Settling a bench bet while I calibrate the generator: what do those initials stand for? Bonus points for the Abbe value we should be logging for CR‑39 versus polycarbonate when setting polish time to keep surface quality consistent and throughput tight.
CR‑39 is Columbia Resin #39; Abbe about 58 versus polycarbonate about 30. “time to keep surface quality consistent and throughput tight.” Agree — using CR‑39 as a 90 s baseline, we drop pressure one notch on poly and add about 25 s with cooler slurry to avoid orange peel while keeping throughput steady; does your line let you cap slurry temp around 18–20°C?
But while you’re calibrating the generator, @mcneil34’s right — coolant 20–22°C, lighter pressure on poly. Which pads are you running?
Calibrating generator? Note ‘Abbe 58 vs 30.’ For poly, softer pad, +15–20 s dwell, slightly lower RPM…
Columbia Resin number 39; Abbe is around fifty‑eight for CR‑39 and about thirty for polycarbonate. Drives me nuts how we fixate on pads and RPM — if you want to ‘keep surface quality consistent and throughput tight,’ drop ceria solids for poly to about 0.5–0.6% and hold pH near 7.5 to curb smear without adding dwell. What slurry concentration are you running on that generator?
While you’re “calibrating the generator,” I’ve had good luck adding a +0.005 mm sphere offset on poly and letting polish bring it in; it cuts edge roll without pushing your polish time. You seeing more haze or fine sleeks when you tighten throughput, @mcneil34?
Columbia Resin #39 (ADC), and I’d log Abbe about 58 vs about 30 but tie polish time to slurry instead — hold SG about 1.7 and temp about 21 C to keep surface quality without blowing throughput. If you need a bump, add a touch of pressure on CR-39 rather than dwell; @jgreen_72 did that cut your haze on poly or do you still prefer the +0.005 mm trick? Either way, stable coolant beats chasing speeds.