify that lines remain
parallel or perpendicular, no matter the changes in design dimensions.
No more graphical layout to make sure curves meet at a tangency, just
select the Tangent Constraint and curves and lines are automatically
constructed to meet with a smooth tangent transition. You can constrain
design elements to meet at midpoints, remain concentric, and maintain
many defined associations. Constraints don’t just define how geometry is
originally created, but maintain their conditions throughout subsequent
changes and modifications to the design!
Parametric
Dimensioning allows designs to be driven by user specified
dimensions, including user defined equations with common math
operations. Dimensions are created to define the length of a
line, not just report the
length of the line you have already drawn. Dimensions drive the
geometry and define the size of lines, circles, arcs, and other
elements of the design. If you want to change the diameter of a
circle, you modify the dimension associated with the circle
rather than redraw or modify the circle.
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With Alibre you are able
to generate complete drawings from your model with such built in
automatic capabilities such as sectioning, detail views, projections,
and a full range of standard drawing capabilities. You can do drawings
with even the free Alibre Xpress version, and export those drawings to
formats such as 2D DXF for manufacturing without spending a dime.
(image used with permission of Cullen
Grace Joinery)
Drawings are created from
the 3D solid model and are fully associative to that model. Change the
underlying model, and the drawings will update to reflect those changes.
Copy your design, change the dimensions and you have a fully completed
and documented variation on your original design as all the copied
drawings will update to reflect the changes to the model. Need to make
similar parts of varying dimensions? Just make changes to the model,
open a drawing that you originally made at 1:1 scale and export a new 2D
DXF of that part. You have what you need to base the manufacture of
another variation on the original part. Do a manual nesting of parts
within Alibre and you can export a 2D DXF of nested parts ready to be
toolpathed for manufacture. Have nesting software, you can import the 2D
DXF files exported from Alibre and start cutting.
(Images used with permission of Cullen
Grace Joinery)
Alibre provides a user
customizable Bill of Material or Cutlist capability which includes part
dimensions you have defined in your model. While the free Xpress version
does not include the customizable BOM capability, you can create a Bill
of Material by using our downloadable template file. A Bill of Material
can then be exported to a .csv file which can be imported into other
software such as a Spreadsheet for further processing. We normally use
only one standard BOM template and post process the exported .csv data
to suit the destination program with scripts we have written in the free
AutoHotKey scripting language. Those scripts are available for download,
as well as our standard BOM template.
What is
Alibre?:
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Alibre Design is
an affordable History Based Solid Parametric Solid Modeling
program, similar to SolidWorks and AutoDesk Inventor (as well as
a host of other expensive design programs). What differentiates
Alibre Design is that it provides
 the essential
capabilities of more expensive design programs at a cost that is
affordable to the woodworker.
Alibre Design was
created for the Mechanical Design market, but is ideally suited
for the woodworker. As with most software vendors, Alibre
provides instruction on how to use the features of their
software (and free training videos). What they do not provide is
how to use those features to create designs for woodworking. We
have tried to remedy this situation by publishing training
material at our website and the
“Instructables”
website
on how to apply Alibre Design to
woodworking designs. The
Alibre Design Tips
column for Cadalyst magazine is another good source for basic use
instructions:
(Table rendering
used with permission of Ian Kirby)
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Alibre Design is NOT a Drafting software as the drawing capability are
intended to be based on a solid model construction. The drafting tools
are incomplete and relatively difficult to use to create a 2D drawing
from scratch. To do so will only result in frustration and
disappointment. Even for a simple rectangular part, it should be modeled
as a solid and then a drawing created based on that part. The drawing
tools are based on such use, and are quite powerful in providing
documentation in this manner.
Alibre Design is
of a class called a “History Based” modeler. The design is
composed of a history of operations or creation of “features”.
As with woodworking, you would cut a board to size before
milling an edge or drilling holes. In Alibre you would first
create the outline of the board and then create the edge milling
and hole features. Unlike woodworking, if you accomplish an
operation out of order, you can re-order the “features” in
Alibre to correct your mistake.
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The free Alibre Xpress
version has a part count limitation, but exporting your design to
SketchUp allows entire rooms to be created using only software available
for free. We create an accurately dimensioned Site in Alibre and
populate it with our designs for an Installation model. From that we
create the dimensioned Shops drawings for customer review and approval.
Fitting cabinets and furniture in an accurate model of the Site helps
eliminate interferences and has greatly improved final installation of a
completed project. We refine the site model as construction progresses
to maintain accurate dimensions and troubleshoot installation
difficulties.
Alibre Design
allows us to create a virtual model of an entire project from
which we can determine construction details, allowable
dimensions, pleasing proportions, and evaluate possible problems
before we even cut the first board. It has made the projects on
which Alibre has been used to proceed smoother and with less
waste than those done previously with 2D drafting software.
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What we hope to
accomplish with this column is to share our experience with
Alibre Design and show how to use Alibre to efficiently and
effectively model woodworking projects of all kinds. Visit the Alibre Design website and download your free copy of
Alibre Xpress and begin modeling your woodworking designs today.
NEXT: From Part to Production
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