Category Archives: Electronics

Magnetic connector for dome (version 2)

I’ve always wanted an easy and affordable magnetic connector for the dome to body connection.  I’ve used the DB25 connector with FlthyMcNsty’s board since the beginning and it works great, but it takes two hands to make the connection.

Here is version 2 of the magnetic connector that I’ve designed.  It uses conductive magnets for the voltage and then a 8 pin millmax connector for the data.  This mirrors the high current board I previously used.  Basically 4 wire for the slipring carry each leg of V+/V- times two as I run 5V and 12V to the dome, and the 8 remaining wires carry data.  Each wire is rated at 2A, so that gives a max of 8A per power leg, each magnet is rated at 8A, but I doubled up just to be safe.  So 2 magnets per power leg.

Here is a list of parts, again this is NOT perfect and will take some builder experience to get it working.  If I have time I may fix the things to make it easier to put together, but mine works so it won’t be a high priority.  Warning – the millmax connectors are tiny and difficult to solder as they are brass pins that heat up great but also melt their own housings.  Tried the solder verisons of them and just melted them all the heck.  So went with the pin mounts and provided a separate pcb board, much easier to solder these.  SO USE AT YOUR OWN RISK.

3D Printed Female end
3D Printed Male plug
3D Printed Male back piece
8 sets of conductive magnets
Male Millmax connector
Female Millmax connector
PCB Board for female end (brd file)
PCB Board for male end (brd file)
PCB Board for Millmax connector X2 (brd file)
5.0 pitch 2-pole screw terminal x2
2.54 pitch 4-pole screw terminal x2

(obviously you’ll need a slip ring and a way to connect it to the dome – this is only for slip ring to body connection)

Here are pictures of the connectors


Video of the mating, sorry for the shaking video as I had one hand on the dome another on the camera.


BB-8 Build

Figured it was time for R2 to have a companion, so started #NOTBUILDINGBB8 thanks to the amazing talents of fellow R2 Builders who created incredible 3D printer files.

Got around to working on the lights, since we don’t know much other than what was shown on stage, this is my take on BB-8s lights.

Click the link below for the instructions/part lists and Arduino code.

Gizmos BB-8 Light Setup

SHADOW + Marcduino – more bells and whistles

So I fell into the R2 Builder sarlacc pit – which is when you complete R2, you have this incessant need to upgrade.  When I was out at events, it was cool having R2, but other than movement and sounds it didn’t do much else.

So I’ve decide to work on a ‘Dome 2.0’ which will have all the panels open/close.  Originally was looking at integrating some of the code from BigHappyDude but then came Vint32 who integrated the Marcduino boards into the Shadow system.  Now I’ll be able to have all the dome panels open and have sequences with very little work on my part.  Having R2 controls on an iPod/iPhone was never my thing, but Vint32s integration doesn’t require that part of the marcduino setup, although you could add it if you wanted both.

Its absolutely amazing the creativity and the talent found in the R2 Builders group!  Special thanks to Vint32 and BlackSnake for tolerating the emails and sharing all the work they’ve done to integrate the Marcduino into the Shadow system.  Thanks to Knightshade for the initial Shadow system and thanks to CuriousMarc for all the work on the marcduino system.

Here is a video of the system on the bench:

SHADOW controller update

I just finished an event at the Washington Nationals Star Wars day, this is my sixth event with the SHADOW system but definitely the largest attended event.  I was wondering how the bluetooth connection of the controller and any interference from the numerous cellphones would affect the system.

Everything worked perfectly without any issues!  The system was rock solid and very stealthy.  Many many times the parents were looking around for who was controlling R2 and they hardly ever found me.

Thanks again to Knightshade for all the work he put into developing the system.  I’d also like to thank Vint32 on the Astromech forum for the code to eliminate the ‘dome twitch’ when two controllers were connected, I’ve had zero twitches since the new code was added.

Several members of the 501st even complementing me on how hidden the controllers were and how that added to the experience.

R2 even made the Washington Nationals Facebook page!  Can you find person controlling R2?


SHADOW control system

I decided to upgrade the control system to the SHADOW system which uses the Sony Playstation 3 Move wand controllers.  These are very easy to hide and have a ton of buttons and options.

One of my favorite features is using the ‘L2’ trigger as a throttle for R2.  Instead of simply switching between low speed and high speed, you can ramp R2 up by pulling the trigger and it works like a gas pedal.  The more you pull the faster R2 goes.  This has worked great in numerous occasions.

Thanks to Knightshade on the Astromech forums for all the time and effort to develop this system.

PS3 Move navcontroller

R2 Dome re-wire

When I first wired up the dome, I got it to work and was happy as I had other pieces/parts to work on.  One of the ‘to-do’ items was to go back and clean up the wire installation. One of the main things that bothered me was the inline resister needed for the holoprojector LED.  I found round circuit boards at Radio Shack, and soldered on the resister and two two-pin headers.  I then soldered on two female connectors to both the wires from the arduino and those going to the LED.  I mounted the circuit board behind the HP, and now I can simply plug-in both the power/ground and the LED making for a simple swap-out if needed.  My HPs do not move, but in the future if I decide to have them move I’ll just relocate the circuitboard.





After cleaning up some of the wires, I used a blue mesh wirewrap to bundle the wires together.  I also moved the 25-pin connector from the vertical piece of styrene to the inner ring for a more solid and easier place to plug it in.

Re-wired Dome

Re-wired Dome

IMG_3248 IMG_3249 IMG_3250

$x Mesh tubing
$x Circuit boards

That’s what friends are for……to help with R2

Started on the Teeces setup for the dome.  Talk about having to solder a thousands things, fortunately Izzy stopped by to help out – ok so I begged him.  I soldered the Front and Rear Logics as he fixed the rear PSI (long story) and soldered the front one.

After we were done, we plugged it all in to see if it worked, he had previously programmed the chip.  Bam!   Absolutely nothing……sad face.  He took a look at all the pieces and parts, re-soldered a few things, changed out a few chips and whamo!  It worked!

I couldn’t have felt more freakin amazed that what I had just spend hours soldering actually worked.  I had never soldered circuit boards before, mostly larger stuff – but I did it.

I was so proud, when my wife got back from bookclub I had to show her.  I was like a kid a Christmas.

Teeces Kit: $
Soldering Iron + supplies: $


It’s Alive!

As more and more parts are nearing completion, I couldn’t resist the urge to get R2 moving.   I’m using the VEX Controller and the Dimension Engineering Sabertooth 2×25 which I purchased for $125.

Here is a short video of R2 moving around.

You can see I still haven’t completed the center foot.  With all the chamfering involved I just don’t want to start on it, been procrastinating.

Motor controller (feet): $125

Main Ankle/Foot Hardware

For the Main Ankles I’m using a 3/8″ threaded bolt, 2″ in length with a steel sleeve for the connection between the main ankle and foot, I didn’t want the bolt threads wearing away the styrene.  The bolt has a 9/16″ head which I’ve marked for easy of finding the right tool in the future.  I glued the washer onto the styrene facing the battery box, but there is not enough clearance for the nut and washer on the outside face.  I’ve drilled a hole in the battery box to allow access for the bolt to be inserted and access to the hardware from that side.   It is tight on the outside so getting the nut on the bolt is tricky until it starts getting threaded.IMG_2737IMG_2738

Here is a picture of the bolt/nut installed, notice the 9/16″ again on the inside so I get the right wrench the first time.

IMG_2911 IMG_2909

I’m going to be using the Jaycar motors ($40/each + $25 shipped) for both feet and the dome as recommended by Dave.  I bought a 7mm/8mm ratchet wrench from Sears for $7.  It works extremely well for attaching the motor support plate to the foot.


I ordered the wheels (T80P-493BG-HS6) and hubs (T80H-SM61) from BaneBots for $37 shipped.


Motors: $105
Wrench: $7
Wheels/Hubs: $37