I dont feel . 001 is needed. I make flat with the grid marks and its always been good enough fir me. I know i have more than . 001 flex while honing.
Nah, no issues here unless you’re careless. I place mine straight down on the stone and then pick it straight up when I’m done checking. I think I got mine in 2014. Next time I’m by the machine shop I’ll have them check it and see if it’s off.As said if you had a true Precision Straight Edge, the last place you would want to put it, is on an abrasive surface.
Loose grit on a flat surface doesn't do it for me. I always follow up with a piece of wet dry paper.I've never fully trusted pencil grids. They can get you in the ballpark but I like to at least do a visual test with a straightedge and a bright light. Rocks don't always abrade evenly, even synths, and the amount of pressure you use can change things too, even if your lapping medium is true. I'm not going for dead flat, just flat enough.
Same. Loose grit is the way to go for quick removal of material, but it can have a tendency to convex the edges and corners a little. I'll use grit until it has maxed out its flatness, then switch to paper or an Atoma plate for the final lapping and smoothing of the stone.Loose grit on a flat surface doesn't do it for me. I always follow up with a piece of wet dry paper.
I would like to think I'm not that picky but maybe I am.
Just for kicks I checked each stone in a 4-stone synthetic progression for flatness after a single honing and I was a little taken back by how out-of-true each one had become after such a limited amount of use.I usually don't care as I would lap my synthetics whenever I use them to avoid building up. However with my jnat I did not lap it often as I usually did just tomo for finish. Been using a fun nagura progression though on the jnat so need to make sure I keep it flat. Might start lapping it after every progression or every other progression.
I use a sacrificial (cheap) straight edge that I check against a good straight edge. Moving a measuring tool around on an abrasive surface is not very good shop practice.
When you use naguras, the areas you generate slurry can develop low spots if you are not working it evenly over the stone.Still undecided on if I am getting s straight edge for the couple years I'm over seas. Have been flattening the jnat more often though, about every other use and results have definitely improved. Don't think it is really something I will worry about with my ark or even 5x2 coti. However making sure the jnat is flat before nagura progression and final finishing has been a nice improvement edge wise.
Why pay for a surface plate that is accurate to 1um if you are just going to throw a sheet of WD on top? What sort of thickness tolerances do you fancy they manufacture sandpaper to?0.0015" translates to 38um. Maybe not practically a lot the first time, but it adds up.
If it were my reference plate, I'd protect it with a sheet of wd sandpaper.