Again..... I wasn't picking on anything, nor implying that either/any of the grinders in the phonts has issues....only using the images to illustrate a point. That being that wheel alignment is VERY difficult to get right in a build, and often either overlooked, or not even considered by many who attempt to build their own grinders.
I totally agree with the litmus test you spoke of. I'm in now way implying that it's impossible to build a grinder where everything is lined up, squared, and true. What I am saying, is that the majority of those who try to build their own 2x72" grinder(s), are very often at a beginner level, and are those who have neither the understanding, nor the fabrication skill set to pull it off. How could I say such a thing? Because I can't count the number of phone calls and/or emails I've received, asking for build help on grinders...... and when I speak of wheel alignment, and the level of precision needed, it's obvious that most of them have no idea what I'm talking about. In addition, many will contact me weeks, or even months later, and they are still trying to finish the build, or correct mistakes to make it usable. THOSE are the instances where I endorse purchasing a "top end" machine...... unless the goal is spend all the time fiddling with a machine, instead of actually using it.