Belly Glass

[ncrguy]

any place online to get glass blanks?

[Amechanic]

Glass blanks? What do you mean by glass blanks?

[ncrguy]

I got some bad glass, don't want to scrap it off, id rather just start with new glass, a blank one

[sixcardmark]

I got some bad glass, don't want to scrap it off, id rather just start with new glass, a blank one

Local glass cutting shop probably be best for that.

[Amechanic]

Ok. In that case just about any hardware store or glass shop will be able to cut you a piece of glass

[Simple Sam]

I know this thread is pretty old but it sounds like something I'd like to try.  Has anybody ever done a reel glass that has things that have to be hidden at times and lit at other times (the "insert coin", "coin accepted", etc)?  If so, what technique did you use?

[essmeier]

It's not terribly difficult to do.  I outlined the full process in this post.

You need to have two printed layers between the sheets of glass.  The top layer is your artwork that's visible when you're playing the machine.

The second layer is a background layer that will be mostly black.

The key is the background layer - it needs to be entirely black except where you need light to pass.

For most applications, the background layer is simply black and white, with the text that you need to see in white and everything else in black.  If you need "Coin Accepted" or "Insert Coin" to appear in some other color, then that portion of the background layer will have to be printed in that color. 

As long as the background layer will allow light to pass through it, the light should pass through to the front and appear as text when appropriate.
Take a look at the last image in this post.

The bottom part of the last image shows an illuminated glass for a game called Base Hit.  Just above the name of the game on the glass, you'll see the number 20 illuminated, and the words, "Game Over" lit above that.

Those are only visible at certain times, and the number 20 is one of nine different numbers that appear in that row, and each is visible only when it's supposed to be.

The image directly above that one shows the back side of the glass and how it was done.  The words, "Tilt," "Game Over," and the row of numbers "13 20 27 25 17 23 10 33 15" only show when the lights behind them are lit.

I hope this makes sense.

[Simple Sam]

Yes, that makes sense and seems not too challenging.  I'm going to try the project using the artwork that is already in this thread since the photoshop stuff is already done and it would make a nice display piece in a backlit box.


If that works out well, I'd like to do a custom belly glass and reproduce a reel glass that is in poor shape.  I'll have to learn how to use photoshop which might be a good retirement project!

[Simple Sam]

So I finally got around to getting this project done.  As previously mentioned, I wanted to do this as a test to see if making a custom glass would give me good results.  I think the answer is absolutely yes.


I tried a couple different methods.  I tried having the images printed on plain and glossy photo paper.  The plain paper did not give a good appearance but the glossy photo paper did.  I backed them with the negative image printed on plain paper.  The images were about one dollar per set.


I also tried using the backlitposters.com product.  The owner contacted me and said that they don't do images as small as needed or to 1/8th inch precision but that he would print them on one sheet and I could cut them to size.  See the attached image.  The total was $20 for the print and $10 for shipping. It was a little tricky to cut the images but it turned out okay; a large paper cutter would have helped.


I sandwiched each between two pieces of glass, 1/8th inch in front and 1/16th inch in back to get it close to the original size.  It was about $16 for each set of glass; getting tempered glass would have about doubled the cost.


In the attached picture, the photo print is in the 742A on the left and the back lit posters is in the 809 on the right.  The photography sucks but the back lit poster definitely "pops" more.  The contrast is better and more vivid.  The photo also looks good but it is a bit more muted.  Based on this comparison, I would make a test run using a print on photo paper and once satisfied with the artwork, print the final product on the back lit poster.


One of the things I noticed is that the original design is actually poorly designed.  The slot machines have two fluorescent tubes that create dark and bright spots in the artwork.  It's more noticeable in person than in the photos but the far edges where the "Golden" and "...ger" are is much dimmer than the center of the artwork.  Since I want to do custom artwork, I'm going to try to avoid the extreme edges.  The original Bally Fruit and Bally surrounded by gold leaf are done perfectly to optimize the existing lighting.  The last photo is in a frame that I built that has led lighting all around the edges which eliminates the dark and bright spots.

[essmeier]

It's interesting that you tested multiple methods side by side. 

I've seen the backlit poster method used in a pinball machine with so-so results, as the artwork wouldn't pass light well enough to be effective for certain parts of the poster that needed to be lit based on game features.   Of course, the pinball machine had #47 bulbs in it, and not a pair of fluorescent tubes.  Huge difference in light output there.

Looks like that method does work well if all you need is to pass general illumination.

I'm not surprised that that the Golden Gate glass wasn't well designed.  That glass was likely designed to fit in multiple machines, and honestly, they likely didn't care about anything except making sure everything lit up and that the name of the casino was spelled correctly.

Thanks for sharing the results.