ZWO EAF USB Powered v 12v Mains Version

[Mikey0368]

I'm wondering if there's anyone out there who has both versions of the ZWO EAF and notices a difference in performance?

I have the older 12v version on my SW Esprit 100ED and it works perfectly. 

I've been using the new USB powered version on a StellaLyra 8" Classical Cassegrain and I use it along with the Hand Controller. It only works when I press the Fast button and it won't move at all on Slow but as I just use it for the Moon and planets I've just run with it. In the last couple of days I've put that EAF on a Skywatcher 300PDS Newtonian and it's even worse. It'll move a bit then beep furiously at me as it's stuck.

The USB is plugged into a powered USB hub and the focuser on both scopes moves well manually (when the EAF isn't fitted) so neither are particularly sticky.

I'll be taking the 12v EAF off the Esprit to try it on the 300PDS to see if that makes a difference but I don't feel that I should need to do that. And if it does work I'll then need to see if the USB version works on the Esprit.

Has anyone had similar problems with the USB version?

[Clarkey]

What is the power output for the USB? Many of the powered hubs still only give a limited power output and it may not be enough for the focuser. I have some USB powered dew heaters but these need either a separate high power USB charger or a fast charge port on a data hub. Maybe it is just drawing too much current?