Thin Neck Thanksgiving- Luke Cave Found Parts Revealed!


Master Member
I have a lot to say about these:
But for now I am supremely thankful for this community and for the support in engaging replicas for these items.

Seen here,
Vintage ruler (not the same brand… not being replicated)
Energy Matrix Dampener tool (real parts being replicated by roygilsing )
And the interior calculator. (Being replicated by someone we all trust)
More details to follow tomorrow on my day off following family celebrations today :)

Happy Thanksgiving


Absolutely MASSIVE shout out to Poikilotherm
For their incredible support in figuring out what is likely the exact assembly inside using only vintage Star Wars verified components.


So, it started from the MOM thread.
while we were looking at *these* images.

v312 brought up this point:
Screen Shot 2022-11-26 at 5.47.32 PM.png

.... right, not a bad heading!

The calculators he was sharing were vintage of different makes, like SHARP, CASIO, TI, etc... small repeated traces on the surface, relatively small IC chips and small capacitors like the one we were looking for.

... I wound up on MyCalcDB and datamath and was searching through pretty much all of the calculators in that time period, and there was one in particular that stood out (considering how limited the internal images are).
The CASIO FX-330

I was staring at the "hooks" on the button traces, and realized that was something *like* what we were looking for! It also had an IC and coloring that was a really nice match- so I found a deal on ebay and grabbed one.

When it arrived, none of the patterns matched up correctly and the IC was too large- however... It did bear a significant enough similarity where I knew a couple things.
The traces were the same style, the edges were routed the same way, and the colors were about right. It had to be Casio, and it had to be about 1982-ish.

So looking through MyCalcDB and filtering my results to some limiting factors- I realized something.
The larger calculators are typically multi-process... but some of the ICs on the CASIO (and SHARP) boards *might* have the proper amount of feet due to the ICs being more "basic-function" smaller process boards.
I noticed that in SHARP calculators- boards had 44 feet for basic 4 function processing but there wasn't any evidence (visually) of the same being true for CASIO on some websites.
So, I started buying up LC units if they were cheap and inquiring with ebay-sellers if they'd mind taking the hood off some of their calculators for sale.

LC-78G I got in first, and confirmed 44 traces and the overall sizing was nice on the IC but the board was all wrong. (note the button traces' shape however, and the RED capacitor setup)
(image from arithmomuseum)

Now, between 1979 and and 1983 they made a LOT of models.
Here are some others I viewed...





Most of the others resembled the LC-78G

That takes us to the 785

You'll note in the photo- all the details are nearly exactly the same as the first FX-330 I got. I had found and ordered the 785 just afterwards (and it cost more)... but I wound up waiting to get it while I did all the other research.
It was very exciting to open up! (And tear apart quickly)
What a close match! You'll notice (despite using our MoM FX board)

That there were some wonderful similarities....


The capacitor footing was even very similar in appearance!
But, unfortunately- this 785B shared NO exact trace pattern to the board in question.
Considering it had a red capacitor and the back matched the photo from MyCalcDB- I did determine I might be out of luck because the photo on MyCalcDB must have been the 785 (blue capacitor after all).

However, a 785 popped up on ebay- and I had to know for sure.
A couple weeks later...
thank god... The photos on MyCalcDB were ALSO the 785B- just with a different capacitor!
Check out the two!


Photo (modification in progress) by Poikilotherm

Photo by : Poikilotherm
785B board on the left, 785 on the right. (DaveP statics)



There are a few small items to figure out- But what is likely a part of the shopping list are:
- TI calculator slide switch
- modified Honeywell momentary switch (Boba Rangefinder)
- Prototyping breadboard
- Batteries from the 785
- fast blinking railroad signal LEDs
- Death Star II structure laser etched brass
I'll let Poikilotherm explain more of the build process when they have a chance :)

REPLICA KITS will be made. A faithful pre-cut REPLICA PCB is in development
but until prototypes are complete I'll ask for your patience until our friends-of-the-board are themselves ready to share more details. DATE TBD ;)


Some of you have messaged me and since have managed to determine on your own what these parts are after your own research or the teasers posted... For allowing me the honor to announce/ reveal these I have to thank you!

For the rest, I hope you enjoy part II.

Sometimes you need to go to the dentist, and it's already awful enough.
In our found items' case... they might be used to loop a thin metal "matrix" around your tooth!
Or "dampen" your throat in the event of a dry mouth during oral surgery!

This particular discovery stemmed from one particular ebay find... and my subsequently being curious enough to buy an inexpensive version to sample the concept. The thing I did not realize (until I was still looking at this particular "nose and throat sprayer") was that the shroud came off the tip- and exposed a very similar looking piece of the puzzle underneath.

Not particularly too long later- some new variants were found.

... and purchased.

YA'LL, let me tell you. Some of these are NASTY!
Besides nose and throat sprayers for essential oils and pain relieving elixers- they were also used as surgery supplements, perfume dispensers, powder dispensers, as well as genital douches.

So while I was exploring dental options to see if I could find more examples of this atomizer-
I found this at auction:
Dental Ivory Matrix Retainer (No.8)
As the cave scene is slowed down- this confusing shape popped up and... this matrix retainer was the first item I'd seen to make sense of it.

So there we have it.
Devilbiss Atomizing Sprayer (nose dampener)
and Ivory Matrix Retainer No. 8

We'll get to *which* Devilbiss on the back-end of assembly and modification:
I want to note and admit that we have not found the *right* matrix retainer yet... but have seen some great leads.
There are modern ones out there-
Antique on left / Vintage middle / Modern (and cheap) right

A note about the cheap modern Matrix retainers on Fleabay- the sellers notoriously send the WRONG ones pictured.

Now how to put them together?


Let's all thank Wilfurd Brimley... he really helped us out on this one.
His kit is very confusing to look at in low resolution until you realize 'how' it is happening ; and where to look.




After staring at this for a ghastly amount of time, and doing some photo-shop mock ups I had thought that the threaded rod on the retainer might pass through the threading under the atomizer.
Once Roy came on to help us out with this, he quickly managed to grab some higher resolution screen-grabs and we realized that the lip of the atomizer wasn't there anymore- and that the retainer was mounted directly from the spine.

So.... the cringe-worthy portion.

....not far enough



Getting it down as far as it needed to go- although the central hole nearly disappears it does expose the lower hole- already perfectly sized for a 4-40 screw. It needed to be drilled a bit further and tapped with a bottoming 4-40 tap.
We are then left with this assembly.
Which, I'm sure you may agree- hits quite the mark.

Considering we can't see a head in the photos- I opted for a 1/4" length flat head 4-40 screw and chamfered the hole on the retainer.

This allows for controlled swivelling, which I believe we can see clearly occurs between the ROTJ cave and Noa's kit in Battle for Endor.

So that's it!
A couple notes:

- The tip has something shoved in it to gain access to the control box switches (Finish nail or mechanical pencil tip/ pin or the like) because the two switches are just that small
- We still need to find the right type of vintage (or more likely antique) Matrix Retainer KNURLING. They began using them in the 19th c.
- DeVilbiss No.152 is the ONLY correct one. Not to say that a 215 or 162 can't be modified but the breather hole for the assembly is in the flange- which we now know has to be removed in order to mount it correctly.

- In order to mount it with this ease you need exactly the No.152

roygilsing and I are happily working on producing pre-modified replicas! There's a thread in the interest forum to continue THAT conversation.
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Ridire Firean

Sr Member
I JUST SCORED TWO RULERS!! One, and then on a whim not a minute after the first, changed my booleans, and found a nearly identical one as seen in the Original Props Blog photo!

The Force is with me! Diving back in for the rest!


Master Member
Thank you for doing this! It has been quite the journey. There is much more to uncover, and more gross medical stuff to clean lol


Master Member
For some additional conversation kickoff:
Would love to see TheRPF army triangulate the knurl pattern on the matrixes via our expanded internet searching means

Below are two samples;
From the mid 20th c.
And late 19th c. respectively.

It would be amazing to find more variants that speak to / make sense of the correct pattern on the prop


  • 65F8BF63-E2A1-43C2-94A8-F461C0F2ECEB.jpeg
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Sr Member
:DAll right, let's get down to business! I'm very confused at the moment, even though I've now implemented the cave segment demo, I'm still making changes to the circuit board.

Because Casio LC-785 classification type very many kinds! It's not just the Casio LC-785A and B...... After my discussion with Bryan, we found that Casio LC-785A was divided into three specifications of circuit boards, which made our progress slow again.

The correct Casio LC-785 calculator is divided into A/1 A/2 A/3. Although the circuit board structure is exactly the same, but out of the pursuit of the maximum approximation of the Hero circuit board, I think we need to work harder and get more 785A series calculators to verify these things.

Among the 7 785A/B calculators I own, I found the 785A/2 board in A very special color [Casio LC-785 A/2] that is close to the color of the Hero board, which makes us a bit confused about the real color on the Hero board. Since there are very few reference images of the Hero board, I think we need more time to find and explore the real IC code and the digital queue on the back of the Hero board..:cry:

Casio LC-785 A.png

Although the Casio LC-785B and Casio LC-785A have different patterns, the assembled LC-785B is still pretty cool!

Casio LC-785B does not have multiple models like Casio LC-785A. It only has two models 1/2, namely Red resistor and Blue resistor.

Casio LC-785 B.png

Casio LC-785 B1.png
Casio LC-785 B2.png

So far I have made the final changes to my Casio LC-785 A/1 circuit board and decorated it with 7Chambers Death Star brass. Of course when I did this I was still confused...... All kinds of problems come up....... As the Casio LC-785A calculator is very rare and rare, there are no more Casio LC-785A for me to continue trying and testing to solve these problems, so our progress is very slow....... So we need more people to join the discussion!;)

Casio LC-785 saber A1.png
Casio LC-785 P.png

What is the stack board in the lower right corner? Where does it come from? Why isn't it on the LC-785A/B board? :unsure::unsure::unsure:

Nevertheless, I made what I saw with my naked eye out of the scraps left over from the trimming of the 785........ I need more people to identify this object!:(:(:(


For Mark Hamill exactly how to light the control box, after our unremitting efforts we found the correct location!(y)

The button is hidden on the side of the stack board!


Then I took out my new Casio LC-785 A/3 for trim and weld testing. Try to match..... as much as possible The results are as follows:......;)


It is getting late and I need to rest. I will continue to update my research results tomorrow....... I'd love to hear what others have to say!:p:p
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Ridire Firean

Sr Member

Now that we're free to discuss these items openly, I'd like to add a WARNING to the "gross"ness that can be found in these antique atomizers...

If you should happen to track one down, handle it with gloved hands and a respirator when unpacking it and while cleaning it. The possibility of dangerous chemical residues is likely quite high. Imagining what kind of tinctures have been sprayed through these has me thinking of 'A Million Ways To Die in the West'.

I'm looking forward to seeing the finalized replicas!

Off to absorb all of this!


Master Member
Yes and they do not really disassemble very much. I thought you’d be able to buy different ones and cobble together pieces but alas, they are either press fit or brazed together. Probably to make an airtight seal so they work properly.

If, like me, you snag a calculator at a thrift store or something, keep the little screws that fit the board, just in case :)

Ridire Firean

Sr Member
If, like me, you snag a calculator at a thrift store or something, keep the little screws that fit the board, just in case :)
I almost had one in my kitchen right now! Same little vintage calculator concept, but a different brand. Close, but does not compute. :( But now I have a theory as for where else to look for the correct one!


Sr Member

So, in order for us to identify the IC code on the prop board, I tried everything to make the image clearer, at least I could see what was on the IC, which unfortunately has been completely erased.With the AI image processing, many details in the image were lost, but I tried to find what I wanted to see to make sure it was real.:(Earlier I tried to identify the correct Casio LC-785 by identifying the IC code on the prop board, but ultimately failed. At least some of the IC codes on the Casio LC-785 I have seen have a lot.....:(


BRRogers told me there was a lot of solder on the circuit board. And it has silver wires. Well, I did see it, and then I started testing and welding and decorating the circuit boards, just for decorative purposes. No function whatsoever!:)


When I checked the red flashing led trigger switch on the board, I found a lot of silver reflection points on the circuit board. Because of these reflection points, I have been hesitant about the location of the red flashing led switch. :Dthd9791 also tells me what it thinks about these reflection points. By the time I got this clearer image, most of the solder spots on the board were already visible!


According to my current knowledge of the prop board, although the board does not have any function, the flashing circuit of the control box was completed on the Casio LC-785 board in the early stage of construction. That means the Casio LC-785 is like a real circuit board![My personal understanding]

The internal circuitry is connected via the brass fly wire on the Casio LC-785! Brass conducts electricity! So by soldering the silver mini wire to the soldering spot, you can get the wire powered up quickly! And it can save about 1.80MM of height space inside.:)[My personal understanding]

Of course, I also found silver mini wires, and thinner ones than that.:)


There was an obvious wire in the lower right corner wrapped in duct tape, I don't know how many wires were in there, maybe two, maybe one. Last night I quickly drew an image of a quick wire run from where I found the solder spot and sent it to BRRogers to look at. Because of the confusion, I feel dizzy, I will upload it later! Of course, there are many ways to weld a circuit on a Casio LC-785 board!

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