Thursday, October 16, 2025
V0.05 Resin Test With Spongy Probe
You may remember that Probe One had a somewhat spongy appearance, and I wondered if it would absorb resin. I fitted it, stuck it in a blob, and yes it does. Whether this is a good or bad thing remains to be fully explored.
Here you can see the dark line of the resin creeping up the probe, above the meniscus of the resin. A reminder that Probe One had a rounded tip rather than a sharp point.
I had updated the png_to_gcode.py script to "dipify" the probe and created an 8x8 pixel hollow square. This is not yet in Github but will be updated after a bit more testing.
After manually aligning the probe with the Stage using Sharpie, determining the location of the resin reservoir (an unshielded smear)
I created several plots for the 8x8 pixel square:
- Spacing 30μm with a dip every 5 dots.
- Spacing 15μm with a dip every 8 dots.
- Spacing 10μm with a dip every 12 dots.
Then, picking points over a ~500μm distance of the reservoir I plotted the squares - without adjusting Z height. All the prints were only just visible and were at the limits of resolution of the guide microscope due to being small and transparent. It was not possible to photograph the results with the binocular microscope.
The 30μm square showed distinct dots of approximately equal size. They appeared even, though when moved to the binocular microscope after UV curing one corner had significantly drifted.
The 15μm square showed the occasional dots attempting to merge, but all dots were deposited. The consistency is TBD because of the viewing issue.
The 10μm square appeared to show contiguous lines of resin with the dot placement barely discernible and possibly part of my imagination. One corner blobbed over into the interior a bit, possibly due to it being the first impact point from a dip. It may be necessary to sacrifice the first dot after each dip to ensure consistency.
The results were visible in the binocular microscope, probably due to the optical effects of viewing slightly different images with both eyes. This means they are not readily photographed, and even with AF Lock the cellphone camera would not resolve the image. Nor would my ancient cheap-arse microscope imager. I transitioned to the bench microscope. Unfortunately the more powerful lenses have suffered over the years, and I could not resolve the image very well. Are are the original and enhanced shots, the smallest square is lower centre:
I attempted to use an ethanol-based safranin stain (which seems to stain every damn thing in the workshop if let loose) to improve contrast but sadly this destroyed the sample. I suspect it rinsed off, even though I used minimal water. I'll try a few different ways of resolving resin features and try again.
It is essential that the results be successfully imaged so that I can determine how many dots can be deposited consecutively, and their quality/height. This will matter even more as we move into 3D and microscopic mechanisms.
