3D Printed Frictionless Filament Holder

This Filament Holder is designed to reduce and smooth out the forces required for a 3D printer extruder to feed filament to the hot end. Ideal for 3D printers with direct drive extruders to help solve issues such as ringing, Z-banding, missed steps, or slipping occurring from excessive and inconsistent forces needed to pull filament from the spool.

Machinery

• 3D Printer with minimum build volume of 220 x 220 x 150mm (X, Y, Z respectively)

Software

• Cura Slicer or equivalent

Materials

• PLA Filament ~ 200 grams
• Elmer's Glue Stick (optional)
• Super Glue Gel (optional)

Tools

• Safety Glasses
• Cordless Drill
• 5mm Drill Bit
• Dremel Rotary Tool
• Cut off Wheel for Rotary tool
• Grinding Wheel for Rotary Tool
• 4mm Hex Key
• (2x) 8mm wrenches
• Hobby Knife

Hardware

• (3x) M5 Threaded Rod, 60mm (2-3/8 inches) minimum length
• (3x) M5 Lock Nuts
• (3x) M5 Hex Nuts
• (6x) Small V-Wheels (5mm ID x 15.3mm OD)
• (12x) M5 Small OD washers (~8mm OD)
• (2x) M5 Flat Washers
• (2x) M5 T-nuts for 2020 series profile
• (2x) M5 x 12mm Cap Screws or Button Head screws
• PTFE BowdenTube for 1.75mm filament. (~500mm)

Download and 3D print the attached files. See photos for recommended printing orientation.

(1x) Bracket

(1x) Arbor Shaft

(1x) Arbor Wheel Cage

(1x) Arbor Nut

(2x) Arbor Spacer Flange

Recommended Slicer Settings:

0.2mm layer height

1.6mm thick side walls (4 line count with 0.4mm nozzle)

0.8mm thick top and bottom walls (4 layers at recommended layer height)

Enable ironing on all top surfaces (optional)

40% cubic infill on all components except bracket

20% cubic infill on bracket only

Slicer Tolerance: Exclusive

No supports needed. Brims are optional for better bed adhesion. Rafts are not recommended.

Glue stick is recommended for bed adhesion while printing the arbor shaft and bracket. The arbor shaft is tall with a small surface area contacting the build plate. The bracket will have a tendency to warp while printing so a glue stick and/or a brim will help with printing these components.

Use a Dremel Rotary tool with a cut off wheel to cut the M5 threaded rod to 60mm (2-3/8) inches long. It may be helpful to use a marker or piece of tape to to mark where to cut. After cutting, smooth off the ends with a grinding wheel or steel file to remove any burrs and sharp edges. Wear safety glasses to protect your eyes from metal debris or in case the cut off wheel breaks, which is common. Also the threaded rod may get hot while being cut and ground so you may want to grip the rod with pliers or a small vice during this step. Take care not to damage the threads if clamping on them.

The 5mm holes in the Wheel Cage are designed to print slightly undersized. Since 3D printers are not usually good at printing small diameters accurately, it is best to drill out the holes to size by hand. This will help ensure the threaded rod fits well without too much play. Use a cordless drill and 5mm drill bit to drill the holes to size. Since this part is printed with 1.2mm thick walls, there will be plenty of material remaining around the hole after drilling. Check that the threaded rod fits well in each hole. If necessary, run the drill bit in and out of the hole a few times until the threaded rod fits. Sand or deburr the edges around the holes after drilling.

Assemble the Wheels to Cage as shown in the photos. Be sure to use M5 small OD washers on both sides of every wheel, 12 total. Install hardware in this order:

Install a M5 Lock nut on one end of each of the threaded rods so the rod ends stick out slightly past the nut.

Install a M5 small OD washer on each rod.

Install a V-Wheel on each rod.

Install another M5 small OD washer on each rod.

Insert rods in 5mm holes in printed cage.

Install another M5 small OD washer on each rod.

Install another V-Wheel on each rod.

Install remaining M5 small OD washer on each rod.

Install M5 hex nut on end of each rod.

Use 8mm or adjustable wrenches to lightly tighten nuts

Check that all the wheels spin freely.

Check that all the pieces fit together before gluing anything. The components are designed to have sufficient clearance between mating parts, but if your 3D printer is not well calibrated, the parts may need some sanding or slight modification in order to fit freely.

Slide the Arbor Shaft through the bracket so the flange butts up against the inner backside of the bracket.

Slide one of the Arbor Spacer Flanges on the Arbor Shaft

Slide Wheel Cage Assembly on the Arbor Shaft

Slide Filament Spool on Wheel Cage Assembly

Slide second Arbor Spacer Flange on the Arbor Shaft

Thread Arbor Nut on Arbor Shaft until snug (Do not overtighten)

After testing everything fits well, it's recommended to glue the Arbor Shaft to the Bracket. This will help prevent the Arbor Shaft from slipping down and parts from falling off while installing spools. You could also glue the first Arbor Spacer Flange to the Arbor Shaft and Bracket, and the Wheel Cage Assembly to the Arbor Shaft, but it isn't necessary. Do not glue the second Arbor Spacer Flange or Arbor Nut because they must be removed when changing spools. Also be sure to clean up excess glue from Arbor shaft and around components so that it doesn't interfere with the removable components.

Mount the Holder Assembly to the top rail of your 3D printer using (2) M5 T-Nuts, (2) M5 x 12mm Cap Screws and (2) M5 Flat Washers. It's best to mount it toward one side or another instead of the center. If the screws are too long and bottom out, you grind the length down slightly or use a few extra washers as spacers.

The spool may have a tendency to unravel while printing, depending on your set up so using a reverse Bowden Tube is recommended. This will also help buffer the forces required to pull filament in a direct drive set up because the print head jerks while printing. This will help prevent issues such as ringing and make the extrusion rate more consistent while printing. The length of the Bowden tube depends on your set up, so it's recommended to start off longer and trim down if necessary. Start by bringing your print head down within 5mm of the build plate and measure the distance between the top of the print head to bottom of the spool. Cut the Bowden to the length measured using a hobby knife or Bowden Tube cutting tool. The tube is flexible so it should bend easily and shouldn't cause any problems on taller prints. Watch it when running taller prints and trim the length if it appears to be too long and causes a problem.

Many Filament Spools have solid cores. However, some spools, such as those made from carboard, do not. You can print out a sleeve so that it fits snug in the Spool ID and the wheels have a smooth surface to run on. Measure the ID of your spool and design a sleeve so the OD matches the ID of your spool. The ID of the sleeve should be 50.3mm (1.98 inches) x 68.6mm (2.7 inches) long.

An example sleeve for common sized Cardboard Spools is attached. It also has a slight OD taper on one end so that it fits snug on the spool.