Low-friction Tom's easy spool holder for Prusa i3 Mk2/Mk3

This is an upgrade to Tom's simple spool holder. I've added two 608 skateboard/fidget-spinner bearings to allow the spool to spin more freely around the 8mm rod. This reduces resistance applied to the extruder and may improve the accuracy of high-acceleration x-axis movements.

The drawback with this approach is that if the bearings spin too freely, the spool can unwind several turns if the x-axis movement is too fast. You can fine-tune the behavior using washers to apply slight clamping pressure on the bearing.

Four alternate spools are provided that will work with 99% of filament brands out there:

• 50mm with a 3-degree draft angle to keep the spool centered
• 50mm with no draft angle
• 30mm with a 3-degree draft angle

• 30mm with no draft angle
  z-height of the spools is 96mm which will fit a variety of filaments and is the ideal size when combining Tom's spool holder with the top-mounted LCD holder.

  Full assembly requires:

• 2 Holder01.stl prints OR 2 spools_combined_TomMartin.stl prints

• 1 spool print
• 2 608 bearings
• 8mm threaded rod (130mm or longer)
• 2 washers
• 2 or 4 8mm nuts (4 recommended to use as jam nuts to prevent vibration from loosening things up over time.

Print instructions

Category: 3D Printer Accessories Summary

This is an upgrade to Tom's simple spool holder. I've added two 608 skateboard/fidget-spinner bearings to allow the spool to spin more freely around the 8mm rod. This reduces resistance applied to the extruder and may improve the accuracy of high-acceleration x-axis movements.

The drawback with this approach is that if the bearings spin too freely, the spool can unwind several turns if the x-axis movement is too fast. You can fine-tune the behavior using washers to apply slight clamping pressure on the bearing.

Four alternate spools are provided that will work with 99% of filament brands out there:

• 50mm with a 3-degree draft angle to keep the spool centered
• 50mm with no draft angle
• 30mm with a 3-degree draft angle

• 30mm with no draft angle
  z-height of the spools is 96mm which will fit a variety of filaments and is the ideal size when combining Tom's spool holder with the top-mounted LCD holder.

  Full assembly requires:

• 2 Holder01.stl prints OR 2 spools_combined_TomMartin.stl prints

• 1 spool print
• 2 608 bearings
• 8mm threaded rod (130mm or longer)
• 2 washers
• 2 or 4 8mm nuts (4 recommended to use as jam nuts to prevent vibration from loosening things up over time.

  Print Settings

Printer: Mk2.5

Rafts: Doesn't Matter

Supports: Doesn't Matter

Resolution: 0.25mm

Infill: 15%

Filament: N/A PLA N/A
Notes:

You can use Prusa's default 0.25mm settings and it will take about an hour to complete.

Adding supports will result in a cleaner surface to fit one of the bearings. Either way you'll have to clean out the bearing area for a good fit.