OpenFlexure Microscope OpenSCAD docs

accessories/actuator_tension_band.scad

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OpenFlexure Microscope: actuator tension band *
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The microscope stage actuators need a tension band to provide a *
reciprocal force between the captive nut in the gear and the *
stage arm. The recommendation is to use a Viton O-ring, but if *
you have a 3d printer can reliably print with TPU filament, you *
can print this instead and use it in place of the O-ring. *
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Print this part using .1mm layer height, with randomized *
perimeter start and end positions if possible. For strength, *
The part should be printed entirely with perimeters, no gap *
fill. The part is designed to be printed with a 0.4mm nozzle. *
Printing with a 1mm nozzle hasn't been tested, and isn't *
recommended.
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(c) Bill Schaller, June 2020 *
Released under the CERN Open Hardware License v1.2 *
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module actuator_tension_band(nozzle_width)

[Source]

module actuator_tension_band(nozzle_width){
    band_height = 1.8;
    ideal_band_thickness = 1.5;
    band_inner_diameter = 30;

    actual_band_thickness = ideal_band_thickness - (ideal_band_thickness % nozzle_width);
    band_outer_diameter = band_inner_diameter + actual_band_thickness * 2;

    difference(){
        cylinder(h=band_height, d=band_outer_diameter, center = true);
        cylinder(h=band_height+1, d=band_inner_diameter, center = true);
    }
}