An adapter for spools of filament that have a small spool wall radius in relation to the depth of the filament

Target Audience:

• Anyone who uses a spool holder setup where the spool rolls on rollers or wheels instead of on a support through the center of the spool
• Anyone who hasn't setup some sort of tensioner on the filament so sometimes if the spool is rolled forward too fast the filament unspools over the edge of the spool

After 2 hours of baby sitting the end of a print job where I switched color to a spool with filament that went right up to the edge of the spool wall, I decided I needed some kind of adapter to give a little extra space when used with my top mounted spool holder setup.

You need to print this setup twice, once for each side of the spool. Once assembled you just compress the feet, push against the side of the spool and release. The spring will tension the feet against the inside of the spool.

The first version I made had a slot on the spool wall that you turn the spring housing support into in order to lock it into place. However after printing it I realized that it really held well enough as a press-fit - so I added and extra press-fit edge and removed the overhang. Both versions are available. I've been using one of each, and some times the press-fit does come apart, but not often. The locking version is always solid as expected.

Resolution: 1mm
Supports: yes
Orientation: Printing on edge for better dimensional accuracy (as uploaded)

Resolution: 2mm
Supports: yes

Only a spring is required, no screws or glue
Spring: ~45mm x 10mm

I had a bunch of springs laying around, the one I used (above) compresses to about 19mm

1. put the spring into one of the spring housings
2. insert the spring and spring housing into the spring housing support and insert the spring into the second spring housing facing the opposite way
3. Push the spring housings into the support, compressing the spring
4. Insert the assembly into the spool wall 90 degrees from the locking edge
5. Rotate the spring housing into the locking edge until it's aligned. you may need to sand the edge of the spring housing support if it's difficult to turn
6. release the spring housings

1. put the spring into one of the spring housings
2. insert the spring and spring housing into the spring housing support and insert the spring into the second spring housing facing the opposite way
3. Push the spring housings into the support, compressing the spring
4. Press the spring housing support into the spool wall
5. release the spring housings

To give the feet a little better grip against the inside of the spool I coated each foot with a little bit of 5-minute epoxy. Hot glue might work too.