Hi Dan
I was using both types of blades, but I don't think that was the problem.
It was between my ears.
Once I started to relax and just gentle the material along, it felt and worked so much better.
I was still holding it down but not trying to push it through the table, which was canceling out the feel for the tool.
If you have played pool, you can probably remember holding the stick too tight which causes
unintended movement when you make the shot. That's what I think was happening. I had noticed when finishing a cut the blade would spring back to one side or the other depending on which way I was pushing it sideways. At first I didn't know how to prevent the side forces. When I eased off all the unneeded pressure, and could feel what was happening, it pretty much went away.
Now that I know what I was doing wrong I think it needs to become a matter of practicing it until it becomes second nature like driving a car without having to think about every move, which is why I'll finish the fretwork train I'm cutting. I don't expect it to be something to brag about, but a lot more fun than just cutting zigzags or wavey lines. I'll just keep it as a benchmark to look at and see whether or not I'm improving.
Thanks,
Gabby