My tramming has improved with my Edge Pro Mini Tram paired dial indicators on a single 1/4" shaft. It was simplicity to calibrate the dials togethr because Edge provide a small magnet which is placed under each probe to calibrate the dial indicators together. I use a piece of toughend 10mm thick float glass to rest on top of my SMW aluminium baseboard. This ensured that I had the smoothest, flattest surface to measure from.
The X direction gave me an error of 0.004" over both dials. While the Y direction was much better and I could not record any error. I adjusted the side to side error by loosening the bolts holding the 80mm HD spindle mount to the HDZ z axis. I gently pushed on the spindle mount in the relevant direction. On completion, I tightened the bolts with a torque wrench to a force of 15 Nm.
The adjustments were still as I had made them so I started surfacing a piece of 15mm thick MDF. The settings for the spindle were 10,000RPM and I used an old 28mm Amana surfacing cutter, I chose a 0.2mm stepdown and a feed speed of 1000mm/min. The resulting MDF board speaks for itself. It could easily be used as it is without any sanding or finishing.