Hi,
Unfortunately there is not a built in way to change the needle in the knob; however there are a couple of things that I can recommend here:
+use the Measurement Studio ActiveX knob control. This control does not allows for a thicker needle, however it allows you to fill with color to the minimum or maximum value. The control will be a bit harder to program that the CVI controls, but the ActiveX wizard make things fairly easy.
+use a mixture of a knob and a gauge indicator to emulate a knob with the thicker needle. You overlay one on top of the other and make some components transparent. You can end up with a nice looking knob with a bigger needle.
Please take a look at the example UIR that I'm including here. Let me know if you have any fu
rther questions on this.
Regards,
Juan Carlos
N.I.