Pen Holder for MPCNC

Attempt at creating a pen holder with a lower spring constant. If preload can be arranged, then this could produce consistent, gentle downforce when drawing.

Update 6/12/2019: implemented several versions of varying stiffness and different levels of deflection.

"High" stiffness, when I print, produces stiffness of about 1 oz per mm.
"Low" stiffness, produces about 0.2 oz per mm.

Depending on the downforce desired, you can choose the level of stiffness and preload. The "low deflection" is intended for less preload, and "high deflection" is intended for greater preload.

As shown in the photos, the small third part is intended to hold the pen in the preloaded position, and additional force on the pen lifts the pen slightly.

The thing is made to be assembled with #6 sheet metal screws.