I created this part to attach a 9g servo to the x carriage I am using. When using Xcarriage, Object cooler, and hotend cooler that "u-design" is using here> http://www.thingiverse.com/thing:31021. This will allow the 9g servo to be attached to the rear where the x axis belt clamps are using 35mm M3 bolts. You must also use the Z probe Holder by "zennmaster" here> http://www.thingiverse.com/thing:167430. In my picture I am using 40mm M3 bolts which work too. Also, Auto bed leveling is AWESOME!