Advancements in 3D
Advancements in 3D

Advancements in 3D

I’ve been working with the 3D-printer. A lot.

Partly because it is fun. Partly because the base product simply isn’t up to the job I want it to perform.

There was a wobble on vertical surfaces, caused by the cheap M8-thread-rods that take the Y-axis carriage up and down being not perfectly straight. This is known as Z-axis wobble. So, they had to be replaced with proper lead screws sporting a squarish thread. That killed the wobble – only to expose the underlying mechanical slack. More on that later, as it’s not so critical to me.

Next was an issue with extruder motor skip, caused by lack of torque. This design features an ungeared direct-driven extruder on the Y-carriage. Good, because it sits right next to the hotend leaving little chance for the filament to flex, bad because it means the Y-carriage gets one motor heavier. Weight impacts acceleration and jerk performance. Oh well – I decided to just feed the extruder motor more power. I ended up replacing all the motordrivers, going from 16-position microstepping to 32 as part of the process.

The issue of creating a proper extrusion path has been a long one too. I’ve worked my way through a number of so-called slicers. A slicer is a tool that will take an object shape (made with a suitable CAD-tool) and transform it into a route map for the printer controller processor. You know; go to [x:y:z], start extruding as you go to … and so on. But there’s more than one way to deposit molten plastic, I can assure you. This means that different slicers will produce different paths – and offer varying tools to the person trying to do the transformation. One being how to implement support structures. There’s a whole slew of different methods and procedure variations you can apply to the printing process, thus coercing the device into generating strong objects quickly while being light on filament consumption. Currently I’m getting settled with Simplify3D – meaning its out-of-the-box-support for my particular printer model could do with a little tweaking. So, because by now, I’ve developed a preference for pre- and post-print-procedure actions that includes laying down a priming ‘strip’, printing and finally moving the printbed forward to present the final result. To this end, a certain mastery of G-code is needed.

If only I could have the machine send me a message saying ‘Done’ and then turn itself off. Unfortunately, the machine’s present PSU design does not allow for this. So; there’s a couple of future upgrade ideas: Replace the PSU with one from a PC and add a mechanism to poke me. I’m thinking 433 MHz home-automation signaling here; much like the door- and motion-sensors already in operation. Wonder if the printer’s controllerboard has a spare IO-pin I can hijack?

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