First build DJT-1 bk

[ross.pearson]

A plate of glass makes a good flat surface for doing this

I agree with this but with a caveat based on my own personal experience. Not all glass is created equal. I have a nice big sheet that I thought might be perfect for flattening my fret leveling beam, but to the naked eye the glass had an obvious bend in it. I ended up using a smaller piece of thicker "float glass" that I checked and double checked with straightedges as best I could.

[McCreed]

I agree with this but with a caveat based on my own personal experience. Not all glass is created equal. I have a nice big sheet that I thought might be perfect for flattening my fret leveling beam, but to the naked eye the glass had an obvious bend in it. I ended up using a smaller piece of thicker "float glass" that I checked and double checked with straightedges as best I could.

That's a good point Ross. The size of the glass is probably a consideration, and maybe I should have been more specific.

The larger the sheet, I suppose the chance of having deviations in it are increased. Given the size of a nut and the small of amount area required to achieve full strokes to sand it, it doesn't need to be very large. I reckon a small piece of garden variety window glass is probably close enough to achieve a very flat bottom of a nut. Whilst I'm not discouraging the effort for accuracy, we're not building Swiss watches either .