Mick, I think the grid snap functionality is really a vestige of the very early days of Autocad, the days that Overseer speaks of, with digitizing tablets for input and very little dynamic entry of coordinates and the like. Snapping to a grid point at a known spacing would be a great time saver in those days, especially in architectural drafting where dimensions tend to stick to nice "round" fractions down to maybe an 1/8th. Now that distances and orientations can be entered dynamically and with a much greater degree of fluidity, the grid snap function is less critical. Hence, it certainly has fallen out of favor generally in the Autocad community. I'd actually be surprised if it was even taught these days.
All that being said, if the grid snap method works for you, than continue on. It's not like it doesn't still work. Like many things, people can become quite adept at something through practice and repetition, that may seem awkward to the rest of us. It would be different if every time you drew a line, you got frustrated and said to yourself, "there's got to be a better way", but just didn't know what it was. You may however consider exploring the other means mentioned here, namely the object snap (osnap) and dynamic entry functions, as 3d cad becomes a greater percentage of the work you do. You'll clearly be doing more 3d cad going forward now that the 3d print is part of your kit-building arsenal.
The advantage to working with cad in a vacuum, is that you only ever need to meet your own requirements. The disadvantage of course is that you may never have reason to learn new things. If anybody ever has questions about using Autocad, please feel free to ask. I'm always happy to proselytize. This even applies to cad concepts and processes in general. While Turbocad or Qcad or other programs may not do things exactly the same as in Autocad, things are very often done in a similar fashion. I can always do a video posted to youtube. Or perhaps even better now, is to do a live call via Zoom or the like.
I get and acknowledge all that but I really am struggling to reason the concept of making things (to me) appear more difficult.
Lets take for example a simple 1 x 1 mm cube, I draw everything to scale and then add the cusp later, in this case the cusp allowance is 0.15 mm.
So doing it the 'modern' way I turn off snap to grid (F9) and for the hell of it the grid (F7) as well, I mean we don't need it now anyway. I've left Ortho (F8) on as the line is a linear movement.
Next I left click the node (it's probably called something else, but in my world it's a node) I wish to move, it changes to red and I drag it to the right. Now I have two choices, watch the numbers scroll up and then when it's at 0.15 release, or, type in 0.15.
I have serious issues with both of those options, in the first instance, how do I know it's really 0.15, it could be 0.148 or 0.152, doesn't matter y'all cry, well yes it does, because if I now have to butt something up against that face and flood fill it, then I may end up with a gap or overlay, both are bad.
The second option requires me to type in 0.15, why, that means I now have to use two hands instead of one, twice the work, twice the effort.
Moving on, or back to Jurassic mode we come to snap to grid.
My grid is already laid out to 0.05 increments, I select my node and simply move it three boxes to the right, in fact it only has to be close as it'll snap to that line when it gets near. I don't have to type anything, I don't have to guess, the line moved exactly 0.15 in one simple click and drag operation.
Unless I missed something really obvious, the Jurassic option is faster, less stressful and accurate (not more, as typing the value is just as accurate).
There will of course be a swathe of yes but what if you need to do this or that, erm, I don't, my etch CAD world consists of three objects, a straight line, an angled line, an arc. It also consists of four operations, join, cut, fill, move.
If I need to do serious 3D work, as opposed to dabbling in model train bits, I'll revert a real 3D engine, namely StudioMax, I used to moderately proficient in that.
The Carrier was never completely finished, the Lynx was the most complex curved shape I had to work with and never got finished, not a flat surface on it; the Black Widow became donor ware (once painted by the graphics artist) to support the real aircraft's restoration. That was a feel good project, we had everything we needed from the sponsors and restorers, works drawings and photos/measurements of any part we wished for.
These were the tail end of my involvement spread over several years, I got ripped off big time over royalties and monies, which was a lot considering the several hundred models I'd made so one morning I just deleted every single digital file and walked off. These are just a few renders left drifting around the archives.
To be fair it was better in the early days working with Microsoft as a beta tester on their flight sims and combat sims as well as being a tester/developer for their modeling tools. Anyone can build a 3D model, the hard part is getting it into the simulator so that the game engine does not crash and it animates accordingly when you click the right button.
I then moved into TrainSims and got ripped off by them as well, that's probably why I don't share my toys or work well with others.