Time to make myself look daft again. The Gecko-drive manual states I need a capacitor on my switch-mode PSU. Now I have come to tune the drives, I understand why, or at least I hope that's the problem. My PSU is without the cap at the moment, and I just can't get the servos to run at full jog speed. I have been concentrating on one axis today, adjusting gain/damping all over the place, and also chnging acceleration settings in EMC. So, if the missing cap is the problem, please advise on what type I need! I am confused by the array of electrolytic caps, but will a standard aluminium electrolytic do it? If someone has a minute, could they go here and do a quick search for 339-7903 it would be appreciated! PSU is 24V 24Amp and that cap is 40v 10,000 uF as recommended in the manual.