Consider the damped sinusoid shown below. For want of a better word this is a “pretty” function that can be used to good effect in some design. I would like to be able to generate variations on this function in quick time.
Instead of drawing splines onto pictures imported into AutoCAD, I am going to use Excel. I create a column for time, which will be the x axis. Then the column for y contains the formula shown below (I have added a factor “A” to denote the amplitude).
Next I combine the x and y values into a coordinate using the CONCATENATE function shown below
Now copy the column containing the coordinates to the clipboard and then go to AutoCAD.
Start the polyline command, click in the command line when asked for a start point and them Right Mouse Click (RMC) and paste. A polyline is drawn through all the coordinates. Enter to finish. As can be seen below the definition is a little bad, so simply decrease the time interval to one tenth what it was before.
This time a much better function results
As per my previous blog, for manufacturing, it may be a good idea now to edit the polyline, change it to a spline fit and then explode to change the lines into curves:
The yellow line below is the fit spline.
The green line is the yellow spline copied exploded into arcs (note there is almost no difference between the two).
Next I join the arcs into a polyline again so I may offset and extrude it (for something that needs to be manufactured).
Have fun making pretty mathematical shapes in AutoCAD!
