4th axis question

[Kent_Norway]

I'm scouting for a 4th axis and I started my initial search on Sherlines pages.
My plan is to use the forth axis in a CNC gantry system as a system for engraving and making inlays in Pool cues.

Has some one any experience with the http://www.sherlinedirect.com/index....Product_ID=127

or the http://www.sherlinedirect.com/index....Product_ID=187

Is there any backlash in the unit and is this good quality ?

I'm comparing with :
http://www.cnc-router-routers.com/ht..._4th_axis.html

and a Techno which I can't find the link to at the moment.

Edit, found it: http://www.cnc-router-routers.com/ht..._4th_axis.html

Looking at the D1.


Any feedback would be highly appreciated.

K