Grass Trimmer Part V2

thingiverse

My grass trimmer has a third party head attachment fitted. I much prefer a fixed head to the original spool tap approach. I often found that the filament broke at the spool opening, which meant opening the spool to rethread before I could continue with my lawn duties. The third party trimmer head is a Saber Cut UN-59K 3 Blade/Line Heavy Duty. I have this head attached to my Makita DUR368LZ 18Vx2 Line Trimmer. After 2 years, one of the filament holders on the third party head broke. This broken part is not available as a spare part, so it was either buy a whole new head or 3D print a new holder. Here is my 3D replacement part. I used PETG filament to make the part. I found that an exact size part copy was not durable in PETG and soon broke. My part version has been strengthened by increasing some of the dimensions and with some subtle design improvements appears to make the part more resilient. Fortunately the 3D part is cheap and easy to replace, so should the other holders break, too, I can replace them, too. During normal use, friction heats the metal screw holding the mount in place. The hot metal screw is sufficient to raise the PETG in contact with it above it's "glass" temperature and will deform, eventually failing. I introduced a LLDPE bush between the metal screw and the PETG mount. The Linear low-density polyethylene (LLDPE) has a melting point of 122°C, providing a heat barrier. LLDPE tubing is commonly used in plumbing applications, so is readily available for others to do the same. The aim of the LLDPE is to separate the hot metal screw, heated by friction from the PETG. Cut the LLDPE tube section of sufficient length to also provide a heat separation from the screw head, too (see included images). With the LLDPE tube section, the PETG deformation is signficiantly reduced, with no noticeable deformation after two 30min sessions of use. My print is made in PETG 1.75mm 3DFillies black filament, with 0.2mm layer height and 100% infill on a PRUSA I3 MK3S printer. I hope that you can find this print useful, too. Remember to leave me some feedback or even a tip to keep me enthused to make more of these drawings. UPDATES V1.0f - To overcome excess heat melting the part, include a cut of LLDPE bush over the screw. Mount mounting hole adjusted to allow for the LLDPE bush.