Help please. Dip switches and mach 3 settings

[Neale]

My X axis ballscrews are also 2005, about 1.7m long, and fixed/floating bearings, so it's a very similar setup. I do not get any significant whip below 4.5m/min which is my max stepper speed (around 900RPM). You do need to make sure that everything is very carefully aligned. That is both bearings and ballnuts - these must be bolted to a surface that is exactly at 90deg to the ballscrew. If anything is slightly out of alignment it can encourage whip, even if it seems to turn OK at lower speeds. I tried to include as many adjustments as I could so that everything could be aligned on assembly. This took some time, but it seems to have worked OK. Don't know if this helps or encourages you, but it shows that your setup can work very well with a bit of setting up and adjusting!