21. February 2017

BeTrue3D Printer build part 5 – LEDs

By BeTrue3D

You might have read my part 3 where I had a section on installing LEDs.

Here are some thumbnails from the previous post.

This blog-post is all about getting it to work, including installing a front-mounted simple mechanical switch.

  1. Planning
  2. Execution
  3. Mounting
  4. Getting 12v in 24v system?
  5. Testing and wiring
  6. LED Installation
  7. LED Testing
  8. Video testing LEDs

I’ve tried taking some more photos due to popular demand 🙂


I had a hope the small on/off switch could be placed as you see on the photo. I removed the bracket, measured up, and drew some lines. I made 0,5mm extra space between the switch and extrusions – giving me some margin of error to work with.


I started out using a small quality drill from proxxon with a pointy tip to get an accurate starting point (I don’t know one of those fancy tools to make a small indentations)

After I had it going I switched to a more sturdy drill and worked on it. Using plenty of cutting oil and cleaning away aluminium parts all the time.

I used a tray as a drill-platform as I do not own a proper workbench (I have a small portable one, but it was packed away). I’ve put it over the sink in the kitchen. Worked great as the metal parts just ended up in the sink, and the drill didn’t go down into a tabletop or similar.

After finishing the pilot hole I measured the diameter I needed for the switch and used the right sized drill for the job.


The on/off switch is within the bracket, so that’s as planned. I had previously used the switch, so allready had in and output wires on it. I use the male plug (2 exposed pins) as input and the female connector as output. Doing it like this, so any wires/plugs with active current is not in the form of bared metal pins.

I soldered on male connectors to the wires coming from the LED strips. Using a portable gas weller solderpen I had from my time as network techie 🙂

I took a photo of the small hand tool, as that is enough of a tool to crimp on most connectors. A proper crimping tool is prefereble, but if you only need it for 1 project it is fine to skip buying it.

Getting 12v in 24v system?

So, the next step is to get 12v in my 24v system, as the LEDs are running on 12v. The Duex5 can be configured to output 12v, so I might go that route eventually, but I’d like to initially have power available to the LEDs as soon as the PSU is on, regardless of setup.

I’m using a small “hardwired” 24v DC to 12v DC step down. It can even output at 3amp, which is a lot for such a small thing! I like these things compared to the one you adjust manually, as they never put out that annoying high pitch coil whine you sometimes get from “normal” DC-DC step down modules.

Photo shows front and rear of the board.

I’m going to solder on small pins, as I’m not sure what I want in the longer run regarding these. Alternative is to just solder on the wires.

Using the foam pads to keep the pins in place while soldering them on.

Ready, get, set go, and finished. The fan is homemade with a carbon filter.. it’s really super nice.

Testing and wiring

I’m using standard female dupont connectors and just using standard  tools.

I have a super nice Lambda Vega-Lite 550 powersupply I found at a bargain price. Going to convert it into a proper “lab psu” at some point with banana plugs etc.

I’m making sure the output is in fact 12v and not something else.

Putting the wires in place using duct-tape (untill I can print some other cable-management things) and mounting the small Step Down below the Duex5. I’ve just used double-sided tape for now, and have not wired it up any further.. propably going to be directly hooked up to the PSU though.

LED installation

This should had been in the previous post, but since I didn’t take any photos of it, I do it now. You can see how the power input comes up through the floor paneling through a small indentation, and each section of the LEDs are conneted using a small piece of wire.

I’ve put white heatshrink over the exposed solderpads.

LED testing

It might be hard to see, but here are 2 photos showing the BeTrue3D Printer with LEDs on and off.

Video showing a test of the LEDs