Using a mini-vat
Testing Procedure
Place the slide in a rig, I built mine out of Meccano parts, easy and moddable. This rig will help positioning the mini-vat repeatedly in the same position and perfectly level using a bubble level from a camera tripod level. This will avoid to cure an uneven, wedge shaped slab.
I use my stock HP VP 6121 DLP projector, with a 200W UHP lamp delivering 2000 ANSI lumen out of the lens. No color wheel mod has been done and even the lens mod is not necessary for the comparative testing of resins.
Use a chronometer to time the experiments.
Flushing and releasing the slab
After illumination, flush any uncured resin with water and/or Acetone. A slab of cured resin remains, neatly taking the form of the rectangle drawn with the black marker on the back side of the slide.
I use an exacto knife to remove the slab from the microscope slide. It is pretty easy to lift as it doesn't stick much. Resins cured with H-Nu470 are more gel like than those cured with BAPO and would need a stronger light source to achieve similar results or a second hardening stage in the sun or UV oven.
Take measures
Use a calliper or thickness gauge and measure the slab's thickness at several spots.
I use 4 measures and average the results, calculate the standard deviation and divide it by the average. These figures give me an idea of the quality of the experiment and the cure speed of the resin system.
Resin Monomer / Oligomer Test
| 2000 ANSI Lumen HP VP6121 DLP projector, 300mm throw distance, 17x13cm build area through back surface mirror, 1ml volume = 5mm resin depth | |||||||||
| Exposure Time [sec] | 60 | ||||||||
| Monomer / Oligomer | Cured layer thickness measures | AVG | STDEV / AVG | Time [sec]/0.1mm | Comments | ||||
| Ethoxylated(4) Bisphenol-A Diacrylate | ED4 | 1.630 | 1.510 | 1.500 | 1.590 | 1.558 | 0.040 | 3.852 | Tough |
| Ethoxylated(10) Bisphenol-A Diacrylate | ED10 | 2.520 | 2.740 | 2.640 | 2.700 | 2.650 | 0.036 | 2.264 | Tough |
