Frequently Asked Questions

Here are some of the most asked questions about CAD

There's more than one CAD software? I'm confused.

There are many CAD programs and they are all different. Most are designed for a specific industry such as architecture or engineering or piping etc., and some are designed for general purpose drafting work.

Begin by matching the industry nearest to what you need from the ‘Industries’ menu above, then select from the products listed. If you are still unsure then contact us – describe your need and we will be delighted to assist you.

Whatever you do, don’t just choose the only product you’ve ever heard of or the one your colleague uses – It may not be ideal for your particular needs and budget. If we don’t supply the product you need we can recommend where you’ll be able to get it.

How easy is CAD to learn?

If it’s difficult to learn or use then we simply don’t recommend or supply it, however all professional CAD software requires some time and dedication to become proficient.

Let go of any urgency or desperation to be an expert overnight. Relax. Enjoy your CAD software and be happy to make mistakes… there’s always the ‘undo’ button!

We find some software to be more suited to the creative types and others more suited to the systematic personalities and we do our best to cater for both.

I did a course in CAD at college and hated it. Can I use your courses?

It is true to say that many colleges still teach outdated software products that are not ideally suited to the industry or needs of their students or they use teaching methods that could be improved. These institutions fail their students badly. Clearly if you are learning software that isn’t ideal then it will not only be slow to use but will be more difficult to learn in the first place.

For many products we offer both online courses and one-on-one remote access training on an hourly basis. 

I am not sure if I need 2D or 3D software?

2D software lets you produce plans, elevations, details and sections in much the same way as drawing manually on a drawing board only faster, neater and more consistently. You are literally drawing on screen, line by line and like drawing manually, elevations and sections are not linked to the plan except in your own mind. Isometric and perspective drawing must be constructed, just like you would do on a drawing board.

If you only create simple diagrams, plan layouts, cutting patterns, shop details etc then 2D is all you’ll need.

3D CAD lets you produce plans, elevations, sections, details, isometrics, axonometrics, parallel and perspective views, as well as renderings and even animations all from the one computer model. Changes made to the 3D model will typically update all the related 2D drawings automatically too. Volumes and materials can also be calculated directly from 3D models.

In most cases 3D is definitely worth the additional investment, not only because you will be able to do more, but because you will be able to better communicate your designs and ideas.

What are the differences in 3D CAD programs?

There are several 3D modelling techniques deployed by various 3D modelling programs. Each has advantages and disadvantages:

Wire-frame/Surface: This is the original and most common method of creating 3D models and allows for the most unrestricted designs. There are rarely any constraints applied to the model and the user has total control over all aspects of the modelling. The disadvantage is that modelling may be slower to produce. It is generally slower to make major modifications to. Surface modelling is often preferred when the shape of the designs are irregular or organic and require ‘rubber-like’ manipulation.

Boolean Solids: This method uses the concept of adding or subtracting 3D solid masses from or to each other to form new 3D object shapes. It is particularly good at performing tasks such as creating holes and protrusions or for massing exercises.

Parametric Feature Based Solids: This method is the most sophisticated and is ideal for mechanical applications where the design is quite structured and many parameters of the design may need to be constrained and later changed at various stages in the design process. Each part of the design such as a hole, protrusion or fillet is regarded as a discrete feature and this is linked to a set of parameters. By changing the parameter value the model is rebuilt from that stage in the models history and the feature is automatically modified. The disadvantage is that the user is required to be very aware of the order in which he or she builds the model features as incorrect ordering can lead to bizarre and difficult to predict results.

Hybrid: These modellers employ a combination of any or all of the above methods in a single program. This gives the ultimate flexibility and capability BUT can be unwieldy and difficult to master. These modellers are often used in the aerospace and transport design arenas as well as some product design and manufacturing fields.

Sketch: This is a sort of free form surface modelling in which the surfaces are merely a mesh of triangles, no matter what the shape of the object. This is good for the early stages of design where dimensional accuracy is less important than speed and visual appearance. 3D models produced in this environment are often exported or redrawn in a more accurate CAD modeller to produce highly accurate drawings for manufacturing processes.

How do I share my designs with others in my profession?

There is no ‘industry standard’ for sharing CAD files. When buying your software, look for a product that supports the formats used commonly in your particular industry. If you are unsure what is used in your industry, contact us as we can assist you.

.DXF (Drawing eXchange Format) is a common method of sharing 2D CAD drawing information from one program to another. Most professional level software supports this format. This is not a good format for sharing models containing complex 3D data. Survey data and point clouds are well supported using DXF however.

.DWG is a format used between AutoCAD programs and is also included as an option to import or export in many other programs. It can be problematic even from one version of AutoCAD to another and should be used with an understanding that it is not ideal nor is it the industry standard, albeit a very common format.

.CAD – CAD International’s latest range of software has adopted the .CAD format for its native file format. These products also exchange drawings via .DWG and .DXF as well as IGES, PLT and several others.

.WMF (Windows Metafile)is the standard for copying drawings into Windows based programs such as Microsoft Word and Excel. Most professional level CAD software provides this option when Cutting and Pasting from the CAD program to Windows applications.

STEP, IGES, STL, Parasolid, etc. are all sophisticated file formats for exchanging 3D data. Others also include VDA, SAT, X_T, SLC, GHS, MTS, 3DS, LWO, OBJ, VRML, RIB, POV, CAD, SKU, SKP and AI.

.PDF is not a CAD file format for exchanging drawings but rather a format for being able to safely view and print drawings. PDF is by far the most common way of sharing 2D documents so they may be viewed and printed. Drawings saved as PDF files may be either Raster or Vector format. We have tools that will allow you to convert PDF files for use in your CAD software.

When exchanging drawings between different programs or between different versions of the same program, you can expect to find minor changes in elements such as font type, size and position, hatch patterns, colour schemes and sometimes line styles. In most cases, especially when working in 2D, these differences rare and are easily remedied.

Why is CAD so different from from say Photoshop?

Vector file formats are based on actual point locations in space that have clear definitions attached to those locations and definitions for the spaces between them. These definitions are translated to entities or objects we see on screen and are referred to as ‘Vectors’.

Raster files are based on a collection of dots that are generally small enough and close enough together that the human eye can not perceive them as such. These dots may be blended or interpreted by the brain as ‘lines’ even though they are actually nothing more than a series of connected coloured dots. Typically a rectangular array of these dots forms a page or image. The images are known as Raster formats and are often generated by scanning pictures or paper drawings, digital photographs and by image manipulation software and basic ‘drawing’ programs. You may have heard the term Bitmap? This is as the name implies a map of bits that form a picture. 

Whilst Vector formats can be scaled and measured precisely, and can be manipulated on a line by line, entity by entity basis. Raster formats can only be edited by virtue of changing the dots that make up the picture or image.

Still need answers?

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