3D printers: Difference between revisions
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Assuming reasonable hotend movement, nozzle size defines your resolution. The nozzle is the most exterior part of the hotend. Hotends can be open source (e.g. the MK8 and E3D v6) or proprietary. You can assume you'll pay a heavy multiple for proprietary hotends, so open designs are desirable. The 0.4mm brass nozzle can be considered standard. Larger nozzles can print the same volume more quickly (assuming sufficient supply from the heating element), are less prone to jamming, and have fewer layers per unit height (possibly resulting in stronger prints). Smaller nozzles can achieve higher resolutions in all three dimensions. Nozzle material governs heat transfer and wear resistance, with the latter being particularly relevant for abrasive materials. | Assuming reasonable hotend movement, nozzle size defines your resolution. The nozzle is the most exterior part of the hotend. Hotends can be open source (e.g. the MK8 and E3D v6) or proprietary. You can assume you'll pay a heavy multiple for proprietary hotends, so open designs are desirable. The 0.4mm brass nozzle can be considered standard. Larger nozzles can print the same volume more quickly (assuming sufficient supply from the heating element), are less prone to jamming, and have fewer layers per unit height (possibly resulting in stronger prints). Smaller nozzles can achieve higher resolutions in all three dimensions. Nozzle material governs heat transfer and wear resistance, with the latter being particularly relevant for abrasive materials. | ||
Within a hotend form factor, there are both all-metal and through-PTFE models, with the latter being more standard. PTFE (teflon) tubing provides a low-friction path for cold tubing through the extruder. Unfortunately, PTFE doesn't like temperatures much above 240℃. If you're heating your material to the melting point of say Nylon-CF, it's going to deform your PTFE. An all-metal hotend terminates the PTFE above the heat sink, permitting higher temperatures in the hotend. Downsides include less filament bandwidth due to increased friction, and less retraction capability due to a larger temperature gradient between the heater and the heat sink. Furthermore, if heat is conducted past the PTFE coupler above the heat sink, the benefits of the metal hotend are lost. A thermistor colocated with the heating element facilitates temperature management of the hotend, and if it provides inaccurate data you're going to have a Bad Time. | Within a hotend form factor, there are both all-metal and through-PTFE models, with the latter being more standard. PTFE (teflon) tubing provides a low-friction path for cold tubing through the extruder. Unfortunately, PTFE and its PEEK insulate doesn't like temperatures much above 240℃. If you're heating your material to the melting point of say Nylon-CF, it's going to deform your PTFE. An all-metal hotend terminates the PTFE above the heat sink, permitting higher temperatures in the hotend. Downsides include less filament bandwidth due to increased friction, and less retraction capability due to a larger temperature gradient between the heater and the heat sink. Furthermore, if heat is conducted past the PTFE coupler above the heat sink, the benefits of the metal hotend are lost. A thermistor colocated with the heating element facilitates temperature management of the hotend, and if it provides inaccurate data you're going to have a Bad Time. | ||
There's (almost) always a bit of PTFE tube between the hot and cool ends of the extruder. In the cool end lives a [https://en.wikipedia.org/wiki/Brushless_DC_electric_motor BLDC] and some gears, responsible for feeding filament from its spool into the hotend. If this BLDC stepper motor rides along with the hotend as an all-in-one extruder, it's known as direct drive. If the cold and hot ends are not conjoined, separated by a longer length of PTFE, it's a Bowden extruder. | |||
<b>FIXME print bed</b> | <b>FIXME print bed</b> | ||
<b>FIXME firmware</b> | <b>FIXME firmware</b> | ||
<b>FIXME automatic leveling</b> | <b>FIXME automatic leveling</b> | ||