Exploring the inside of the Rangefinder (possible found part alert!)

So, all this madness started when I replyed in this thread ==> My ROTJ Fett build WIP. It was OK at first, but while I did my second reply...

RafalFett said:

In some of the exibit images you can clearly see 3 green wire-like parallel lines going partially under/through the bottom of the perspex block.

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...I also took a better look on some images saved in my PC and I stopped at this image:


Then I looked at the Supertrooper Documentation - Helmet image, more exactly at the '3 lamps-white'...


...then again at the first image and again the Supertrooper page and again the first image, and then... it hit me! I did a quick search on the net and I got this term: GRAIN OF WHEAT. This is the name of the light bulbs (diameter varying from 1mm to 3mm, or bigger) used by hobbyist, in some fields of the industry and even for medical or optical instruments; I'm pretty sure they used these lamps in the Star Wars studio scale models too.
3mm diameter/7mm length GoW light bulb.

2mm diameter/6mm length GoW light bulb.

1mm diameter/3.5mm length GoW light bulb.

And some images of older (I'm not sure about how old are these) GoW light bulbs:


Here are some comparison images of the ESB and ROTJ perspex block channels and some 1mm and 2mm diameter GoW (Grain of Wheat) lamps:




The ESB channels looks closer to the 2mm diameter GoW lamps, while the ROTJ channels are in the range of the 1mm diameter lamp.

We know that the ESB perspex block does not have the same shape as the one in the ROTJ rangefinder body (the original image was replaced with a better one):


The ESB style is (was) also present on the Supertrooper/Pre-Pro #1 helmet, while the ROTJ style is (was) present on the Pre-Pro #2, Pre-Pro #3 and Sandy helmets.

And another fact: did you knew that the perspex block was made from 2 pieces glued together? Well, then here's the proof:


Additional images of the 2 part perspex block:





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Update 20-01-2013
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Here is a bit of history about the 'wheat of grain' light bulbs (shorter version; for the full history go here ==> Comments on the "Grain of Wheat" Lamp):

It was the writer's intention to write a short story about the "Grain of Wheat" lamp, which, at one time, was the smallest of manufactured incandescent lamps.

The writer's knowledge of the grain of wheat lamp comes, in part, from two technical articles which were coauthored by Dr. William E. Forsythe in 1931 and 1932. The characteristics of the lamps measured by Forsythe are:

diameter of cylindrical bulb = 2 mm (0.078 inch)
bulb length = 8.7 mm (0.342 inch)
filament temperature was 2100ºK (2115ºK maximum)
volts = 1.5
consumed 0.17 watt
operated from a single dry cell
weight = 0.06 gram
candlepower = 0.028

These characteristics are mentioned because the term "grain of wheat" today applies to lamps of various voltages and sizes; this can be determined by putting the term in the search engine Google. Since about 1908 "grain of wheat" lamps contain a tungsten filament. Prior to that the filament was made of carbon.
The earlier of the Forsythe articles is dated December 1931. The writer therefore attempted to determine just when the term "grain of wheat" was first used for a sub miniature incandescent lamp. Such a date was never found. However some information regarding the use of such lamps was revealed.

It should be mentioned that the grain of wheat lamp is still widely used today as an indicator light, in model railroading, in doll houses, backlighting, etc. In addition, it no longer can claim to be the smallest incandescent lamp. Today "Grain of Rice" lamps exist as well as micro lamps. A picture of the relative sizes of these lamps is shown above.

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And more info here ==> Dollhouse LIGHT BULBS

The idea is that whatever these light bulbs are called now (GoW - Grain of Wheat, GoR - Grain of Rice or micro lamps), our task is to determine the exact size (mainly the diameter) and the position of these light bulbs in the perspex channels. My interpretation is based only on images from the Gallery and because the nature of the perspex block to magnify (+ or -) or to distort the inner channels, my measurement are not set in stone. Some of the rangefinder templates (WOF - WizardOfFlight and SS - SingleSeat) has a 1.5mm diameter for the perspex channels (somewhere between my 1mm and 2mm light bulb sizes) but these measurements might be off too because of the inner distortion seen in the images.

Here are some images with the working (or possibly working) Rangefinder red LED lights:


And another image with the perspex side view (more or less):


For the ESB light I can't take credit, because it was already noticed by Tyler Durden and Art (read more here ==> ESB Rangefinder inner light)


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Update 26-01-2013
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This update is mainly for images posted further down in this thread and its purpose is to keep all the images and the info in the first post too.



I made this file for fun and is partially perfect for this thread because of the blinking LED sequence in the rangefinder, it also has the chest light sequence presented in this thread ==> ESB Chest Display Sequence:



The rangefinder sequence is 0.5 second for each LED while the chest light sequence was slightly altered to fit in the LEDs sequence (the full sequence is presented in the ESB Chest Display Sequence thread). Also note that your browser might not run looped the GIF file, but if you save it and then open it with an image viewing program, the animation will loop again.

Have fun!

Very cool! :cheers

Intersesting with the LEDs. I assumed the line you are referring to that possibly shows a join between two pieces of the lens block was a scribe line. When making my lens blocks from Perspex I scribe all around before cutting and this line is left as an artifact.

Great catch.

Very interesting! You could also try a search for "grain of rice" bulbs. Pretty much the same thing.
I know that these small bulbs used to be used very often in model railroading. Not sure if they've
been replaced with LEDs in modern usage.
I also know that the grain of rice bulbs (and possibly the grain of wheat bulbs) were available in
different colors. Maybe the top 2 red ones were actually these types of bulbs also.

You've done it again Raf! Awesome discovery

WOW. I feel like I kinda had a part in instigating this. Amazing amount of attention to detail in your research Raf. Where would we be without all the info you have shared? :cheers Thank you for doing the work to make our costumes more accurate.

Great work!
You really do have this research thing down.

The first post was updated with the following additional infos and images:

Added more reference images to sustain the 2 piece perspex block theory.
Replaced the ESB/ROTJ comparison image of the perspex block side view and also added the 2mm and 1mm light bulbs.
Added a short history about the WoG light bulbs (with links) and some info at the end of the first post.

locitus said:

Very cool! :cheers

Click to expand...

Thanks!

terminal fettler said:

Intersesting with the LEDs. I assumed the line you are referring to that possibly shows a join between two pieces of the lens block was a scribe line. When making my lens blocks from Perspex I scribe all around before cutting and this line is left as an artifact.

Click to expand...

That might be possible, but looking at the C-IV hi-res images (made by Britt Dietz and Jose Salcedo) in the Gallery it looks like made of 2 parts:



The triangle part on the bottom looks dirtier and out of place than the main perspex body. Whatever method was used, these parts originally were hidden by the rangefinder casing.

And because you do these perspex blocks, I was thinking of you regarding some tests (if you have the time and/or you are willing to do it) to see the exact position (at the beginning, the middle or the end of the channels) and the light power emitted by these GoW light bulbs.

SPY007 said:

Great catch.

Click to expand...

Thanks a lot!

superjedi said:

Very interesting! You could also try a search for "grain of rice" bulbs. Pretty much the same thing.
I know that these small bulbs used to be used very often in model railroading. Not sure if they've
been replaced with LEDs in modern usage.
I also know that the grain of rice bulbs (and possibly the grain of wheat bulbs) were available in
different colors. Maybe the top 2 red ones were actually these types of bulbs also.

Click to expand...

The main term is 'Grain of Wheat' and if you search eBay, you'll fine lots of these types in different sizes and specific volt/watt. The top red lamps looks LEDs to me, but might be GoWs as well.

Darth Voorhees said:

You've done it again Raf! Awesome discovery

Click to expand...

Thanks! You are too kind!

sgtski said:

WOW. I feel like I kinda had a part in instigating this. Amazing amount of attention to detail in your research Raf. Where would we be without all the info you have shared? :cheers Thank you for doing the work to make our costumes more accurate.

Click to expand...

Thanks! Yeah, sometimes this type of replying gives me the hunger to research some parts and often realize that some of the facts as I/we knew were different or wrongly attributed. But we are all humans (don't we?) and we are subjects to mistakes.

kbrosseau said:

Great work!
You really do have this research thing down.

Click to expand...

Thanks a lot! I guess I have some...

OK I'm seeing the two separate sections of the lens block from your reference pictures. I have Perspex to hand so let me make a piece to see how this looks.

terminal fettler said:

OK I'm seeing the two separate sections of the lens block from your reference pictures. I have Perspex to hand so let me make a piece to see how this looks.

Click to expand...

That's great! Can't wait to see the end result.

RafalFett said:

Thanks! Yeah, sometimes this type of replying gives me the hunger to research some parts and often realize that some of the facts as I/we knew were different or wrongly attributed. But we are all humans (don't we?) and we are subjects to mistakes.

Click to expand...

I don't think of them as mistakes. Finding the origins of these tiny details is extremely tough and above my skill level. I think of it more as an evolution. The more you/we find, the more mysteries we will uncover.

You're a genius captain!

sgtski said:

I don't think of them as mistakes. Finding the origins of these tiny details is extremely tough and above my skill level. I think of it more as an evolution.

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Well sometimes a mistake will lead you in another good direction; in my case: the 4th shin tool, where I thought that this tool was a hand telescope's casing, but at least I did some measurements of the 4th tool and the telescope (after I bought one), which was used as the Supertrooper/Pre-Pro/Promo sling gun barrel.

sgtski said:

The more you/we find, the more mysteries we will uncover.

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But sadly the mystery of Boba Fett will go too...

Jayvee said:

You're a genius captain!

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He he (how fast I'm upgraded and downgraded with these ranks... the last time I was some kind of Amiral?) Thanks for the kind words!

Here you go, no easier to make, if anything a little more fiddly because the triangular section is so small. What it does allow is a much cleaner angle where the polaroid section butts up to on the underside.

That was quick, TF!

locitus said:

That was quick, TF!

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Any excuse for a fettle in the workshop.
As luck would have it I have been working on some new lens blocks anyway.

I'm waiting on a new milling vice so will be adding the three correct holes soon...It will be good to add some of those lamps and see how the lens block looks.

Good job Rafalfett...

It looks awesome! You can hardly see the 2 separate pieces when it's 'brand new' (this might be because it's not installed in the painted RF housing) but with a little weathering will look like the original:

terminal fettler said:

Any excuse for a fettle in the workshop.
As luck would have it I have been working on some new lens blocks anyway.

I'm waiting on a new milling vice so will be adding the three correct holes soon...It will be good to add some of those lamps and see how the lens block looks.

Good job Rafalfett...

Click to expand...

Thanks for the kind words! I will wait to see the perspex block with the 3 holes and the GoW lights installed. I'm guessing that you will need 3 bulbs with 12v that you will run with 4 batteries with 1.5v (the helmet electronics shows a 4 battery tower). I say this because in every image we see with the rangefinder in the down position and the red LED lit, we never see a white, bright light coming from the inside of the perspex block, so you need to do less light by using higher voltage bulbs with lower voltage batteries.