Setting the Tab Density and the Tab Width is accomplished in the Mode Selection screen. Now, that screen can pop up and disappear quite quickly, so it's important to know that should it get past you, all you have to do is to press the MODE/BACK button to bring it up again. In fact, if you immediately press the MODE\BACK button as the machine is starting up it will stop at the Mode Selection screen.
I've had some questions about how the Tab Density and the Tab Width settings should work. Here is a short YouTube video that demonstrates it.
I've had a couple of reports that some users are having difficulty getting the Width to change. It's not been a rash of reports. But, if you are using the techniques in the above video and are not getting the same results as you see in the video, you should contact Craftwell.