Filament Spool

This spool holder is relatively independent of the rest of the Jiggit project, so I've put these pieces up on thingiverse as thing 4828118.

Imagine this Chef's Path extra tall cereal container holding a spool of filament instead of cereal:

It would need something to hold the spool so it could easily roll to dispense filament. It could feed the filament up through a PTFE tube into the extruder. It would need some sort of structure inside the container to stabilize the rollers.

To 3D print such a structure, I'd need a model of the inside of the container. I could produce it by 3D scanning a plaster cast made with CraftWrap. After it dried enough I could get the cast loose from the bottom by loosely stuffing the container with cushioning material, putting the lid on, and turning it upside down and pounding on my leg till it comes loose. I could then put it on a rack to get throughly dry before trying to scan it:

The spool holder with the bearings is a completely unmodified TUSH - The Ultimate Spool Holder, I'll just want to print pieces to go in the bottom of the box with slots they can fit in with exactly the right separation for the spool I want to use (and I should be able to swap out different base plates for different size spools).

Leaving it in the oven on warm overnight reduced the weight considerably and left it bone dry. Time to spend hours in the scanner next.

Didn't actually take hours, only about 20 minutes for each end (the scanner often balks at scanning some things, but it seems to love plaster). I saved the .stl file from the scanner and chopped a layer off the end that goes in the handle to print a test piece:

Now need to do the same with the other end and come up with a scad file I can parameterize with the width of the spool, then print the real pieces for the spool I plan to test on jiggit.

I've designed and printed the real pieces. The openscad file has modules I can plug the spool width into to customize for different spools. This case is for a spool of PLA I've had laying around for a long time. Here we see everything working perfectly. First the printed parts go in:

Then the rollers fit perfectly in the slots:

I can shake the container at this point and nothing rattles. Everything seems to be perfectly press fit. Then I can put in the spool:

The spool seems to spin nicely with no resistance when I roll it. Now need to make somehing to guide the filament into the bowden connector I'll be screwing to the top of the container.

If I get really carried away, I can design something to fit in the hub of the spool and stick out almost to the walls of the container so the spool can't tip over (but no real reason to do that unless I actually have a tipping problem some day).

I've got the parts for the filament guide printed to make the completed spool holder container now. Used the top printed part as a drilling guide:

Here's what the parts look like. The cone goes inside the box to provide a smooth path for the filament, the disk holds the M6 nut the connector will screw into and goes on the outside of the box:

Here are the cone and disk fully assembled and bolted to the lid:

Put it all together and feed the filament through the hole and you get this:

Now just need to get the printer ready and connect the right length of tubing to the container to feed filament into the extruder...

Did that, here's the final configuration with filament running all the way from the spool up through the extruder and over to the hot end through the PTFE tubing:

Checked that the extruder had no problems at all different positions on the print bed. The tube is long enough to reach every corner, and the filament extrudes OK in every position. Here's the blob of string I dragged around to different positions while testing:

I suppose I should try printing something next, but I can see the printbed tilt a little when it changes direction from up to down, so I have a feeling I'll need a lot of adjustment before it really works (or maybe rebuilding the bed with shafts and linear bearings - they aren't too expensive on amazon :-)..