Just ordered some of these bulbs to do a test. Also, from your pic of the ESB RF top that's partly hanging out, Rafalfett, it looks like there is a 1mm or so section of aluminium on the inside of the RF block?
I noticed too that there's something under the perspex block, and I assumed that its purpose is to let the perspex block to sit at a specific distance in the RF housing. Here is a drawing (a WiP of my new RF templates that will be awailable with my RWH v2 helmet templates) that shows with approximation these 'spacers':
The Rangefinder casing thickness is around 2mm and the spacers are 1mm for the ESB and 1.5mm for the ROTJ. The image is an interpretation of the movie era RF setup for both ESB and ROTJ.
Looks good there.
I just received a precision vice so have been able to accurately drill the three holes into the RF block. A nice slow speed and feed rate keeps the bit straight and doesn't melt the Perspex...
What a piece of beauty! Just need some light (I know they are on their way to you) and some experiment with them and we'll have some great rangefinders... I hope.
Keep up the great work!
RafalFett, you are brilliant and I can verify that you are indeed correct on both the wheat lamps and the 2 part Perspex. There are three wheat lamps in the perspex in addition to the two red LEDs that everyone already knows about.
The metal is not a spacer, but serves to reflect the light of the wheat bulbs. Also, it covers the entire top of the perspex.
The perspex is simply pressure fit into the rangefinder (with doublesided tape holiding it in place). The reason you are seeing a difference between the RotJ and the ESB is most likely due to the perspex not having been cut exactly the same thickness from helmet to helmet.
It looks like the PP2 might not have the metal section glued to the top of the block, so we are seeing the adhesive part through the Perspex.
That's it. So on the PP2 the aluminium foil isn't there...
Because you have the wires running into the Perspex block powering the grain of wheat bulbs, when the adhesive strip fails, as seen on the ESB hero, the only thing preventing the block falling out are those wires. This is why the narrow end of the block has slipped out, revealing that aluminium backing sheet.
Added some of the images scattered through this thread to the first post, and some additional ones too.
The grain of wheat bulbs are a good fit into the holes in the perspex, but aren't a tight fit. The wires are actually pretty strong and I suppose they could provide some support, but again, the true support is coming from the rangefinder body itself.
Also, I think it is highly unlikely that the drill holes or drain of wheat bulbs would be different from helmet to helmet. There might be slight variances in the perxpex, but I would tend to believe those aspects are the same.
And I'm guessing the slightly angled in front side of the RF housing ( where as the back side of the housing is square to the top ) provides that grip from a bit of 'flex' in the housing material?
You may find the discrepancies in the three holes diameters may be caused by the drilling process. Too fast and not clearing out the Perspex swarf can result in a slightly larger bore...
Also, the grain of wheat bulbs are much longer than anything that has been posted so far. I did a quick google search and couldn't find any that directly matched the originals in overall shape.
This thread is a perfect example of what a forum should be; everyone working together to get the most accurate information. Art, thanks for starting this thing and allowing noobs like me to be a part of it.