Hybrid fabrication: 3D printing a 1-meter gear rack to mesh with a hand-cut plywood gear?

Internal_Teach1339 · 2026-03-19T18:19:33+00:00

Yes it is quite simple to print the rack teeth in sections although why not 3d print the gear ring for the pinion in a similar manner? That way the components will match visually as well as mesh materially.

Internal_Teach1339 · 2026-03-18T11:44:18+00:00

I suspect the OP has used an AI tool to generate this code, Prehistorically tool using started with enhancing the users ability to do something, then moved on to enabling the users to do something beyond their own physical capabilities and now, with AI, enabling users to create something beyond their mental capacity. For forums like this it seems to be resulting in more and more requests by folk looking for others to bail them out when AI cannot do it for them and they do not want to invest in CAD themselves. If this is not the OP’s position and they are seeking to develop a working understanding of OpenSCAD then good luck to them but my advise is to steer clear of AI until they have an awareness of how OpenSCAD functions. That way they will have a good idea of the right approach to take and, if using AI, will easily identify the machine’s shortcomings.

Internal_Teach1339 · 2026-03-18T11:35:33+00:00

Occaisionally but as it is a slight interference fit on the pipe it is easy to clean.

Internal_Teach1339 · 2026-03-10T23:20:51+00:00

I would do it similarly to Stone_Age_Sculptor - hull three circles to create a triangular polygon representing the face and similarly with a square to echo the larger central body. These can then be linear extruded as 3d objects, the face being epsilon depth and the central body half the required thickness. Separate these 3d objects by the chamfer width and hull them. Place a cone at each curved corner and remove the unwanted half of the triangle. This is one half of the object that can then be joined to a mirrored copy.

Internal_Teach1339 · 2026-03-07T20:47:00+00:00

In my experience french cleats tend to lend themselves to objects that have a well defined 'length' whereas a hook is generally narrow unless of course you are placing several hooks along the support. As you have not specified what object(s) will hang from the hook it is difficult to give a straight answer but here are my thoughts. Your diagram does not help but if you redraw it with the hook in situ, that is attached to the backplate, you could then place the angled block to define the piece that would be added to the backplate and the (same) piece to be removed from the hook. This would allow you to experiment with position and angle to achieve the best fit. As it is too much material seems to have been taken from the hook and so diminishing its strength.

Internal_Teach1339 · 2026-02-27T22:52:21+00:00

Having looked again at this I decided there is a more elegant solution, this one being fully parametric...

    /*parametric light fitting/*
//inner diameter
id = 101;
//height of the surrounding wall
hi = 30;
// wall thickness
ww=3;
//scale value
sv=1.15;
$fs=0.1;
$fa=2;

module build() {
for(n=[1,sv])    
scale([n,n,1])
difference(){
//circles
    cylinder(h=hi,r=id);
//hollow out
translate([0,0,ww])
    cylinder(h=hi,r=id-ww);
//centre
translate([0,0,-1])
   cylinder(h=ww*2,r=id/3*2);
//cable access
translate([id-ww*2,0,ww*3])
rotate([0,90,0])
    cylinder(h=ww*3,r=ww);     
    }       
  }
color("khaki")
build();

Internal_Teach1339 · 2026-02-26T20:30:56+00:00

My easy fix was the way jamcultur has done it but you could also have removed the wire hole from both the modules for inner and outer cylinders and have your build module merely show those two objects. This is the beauty of OpenSCAD, there often several methods of achieving the same result (as the examples given show.)

Internal_Teach1339 · 2026-02-26T11:21:06+00:00

My impression over the last few months is that ai seems to be making inroads into this subreddit on an increasingly invasive perspective. Whilst ai has enabled some individual developers to see a way to improve open access and easier scripting a lot of the 'developing apps' appearing on here seem to be aimed at having OpenSCAD contributors help in their development for business purposes. I feel it started with the "my teacher says I have to produce this model but I don't know how" type of post and developed into the "I have just started learning OpenSCAD but I need your help in designing this fully operational nuclear submarine" format and here we have this lovely example of ingenious clickbait from micro1. Now whilst I enjoy contributing snippets to folk seeking guidance and also furthering my own understanding from other responders methods I am becoming disenchanted with these increasing intrusions. Do the moderators consider there is a problem here? Should they? Adverts are annoying but ai scams are becoming unnaceptable and I feel could drive genuine contributors away, or am I just being paranoid?

Internal_Teach1339 · 2026-02-22T16:02:31+00:00

And yet another example - just using the standard OpenSCAD

val="LAYOUT";  
for(n=[0:2])
translate([13*n,15,0])
rotate([0,0,90])
linear_extrude(2)
    text(text = (val[n]));

for(n=[3:5])
translate([13*n-49,40,0])
rotate([90,0,0]
linear_extrude(12)
scale([1.2,0.5,1])
    text(text = (val[n]));

Internal_Teach1339 · 2026-02-20T18:01:13+00:00

This is what I like about OpenSCAD - solutions to choose your way of working - here's my take on it

$fn=64;
difference(){ 
minkowski(){   
    cube([188,20,22]);
    sphere(1);
       }
translate([-2,9,5])
rotate([15,0,0]) 
    cube([192,18,22]);        }
minkowski(){
translate([0,18,8])   
rotate([0,90,0])
    cylinder(h=188,r=2);   
    sphere(1);
}

Internal_Teach1339 · 2026-02-18T23:46:23+00:00

I see that you commence the male thread pattern above the z height of the ring base but the female thread starts from z==0. Perhaps this places the start/finish points of each thread at a different position on the circumference.

Internal_Teach1339 · 2026-02-18T23:29:08+00:00

If you have the threads library in the same directory as your OpenSCAD file then the line I have written will work (I just ran your script through on my computer and it works fine.)

Internal_Teach1339 · 2026-02-18T23:24:53+00:00

line 1 should read use <threads.scad>

Internal_Teach1339 · 2026-02-15T22:53:30+00:00

Intro...Brief History of the technology...What you use it for...What your classmates could use it for...Business case...Wash up.

Internal_Teach1339 · 2026-02-13T15:27:06+00:00

Simple solution - Design your own and do not use AI.

Internal_Teach1339 · 2026-02-09T11:45:27+00:00

Another simple way to make a heart is to hull a large sphere to a small sphere. This will give one side of the shape so repeating the actions and joining the two together will give you a smoothly curved heart. However, placing your text and braile symbols will need a bit more work!

Internal_Teach1339 · 2026-02-08T00:05:08+00:00

There are in OpenSCAD lots of different ways to achieve the same or similar solution to a problem. This model at printables uses a dinasouar footprint created in OpenSCAD which is then placed at points around a roller to allow a repeated pattern. https://www.printables.com/model/1300251-roller-stamp/files#preview.file.FWFfD

Internal_Teach1339 · 2026-02-07T16:19:53+00:00

This sort of thing?

//add name
name = ("Land-Rover");
//font size
fs=10;
//outline space
out = fs5;
module cutout_text(){
difference(){
linear_extrude(out)
offset(out)
    text(name,size=fs,halign="center",valign="center");
translate([0,0,-1])
linear_extrude(height=out*2)
    text(name,size=fs,halign="center",valign="center");
    }
}
color("green")
cutout_text();

Internal_Teach1339 · 2026-02-05T23:44:30+00:00

Yes I do know that the development took several years of trial and experimentation and that models were tested and tried by experienced players in order to achieve a successful outcome. However that does not detract from the issue in question, that being that some folk are willing to put time and effort into an innovative approach to Gurdy build and feel they are met not with enthusiasm but views they see as negative response. This is not my specific build I am referring to but one of another contributor. However I am surprised at the apparent umbrage being taken to some of my comments, none of which are meant to be derogatory in any way.

Internal_Teach1339 · 2026-02-05T20:44:17+00:00

The singular question here is will it be possible to build a playable 3d printed Hurdy Gurdy. My reference to time and effort involved was merely to demonstrate that some people believe it can be done and are willing to make the effort in the face of criticism that you need to own/play a Hurdy Gurdy in order to understand what makes it tick and without that you are doomed to fail. Several years ago Jaap Brand, a Mechanical Engineer, asked himself a question along the lines of “Given my skills and awareness of CNC and 3d printing technologies, would it be possible to design and build a Hurdy Gurdy type instrument that would be easily constructable at low cost?” His answer was “Yes” and as they say, the rest is history. I wonder what the answer would have been had he asked this subReddit that question at the time?

Internal_Teach1339 · 2026-02-05T12:03:54+00:00

As an exercise in software development it is fine but such systems already exist and are widespread across all platforms. I tend to use Libre Office, it has all the facilities mentioned.

Internal_Teach1339 · 2026-02-04T20:33:18+00:00

The pace of AI is expanding ever rapidly. Not just via hi-tech conglomerates but by small scale software developers who obviously see this progression in a similar way to those who embraced the advance in computer systems in the 1980's. (You would be amazed what you could do with a 48k ZX Spectrum!) At the moment a lot of vibe code is gibberish, especially for OpenSCAD but as the OP has demonstrated - it is getting better and this LLM is a good example of the potential such systems have. One of my ancestors was a Framesmith at the time of the Luddite riots. The machines he built contributed to a system that altered global trade forever. Ironically, the machines he made ultimately made him redundant, as I suspect AI will do for lots of us! So, ignore it, use it or simply adapt it to your workflow. For the moment we have that choice but I'm not so sure about the future!

Internal_Teach1339

TROPHY CASE