Hi all,
We (myself and a few high-schoolers) are building an extruder of our own design, but using design ideas from Mendel and others. Thinking we can simplify the build if we use a geared stepper such as
this Kysan geared stepper. However, I need to know if this will work...
Torque: Stated as 210mN.m, which translates to 29.7 oz-in, which is apparently at the motor, so with the 10:1 gear ratio, that's 297 oz-in at the output shaft (that the filament sees). This is much higher than Adrian's extruder at 107 oz-in, or Wade's at 244 oz-in. For the latter two, I'm calculating based on the specified gear ratios.
Speed: The 10:1 gear ratio is slower than others, but no where have I seen that motor speed is an issue.
Heat: By eliminating the gears, we plan to knurl the end of the output shaft, and with the metal gears and housing wondering if heat would be an issue where it touches the filament? We will probably have a fan to help cool the upper part of the extruder (filament feed, etc).
Drop size: Using 3mm filament, the 10:1 gear ratio and 0.9-deg steps will mean finer steps, so that's 0.444mm
3, before any microstepping. Using 1/8 microstepping, that's about 0.056 mm
3 per "drop".
Any thoughts on these, or any other thing we need to be concerned about? We have drivers to support this.
Thanks.