After putting the Qcad aside for a few weeks, I started reading the book from cover to cover This morning I reached chapter 6. I started using qcad for some diagrams for a book of mine, but now decided to do the right thing - read your book first, rather than keep on reinventing the wheel.
First and foremost, it is a very impressive little book. I have drafted with AutoCAD many years ago and more recently with Turbo CAD. The latter has quite good manuals, but yours is better!
Now for an excuse clause: I will attempt to report any glitches that I have found. It is a kind of nit picking, so I ask to be excused if I blunder and claim shortcomings when when the shortcoming is my memory. My excuse is that I am a really old man, work alone and do not discuss my reports with other people. Also, I am an inveterate bad speller!
The topic "The Book" of course is Andrew Muston's "QCAD - An Introduction to Computer-Aided Design" and in the following I will refer to a page number of this book. I use Linux Qcad-pro.
p22 I installed qcad in /opt/qcad/ directory. I think there was a suggestion in one of the readme files to install in /opt directory and I followed that. To start qcad from KDE one need to create a new "link to application" and in its properties enter the "/opt/qcad/qcad" then choose a suitable icon. (Or use CLI, of course.) I found that the book explanation with version number as part of the directory name somewhat confusing and unnecessary. Just my opinion!
p23. "You can always change this setting later in the application or drawing preferences" - how? I am now reading page 53, but have not seen how (Frankly, I recall seeing it when I was mucking about in qcad "reinventing the wheel" before I got the book.) I think it would be better to mention briefly on p23 or really soon after.
p46 Table 5-1 Heading directly under "Example uses" missing: It should be something like "Paper sizes" (though many people will twig to it without the heading). Also the word "standard" is better replaced by "conventionally" in the discussion of line thicknesses. Standard is something that is written and widely accepted, viz. ISO. Admittedly, the line thicknesses that you recommend are ISO, hence "standard".
Remarkably few typos so far (and I have reached chapter 6). Congratulations on accuracy and precision (I like the distinction you draw between the two).
Algis Kabaila, MEngSc, PhD(Eng)