Variable Spool Holder

UPDATE - I will be changing the thickness of the plate to allow a standard ballpoint spring to work. And changing the center hole to allow for standard ½" shaft bearings to press fit.

Who: Paper Printing Professional migrating to 3d Printing

What: One-Size-Fits-All Spool holder which results in a common 25mm shaft size. Designed to hold almost ANY size spool shaft its completely variable within it's construction limits. An OPTIONAl version has a keyed shaft which matches the takeup shaft on the Filament Spool Winder by V3 Precison.

Why: Prompted by the inability of filament producers and printer manufacturers to standardize on a single spool shaft size.

Specifications:

Material: PETG Recommended - Sprocket and Pawl assembly may wear in PLA.
Resultant Shaft size: 25mm
Spool Shaft Size: From ~52mm to ~152mm
Total Thickness: ~10 mm Left Side, ~10mm Right Side

Component Listing:

Left:
1x - RatchetOuterSpiralLeft.stl
1x - Pawl_Left.stl
1x - NoKey-RatchetInnerStraight_Left.stl (for non-keyed shaft)

Right:
1x - RatchetOuterSpiralRight.stl
1x - Pawl_Right.stl
1x - NoKey-RatchetInnerStraight_Right.stl ( for non-keyed shaft)

Common:
2x - PawlButton.stl
6x - OuterJaw.stl
6x - Jaw.stl
2x - Pawl Compression Springs (~1.5mmx10mm - NO - a ballpoint pen spring >2mm won't fit but I have some leftover the correct size if you print this and contact me)

Optional for Filament Spool Winder by V3 Precison :
1x - RatchetInnerStraight_Left.stl (for keyed shaft)
1x - RatchetInnerStraight_Right.stl (for keyed shaft)
1x - SpoolSpacers.stl (several thicknesses)

Assembly:
Simple and straightforward - both left and right are the same construction.

One end of the spring is hot glued in the ‘Spiral’ part pawl channel. The other end is superglued to the Pawl - See pic4.
The Pawl Button is superglued to the Pawl from the outside of the 'Spiral' part - See pic2.
The Jaws are press fit - no glue required - onto the Outer Jaw after the two halves ‘Spiral and 'Straight’ are laid with the inner faces together See pic3.

Operation:
Rotating the two halves of each side increases the radius of the ‘Jaws’ towards the outer edge. Pressing the Pawl button towards the center shaft releases the pawl from the sprocket and allows you to decrease the radius of the jaws. 

Do's:
This assembly is will 'gently' hold a 1kg spool centered on a ~25mm shaft.
Change sides of the spool to allow for a change in rotation of the spool. 

Don'ts:
The holder should always be trying to increase the radius when it is rotated in the direction of the shaft. The opposite rotation will place undue force on the jaws, pawl and sprocket.
Don't try to over-tighten the jaws on the spool. It's meant to keep the spool centered - not braced.

Options:
Add an optional ‘spacer’ so your spool holder doesn't run into a shaft wall/end.
Use the ‘keyed’ shaft version to force a spool to rotate with the shaft it's on. :-)

I am planning on providing different shaft sizes in the near future. 
If you are interested drop me a line.