dual e3d support

I designed this support with huge amount of adjustment and few complex pieces.
You will need 3X SCS8UU (LM8UU+aluminium bearing block),ordinary in prusa clone kits and 4X M3x25 bolts
there is no belt tensioner,i suggest this https://www.thingiverse.com/thing:1683070 from freemark.

installation advice:
1:lower the z carriage as much as possible.
2:screw the chassis and belt fixation.
3:install the two extruder but do not tighten the screws.
4:lower the two hotend in the contact of the bed.
5:tighten the screws very hard on the side of the dovetail.
6:tighten the screws moderately in front of you.

25/03/18:Adding a vent kit for 50X50X15 blower and 30X30X10 fan
07/04/18:update the fan mount for give more strength and a non slippery with lug