Is this 3D model free to download?

Yes, Prusa i3 MK3 (MK2S) filament runner for external spool is free to download from Thingiverse. Open it in the free Thinger app, or use the "Download from Thingiverse" link to open the original listing by the creator.

Where do I download the STL file?

The download is hosted by Thingiverse. Use the "Download from Thingiverse" link on this page to open the original listing and grab the file, or save it to your print queue in the free Thinger app.

Designed by jltx, published on Thingiverse. Please credit the creator when sharing your print.

Can I print this at home?

Yes. This is a printable 3D model intended for home FDM and resin printers. Check the original listing for suggested print settings.

Prusa i3 MK3 (MK2S) filament runner for external spool 3D printable model by jltx

Prusa i3 MK3 (MK2S) filament runner for external spool photo 1

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Prusa i3 MK3 (MK2S) filament runner for external spool

Source: Thingiverse by jltx

The Prusa i3 MK3 (MK2S) filament runner for external spool is a free printable 3D model from Thingiverse by jltx. I'm not a fan of cantilevering a big heavy spool off the top of the printer frame, so I go outboard. You can download the STL file from the original listing below and print it at home.

Open in Thinger (free) Download from Thingiverse

417 saves Source: Thingiverse Updated 2026-10-15 License: CC-BY · commercial OK 7 makes Category: 3D Printer

Tags: Prusa, i3, MK3, (MK2S), filament, runner, for, external, spool

About this model

I'm not a fan of cantilevering a big heavy spool off the top of the printer frame, so I go outboard. This is for use with external spool holders. I recommend: print 2 of these and sandwich a 608 bearing between. Insert in hex hole at top of Z axis. Just slide filament through angled slot and get friction-free feed. 12/23/17: can get tight printing with Z > 180mm. So I added a lift piece you can stack underneath the runner. You can add this even with a print going. 'F' marks the front. I also tweaked the runner a bit to be smoother. 1/27/18: added version with slightly wider clearance to account for bearing manufacturing variability if you encounter rubbing. Added pic of a good reason to go outboard. ###More parts see Taurus line of upgrades for best performance. --- I have many parts for M…

Frequently asked questions

Is this 3D model free to download?: Yes. Prusa i3 MK3 (MK2S) filament runner for external spool is free to download from Thingiverse. Open it in the free Thinger app, or use the "Download from Thingiverse" link above to open the original listing.
Where is the STL hosted?: The download is hosted by Thingiverse, not by Thinger. We link you directly to the original listing by jltx.
Who made this model?: Designed by jltx, published on Thingiverse. Please credit the creator when sharing your print online.
Can I print this at home?: Yes. This model is intended for home FDM and resin 3D printers. Check the original listing for suggested print settings like layer height and supports.