Monday, June 27, 2011

What are typical scales used in drafting?

2:1 – double scale – 1” on the drawing = ½” in actual life
1:1 – full scale – 1” on the drawing = 1” in actual life
1:2 – half scale – 1” on the drawing = 2” in actual life
1:4 – quarter scale – 1” on the drawing = 4” in actual life
1:10 – 1 tenth scale – Etc..
1:20 – 1 twentieth scale – Etc..

Sunday, June 19, 2011

How do you deal with a large assembly in CATIA?

Here are a few notes on the best practices for dealing with a large assembly in CATIA V5 (although this information can also be applied to other CAD systems as well).
Temporarily hide model
Hide a partial model
Visualization mode
DMU Analysis
Creating Drawings
Node Deactivation
Update BOM
Update Assembly constraints
Design in context
Deactivate Component
Using knowledgeware rule
Improve Graphic Performance
Good = Hide Component
Better = Deactivate Node, Visualization Mode
Best = Unload unneeded components
Improve CPU Performance
Unload unneeded components
Use Deactivate component via Knowledgeware
You can only modify geometry when it is fully loaded and activated

Monday, June 13, 2011

Robocoaster Model

I constructed a recreation of a Kuka robocoaster in CATIA. I used the car from my cantilevered roller coaster simulations to save time. The track is created using three sketches with laws (one overhead, one side profile, and one for banking). I made this in about a day so please excuse the lack of detail. The purpose was more to show proof of concept that this was possible to create with CATIA.

For the simulation, I used the DMU Kinematics workbench. There are four user input commands to (1) drive the robotic arm down the track (2) horizontal rotation about the z axis (3)vertical rotation of the upper arm (4) rotation of the seats about the upper arm axis. In fact, in one of the video clips there is a fifth command- the rotation of one of the domes on which video would be projected, similar to the Harry Potter ride at Universal Orlando.

Thursday, June 9, 2011

What does a CAD Designer do?

What does a typical CAD designer do? The responsibilities of a CAD Designer are the following:

Design 3D models and assemblies in various CAD packages including CATIA V5, UG‐NX, SolidWorks, Pro/E or

Inventor from conceptual designs, reverse engineering layouts, or legacy data.


Activities and duties:

The following duties and responsibilities are illustrative of the primary functions of this position and are not

intended to be all-inclusive:

  • Create manufacturing drawings of assemblies and models including GD&T and B.O.M. information
  • Interpreting 2D drawings for conversion to 3D models and assemblies
  • Successfully convert 3D models from one CAD format to another.
  • Create or re‐master new 3D models from conceptual designs
  • Use specialized modules in CAD packages such as FTA, SMD, Piping/Tubing as required
  • Track own progress against bid hours using sources available to ensure project deadlines are met
  • Make decisions concerning personal time management and task prioritization to deliver quality service,

on time and under budget



  • Ability to check manufacturing drawings to determine proper fit and function, correctness and
  • completeness of information
  • Must have strong mechanical aptitude, good reasoning and problem solving skills
  • Knowledge of Data Management and Configuration Management principles
  • Strong verbal and written communication skills
  • Ability to work in a team environment
  • Ability to function with minimum supervision

Thursday, June 2, 2011

Managing Large Assemblies in CATIA: Visualization Mode

Using visualization mode in CATIA versus design mode improves performance by not loading the mathematical data of the part into memory, only a visual of the geometry is loaded into memory.

The first time a part is loaded into CATIA using visualization mode:

  • CATIA creates a "lighter" version of the model and saves it to the hard drive.
  • Because it creates this light version the first time, it takes longer to load.
  • Successive loads of this model, read the "light" version, which results in a quicker load time and better performance

The file type is saved as a .cgr – CATIA Graphic Representation. CGR files are not downward compatible (Cgr files created in V5R14 cannot be read by CATIA V5R13 or lower)

  • Upward compatibility
    • Files are upward compatible.
    • However, in V5R14 cgr files were optimized (I recommend rebuild the cgr files if upgrading to V5R14)
  • Sharable
    • Set storage directory to server
    • Also called Released Cache