YARSH (Yet Another Retracting Spool Holder)

thingiverse

A self retracting spool holder to prevent the filament from unspooling during print. It helps to maintain a constant amount of slack between the extruder stepper and the spool. <p>This is a remix, but I couldn't work out how to attribute the originals via a Thing ID of Thing File??? So first, many thanks to:-</p> <p>entomophile - for the ratchet and Pawl</p> <p>nathansc - for the spool holder</p> <p>This spool holder will stop the filament from unspooling in two ways. </p> <p>First, it will not spin backwards unless you lift the pawl. </p> <p>Second, the sprung pawl will retract the filament by about 10mm if there is any slack between the spool and the extruder stepper. It works a bit like a finger pulling on the ratchet to retract the filament quite gently. It doesn't appear to offer too much resistance as my filament is pulled through just fine. </p> <p>It has solved my problem of filament springing off the roll. It doesn't have the large and complex print that fully retracting designs have, but I only needed a very small amount of retraction. </p> There are 2 versions depending on which way around you mount your spool. One allows clockwise movement and the other counter-clockwise. It probably won't work if the filament run doesn't line up with the extruder stepper, i.e. if the filament bends 90 degrees and touches the edge of the spool but I haven't tried that. <p> <p> You will need <p> 6 printed parts, choose an option for parts 3, 4 and 6. <p> 1x M8 Hex headed bolt for the main spool body between 100 - 120mm <p> 2x Standard 608ZZ ball-bearings (8x22x7mm) <p> 2x M8 Hex nuts <p> 1x M3 bolt and locknut <p> A few M3 and M8 washers for spacing. <p> You will need to mount the sprung pawl with a bit of tension before fitting the rest of the spindle. The more tension you add, the more force is applied to the ratchet for retraction but this also adds drag so you can tune it to your setup. It can then be tightened in position. The spool is then put together as per the original. <p> Happy to respond to questions about assembly etc as I'm sure I didn't explain it very well. <p>I have noticed that if the spring is not tensioned enough and the pawl not aligned correctly, the spool can spin backwards. Just make sure the pawl fits snugly into the ratchet and it shouldn't roll backwards.