Modifying .stl file found on Thingiverse

[reachmeplace]

Hi, I'm new to Meshmixer. I downloaded an. stl file from Thingiverse. I now want to modify it by making the "knob" part of the crank 1/2 the size it is and make that same "knob" a little longer.  I tied to upload the .stl  (33kb) but I get an error message it's not the correct file type? Here's a screenshot of it in MeshMixer. Here's the  link https://www.thingiverse.com/thing:101313 Thank you!

[reachmeplace]

Hi Andrew,

I'd like the crank handle "arm" (which reaches up which is placed in the
hole to crank the device) to be very thin - the hole is about 1/8 of an
inch (the width of a Papermate 1.o M ballpoint "stick" pen.

The height (length) of the arm to crank to about about 3.5-4 inches.

Thank you so much!

[hfcandrew]

I need ALL the parameters, in millimeters.

// Diameter of nut in mm
nut_diameter = 100;

// Depth of nut in mm
nut_depth = 15;

// Side wall thickness for nut chamber in mm
side_wall_thickness = 5;

// Length of arm in mm, from center of bolt to center of handle
arm_length = 222;

// Length of handle in mm, the length protruding from the crank
handle_length = 100;

// Diameter of handle in mm
handle_diameter = 20;

[reachmeplace]

The default settings all work well except the crank "handle" (arm) needs to
be a lot thinner.

// Diameter of nut in mm
nut_diameter = 30;

// Depth of nut in mm
nut_depth = 15;

// Side wall thickness for nut chamber in mm
side_wall_thickness = 5;

// Length of arm in mm, from center of bolt to center of handle
arm_length = 100;

// Length of handle in mm, the length protruding from the crank
handle_length = 50; So, MAYBE this sgould be 100 instead to be longer???

// Diameter of handle in mm
handle_diameter = 20; MAYBE this should be 5 so it's thinner - about the
width of a Paper Mate 1.0M ballpoint stick pen

/* Hidden */
handle_radius = handle_diameter / 2;
nut_radius = nut_diameter / 2;
nut_cyl_radius = nut_radius + side_wall_thickness;

include ;

difference() {
union() {
cylinder(h = nut_depth, r = nut_cyl_radius);
translate([arm_length,0,0])
cylinder(h = handle_length + nut_depth, r = handle_radius );
linear_extrude( height = nut_depth)
polygon(points =[
[0,-nut_cyl_radius],[arm_length,-handle_radius],[arm_length,handle_radius],[0,nut_cyl_radius]]);
}
linear_extrude(height = nut_depth) {
hexagon(nut_radius);
}
}

Thank you!!

[hfcandrew]

here

[reachmeplace]

What changes did you make in OpenScad to export the file as a thinner crank handle? I can't see that for the finalized .stl in OpenScad as it will only open scad files? I had tried earlier today opening the crank handle in Openscad and deleting the crank handle and typing in 5 but I saw no changes either once I typed in the 5 nor when I exported the file as an .stl. Thank you ever so very much!

[hfcandrew]

I did nothing different than what I have said and shown via the video

1. Set the parameters as required
2. Click 'Render'
3. Click 'Export as STL'

I have no explanation as to why this is not working for you.

[reachmeplace]

OK, thank you.

[reachmeplace]

Hi, as a newbie I'm not sure if posting an Openscad questionhere is approgpriat so my apologies if I've offended anyone.

If there is a better forum for OpenScad questions I would so appreciate you pleas shrare a link to that forum.

Openscad seemed like an easy to use application and the 1st time I used to make an object taller and thinner  it worked by just typing  in new numbers. After that, when I wold type in new numbers  it never changed the look of the object. I even uninstalled and reinstalled but that made no difference.

I’m trying to just widen this .stl file I found on Thingiverse

https://www.thingiverse.com/thing:3131119

Poker chip

by That_sweet_1_fps October 01, 2018

https://www.thingiverse.com/that_sweet_1_fps/designs

It’s a poker chip but I wanted to make it wider. It seems to measure 1.5 inches wide now but I wanted to make it 1.75 or even 1.85 inches wide.

How can I easily (best) widen this file using OPenscad?

Thank you so much!

[hfcandrew]

I feel like you are confused on what OpenSCAD and Meshmixer is.

[Anonymous]

You need to understand the difference of formats which describe a body by some math functions (CAD files) or via some mesh of triangles. This difference is similar to the difference of pixel- and vector based 2D image applications. It's hard to edit a photo made of pixels with vector graphics tools.

Your source file, a STL is a mesh format so Meshmixer is the right tool and I gave you the HowTo do this in Meshmixer here.

No problem if you ask questions on third party applications. We'll try to give you an answer - if we know a solution. But here aren't the experts on those apps...

[reachmeplace]

I probably am! I download OpenScad which world the 1st time to modify an
image but then didn't.
I thought Meshmixer was a completely different software program which I've
never used.

OpenScad seemed user-friendly for a newbie?

Thank you.