Why you may wish to use OpenSCAD for 3D Print Designs vs Tinkercad

[Mark Johnston]

Recently Fusion360 which I have greatly enjoyed is expired and harder for me to get re-enabled for a few reasons.

I am now thinking this will be my approach:

- For quick designs that are a fast part to solve some specific need I will move back towards the usage of TinkerCad.   This is not the purpose of this post but I do endorse Tinkercad to be a part of the set of tools to be considered for quick parts.

- OpenSCAD has it's place as a fantastic way to have certain often used but often different designs and this is the purpose of this post.

I'm starting to build up code for OpenSCAD due t Fusion360 starting to be more limiting and wanting full buyin (fees per month) to get me what I used to use for hobby work for free.  This is inevitable with many of the  'first hit is free' packages so is not unexpected.

OpenSCAD is in fact ideal for very common things you may want to make such as a case for some project and that is what I am going to give out today.

I present here source code for my current (but always morphing) OpenScad 'project box' code.   This box allows enabling of many things or just generating a basic 'box'.

Best to RTFS but in short here is what this offers at this time as given here:

- A basic box with a lid that fits nicely without screws.  glue it with mild glue if you must

- Holes for potentiometers or switches in the lid

- Standoffs for your PC board. In this case my Esp32 Mark-Toys.com Esp32 dev board

- Display board with standoffs.  In this case my favorite 1.3" OLED on I2C board

ALL of this stuff can be considered a 'template' for your own needs and just supplies you with a sort of 'boilerplate' for your own stuff if you 3D print things like cases WHICH is in fact one of the most useful things I do with my printer although I do many other parts too.

Download OpenSCAD on your platform of choice then you can use this source and it shows nicely the box you will end up with.

After that use 'File Export' and export the .stl code then form gcode using something like Cura or other more powerful tools.  Print it and PRESTO!  Custom case!

Sadly there seems to be no nice file attach so here is the scad source (in the raw).

I will try to post this in a better way like on my Thingiverse site but anyway, here we go!

// --------------------------------------------------------------------------------------------------------------------------------

// ProjectBox source code for use with OpenSCAD 

// 

// OpenSCAD Project Box: Use as a template for your box or to start with OpenSCAD

// Started Off Of Procedural Project Box v1   Was called the CudaTox, 2017

//

// Added Mark-Toys Esp32 PCB with standoffs, USB jack hole, OLED display, panel holes

// All of these extras can be enabled or disabled with the do_ type variables

//

// This box supports the Esp32 board from Mark-Toys.com and my favorite I2C  1.3" OLED display

// Consider this an example template for getting started in OpenSCAD!

// My 3D printer can do fairly precise edges.  You may have to tweek things to fit.

//

// PCB and OLED display are placed relative to lower left standoff as seen in render

// You can resize the PCB or OLED display and then place it with one X-Y pair

// Because the lid is upside down keep in mind that left to right are inverted positions

//

// Enjoy!  make Stuff!   Mark Johnston

use <Chamfer.scad>              //Allows window with slanted edges

// Inside open space and wall thickness in mm of the main box itself. 

inside_width  = 80;             //Inside open space in mm for the width

inside_length = 58;             //Inside open space in mm for the length

inside_height = 20;             //Inside open space in mm for the depth inside the box

wallThickness = 1.8;            //Wall thickness in mm

edgeRadius    = 1.5;            //Box rounding. 0=square,2=2mm. <= wall thickness

// Options for the Box are rendered if not set to 0  ---------------------------------

// If these are set to 1 then also set parameters for the components enabled

do_pcb_mounts = 1;              // PC Board Standoffs

do_lid_holes  = 1;              // Drill holes for controls in the lid

do_usb_hole   = 1;              // USB jack hole to put cable into a board

do_display    = 1;              // Hole for display (number is display type, 1=1.3" OLED)

// -----------------------------------------------------------------------------------

// A couple references useful to place items relative to center lines

center_X      = (inside_width/2) + wallThickness;   // Useful for centerline of width

center_Y      = (inside_length/2) + wallThickness;  // Useful for centerline of height

center_height = (inside_height/2) + wallThickness;  // Useful for centerline of height

// Paramters for the lid and general construction usage (some a bit obscure)

extra_lid_thickness = 0.5;      //Need to read the code to understand this, just leave it if not

lidThickness  = wallThickness + extra_lid_thickness;  // total lid thickness

lid_fit_tol   = 0.2;            //Smaller for tighter lid. Use 0.4 for loose

lid_lip_depth = 2;              //depth the lid lip drops into the main body

fnDflt        = 36;             //Quality. Number of segments to approximate circle

                                

// The 4-board standoffs in the call to 'standoff' 

pcbWidthEsp32 = 42;             // Mark-Toys Esp32 pcb

pcbLengthEsp32= 32;             // Mark-Toys Esp32 pcb

pcbWidthArNan = 41;             // Arduino Nano pcb

pcbLengthArNan= 15;             // Arduino Nano Pcb

pcbOriginX    = 7;              // X for first origin standoff (easily move entire 4 standoffs)

pcbOriginY    = 7;              // Y for first origin standoff (easily move entire 4 standoffs)

pcbWidth      = pcbWidthEsp32;  // spacing between PCB holes on one side

pcbLength     = pcbLengthEsp32; // spacing between PCB holes on one side

standoffDia   = 4;              // Diameter of each PCB standoff and other standoffs

holeM2p5      = 2.3;            // Hole size for M2.5 screw

holeM2p0      = 1.8;            // Hole size for M2.0 screw

pcbScrewHole  = holeM2p5;       // screw hole size for PCB screw

oledScrewHole = holeM2p5;       // Screw hole size for OLED display

// Parameters for hole in side for USB jack

usbSizeY      = 12;

usbSizeZ      = 8;

usbHoleYEsp32 = pcbOriginY + 23.5 - (usbSizeY/2);   // Place usb jack for Esp32

usbHoleYArNan = pcbOriginY +  7.5 - (usbSizeY/2);   // Place usb jack for Arduino Nano

usbHoleY      = usbHoleYEsp32;

usbHoleZ      = 4.5;

// OLED Display Hole and standoffs

// Win size and holes remain, just change oledOrigin values to move display

oledWinWidth  = 32;             // Side to side window size

oledWinHeight = 20;             // Top to bottom windown size

oledOriginX   = 45;             // Places OLED display with 1 corner standoff

oledOriginY   = inside_length - oledWinHeight - 11; // Places OLED display 1st standoff

oledHolesX    = 30;             // Distance between standoffs in X

oledHolesY    = 28.5;           // Distance between standoffs in X

outside_width = inside_width + wallThickness * 2;

outside_length = inside_length + wallThickness * 2;

//Standoff module will render 4 standoffs for a PC board

//

// height    Height of the standoff above the base

// diameter  Outer diameter 

// holeDia   Diameter of the hole in the standoff

// firstTX   X location of lower left first standoff center

// firstTY   Y location of lower left first standoff center

// firstTZ   Z location of base of the standoffs

// pcbWidth  X distance between centers of standoffs

// pcbLength Y distance between centers of standoffs

// fn        A quality number. # of segments to approximate circle shapes

//

module standoff(height, diameter, holeDia, firstTX, firstTY, firstTZ, 

           pcbWidth, pcbLength, fn=fnDflt){

    //Standoff 1

    difference(){

        translate([firstTX, firstTY, firstTZ])

            cylinder(h=height, d=diameter, $fn = fn);

        translate([firstTX, firstTY, firstTZ])

            cylinder(h=height, d=holeDia, $fn = fn);

    }

    //Standoff 2

    difference(){

        translate([firstTX+pcbWidth, firstTY, firstTZ])

            cylinder(h=height, d=diameter, $fn = fn);

        translate([firstTX+pcbWidth, firstTY, firstTZ])

            cylinder(h=height, d=holeDia, $fn = fn);

    }

    //Standoff 3

    difference(){

        translate([firstTX, firstTY+pcbLength, firstTZ])

            cylinder(h=height, d=diameter, $fn = fn);

        translate([firstTX, firstTY+pcbLength, firstTZ])

            cylinder(h=height, d=holeDia, $fn = fn);

    }

    //Standoff 4

    difference(){

        translate([firstTX+pcbWidth, firstTY+pcbLength, firstTZ])

            cylinder(h=height, d=diameter, $fn = fn);

        translate([firstTX+pcbWidth, firstTY+pcbLength, firstTZ])

            cylinder(h=height, d=holeDia, $fn = fn);

    }

}

// Form solid rounded box of outside dimensions

// x,y,z are outside dimensions of this solid box for the chassis

// r     This is a rounding factor to form rounded edges

module rounded_box(x,y,z,r){

    translate([r,r,r])

    minkowski(){

        cube([x-r*2,y-r*2,z-r*2]);

        sphere(r=r, $fs=0.1);

    }

}

// A non-translated USB jack hole expected to be at 0 X side along the Y-Z side

module microUsbHole(y, z) {

    rounded_box(6, y, z, 1.0);

}

// A rectangular hole for display that is offset from mounting hole origin

// This is for a 1.3" OLED display 

module oledWindowHole(oledOriginX, oledOriginY, oledWinWidth, oledWinHeight) {

    

    //Taper on the window which makes it more complex. 

    translate([oledOriginX-1.5,oledOriginY+5,-lidThickness-1]) 

        chamferCube([oledWinWidth+1, oledWinHeight+1, (lidThickness*2.5)], 

            chamfers = [[1, 1, 1, 1], [1, 1, 1, 1], [0, 0, 0, 0]], 

            ch = 1, ph1 = 1, ph2 = undef, ph3 = undef, ph4 = undef, 

            sizeX = undef, sizeY = undef, sizeZ = undef, chamferHeight = undef, 

           chamferX = undef, chamferY = undef, chamferZ = undef);

    

    // Straight edges no taper

    //translate([oledOriginX-1.5,oledOriginY+5,0]) 

    //    rounded_box(oledWinWidth, oledWinHeight, lidThickness+1, 0.1);

}

// The standoffs for the OLED display. Needs to be separate

// 4 standoffs for m2.5 5mm long wood screws are placed with one hole's x,y

// All the parameters are globals but placement is with oledHolesX and oledHolesY

module oledStandoffs(oledOriginX, oledOriginY) {

    // OLED PC standoffs height, diameter, holedia, X1, Y1, Z1, pcbWidth, pcbLength, fn=quality

    standoff(2.5, standoffDia, oledScrewHole, oledOriginX, oledOriginY, 

        wallThickness+extra_lid_thickness, oledHolesX, oledHolesY, fn=fnDflt);

}

// A round hole in the front panel where it is placed by x,y and has diameter in mm

module holeInLid(x, y, diameter) {

    translate([x, y, 0])

        cylinder(r=diameter / 2, h=lidThickness + 1, $fn=fnDflt);

}

// Form the main box without a lid.

// Remove the call to standoff() if no PC board standoffs are required

module main_box(){

    // 

    difference(){

        difference() {

            difference(){

                rounded_box(outside_width, outside_length, 

                    inside_height + wallThickness + 2, edgeRadius);

                translate([0,0,inside_height + wallThickness])

                  cube([outside_width, outside_length, inside_height + wallThickness * 2]);

            }

            

            // Subtract away inside open space for the box

            translate([wallThickness, wallThickness, wallThickness])

              cube([inside_width, inside_length, inside_height + wallThickness]);

        }

        

        if (do_usb_hole > 0) {

            // Make a hole for USB power jack

            translate([0, usbHoleY, usbHoleZ])

              microUsbHole(usbSizeY, usbSizeZ);

        }

    }

    

    if (do_pcb_mounts > 0) {

        // height, diameter, holedia, X1, Y1, Z1, pcbWidth, pcbLength, fn=25

        standoff(3.5, standoffDia, pcbScrewHole, pcbOriginX, pcbOriginY, 2, 

            pcbWidth, pcbLength, fn=fnDflt);

    }

}

// Form a lid with a lip to fit within the main body

module lid(){

difference(){

    rounded_box(outside_width, outside_length, wallThickness * 4, edgeRadius);

    translate([0,0, lidThickness])

        cube([outside_width, outside_length, inside_height + wallThickness * 4]);

}

//Lip to fit within main body is added here. lid_fit_tol defines how tight lid fits

lip_width = inside_width - lid_fit_tol;

lip_length = inside_length - lid_fit_tol;

translate([(outside_width - lip_width)/2,(outside_length - lip_length)/2, wallThickness + 0.5])

    difference(){

        cube([lip_width, lip_length, lid_lip_depth]);  // solid cube over full lip area

        translate([wallThickness, wallThickness, 0])

                // Subtract away main inside area so we have only thin lip

            cube([lip_width-wallThickness*2, lip_length-wallThickness*2, lid_lip_depth+1]);

    }

}

// --------------------------------------------------------------------------------

// --------------------------------------------------------------------------------

// Render the full box body then the lid

//

main_box();

// Render the lid off to -x area and positioned relative to OLED Origin standoff

translate([-outside_width-10,0,0]) {

    difference() {

        

        // Render the lid which will be solid with a lip then be modified with holes

        lid();

        

        if (do_display > 0) {

            // Hole for the OLED display itself.  

            oledWindowHole(oledOriginX, oledOriginY, oledWinWidth, oledWinHeight, 6);

        }

        

        if (do_lid_holes > 0) {

            // Define holes X,Y, diameter in mm for switches and pots and jacks here 

            holeInLid(center_X + 10, 13, 6.2);  // pushbutton or switch 

            holeInLid(center_X + 30, 13, 6.2);  // pushbutton or switch 

            holeInLid(22, 50, 6.2);  // pushbutton or switch

            holeInLid(22, 34, 8.3);  // Potentiometer

            holeInLid(14, 13, 8.3);  // Potentiometer

            holeInLid(32, 13, 8.3);  // Potentiometer

        }

    }

    

    if (do_display > 0) {

        // OLED PC standoffs at this origin

        oledStandoffs(oledOriginX, oledOriginY);

    }

}

[Sergei Grichine]

May I offer my collection of prints in OpenSCAD:

https://github.com/slgrobotics/Misc/tree/master/OpenSCAD

I must confess that all my attempts to use WYSIWYG CADs failed miserably, but after a very short learning period OpenSCAD became a go-to tool.

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Best Regards,

-- Sergei

[Richard Chycoski]

I agree - OpenSCAD is a fantastic tool.

If you need WYSIWYG, this isn't your tool, but if you "think in numbers", this is it!

Like Sergei, I do much better with numbers than WYSIWYG CAD tools. It took me a little bit to learn how to make the shapes that I want, but once I got the hang of functions like 'hull', it was off to the races!

You do have to get used to using the 'translate' function, but I learned this a long time ago programming PostScript.

I have some box functions that I've used to build a custom cover for the end of my 3d printer's power supply, and 'launch button boxes' for pneumatic 'rockets' for a physics lab at the local high school, and I want to extend the modules further for more general use. I'm currently getting ready to print a replacement bracket for one of my fridges using the same box tool modules.

My approach to modules is a little different than Mark's - I have separate modules for each of the options, and use union and difference functions, then call the modules as needed after the basic box module has been called, rather than having option variables. This lets me do things like adding multiple replicas of the same options at different locations on the box (e.g., multiple potentiometer or switch holes on different locations on the box). I've yet to create top/bottom/left/right/front/back modules to take the hassle out of translate calculations, but these are on my list of things to do.

I do want to make a more general box module with direct options for lids, screw holes and such that are the parts of a "basic box" (much as I would find in a store-bought box), but I'll leave the customisation to separate modules as I do now.

I really like being able to create absolute custom plastic boxes! I was 3/4 of the way through a project using a couple of ATmega 328s (programmed in an Arduino) with optical encoder knobs, push buttons, switches, and an LCD display, to be used as a 'control panel' for other projects and my HP scope-with-no-knobs (ech!).

I had bought a commercial plastic box that I wedged everything into - but with some compromises. I'm going to build a custom box that will make it easier and more comfortable to use.

I highly recommend that you try building some OpenSCAD modules 'from scratch', to get used to its basic building blocks, especially hull, translate, union, and difference. Try building a all-rounded-edge box using 'sphere', 'translate', and 'hull'. Next, try a box with rounded edges on the top and sides, but with a flat bottom.

Now put some holes in the box for switches, displays, connectors, and such.

Don't worry too much about programming style while you get used to OpenSCAD functions, but after you learn how to use the functions you can build 'cleaner' modules to make it easier to work on them over time.

(Sorry, long time professional programmer advice!)

Once you get used to the OpenSCAD functions, you can take available modules and customise them as needed. My first use of OpenSCAD was to make a knob for our shower - I took one of the modules from thingiverse and modified it to fit - this was a bit puzzling, but I did get a working shower knob. I would have had a much easier time of it if I had created some of my own modules first - and the knob would have looked much nicer, too! That reminds me, I do need to redo that project... so many projects, so little time!

- Richard, VE7CVS

On 3/21/21 7:22 AM, Sergei Grichine wrote:

May I offer my collection of prints in OpenSCAD:

https://github.com/slgrobotics/Misc/tree/master/OpenSCAD

I must confess that all my attempts to use WYSIWYG CADs failed miserably, but after a very short learning period OpenSCAD became a go-to tool.

On Sun, Mar 21, 2021 at 3:30 AM Mark Johnston <mjst...@gmail.com> wrote:

Recently Fusion360 which I have greatly enjoyed is expired and harder for me to get re-enabled for a few reasons.

I am now thinking this will be my approach:

- For quick designs that are a fast part to solve some specific need I will move back towards the usage of TinkerCad.   This is not the purpose of this post but I do endorse Tinkercad to be a part of the set of tools to be considered for quick parts.

- OpenSCAD has it's place as a fantastic way to have certain often used but often different designs and this is the purpose of this post.

I'm starting to build up code for OpenSCAD due t Fusion360 starting to be more limiting and wanting full buyin (fees per month) to get me what I used to use for hobby work for free.  This is inevitable with many of the  'first hit is free' packages so is not unexpected.

OpenSCAD is in fact ideal for very common things you may want to make such as a case for some project and that is what I am going to give out today.

I present here source code for my current (but always morphing) OpenScad 'project box' code.   This box allows enabling of many things or just generating a basic 'box'.

Best to RTFS but in short here is what this offers at this time as given here:

- A basic box with a lid that fits nicely without screws.  glue it with mild glue if you must

- Holes for potentiometers or switches in the lid

- Standoffs for your PC board. In this case my Esp32 Mark-Toys.com Esp32 dev board

- Display board with standoffs.  In this case my favorite 1.3" OLED on I2C board

ALL of this stuff can be considered a 'template' for your own needs and just supplies you with a sort of 'boilerplate' for your own stuff if you 3D print things like cases WHICH is in fact one of the most useful things I do with my printer although I do many other parts too.

Download OpenSCAD on your platform of choice then you can use this source and it shows nicely the box you will end up with.

After that use 'File Export' and export the .stl code then form gcode using something like Cura or other more powerful tools.  Print it and PRESTO!  Custom case!

Sadly there seems to be no nice file attach so here is the scad source (in the raw).

I will try to post this in a better way like on my Thingiverse site but anyway, here we go!

// --------------------------------------------------------------------------------------------------------------------------------

// ProjectBox source code for use with OpenSCAD 

...

--

Best Regards,

-- Sergei

--

[Chris Albertson]

My criteria for 3D CAD is "Could I make the plastic housing for a typical battery-powered drill with rubber overmold."  These cases are sculpted to fit the hand on the outside and have rounded corners but inside there are geometric and precision placed mounting points and threaded holes for the motor and gears.

I'd not going to make a drill but if my CAD sysm can't make a drill all my robot parts will be simplistic box-like geometric shapes and not the organic compound curves I want.

Also, while the free version of Fusion 360 does lack features will you really miss 5-axis CAM?  Do you have a 5-axis milling machine.   My machine has only 3 axis so I don't mind that the free version of Fusion only does 4-axis CNC milling.  Even the crippled free version of Fusion is still more capable than any of the others.   Only OnShape comes comes close it you don't need CAM to drive CNC machines.

I think CNC is relevant now even to home based hoby users.  The cost has come down to under $2k and I see that 3D printing is not cutting it for robots with legs, the forces are too high for plastic.

OpenSCAD is good for those few parts that can be define algorithmically.  Gears are a prime example.   But I cheat and download finished gear CAD files from McMastr Carr and the like and never have to design gear tooth profile.

To view this discussion on the web visit https://groups.google.com/d/msgid/hbrobotics/CA%2BKVXVMQzwZhzypLMKnOavsRqTNWc-GQ-NbPiUE4%3DdcjYFQiFA%40mail.gmail.com.

--

Chris Albertson
Redondo Beach, California

[Chris Albertson]

On Sun, Mar 21, 2021 at 10:08 AM Richard Chycoski <ve7...@gmail.com> wrote:

I agree - OpenSCAD is a fantastic tool.

If you need WYSIWYG, this isn't your tool, but if you "think in numbers", this is it!

But many times you can't.  Try designing a pair of eyeglasses frames on OpenSCAD.   It only works for the special cases where you can use simple geometry.     Or worse, it forces you to use only simple geometry to solve every problem.

It is the same thing as when all we had were hand driven milling machines.   Every part had to be designed such that it could be cut by turning only one hand crank at a time.  This constrains the possible shapes.  But now computers can run 5 axis all at the same time we can make different shapes.

[Richard Chycoski]

I could probably make eyeglass frames rather quickly using OpenSCAD, if you like them in total-nerd-style. :-)

I've always been about function over form, and might even suggest Blender as an open package that is much more capable of 'form' - but the learning curve is apparently rather high (I have not yet learned Blender myself).

Here's a short tutorial on how to make complex organic shapes using OpenSCAD:

http://makerblock.com/2014/03/openscad-intermediates-how-to-make-complex-organic-shapes/

Could you make the outside of such a shape like this, and the inside like a handrill? I don't know that yet.

But - would you imagine this project done in OpenSCAD? It was! :

https://www.thingiverse.com/thing:2409917

For more examples, see:

https://www.thingiverse.com/tag:openscad_library

When I first started using OpenSCAD I thought that it was very limited in capabilities and that I wouldn't get far with it, but I liked the non-GUI approach, so I gave it a try. It may surprise you in what it can do. It did, me!

I don't suggest that OpenSCAD is for everyone or every project, but for me, I could produce usable 3d models to print much more quickly and more accurately than with the free/open GUI CAD tools that I tried. I'm not interested in using the restricted versions of commercial tools as these are getting more and more constrained and restricted over time. I'd rather invest my time in learning a tool that won't become pay-only in the future, requiring me to go off and learn yet-another-tool. This has become so common for CAD tools that it's not a matter if your favourite 'free' (gratis - as in beer) commercial tool is going to get locked down - it's when.

To me, the best of all worlds would be a free (libre) tool that has full GUI and parametric entry. I don't live in that ideal world, and do not have the time nor inclination to embark on a project to build such, so have chosen a tool that my brain can wrap its head around (hmm, how does that work? :-) and get useful results.

I understand that not everyone has the same requirements - to each his own. C'est la vie! :-)

- Richard, VE7CVS

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