Remix of Robin7331's baseplate.
The main modification is this plate is meant to be used with the "Improved Extruder Arm" from vicviper (https://www.thingiverse.com/thing:1868163) - New See below for my modification of the arm or go to https://www.thingiverse.com/thing:2517811.
This required the following modifications:
1) Lowering the height where the elbow of the arm sits.
2) Moved the back wall where the spring sits. The original design had the spring too tight for this arm. New Info: This might create less tension than is needed. Please try my modified arm that allows for adjustable tension (https://www.thingiverse.com/thing:2517811)

Additional modifications:
1) No need to undo the extruder stepper motor. The hole has been widened so the plate can fit over it.
2) The hole for nut of the pneumatic fiting has been widened since it was a tight fit.
3) The bridge over the gap has been beefed up.
4) The hole for the throat of the tube fitting has been bevelled so it can be tighted and catch the nut easier.

The one issue is that when assembling the plate will want to ride up when the two back screws are tightened. Recommendation is to not tighten all the back screws, and then install the screw for the extruder elbow. Tighten down evenly and maybe hold the front of the plate was doing it so it sits flushed. The slight tilt doesn't effect the alignment in the tube but be careful that the bearing is sitting nicely (aligned) for proper tension on the stepper sprocket.

New:Modified "Improved Extruder Arm" (https://www.thingiverse.com/thing:2517811) to allow for adjustable tension with a screw. This should increase spring tension.