Slothfurnace.com Presents: the ROTJ Luke Skywalker Lightsaber

A Return Of The Jedi Luke Saber, with crystal chamber, thin neck, and detachable blade.  Normally this kind of thing takes me about 4 to 6 months, this one took four, as I was under a deadline for Christmas.  This instructable was written based on my step by step photodocumentary at  http://www.slothfurnace.com .  You can see more prop builds and more description there.

Step 1: Initial Sketch

My initial sketch of the project, I *think* I can get it all in there.  This will have a springloaded expandable crystal chamber reveal, and a detachable blade.  As well as a thin neck, and as close to "movie accurate" dimensions as I can get.  I usually start with a sketch, trying to visualize all the parts I will need to machine, the way they go together, the way they will move or work, etc.  The challenge of these projects is to "hide my work" within the confines of the original dimensions of the prop.  I will use the ribbed pommel as my chamber release knob, and attempt to hide the rest of the details inside the saber.

Step 2: Grip and Chamber Cover

For the ribbed grip section, I start with a 1.5 inch outside diameter tube of 6061 aircraft aluminum, with a one inch inside bore.  With it chucked up in my lathe, I mark light tooling marks on the outside at 0.32 inch intervals so I know where my grooves will go.

When my marks are done, I begin to cut grooves.  

I also leave a bit of material on the rear, so when I drill my template through that section, and cut it off, I will be left with proper holes in the grip section, and a piece of aluminum with corresponding holes I can use as a hole transfer template.

Step 3: Support Rods and Main Can

Once the grip section and hole transfer template are parted off, I take a piece of 1.5 inch tube and hollow it out for my transfer template.  This template will sit inside this hole, and allow me to mark holes that will line up with my front grip.

After drilling my holes and threading my grip section for 6-32 threads, I run my support rods through the main can and into the grip section.  These rods move freely through the holes in the can, and will allow me to open and close the crystal chamber.

Step 4: LED String

At this point, I begin the LED string. The LEDs I am using are extremely bright, can put out from 7200 mcd to 21000 mcd at 525 nm. That's MUCH brighter than anything I have used to date. To begin the process, I use my flat needlenose pliers to fold out the leads so that they are straight out, and as flat to the bottom of the LED case as I can get them. Now, I use my regular needlenose pliers as both a spacer, and to hold it while I bend each lead back down. I try to make as close to a 90 degree sharp angle as I can, while holding the lead in the same spot each time, as the pliers are tapered.

Consistency here is key, as it will make a big difference in the straightness of the LED string

Next step, folding over. I use a scrap piece of shelving track for this, so my bends are the right angle and length every time. Again, consistency is key here. It won't be perfect, but the closer to uniform you get, the better.

Always make doubly sure that the bends here go the right way. I always point the "arrow" part of the LED up when I bend, so that the positive and negative leads always go the right direction. Saves me from having one reversed.

Now that they all are bent, it is time to assemble them together. This is one of the more tedious steps, but it will be worth it when they come on for the first time.

Assembly, here I make sure my leads are all correct, positive down one side, and negatives down the other. I will assemble six sets of 12 to 14 LEDs like this, depending on length of blade. Pass one LED's leads through the shoulders, and bend up and crimp with needlenose pliers.

This is a section of 12 LEDs. This will go on the rest of the strip I already have made after soldering and trimming.

To solder, I have a little anvil with a magnet on top, this keeps my LED string section in place while I solder, and the magnet is also handy for when I trim the extra leads off the sides. The magnet collects the leads, instead of them getting in my carpet, and in my foot.

Here I have several sections placed into the diffuser foam tube, and test lit. It is unbelievably bright, pictures don't do it justice. It hurts to look at it without the diffuser foam, and I think once I get them all assembled, it will be one of the brightest sabers I have ever seen.
This blade is made up of 90 LEDs.

Step 5: Crystal Chamber Details

Did a little work on the crystal chamber tonight, the crystal mount anyway... I fashioned this out of a scrap piece of brass, something out of an old dentist's tool I had laying around. Polished the outside, cut a ring for the LED holes and crystal screws, and a groove for floating the positive lead ring.

This is the way the leads connect to the positive and negative floating rings behind the crystal mount. There's enough space here to isolate them, and they look nice.  Now I have the correct three way radially symmetrical support rods, instead of the 4 way I had earier. These support rods go through two identical harddrive motor mount housings, and I shaved one down to fit inside the one inch diameter hole in the foreward grip, the other is notched to let the forward grip posts slide through.

I'll be replicating my radiator section from the graflex on this saber, only much smaller.. instead of it being based on 6-32 rods and nuts, it will be based on 4-40.

At this point, I decided to work on the radiator section, recreating that part from my graflex saber in this one, but at a much smaller scale. Previously, I had bolted the brass sheets to a block of wood and cut them down to size on the standup belt sander. This time I wanted an easier way to do it, so I cut, drilled and bolted the one inch square sheets to the top end of my crystal chamber, using the same support rods.

After using the lathe to turn them down to the right size, and dropping off a few that were bent, I was left with 6 or 7 that I liked, and then drilled them out hollow. This was much easier on the lathe than what I did previously.

Deciding to keep five of them, I spaced them out and sanded the sharp edges down on the outside and inside.

After spinning them to get nice radial sanded texture on the faces, I then used the dremel to cut away the section I didn't need, leaving the spot for the wire conduit on one side.

Step 6: Copper Neck Section

This plug will fit into the forward grip, and be interchangeable between an emitter/neck with blade, and one without.

The slightly raised lip fits snug into a tiny bevel in the shoulder of the forward grip. A black setscrew will secure this, and be well hidden in the groove after it's painted.

The copper collar that goes on the top section of the neck, I had to cut off with a hacksaw from the main stock, so I wasted as little copper as possible. Also, I hate this particular alloy of copper, as it's extremely difficult to machine. It work hardens pretty fast, and gets gummy.

After shaving off the hacksaw side, polishing and slipping it on to the neck.

Also shown is the other bladed neck.  This one I machined to barely fit around the 1 inch outside diameter polycarbonate tube I use for the blade, and an aluminum plug that barely fits inside it.  This is all press fit together and attached to the other neck.

Step 7: Emitters

Here I am starting the emitter. I have a couple of emitters for reference, one from Rylo, one from the RPF, and I am sort of averaging those together for mine.

The bottom section machined, I'll drill this for a threaded 3/8 hollow rod, and flip it over to do the top section.

However, I couldn't resist putting the Rylo emitter on just for grins. It's really coming together!

Step 8: Pommel and Chamber Lock

Here we come to a pretty big section.  The twist lock pommel.   First, I start with a sketch of how I want it to work.  The support rods will interlock with these cams that rotate with the pommel, and one will have a larger diameter lug on the end that will lock up inside the mechanism. 

I also have to drill out the pommel for the speaker, and sound hole.  Once this is done, I mark and drill my holes for everything, then tap so I can reassemble it later.  You'll notice I machine off a couple plates that go on either side of the locking lugs that attach to the pommel. These plates are a slightly larger outer diameter than the locking lugs, so that when it's installed in the main can, the pommel and locking lugs can rotate freely.  The brass screws act as rotational stops as well as holding the plates together.  There are spacers between the plates so that as I tighten the brass screws, I leave just enough room between the plates not to restrict movement of the lugs. 

Step 9: Painting the Grip

Painting the grip section, I taped off the back and front, and carefully spray painted with black enamel. Before painting I made sure to polish and wash with dish detergent to remove all dust, oil, etc.

After painting, I  allow the grip enamel to cure before I shave off the outermost raised areas to reveal the aluminum beneath, leaving the paint in the grooves.

Step 10: Control Box

Now I need to start on the control box. After designing how I want my switch to work, with activation on one side and aux on the other, I take a TCSS box1 and shave down the sides so there's no groove, then polish away the machine marks.  I add my 90 degree tactile switches to some perf board, and place it for a test fit.

Then I machine out the slot in the box for the aluminum rocker switch, and then machine the rocker switch to fit the slot, and with holes to go down over the tactile switches.  Once I know that works, I drill holes for the triangle LEDs, and file them from round holes to triangles to fit the LEDs.  Once I get that done, I have to mill out the box cover plastic a bit to fit everything, then wedge it all in.  I then add my resistors to the LEDs, and assemble everything.

Step 11: Final Assembly

After the machining is done, now we do wiring.  The most challenging part for me, anyway.  You can see here the crystal chamber base, with the wires threaded through the base, into the brass and copper tubing I use to hide my wires that run the length of the chamber, and into the chamber cap.  This is where the wires for the recharge port and the LEDS in the blade go.  The chamber cap houses the mini DIN plug that hooks into the mini DIN plug in the bladed and non bladed emitter sections.  I use a shotgun magazine spring to go between the cap and the top of the chamber where the bladed and non bladed emitter sections sit.  This spring is what pops open the chamber, unplugging the DIN connectors.

Also shown are my cathode leads from the LED string blade, marked with a sharpie from 1 to 6 and anode, so I keep them all straight.

Next we see the soundcard assembly and then the 4 AAA rechargeable batteries that power the saber.  Everything barely fits inside. 

Step 12: Finish Pics

Now that it's done, I notice I especially like the subtle weathering in the crevices of the copper, I hadn't planned on that, but I like the way it looks.


This vid is of the blade in action

http://www.youtube.com/watch?v=04zJeHIBBfM&feature=player_embedded

This vid is of the chamber reveal

http://www.youtube.com/watch?v=z3xxuGeLZcg&feature=player_embedded

Also shown is this saber next to a few others I have done, as well as the licensed mini replica from Master Replicas.

Thanks for looking, more details on this and other projects can be found at http://www.slothfurnace.com