Construction of Telecortex LED panels

This post will be talking about how the Telecortex LED panels are constructed. The aim was to make something cheaply, quickly and for it to be transportable (light). There are two sizes of panel to suit the 2V icosahedron dome design, the design was planned out in CAD and then transformed into the real world with a lot of time and effort by myself and friends.

The LED panels consist mainly of a a material called coreflute, it is basically a plastic cardboard, often used for signage and is just about perfect for our application. The flexibility of the coreflute has caused us some issues (talk about that later) but it is quite a robust material and very cheap.

 

To cut the large rectangular coreflute panels to size we built a temporary table saw out of plywood and a circular saw (I wouldn't advise doing this but necessity is the mother of all inventions). We also built an adjustable angle guide to aid us in cutting the sheets of coreflute consistently, unfortunately I don't have any photos but it was built from two pieces of striaght wood, a few hinges and a large piece of threaded rod to act as the adjusting side.

 

The size of each LED panel meant that we couldn't fit the whole panel in one contiguous coreflute sheet, to solve that we cut each panel as two pieces and then using thin wooden dowels pushed into the corrugations. Hot glue seems to be one of the only things that sticks to coreflute, we used a thin strip of coreflute hot glued along the spine to keep the two halves from separating.

 

The panels were marked out where an LED strip should be placed, the LED strips were cut to length and then carefully stuck down along the marked lines. We cut wires to the right length to go between the LED strips in the centre to carry power and 2 signal wires were done between the start and end of each LED strip to form a zigzag pattern of LED strip.

 

Due to the flexibility of the material we were getting the solder joints breaking over time due to metal fatigue. To mitigate this we have added aluminium extrusions to the front and back of the panels, this stiffens it up significantly and prevents the hand soldered wires from breaking due to metal fatigue.

Each LED panel has a 48V>5V power supply as discussed in one of the prior posts, this is cable tied to the backside of the panel. The photo below is prior to adding on the aluminium extrusions for rigidity.

The first iteration of the control electronics simply had a 4 pin automotive style connector on each panel which had 4 connections, 48V, SPI data, SPI clock and ground. This was good for a quick assembly and cheap but we were getting signal drop outs which would cause large visual glitches.

This was a lot of labour to produce each panel but they look amazing when running together.

In a later post I will talk about how we upgraded the electronics to fix the electrical interference and visual glitches by using a CAT6A network cabling instead of individual wires like the earlier version.

A faster way to batch export STEP files from Fusion 360

Recently, I have been using Autodesk Fusion 360 for some complex assemblies, which often means exporting a lot of individual bodies into STEP files. If you've done this manually before, you likely know the pain of right-clicking, selecting export, waiting, and repeating the process for every single part.

I initially wrote a basic script to automate this by simply hiding all the bodies except one, exporting the main document, and then repeating the process for the next part. It worked, but there was a massive catch, very time the script toggled visibility and exported, Fusion 360 triggered a timeline recompute. Because my design was parameter-heavy with a long history, exporting a bunch of parts took an agonizingly long time while the Fusion interface locked up.

To get around this, I designed the script to completely bypass the timeline history bottleneck.

The Solution

My script takes a completely different approach to exporting. Instead of fighting the timeline on the main document, the script works like this:

1. It iterates through the design and finds every body that is currently set to visible.
2. It silently creates a temporary "Direct Design" document, which has no timeline history at all.
3. It copies the visible bodies into this temporary document while maintaining their exact global assembly positions.
4. It exports each one as a pristine .step file directly to a folder you select, and does it almost instantly.

Why it's useful

Because it uses temporary direct modeling documents, there are no parametric history recomputes. What used to take a few minutes now takes seconds. The script also preserves the global coordinates of every component, so if you bring the exported STEP files into a slicer or another CAD program later, they will all assemble perfectly in place.

For naming, it automatically names the exported files based on the component and body name (e.g., Bracket:1_Body1.step). This saves you from ending up with a folder full of files mysteriously named "Body1".

Using it is pretty simple. Just hide the parts you don't want, ensure the bodies you do want are visible, and run the script from the Fusion 360 "Scripts and Add-ins" menu.

In Action

First, make sure the bodies you want to export are visible in your browser tree:

Next, pull up the Scripts and Add-ins dialog and run the step_exporter script:

It will prompt you to select a destination folder for all of your STEP files:

A quick progress dialogue pops up while it churns through the visible bodies (since it skips history recomputes, this goes very fast):

And just like that, your folder is fully stocked with cleanly named STEP files, ready to drop into your slicer or hand off!

All the python source code and instructions are available on my github here.