tolv - a parametric light source

[kryptokommunist]

Hi there folks,

maybe some of you know me from the Jupyter Notebook GSoC project. This post is about a light object project that got me into using FreeCAD and this week I finally put in the finishing touches so it's almost ready for production. A friend of mine helped me designing a PCB and only a few details are missing. The LEDs to be used are RGB controllable, but only per stripe, something like these.

The name tolv refers to swedish for twelve since the lamp in the current configuration has twelve aluminium bars. The great thing about using FreeCAD is that the entire design is parametric, so different designs with varying number of aluminium bars, diameter, angles can be created in an instant.

While modelling the main issues I encountered where that FreeCAD (0.18 on ArchLinux) freezes after most operations for 10-30 seconds (probably due to the number of operations that are recalculated each time?) and then the naming of edges and faces change internally after deleting things or adding new things after older operations (I guess this refers to the topological naming issue?).

You can download the file here. Since I just got started with FreeCAD I'm sure there are a lot of things that go against best practice. So if you're interested in the project and find issues please let me know

I still need to integrate the KiCAD pcb design into the model and improve the attachment mechanism to fix the aluminium bars (preferably threaded inserts).

tolv_transparent.jpg (95 KiB) Viewed 3015 times

This part will hold everything together (aluminium bars and electronics) and will be 3D printed. The three holes on the top will be used to hang the lamp to the ceiling. Also a version with 2 meter long aluminium bars that just stands on the ground is planned.

tolv_1.png (262.31 KiB) Viewed 3015 times

tolv_2.png (237.59 KiB) Viewed 3015 times

tolv_3.png (216.32 KiB) Viewed 3015 times

tolv_pcb.jpg (160.09 KiB) Viewed 3015 times

phpBB [video]

[M4x]

Thank you very much for sharing! I'm on my phone right now but I'll check it out further when I'm at my PC.

Are you going to publish everything under a open licence? Do you have anything to share regarding the design process and so on?

What you've described is probably a Topological_naming_problem. Speaking of it: I think the dimension in your second drawing broke.

[kryptokommunist]

Are you going to publish everything under a open licence? Do you have anything to share regarding the design process and so on?

That is a good question, I definitely want to publish the sources. With licensing I'm not even sure how the CAD model is seen legally. If it's just like Code I'd do a GPLv3.

What you've described is probably a Topological_naming_problem. Speaking of it: I think the dimension in your second drawing broke.

Thanks for letting me know. This is also due to topological naming I guess. It's now fixed in the git repo.

So for the design process it all basically started with an art installation I did on a festival. The goal was to create the sensation of floating aluminium bars in the air. I already was thinking about how to streamline this into an solid object. Then some time later I came across an coat hanger and I remembered the previous light installation. The coat hanger design was actually more what I had in mind when creating the floating aluminium bars. From there it just took some time to start. The design process was quite straight forward. I basically just wanted to have a bunch of aluminium bars in this hourglass shape and starting from a cylinder and I incrementally improved the design.

garbicz.jpeg (229.18 KiB) Viewed 2740 times

coat_hanger.jpeg (72.52 KiB) Viewed 2740 times

[carlopav]

Really interesting! Nice work

[paullee]

garbicz.jpeg

This image looks awesome !

[paullee]

You can download the file here.

BTW, the link is not working

[kryptokommunist]

BTW, the link is not working

Fixed it, download away :

You can download the file here.

[paullee]

Thanks !

[M4x]

Are you going to publish everything under a open licence? Do you have anything to share regarding the design process and so on?

That is a good question, I definitely want to publish the sources. With licensing I'm not even sure how the CAD model is seen legally. If it's just like Code I'd do a GPLv3.

I've just looked into it because I'd like to publish the project I'm currently working on using a open license too. I've chosen the CERN Open Hardware Licence (OHL or CERN OHL) [check out https://en.wikipedia.org/wiki/CERN_Open ... re_Licence and https://www.ohwr.org/cernohl].

From the Wikipedia site "Open-source hardware" (Licenses):

Rather than creating a new license, some open-source hardware projects use existing, free and open-source software licenses.[41] These licenses may not accord well with patent law.[42]

Later, several new licenses were proposed, designed to address issues specific to hardware design.[43] In these licenses, many of the fundamental principles expressed in open-source software (OSS) licenses have been "ported" to their counterpart hardware projects. New hardware licenses are often explained as the "hardware equivalent" of a well-known OSS license, such as the GPL, LGPL, or BSD license.

Despite superficial similarities to software licenses, most hardware licenses are fundamentally different: by nature, they typically rely more heavily on patent law than on copyright law, as many hardware designs are not copyrightable.[44] Whereas a copyright license may control the distribution of the source code or design documents, a patent license may control the use and manufacturing of the physical device built from the design documents. [...]

and

The Open Source Hardware Association recommends seven licenses which follow their open-source hardware definition.[50] From the general copyleft licenses the GNU General Public License (GPL) and Creative Commons Attribution-ShareAlike license, from the hardware-specific copyleft licenses the CERN Open Hardware License (OHL) and TAPR Open Hardware License (OHL) and from the permissive licenses the FreeBSD license, the MIT license, and the Creative Commons Attribution license.[51] Openhardware.org recommended in 2012 the TAPR Open Hardware License, Creative Commons BY-SA 3.0 and GPL 3.0 license.

Regarding the CERN Open Hardware Licence (OHL or CERN OHL) from there homepage:

The CERN–OHL is to hardware what the free and open-source licences are to software. It defines the conditions under which a licensee will be able to use or modify the licensed material. It shares the same principles as free software or open-source software: anyone should be able to see the source – the design documentation in the case of hardware – study it, modify it and share it.

[Gregory son of Carl]

I've chosen the CERN Open Hardware Licence (OHL or CERN OHL)

I'll add that there are 3 versions of the CERN-OHL: The strongly-reciprocal(S), weakly-reciprocal(W), and Permissive(P). I'm no expert, but I will describe the differences as I understand them.

(S)strongly-reciprocal: the black hole license, share-alike and the kitchen sink. all revisions or modifications of the hardware must also be published under this license and any products included with the covered source become covered by the license too.
(W)weakly-reciprocal: the sticky license, share-alike, GPL for hardware. Revisions and modifications must also be published under this license, but products included with the covered source are under no obligation to become open-source.
(P)permissive: the leniant license, MIT or LGPL for hardware. Revisions, modifications, or any products included in the covered source are not required to also be published under this license.

A hardware project analogous to the FreeCAD project would most likely prefer the CERN-OHL-P.