I thought to try making one myself on SketchUp, but I wouldn't know how to create the side notches.
It needs to be approx. 13mm height, 18mm diameter at the inside end, 17mm at the outside end, and the inside needs to be 3.15mm hollow before the D part of the hole starts (if this makes sense).
I included the dimensions in my initial message
, I'm curious how one does the lines (?) on the side of the knob
stl_h=15.0; // orig. height
stl_d1=22.1; // orig. top dia. (ignoring rounded top edge)
stl_d2=24.6; // orig. base dia.
stl_fr_h=7.0; // orig. inner cone height (to D shaft)
stl_fr_d1=6.13; // orig. inner cone top dia. (at D shaft)
stl_fr_d2=20.2; // orig. inner cone base dia.
stl_shaft_d=stl_fr_d1; // orig D shaft dia
stl_shaft_l=7.15; // orig D shaft length, from cone top
stl_shaft_f=4.8; // orig D shaft thickness at flat
The knob was rotated flat, wide end down before measuring, and was found to be off-center by approx. 0.06mm in X and 0.03mm in Y.With the little 3D stuff I've done, I'm curious how one does the lines (?) on the side of the knob. My thought was inserting half circles one at a time, but it seemed to time consuming to be the correct answer.
Even better, I would contact the original designer to ask if they have the original 3D CAD file. Working with STL files, even if converted to a solid model, is an awful experience.
sudo apt-get install openscad
so you can easily tweak the shaft (and other knob) parameters yourself. // Fixing up a STL file for EEVblog u:bostonman
// ref: [url]https://www.eevblog.com/forum/3d-printing/resize-a-stl-file-for-me/[/url]
/* [New Knob] */
knob_h=13;
knob_d=18;
shaft_d=6.0;
shaft_f=4.8; // ***best guess***
shaft_l=12; //from knob base, ***best guess***
recess_d1=shaft_d; // recess top dia - make bigger than shaft if flat step wanted
recess_d2=14; // recess base dia
recess_h=3.15;
/* [rendering] */
fill_overlap=0.05; // to guarantee solid
slop=0.1; // increase critical hole diameters by this to print to size
$dd=1e-3; // tolerance for face alignment
$fn=120; // circle rendering facets
/* [Orig. STL] */
stl_h=15.0; // orig. height
stl_d1=22.1; // orig. top dia. (ignoring rounded top edge)
stl_d2=24.6; // orig. base dia.
stl_fr_h=7.0; // orig. inner cone height
stl_fr_d1=6.13; // orig. inner cone top dia. (at D shaft)
stl_fr_d2=20.2; // orig. inner cone base dia.
stl_shaft_d=stl_fr_d1; // orig D shaft dia
stl_shaft_l=7.15; // orig D shaft length, from cone top
stl_shaft_f=4.8; // orig D shaft thickness at flat
// //tweak parametrics to fit the origanal knob
//# cylinder(h=stl_h, d1=stl_d1, d2=stl_d2); // bounding conical frustrum
//# translate([0,0,stl_h-stl_fr_h]) cylinder(h=stl_fr_h,d1=stl_fr_d1,d2=stl_fr_d2); //inner cone
//#translate([0,0,stl_h-stl_fr_h-stl_shaft_l]) dshaft(stl_shaft_l,stl_shaft_d,stl_shaft_f); // d shaft
module dshaft(l,d,f){ //l=length, d=dia, f=thickness at flat
intersection(){
cylinder(h=l,d=d);
translate([0,f-d,l/2]) cube([d,d,l],center=true);
}
}
module knob_shell(h,d){
scale([d/stl_d2,d/stl_d2,h/stl_h]){
translate([0.06,0.03,0]) // it was off-center!
rotate([90,0,0])
import("Knob_D_shape_rotary_encoder.stl", convexity=3);
translate([0,0,stl_h-stl_fr_h-stl_shaft_l-fill_overlap])
cylinder(h=stl_fr_h+stl_shaft_l+fill_overlap,d1=stl_fr_d1+2*fill_overlap,d2=stl_fr_d2+2*fill_overlap); // infill
}
}
// render the resized knob
//render() // only needed (for preview) if graphics driver OpenGL is broken!
difference(){
knob_shell(knob_h,knob_d); // main object
// --- cuts ---
translate([0,0,knob_h-recess_h+$dd])
cylinder(h=recess_h+$dd, d1=recess_d1, d2=recess_d2); // cone
translate([0,0,knob_h-shaft_l+$dd])
dshaft(shaft_l+$dd,shaft_d+slop,shaft_f+slop*shaft_f/shaft_d);
}
[code]
forget my last post,heres the correct version