New thoughts on the Obi ANH 'Reflector'

Thanks to the HD caps provided by defstartrooper, here's a new idea about what the 'reflector' in the Obi saber looked like.





The idea is actually not unlike something floated in the old reflector thread years and years ago. It was probably Howard's idea, he has a knack for suggesting true ideas before their time.

The CAD model isn't mirrored so it's hard to fully evaluate how well it's working at some angles, but as you can see in this early test of a very deeply angled reflector the reflection pattern shows promise.



I'll be refining it some more over the next few days.

What are we looking at here? Just a 1 inch OD piece of tubing with a center hole a little bigger than 1/2"?
It looks like a simple aluminum spacer set 1/4" from the inside edge of the emitter.

Something like this...
McMaster.com
Part Number: 92510A823
Aluminum Unthreaded Round Spacer 1" OD, 3/4" Length, 1/2" Screw Size

Thanks for the kind words, Andres. :$

The reflection angle is the key to this piece IMHO.

Russ is going to machine an aluminium piece from Andres' specs then polish it up. Once that's in Andres hands he'll be able to estimate the angle so much better so as to refine the reflector element in the design.

Chris, I think the reflector component was probably from a torch - with a few other perhaps ill-fitting elements cobbled together to make the whole neck stem / balance pipe stay together.
Strange that they would go to so much trouble to put the reflector in the prop. Perhaps (and it's a big perhaps) the reflector idea was used first on the spinning rod version to add a little light upward, and that element of the design was carried over to this version?
I don't know which version was built first.

A big hats off to Andres for working out (in my view) exactly what's going on inside the saber's emitter - this was driving me nuts!
There are clearly different 'stages' inside the emitter before the reflector component is reached and that's something I just couldn't see at first.

Looks about right to me. GREAT JOB! :cool

Thanks guys.

Chris--you are essentially right, but the surfaces are angled and I have bowed to the 'lip' at the bottom.

Now I just want someone to find a weird dual-reflector adjustable-bulb military flashlight or something to make sense of this for me.

... or maybe it is just a steel washer.

If you want to see a washer in those pics above, then you can see its inner rim in several pics.

Darth Lars said:

... or maybe it is just a steel washer.

Click to expand...

If it's just a steel washer, how would it have attached to the grenade?

FB

I think calling it a reflector is misleading. There's very little surface area for "reflecting". IMHO it's probably aluminum hence the metal color difference seen in pics.

Why does the inside hole taper? I don't see any proof of this and it seems to merely come from the "reflector" mindset. I'm not sure the front face of this piece is angled. Any 3D comparisons between flat and beveled?
How about another 3D model render with flat front and no taper on the inside hole? (at least for comparison)

I'm concerned this "reflector" idea is guiding the design based on what we expect to see (because it looks like a flashlight) rather than what is actually there.

I wouldn't call it a washer either because of it's thickness, more accurately a spacer or just a piece of thick walled tubing.

Since the visible hole at the front is smaller than the grenade neck it's presumed the end of the part we don't see is a two stepped hole (grenade neck diameter hole stepping down to the smaller 'emitter' hole).

franz bolo said:

If it's just a steel washer, how would it have attached to the grenade?

Click to expand...

Sorry. I meant that what we see might just be a steel washer.

I would guess that it is held onto the grenade with a 7/16 UNF bolt, alternatively a nut and a short piece of threaded rod.
One or two washers stacked on top and one washer underneath. All glued together and to the inside of the balance pipe. Then the emitter would just screw on onto the grenade stem. Just something simple and straightforward. No escutcheon, airplane part or anything else exotic or custom-machined.

Wouldn't a steel finish be just as likely as aluminum finish?

Chris – I’m not trying to mislead anyone by calling it a reflector.
I see a big hole tapering to a small hole with a shiny surface between the two – hence ‘cone’ and ‘reflector,’ cone reflector. I don’t see a hollow tube.

Of course – anything could have been used to tie these two pieces together way back then. Guessing the threading is a useless exercise. As Andres has pointed out in Russ’ thread, no two grenades are alike.
I believe guessing a bolt or a nut and threaded rod was used, fails to acknowledge the craftsmanship of the person responsible for building this prop.
Imagine him sitting there with his pile of ‘junk,’ mating the two pieces together in the air in front of him. Grenade in one hand, balance pipe in the other, nodding his head. He knew he wanted those pieces to fit somehow and he persevered.
For what it’s worth I believe he was as determined with the look of the saber’s interior look, as he was with it overall. Again, if we’re playing guessing games then I guess he had a brief of what this prop’s function was, and decided to use a shiny surface inside the balance pipe.
If a threaded (and agreed, much simpler and straightforward) rod, bolt, nut system was used, then there would be no need for adhesive. Force (no pun intended) the bolt or whatever into the neck thread and simply work outward until there’s enough material to fix to the balance pipe.
However, the pictures we do have show evidence of either solder or glue blobs protruding from the rear of the balance pipe, pointing toward the prop builder’s use of something far more pleasing to the eye and yes, perhaps even exotic.
Still – if anyone can present comparison renders as Andres has above, pointing toward another method of attachment, then I look forward to seeing them.
If anyone would prefer a bolt, a few washers and a nut inside their emitter then I'm sure Russ has plenty on hand in storage which will do the job.
I know it would save everyone a lot of work.

Howard - Can you honestly tell me you can see for certain that the interior piece is angled from just those few fuzzy screencaps?
It seems to me this is an awful lot of detail to assume without reference to back it up.

The size and shape would not function well as a reflector in the real world - not enough surface area and the angle is too shallow. To assume the front angle is one thing, to assume the inside taper as well takes even a greater leap.

To illustrate my point...
Below are two versions of the 3D rendering.
- The top one has a completely flat surface inside no tapers at all.
- The middle is Andres original.
- The bottom is the HD screencap



"However, the pictures we do have show evidence of either solder or glue blobs protruding from the rear of the balance pipe, pointing toward the prop builder’s use of something far more pleasing to the eye and yes, perhaps even exotic. "

For the record I'm not saying they used washers and bolt. I believe it's something like what you have in mind just without the angles (perhaps a machined down turntable weight?).
The solder or glue just indicate it was something that wasn't really meant to fit together. I highly doubt the designer was overly concerned with interior construction when the outside is so shoddy (wire holding the gear on?).

I believe you and Andres on the right track, but assuming too much because of what you want to see. I admire the dedication of both of you to this prop a great deal. I just think you've lost some objectivity. Even in your post above you're projecting yourself into the original prop maker's role. I wish the original builder cared as much as you or I, but I don't think they did from the visual evidence.

Serafino said:

The CAD model isn't mirrored so it's hard to fully evaluate how well it's working at some angles, but as you can see in this early test of a very deeply angled reflector the reflection pattern shows promise.

Click to expand...

Are these pics even relevant since most of what we see of the "deeply angled reflector" should be the side walls of the balance pipe interior?
The 3D model has a very shallow bevel to the front face of the piece.

Hi Chris,

Yes, I see a cone. It's not what I want to see, because frankly I could see something far easier if I wanted to, to connect the two components together, and save myself and Andres the many hours of discussion and emails and comparisons, working out the angle and reflectivity.
When Russ has machined a test cone and Andres sets up a comparitive photographic test, then we'll know more. Who knows - that test could point to a simple hollow tube - but from the cloak cap, I doubt it.

I'm tend to trust my eye regards fuzzy screencaps.
Remember this?



From this pic I postulated the ring of holes was sloped, and I stuck to that belief while everyone else said I was wrong.
The V2 run Russ produced from a blueprint drawn up by myself and Pat turned out to be just a few mm too long when compared to the MR version.
Okay - I'm not saying I can never be wrong, and I'll be very happy if evidence comes about which nails this detail without any need for lengthy analytical tests. But at the moment all we have (as usual!) are these fuzzy caps.
I don’t concur the reflector area is not shaped correctly to be a reflector. It could have been cut down, and more to the point, we have absolutely no idea where this component came from. It could very well be anything from a military piece to a trombone mouthpiece.
At the end of the day, this thread is designed to show everyone what we’re intending regards the connecting piece for the emitter and grenade. If anyone isn’t happy with what we’ve come up with, then no problem at all, they’re obviously free to attach the two parts how they see fit.

I don’t think we’ve lost our objectivity, and by no means am I projecting myself into the prop builder’s role, I was simply suggesting a possible mindset the gentleman may have had whilst working on this prop.
Okay – it’s beat up and not the most glamorous piece in the history of props, but the wire may have been added at a later date – considering how well the booster and clamp fit together anyway, and the fact we know it wasn't very well looked after during the shoot.

Okay, I keep going over this and right about when I’m ready to post, my ideas change.

So I’m just saying: I’m working through this whole question all over again and will post my comments as soon as I have anything solid--hopefully in a day or two.

Chris, just to clear the air, I’d like to ask that next time you keep the accusations of non-objectivity to yourself. They were irksome and unfair and I’m not interested in putting more effort into ignoring them.

That said, after carefully considering your ideas about the emitter, I’m leaning towards agreeing with your ideas about the shape.

It does appear that the front face of the ‘thing’ in the emitter is most likely flat. I could not create an ellipse of the correct proportions which would fit the lower position of the hole needed for an angled surface.



In the end the only ellipse which worked represents a hole smaller than my previous design (about half the size of the ID of the emitter), and in the same plane as the front face of the ‘thing’. (The dot you see is the center of both the 'thing' OD ellipse and the 'hole' ellipse.)

Once that new hole size is in place, the reflection shape in the hole which led me to feel the hole was conical goes away.

The shape is decidedly homely, but I find I am unable to convince myself that it’s wrong.

I do still think the hole is relatively shiny, I can't explain the high contrast reflection pattern otherwise.

3D comparisons:



These are about as 'kinda sorta' as my last ones, but the right hand comparison is growing on me--absent the grey 'blob' right under the hole (which doesn't integrate with anything else to date either), it looks pretty good.



Ultimately it's the geometry in the 'cloak' shot which trumps everything else for me. The enigmatic aspects of the screen caps just above 'feel' like angled surfaces, but I suppose they must be the result of other sorts of lighting or texture effects.

I just stacked six washers in my emitter, and got something visualy very close to those screen caps.
The fit is a little off, but i wraped the washers in some plumbing tape and they fit snug as a bug.

Excellent analysis, Andres!
Although I still see a polished cone shape in there.

I think I know what was used to attach the two pieces now.
Pics later today.

Imageshack's not working at the moment - so I can't post pics, perhaps later...

Anyway, if you have an original booster, unscrew the cap and turn it over.
There you'll find a 'cone' with (if it's seen action like mine) deposits of banding on the reflective surface.
This banding matches the banding seen in the cloak screencap.
This part will almost fit perfectly into a balance pipe, but will need the thread sanding down a little and the ring of holes on the piece removed completely.
On the rear is an hexagonal 'bolt' section, which I believe we can see the remains of in the pic showing the crimping of the emitter's first stage. I think this is how the two pieces were fitted together, the crimping held the hexagonal bolt, and therefore the 'cone' in place.
How the grenade neck stem was secured is a mystery though.

I'm firmly convinced this booster part was used inside the emitter.

Howard said:

I'm firmly convinced this booster part was used inside the emitter.

Click to expand...

Could be. I'll check when I get home. So what went below the Booster Bearing then?

How did it attach to the grenade?

FB

I like where this is heading.......it's beginning to make more sense and expain what we see in the screen shots. Great work so far guys!!!

Dave