|Mini Kossel with flying extruder|
|MK8 extruder with suspension bracket attached|
|Moving extruder power cable to the effector wire harness|
|Heat-damaged PLA fan duct skirt|
|Remixed and improved ducting skirt, note the zip-tie on the right|
|Pulley bearings, 1/4-inch shaft and part of the counterweight|
|Using the cable to loosely suspend the extruder during install|
|Temporary anchor for zip-ties|
Initially, I had thought to try running with just zip-ties holding the extruder block to each of the carriages, but that proved unworkable due to the zip-ties restricting the range of motion. The basic idea of suspending from the carriages would probably work if you used some form of elastic for the cables, but that still leaves a 400-gram weight sitting in the middle of the frame, so it would definitely lower the maximum attainable speed.
|Initial configuration idea, doesn't work with rigid cables|
|Initial Z-tower pulley mount|
|Upper pulleys 2/3 installed|
As you can see, I'd initially thought to use just the zip-ties to hold things in place, but that resulted in some strange glitches during homing, so I switched to the full counterweight option. After I'd installed the first couple of pulleys, I realized that the counterweight would hit the back of the z-tower carriage, so I designed a short arm with a 608zz on the end to act as a spacer. Other hardware used in the spacer arm was 3 M5x35mm bolts, 4 M5 nuts, and 1 M5x10mm bolt.
|Spacer arm fully assembled|
|Spacer arm fully installed just below the top triangle|
As for the counterweight, I just used a small scale to measure the approximate weight of the extruder assembly, roughly 395 grams, then found a combination of old washers and stuff that was reasonably close to that weight to use for the counterweight, ended up at 405 grams, then tied the lot to the end of the string/rope. As for the print quality, I still need to retune the retraction settings, but it's a drastic improvement over the original configuration, with a much finer surface finish. Here's a couple of #3DBenchy prints for comparison, the Green one is from the filament comparison post with the original configuration, the gold one is done with the new configuration.
|#3DBenchy 32-bit on the left, 8-bit on the right|