Technical Drawings

Technical or Reference Drawings

Unlike patent drawings, technical drawings are great for reference. Before we had 3D printers or CNC machines, machinists, fabricators, building contractors (and the list goes on), would rely on technical drawings to create an accurate project. Every angle was explained, hidden lines were essential and the cut-away, or detailed view, gave much needed information. This still holds true today however, with the introduction of CAD/CAM into the manufacturing process, the technical drawings have an alternative use.

Not to Change the Subject but, What's a CAD File ?

Today, the 3D printer and CNC machines read files (three dimensional files) that then create parts. If you have a flaw on the virtual model, it’s duplicated in the CAD file.  There’s no machinist to back you up by finding your flaw and giving you a call. That flaw will get produced and, produced very well I might add.

When parts don’t fit, it’s usually too late. The 3D printers or CNC use whatever parameters they’re given, period.  So it’s very important to get the model right. Computer aided design has given us the tools to fit parts with exact clearances needed. The computer can’t do all the work though. You have to know what clearances are acceptable or appropriate for the materials that are being used. Also, heat and loads have a lot to do with clearances.

cad file cnc plasma cutting

So What's a Technical Drawing Good For Then ?

exploded view of 3D model

So what’s the point of engineered or technical drawings then? If you make the drawings on a CAD program, you can use them for dimensional insight, into the model. You can “check” the model by looking over the drawing. If you find a problem, you can go back into the model, make your changes, then reboot the drawing and the changes are reflected in the drawing.

In CAD, you have what’s called, “part interference”. It checks for interference between parts during motion. But technical drawings are a way to look at the 3D model through dimensions.  Sometimes, dimensions can bring you back to reality. If you used this method before there was CAD, then it makes more sense and it helps. Otherwise, there are generators in the CAD software that help with diagnosis of assemblies such as stress testing and dynamic simulation, just to name two.

Are There Any Other Uses ?

Another, off the subject use for technical drawings is that they look great for posters and flyers. I know, I know. I like ’em though. You can make some really cool views. You can change the materials of your model to give the model a new appearance. Some parts can be shifted to transparencies, sectioned views and the list goes on.

So, in summary, technical drawings and CAD files each have their own unique uses and one couldn’t replace the other. Then, different from both the CAD file and the technical drawing is, of course, the patent drawing.

Dimensional Reference Drawings

technical drawing of a differential puller for a 2.5 ton rockwell
Brake Pad dimensioned drawing
jack screw cap
Inner upper bracket
Universal body
exploded view of 3D model

A note on engineering drawing; the drawings shown here are a good example of what the USPTO will not accept for patent drawings. They look great, are wonderful reference but a computer can’t read them and the patent office won’t accept them. That’s not to say they’re not useful, just that they have their limitations. Now don’t let yourself get confused like our friend on the right here. Patent drawings are actually easier to make than these.

big buck bunny picture
“Whatever you can do, or dream you can, begin it…Boldness has genius, power and magic in it.”  Goethe