Cylon PCBs are IN!

I get home a couple of hours before heading off across thecountry for Southern Expo this weekend to find the the PCBs for the Cylon raider lighting have finally arrived!

 I’ve been hoping they would come all week when I had time to build one for the show – now I’ve been dashing around like a mad thing trying to do it NOW as well as all the other show prep. But I managed to put one together (using a home made acetate sheet solder paste stencil) and wouldn’t you know it it worked first time!! Talk about chuffed!

Here it is just blu-tacked into the head – it’s still going to need a bit of plastic removing from inside for a really snug fit, but you get the idea.

Here’s some shots of it roving away – I don’t have time to do a video right now but will do as soon as I get back from the show.


Cylon Raider Engines

While I wait for the first batch of PCBs to be manufactured, I’ve started work on the engines and how I’m going to mount the LEDs inside them. Given these will be high brightness types, light leakage through the plastic can be a problem, even when painted. The best approach is to use something totally opaque on the inside of the parts. Kitchen foil fits the bill nicely and it will help reflect the light around the inside of the engine.

I glued a small piece of foil into each engine half with PVA, making sure it was burnished into all the corners and then trimmed off the excess once it had dried. I also made a couple of small bulkheads to go into the back of the engines – I used the kit pieces as a template to draw onto some 0.5mm styrene and then sanded them to fit inside snugly. A 5mm hole was drilled in the centre of each for the LED to poke through.

Handy tip – it’s really hard to drill neat holes in thin styrene without the drill bit snagging if you are doing it by hand, or the styrene melting from friction heat if using a hobby drill. In this case I drilled a small (1.5mm) pilot hole and then used a tapered reamer to enlarge the hole by hand until it was exactly the right size for a snug push fit.

A strip of the foil was removed at the back of the engine so the bulkhead could be glued in place. The two engine halves were then stuck together and allowed to dry. There was still a bit of light leakage along the seams so an extra strip of foil was glued in on each side to cover these.


The bulkheads were secured fully in place with an extra bit or 5 min epoxy (you don’t want to push them out when fitting the LEDs later!) and then the area behind them was painted black – any excess light out the back needs to be blocked. I shall probably cover over the back ends completely one the LEDs are fitted.

The wires for the LEDs need to come down from the module in the head – I drilled a 6-7mm hole through the body section and the underside head plate midway between the two rear mounting lugs on each to ensure the holes matched. From here you can feed the wires down to the back of the engines without further surgery.

I still need to think how / where to extract the battery wires. I’ve thought about a 2mm power plug/socket arrangement and a new base, but it would be nice to use the original stand too. Does it really need to be removable? Makes packing for shows easier, but it’s not the end of the world. I could run a couple of strands of wire-wrap wire down the back of the stand arm, and even fit a single 3V CR123 sized cell under the base… Food for thought.

Moebius Cylon Raider Lighting

My next lighting project will be for the new 1:32nd Cylon Raider kit just released by Moebius. I’ve been thinking about this since seeing the 3D printed prototype Raider at Wonderfest last year, but I’ve been rather worried by the size (or lack of) of the head and the space within it for the electronics.

I started reducing the circuitry down to the absolute bare minimum – starting with a simpler ATTINY 2313 microcontroller. This will run happily on 3v using the on board oscillator so no external timing components are required. It will only be driving one LED per output so no additional drivers are required. That leaves just the controller, one decoupling cap, 8 eye LEDs, 2 engine LEDs and 10 resistors.

A quick bit of coding provides a nice sweep effect for the eye, and a little bit of random flicker for the engine leds:

The next stage was to somehow cram this into the head of the Raider. Using all surface-mount components, I have drafted up a PCB That is just 50mm long and 12mm wide. This will have end-facing SMD LEDs on the end so that the whole board can be dropped into the head cavity as a complete unit. A small amount of surgery may still be required to get the board to sit at the right angle. The only additional wiring will be for the battery (external) and to the engine LEDs which will be mounted in the body.

Here’s a printout of the board in situ: