Preface: I don't know circuit simulation very well. It's a gap for me, one that I plan on filling soon but for now some help would be very appreciated.

I am getting started on a variable current driving circuit design and just wanted to play around with some of the example circuits I'm reading about, but I never seem to get any meaningful current out - the most I've gotten is 700mA out of example 2, and that is with a super small load (0.0001 ohm, and actual load will be 1-10 ohms.) I'm hoping to be in the 0.5-5A range. Can anyone help identify what I might be doing wrong?

Example 1:

Example 2:

Both of my examples are from this article.