I spent about 1.5 hours wet sanding the ID of my DEC ring gear to address the 0.003" out of true I measured and get the DEC axis rotating easily (thanks Bob for the suggestion of looking at the rub areas) and finally PHD2's Guiding Assistant is able to measure backlash! Last night I wanted to test my guiding and since everybody else seems to be shooting the Horsehead Nebula and Flame Nebula, I thought I would give it a shot in horrible Bortle 9 Houston skies with bonus Christmas lights adding to the mix...
20x 240sec @ ISO1600 lights, 10x darks, 20x flats, 30x bias. Shooting with the UHC filter and with the 'Blue' channel discarded.
My collimation a touch off and seeing/transparency was poor-to-average, but the good news was that my PHD2 guiding total was just at 1.00" (0.84" RA, 0.55" DEC). Now I just need to get myself to a darksite...
Mount: ES PMC-8 EXOS2-GT
Scopes: BRESSER 208mm f/3.9 Newt + ES HR Coma Corrector, Celestron C90 Mak, generic 50/191mm guide scope
Cameras: Canon 5DmkII, Canon EOSm, T7C (ZWO ASI120MC clone)
Misc: 2" Optolong UHC filter, Raspberry PI 4
Software: INDI + Kstars + EKOS, DeepSkyStacker, GIMP, Lightroom