Dollo 3D Printable 3D Printer

[spegelius]

On Dollo rebuild I've been experimenting with the extruder positioning. Some while ago I designed an extruder riser for my Tronxy X5S (https://www.thingiverse.com/thing:3271808) and originaly I used it on Dollo too, but then I wanted something more adjustable, so I designed this arm that is built on parts that can be rotated to get the desired position. Works ok, but it's bit wobbly so I'm going to print another arm on the other side to support the extruder better.
Using an extruder riser allows for sorter bowden tube. I haven't measured the difference but it's about 20cm compared to the original position without riser. Currently I have 2.5mm retraction with linear advance value 0.3. The bowden tube is about 45cm.
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I swapped a Volcano on the Dollo rebuild as I needed the E3Dv6 on another printer. I tried some 1.2mm nozzle printing. It's a kinda new area because the amount of material moving through the nozzle is quite a lot more than normally. Tuning the retraction is hard to get perfect, on my test I didn't get it completely nailed down and it's not just about the retraction amount.
I printed a couple of pieces to test out full print height and Volcano. Both are ~40cm tall and have only one 1.2mm perimeter. This sows on the owl since some areas aren't properly supported and there's gaps and artifacts.
Material used was PLA, about half a 1kg roll I think.
The vase print was supprisingly fast, only about 7 hours.
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Other small thing on Dollo rebuild:
- swapped X and Y motor gears, they were getting a bit of backlash due to the printed gears starting to get loose on the motor shafts. Did some refactoring on the desing too.
- currently running Marlin 2.0.5.3 on the SBase and no problems
- Z accuracy is a bit of problem when using mesh bed leveling, which is expected due to the printed 'bearings' that do bind a bit. With mesh bed leveling, the bed just doesn't do those very small movements. Also the printed Z-rod nut has bit of backlash.
To combat this I made a poor-mans lock nut from TPU which acts as a kind of psring and takes the slack off, which helps a bit.
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