“mass” production

The demand for my CD-changer emulator is picking up, so I’m making several boards at the same time. Placing of the components on the board by hand and re-flow with hot air.

These 6 board take about 4 hours in this stage plus another 4 hours or so to solder the optical connector and other connectors. My hands feel tired after a while. I’ve heard that good scotch helps with this condition.

SMD stencil printer is so cool

If you can’t recognize what this is, here is an explanation.

When creating PCBs, one can order a stencil – usually from a thin sheet of stainless steel. On this stencil, there are cut small holes (with a laser cutter) where one is supposed to apply solder paste on the PCB.

So the operation is: you align the stencil on top of the PCB; then squirt some solder paste on top of the stencil; then use a flat “applicator” to smudge the solder paste over the stencil holes. In the end, you lift the stencil up, and you end up with the solder paste applied in a thin layer over the solder pads on the PCB.

To aid in this whole process is this contraption – a stencil printer. You align the stencil on the device and put come L shaped holders on the bottom to hold the PCB in place. The bolts on the bottom are to help to align the stencil and the PCB. When the alignment is achieved you put the PCB in the holder on the bottom; lower the stencil; apply solder paste; lift the stencil; remove the PCB. The whole solder paste application takes about 1 minute.

I should have gotten it sooner. My only regret is not getting a larger size printer, as you can see the stencil frame is a bit larger than the printer base – it still works though.

Fun with colors

I’m very pleased with the new box design. It allows me to play with multiple color plastic, so just in time I created a “4th of July” (red, white and blue) device edition.

The new Pi Zero version is ready

I had to re-design the new box. Before I was trying to make it from 2 parts – top and bottom. This process had issues because the bottom part would not 3D Print correctly – it would keep curling up due to stress in the ABS material.

So finally I made the box bottom from several pieces. The bottom has 4 curved corners and 4 side panels, which slide down – you can see one of the side “panels” in this picture.

Also, you can see the size of the old device version compared to the new version.

The new design is shaping up

I was not satisfied with the previous Pi Zero board, because it was larger than the Pi, so here is a new version which has the same size as the Pi Zero.

Here is the new board mounted on top of a Pi Zero:

The spacers are a bit too short – you can see the bolt hitting the HDMI connector.

Here is the final version in a new box:

The unsung hero – my first 3D printer

I got this great 3D printer – the Rigidbot – from Kickstarter. The project was only a year late, but they delivered excellent kit. As with many 3D printers it has become a labor of love.

Here it is pictured with a few upgrades, thanks to the excellent community wiki page as well as the Google Plus forum.

I printed so many connectors and parts for the CD-changer emulator project. It never broke down on me.

I changed the connector to the bed heater because the original was prone to melting down.  There are a few excellent upgrades for the printer offered by Peter Stoneham. I have his single extruder mount; ingenious belt tensioners; metal bearing holders. I also printed a few excellent mods by Walter Hsiao. He wrote an excellent article summarizing his updates.

The hotend is E3D V6 with an auto-leveling probe. I still use the original controller board with Marlin 1.1.8 and the original power supply. This GitHub repository has all the latest updates and modifications for Peter’s extruder,  16T pulleys & auto leveling probe.

Where are my Pies?


The Raspberry Pi foundation did something weird, and all Raspberry Pi model A+ disappeared from the market. I could not order anything.

A month later they announced a new board – the Raspberry Pi Zero. It was great except it was also made from unobtanium. I managed to get a grand total of one from an eBay scalper.

Anyhow, I had to design a new version of the CD-changer emulator which worked with the Raspberry Pi Zero because it looked like the days of the A+ model were numbered.

So this is the first board I did, which was just a bit bigger than the Zero itself. On the image, you can see the board in a new box for it. The Pi Zero is MIA.

Also, my SMD soldering skills have improved slightly.

Updated box design for the CD-changer emulator

This was one of my favorite color combinations for the box of the CD-changer emulator device. This version has vents on the side – not because the device was overheating, but the box was easier to print this way. Without the vents, the ABS plastic would curl up, and the box looked very weird.

With this particular unit, I had some trouble with the optical connector not locking to the plug and had to improvise with some wire to hold it in place.

By the way, this re-design of the unit box was prompted by customers returning the device in half-melted form. In the initial version, the box was printed out of PLA which was getting soft in the summer temperatures in Texas and Arizona.

So I had to print all plastic parts our of different plastic – ABS, which has a higher melting temperature.

The 14″ Jaguar navigation screen that never was

This is one of these projects that I never finished. I managed to hook up the Jaguar navigation unit to the Realtek LCD controller board and in turn to an old 14″ laptop screen.

I had to tweak the Realtek firmware a bit to accept the video signal from the nav unit, but you can see it was working fine.

The imaginary goal was to replace the LCD screen in the factory unit with a better resolution screen. However, in the process, I was not able to find anything I liked with a side that would fit the Nav unit and would not require major surgery.

In the end, it was a cool thing to play with, but never saw the light of day. Here are a few more pictures of the Nav UI.

As you can see the 14″ screen does not have the correct aspect ratio – the circle is a bit squished.

Here are a few pictures of a screen I was considering as a replacement of the factory unit, but in the end, it was just a bit too big.