The ANH Obi Springloaded chamber reveal saber is my "holy grail" saber. Everything leading up to this has been practice to me. This saber was completed in approx. a year and a half.
CF-LS 5.5 running MadCow's Heirloom font with my custom menu and boots
7.4V Battery pack (2X 18350 Li-Ion batteries with remote PCB Protection)
Activation/Aux custom tilt switch as foreward transistor greeblie
84 High Power LEDs wired Seriallel in blade, 5 in chamber (each of the chamber LEDs wired to blade segments 1 through 5)
Steel Russrep Emitter, steel russrep grenade, brass russrep windvane, steel russrep booster, steel russrep pommel (All heavily remachined and weathered by yours truly)
Recharge port under rear transistor killkey
Interchangeable bladed grenade/emitter section and lit non bladed grenade/emitter section
springloaded aqua aura quartz crystal chamber with custom brass chamber parts
2Watt speaker in pommel
Vintage Exactra bubblestrip
9x20 Machine Lathe
Micro Milling machine
Various hand tools, taps, dies, etc.
Resource Websites for Parts, Wiring Diagrams, and general information:
Step 1: Sketches, Sketches and More Sketches.
First off, I need to decide what this saber will actually DO. I want it to be a springloaded reveal, but I need to make sure very few if not none of my moving parts exceed the boundaries of the original prop. I want it to look like the original prop as much as possible. That means designing controls into it using the existing surface features in the design, and attempting not to introduce new visual elements.
Drawing these parts in cutaway view helps me prepare for the machining and construction of the project.
Step 2: Assemble Parts and Materials
The original ANH Obi saber was made from an assortment of parts that were chilling in the prop room. From the pommel forward, it was an Armitage Shanks sink knob, an ANM2 30 Cal Machinegun booster, a vintage Graflex flashgun clamp, a couple motorola transistors, an exactra calculator bubble strip, a British WW1 rifle grenade, and a Derwent jet engine interconnect from WW2.
Since I neither have a time machine or the money it would take to purchase the actual vintage parts for this, I turn to some machinist friends of mine to reproduce the grenade, pommel, and emitter. These parts are too complex for me to create in my machine shop / garage, and are extremely faithful reproductions of the original parts.
As this will be a saber that has a bladed end and a non bladed end, for display variety, I need two sets of grenade/windvane/emitters.
I also have acquired a prototype LED string version of a Crystal Focus 5.6 soundboard from Plecter Labs for use in this project.
Step 3: Internal Structure and Frame
Because I have to fit batteries, speaker, soundcard, crystal chamber, etc. into the physical boundaries of this saber, I will need to hollow out a lot of the parts I have.
Step one of this, is boring out the ANM2 Booster replica to a very thin wall, so I can slide it over my battery can / soundcard and speaker holder.
The clamp will go around this part, hiding the two Li-Ion batteries that are nestled into a slot milled in the side of the can, and the crystal chamber will mount to the end. The speaker will mount in the pommel section, once I bore out more metal from the pommel cap.
Step 4: Chamber Reveal Latch
The key to the springloaded chamber reveal is the latch. When I was designing this saber, I had to come up with a different way to open the chamber than my Luke ROTJ saber. Because the ANH Obi is a collection of parts, I had to get creative with how to open this one. I found a natural gap between the Graflex clamp ears, and the clamp lever bolt a natural place to pivot a hook. The other end of the hook terminates in a lever, which can be pressed at the back of the clamp to lift the front end of the hook out of the grenade slot, and allow the chamber to snap open.
Step 5: Crystal Chamber Construction
For the chamber itself, I created most of it from solid brass stock, rounded the pieces off in my lathe with my radius turner, and set them in the milling machine for drilling.
The internal struts are 4-40 threaded rod, and the bulky domed fins are the same stock as the chamber mount. Domed on both sides, then milled off on one end. Each strut is also covered in threaded brass spacers machined from thinner rod.
The crystal is a quartz aqua aura, and it is hand fit into the crystal chamber mount center, by milling slight depressions on the inner wall of the mount, and sliding the crystal in, marking where it stops, milling for that corner or protrusion, then dropping it further in.
A quick test lighting of the four LEDs shows how the light will play. There are three LEDs embedded in the outside of the mount, and one underneath the crystal in the base.
Step 6: Recharge Port and Main Switch
Since I am using a rechargeable internal Li-Ion battery pack, I need a way to plug in the charger when the power gets low. I needed to hide this port someplace, since the original prop didn't have a visible external recharge port.
To do this, I selected one of the transistor decoration (greeblies) to hide the port under. This greeblie had the transistor above a heatsink detail, which is perfect for this use. I drilled and tapped an appropriate piece of aluminum in the shape of the heatsink under the transistor, and cut it off to the right length. This nut now holds the recharge port securely, through the graflex clamp.
For the switch, I had the same problem. How to hide an activation and auxiliary switch among the extrernal details of this saber? Use the front transistor for both switches!
You can see I embedded two small tactile switches in the wall of the battery can, and machined a pivoting swing arm with a threaded spot for a "transistor" that would allow me to swing the switch up for Aux, and down for Activation. This transistor piece floats through the graflex clamp hole that already existed, I just needed to file it a bit to allow the swing arm to travel to the switches.
In the last couple of pics on this step, you can see the extent of the machining needed to accomplish this, as well as a lot of the finished internal frame and chamber.
Step 7: Keeping It From Flying Apart...
As the grenade is under pressure from the spring to open, once it does, I need to make sure it doesn't fly off the end of the crystal chamber. To do this, I machine a spot for a small 6-32 cap screw to sit in such a way that its head extends past the wall into the opening of the grenade. I then machine a track for this screw to travel into the exterior chamber wall, and a "keyhook" so that a slight turn of the grenade will allow me to remove it completely. That lets me interchange the bladed and non bladed sections.
Step 8: Stringing Power Lines
So at this point, I have a lot of things squared away in the design, but a big hurdle is transferring power from the main section to the blade. I will have 6 ground wires and one positive wire to transfer from the soundcard all the way through the saber to the blade, and still allow me to interchange the bladed and non bladed sections.
To accomplish this, I am using a mini DIN plug at the top of the crystal chamber, which will plug into a mini DIN plug at the base of the brass windvane section. From there on, I have to design a way to keep the wires from tangling when it's assembled, hollow out part of the brass part for the plug housing, and make sure that everything stays ALIGNED or it won't plug in when the chamber is closed.
The plug is snugly fit to an aluminum blank, which is hollow, and threaded on one end to accept the steel 3/8 threaded rod, which is also hollowed out. This rod goes through the brass, and into the blade blank, which is what will hold my polycarbonate blade against the emitter.
Step 9: LED String Blade
Speaking of the blade, I need to drill out 84 LEDs. Why do I do this? These high power LEDs are built to shine light forward, rather than to the side. Since the LEDs will be in a string, all the light would spill into the one above it. I need to redirect this light more to the side, so I chuck each one up in the lathe and carefully drill the dome out, leaving a concave cone in the top of the LED. Being careful not to drill too deep and hit the lighting element.
These are wired "Seriallel" meaning, there are six segments of two parallel segments of 7 serial wired LEDs.
A quick test at low power shows they all work.
Step 10: Hiding My Work
One of the things I keep in mind when building something like this is, "Hide my work"
I don't want to see visible screws, wires, "earthly" things that would not be visually appropriate. Therefore, I want to cover my wiring as it goes through the chamber. Selecting some vintage wire mesh wrap, I carefully cover my wires as they go across the chamber.
Step 11: Weathering and Blade Assembly
We can't have a pristine lightsaber in the desert, can we? By the time A New Hope happens, this saber has been bouncing around the sands of Tatooine for a few years, and should look as such. I use Birchwood Casey super blue to darken the steel, and Brass Black to darken the brass. Then I put it in the lathe and lightly spin it off the edges, then another coat or two if I need it, then more buffing, till I get a look I prefer.
The final blade assembly shows the threaded hollow rod and plug that fits inside the polycarbonate blade, pressing it against the emitter section shown below. A tight sandwich like this, and then a couple of setscrews under the emitter exterior insures this part will be rock solid. Duelworthy in fact.
The last picture shows me soldering the mini DIN plug to the LED string blade wires.
Step 12: Final Assembly and Soundcard Settings
Whew! It's hard to compress a year and a half worth of work into one instructable, but here she is, finished.
The soundcard supports 6 soundfont banks, and one iSaber audio bank of up to 50 MP3s. The CF-LS had to be set for a heavy saber, as this thing is mostly steel and brass. Overall, I am very pleased with the project.
Thank you so much for looking!
More detailed build log available here:
First operational video:
Crystal chamber operation
iSaber progresive bargraph operation
My daughter having fun with it:
Grand Prize in the
ThinkGeek Sci-Fi Contest