20230924 Razor Crest Engine Stencils

20230924 Razor Crest Engine Stencils

You can immediately see how cramped my working space is.

This came about more than a month ago from JLCPCB but I was too busy to open it. Not only that, looking for a working space big enough was also another issue. To be honest, I forgot about the huge size of the solder paste stencil, which measures close to an A3 sheet give to take. So, it was quite a challenge to reveal it on my Works table where space is a premium.

After opening it, the first thing on my mind was, how the heck am I going to store this after use?


The solder paste stencil from JLCB PCB is a thin sheet of stainless steel metal. It has holes cut out so you can accurately apply the solder paste on the SMD solder pads on your PCB. Think of it as a form of silkscreen mask for colours. The stencil from JLCPCB is huge and it offers a usable area of 290mm x 190mm.

The metal stencil was protected by being sandwiched between two wooden boards.

The next step is to create a jig to secure the PCB under the stencil so that the stencil aligns as accurately as possible with the PCB’s solder pads. This is a very simple step but unfortunately, my PCB design is round and not rectangular. When I have more time, I will need to look into this issue. Do watch the YouTube video below, courtesy of Electronoobs, who demonstrates how the stencil is to be used.

YouTube video courtesy of Electronoobs and JLCPCB
The main intention of using this stencil is so that I can get more soldering done and in a more reliable fashion.
See those small little eight rectangles grouped together in two rows? There are 6 of them. These are for the SMD resistor arrays where it was so difficult to solder them reliably. I had to use plenty of solder flux and lots of checking to make sure those darn thing was soldered.
20230924 Razor Crest Engine Stencils
Looking at the board, there are at least a minimum of 112 soldering points to consider. This would take at least maybe close to an hour since most of the time was me double-checking the resistor arrays. Hopefully, once I get used to the solder mask, I can significantly cut down on the soldering time.
Trust me. There ARE 112 holes in there. Let’s say I use an average of 20 seconds to align and solder at least one component, a pair would take me, maybe, close to an hour and a half, including testing (OK, make that almost two hours).


When the stencils arrived, so did the latest revision of the Razor Crest’s Engine PCB. I would have stopped with only two revisions but I had to modify the design to use the stencil.

1st Version

This was the very first version where the 5730 LEDs successfully lit up without any heating issue. It is connected via a 6-way ribbon cable.

2nd Version

The two red navigation LEDs were added in and the circuit was slightly modified to still use the 6-way ribbon cable. Once I realised that the Engine would not be ON when it has landed (ie Standby Mode), neither were the pair of red LEDs. This means that there are now only 6 wires treading inside the model from the Engines instead of 10.

3rd Version

The outer ring of 0603 LEDs were brought in closer to the centre by about 0.5mm. This is so that they do not get knocked/ destroyed by the plastic edges when inserting into the engines. It also has markings to identify the polarity of the 0603 SMD LEDs when populating the PCB after the stenciling stage.

How the boards have evolved. Although at a glance they looked the same, there are a lot of differences between each revision.
Posted in A Piscean Works Blog, AMT, Artwork, Computers, Design, Electronics, JLCPCB, Printed Circuit Board, Razor Crest, Revell Germany, Scale Lighting, Scale Models, Sci-Fi, Spaceships, Star Wars, Techniques, Technology, The Mandalorian, Tools, Upgrade Parts.

Leave a Reply