ROTJ blue clamp card details

[corliss1]

Is there a consensus on a real-world part for this yet? I was going through my old electronics pile and found a blue board that looks like a nice match:

I specifically tried to take that picture in weird lighting so you can see how the blue shifts. Here is the same card under VERY bright white light against a black background:

It's got the right spacing, 13 traces per 2 inch section, and would fit well in the clamp when trimmed.

So what do you all think? I looked around a bit but didn't find an official find of the correct card, but of course I could have overlooked that.

 

[marker2037]

That does look spot on. Nice find if you're looking for an original part.

 

[corliss1]

Just seeing if the community likes it - if so, for once, these are not a totally unobtanium part.

 

[BlandoCalrssian]

The Vector extension board is a good vintage option. I think there’s disagreement over whether or not its “the” source but the I think the traces are the same width and spacing, and the silver plating can be buffed off to reveal brass underneath. Plus you can probably get a dozen clamp cards from one board if cut properly.

 

[corliss1]

That does look pretty good too.

 

[Darth Lars]

In my interpretation, the original card is turquoise (check) and has copper traces (check), but ... the card is also about as wide as the control box: 17-18 mm. The copper traces go the entire width of the board.
Are your traces that long?

I also think that the thickness of the original card is probably a bit thinner than the industry-default 1.6 mm (which I have experimented with before shaving it down).

 

[corliss1]

No, these traces aren't that long.

 

[BRRogers]

Vector board is good.
But…
The board (we as a group of likeminded individuals are looking for…)
Is a blue core FR2
Green soldermask topcoating.

To clarify, it is *copper* cladding and the coating was usually TIN to be burnished off.

Conformal coating leaking from BOTH sides of 18mm worth of traces has been what is stumping me. One side is squared off and the other side is scalloped. In my opinion that is one side dipped… dried vertically, and the other side dipped and dried flat… or brushed on flat.

For the record the casting has a visible and physical step that shows this, and as I share in the photo below, is the only thing that makes sense of the reference photos from the standpoint of a common pcb production technique employed from the 60s until today as well.
Conformal coatings are used less frequently today because the components themselves are often rated for usage that old components weren’t. (IE possibility of liquid or vapor contact that could create shorts in old boards during their use would be a reason to conformal coat… as well as heavy use. Conformal coat would ensure plating and components had an extra binding layer beyond lamination or solder)

 

[BRRogers]

Part 2:

There are OTHER Vector 3690 boards that employed a blue FR2 solid core substrate but have a green hue in the surface. These look great as Luke Hero boards… and are very different tones from the blue/white laminate FR2 Vector 3690s. They almost
Have a deep ocean blue tone at first glance.

However, no soldermask and no conformal coat.

There are an insane amount of boards out there from the prime time period… but I’ll say this. Not a ton of manufacturers were doing that combo.
Blue substrate with green soldermask.
And… you’d need to be doing a specific kind of work and function to have conformal coat on both sides of the traces.
Currently I’m rummaging through anything that resembles early computer aided mechatronic/cnc production drives (or edge extenders / extensions / flip chips… which had a lot of conformal coating looking at Landis flip chips) (already checked, traces too thin) but some nice color combos and conformal coat samples there.

 

[v312]

What do you think about the wear on the card edge? Kind of looks like the trace is painted over...

 

[corliss1]

Or the card actually got used and that's just real wear from handling, or creating the prop. *I* don't see paint there.

 

[v312]

Could be just the picture quality, but it does not look like a worn metal trace, more like a worn paint. Don't get me wrong I know there are real traces/contacts on the board as can be seen very well here for example:

I'm just wondering if that's their original color or they were painted over ..

 

[corliss1]

And with that corner being exposed too, I would vote for handling since it would get rubbed a lot. We could be seeing different things though - you know how that goes around here

 

[v312]

Or maybe the original board had tinned traces that were not painted, but the board was brushed with some sandpaper to remove the layer and expose the copper core of the traces? That would also explain the kind of smooth wear I'm seeing. I'll test with one board that I have and post some pictures of the results later.

 

[BRRogers]

if the tin was removed and the copper laminate is thin, it can be sanded right through down to the board. If it’s done gradually like a gradient, like that.

I pretty firmly believe that’s just where they got sloppy getting the board cut and softened after the tin was removed. (Or gold or soldermask) Depending on *where* it actually was in the tbd board

 

[v312]

Here's the board that I have

I've sanded it to shiny copper, than weathered it. I guess if I sanded it long enough I could get exactly that kind of wear. But it was going to take too much time so I used a file on one of the corners.
The board is not a perfect match, but after the treatment I think it looks close enough to the replica from my hero.