DIMENSION PROBLEMS- Help

[KenW]

That is exactly how I do it...

However the needed correction will be affected by overall volume and relative X, Y, Z dimensions as the "tiny mushy bricks" pile up--any "average" correction will be just a good place to start based on experience and what your gut tells you.

Keep in mind that while the Z-axis resolution for your Saturn is variable in 0.00125 mm (1.25 micron) increments via layer height, X & Y maximum resolution is fixed by the LCD pixel size (0.05 mm, 50 microns).

Actual print dimensions (even if 100% accurate) will always be multiples of those maximum resolutions.

Keep in touch and let us know how things are going...

Thanks for all your help Cliff.  Will keep in touch.

[KenW]

[attachment=500]Ok, new dilemma.
I think that I have an understanding now about shrinkage, and I make one print, measure it and come up with a percentage of shrink that I add to the next print.  All has been working ok, except for the attached.  This is perfectly round, so why is it shrinking in two different directions?  I'm printing directly on a magnetic plate and no matter what settings I use, it still is out of round by about 2mm.
Any ideas?

[cliffyk]

There does not seem to be an attachment?

In what axis is the sphere 2 mm undersize? What exposure times are you using--my first thought is that there are too short?

[KenW]

cliffyk pid='3577' dateline='1645560276']There does not seem to be an attachment?

In what axis is the sphere 2 mm undersize? What exposure times are you using--my first thought is that there are too short?

Hi Cliff,
The X axis is 2.04% smaller and the Y is 4.94% smaller.   If I scale up the part using those percentages, then the part comes out correctly.
I'm using Siraya fast resin and their recommended settings:35s bottom exposure and 2.5s regular exposure. 
My workaround seems to correct the part, just seemed odd that one axis was different than the other, given that the pixels I thought were square.
Ken