Mini Kossel doubled frame top vertex - for 1515 extrusion

thingiverse

I built a larger version of the Mini Kossel and found that the frame would vibrate noticeably when printing quickly. The bottom corner mounts were already well-suited for their purpose, holding stepper motors securely, but the top corner pieces were small and relied on just one bolt to attach them to the vertical extrusion. I modified the original frame_top part to create a larger version with room under it for the end stop switch mount. To assemble this modified part, print the default model just 5mm or so tall, then pause the print and check the fit against your extrusions. Make sure to clean away any residual brim from the bottom layer inside the hole, as a snug fit is essential. I prefer it so tight that for final assembly, I must warm both the part and the extrusion's end with a heat gun before gently knocking on the opposite end of the extrusion. First, place the part on a piece of wood at floor level, then align the extrusion directly above it. Next, firmly tap the extrusion through the part to secure it in position. Before transferring the assembly to the cooler section of the extruder, slide the modified part several times over the hot end to create an extremely tight seal. Once all parts have cooled completely, the new top piece should slide easily off the extruder's mounting rod. Remember that some fine-tuning may be necessary: adjust the tolerance_frame_dmk value if your modified top corner piece is too loose or snug for optimal fit with your extrusions.