Does anyone have experience / thoughts with a glass playfield ???

[swinks]

Hi guys

All the talk about the Jersay Jacks new pinball has got me thinking of a way to improve a pinball's design - playfield wear being one.

What if the main playfield was GLASS, how would it wear and perform with steel balls shooting across it.

My thoughts were, what if a glass playfield was water jet cut and then toughened and used for game play. The design of the playfield could be in a way that the playfield would actually have 2 playfields with the main one having a recess for the glass panel to drop into. Then all the lighting is fastened to the underside of the bottom timber one - no need for inserts. Then the playfield graphic could be printed and mylared similar to the last 10 years backbox translites and this is then sandwiched between the glass and the playfield. This feature of the translite could allow for different designs / colours etc at a relative low cost. The bottom playfield could have lots of globe holes allowing various layouts for various graphic designs - could be a sport theme, movie theme, random other theme playfield translite. The top playfield would be fairly limited to each machine design with pop bumpers and other mechanical features having a fixed location. Therefore a person could get one machine but get a second or third playfield translite for variety - looks that is.

With this I think you wouldn't have to worry about polishing the playfield, and to upgrade the glass to a new piece - remove a few items and drop a new field glass in and away you go. I am sure there are some issues and we would have to change the way we think and possibly transporting the glass playfield could be a issue. Maybe the service side of things may be better ????

I came across this Black Hole Pinball with a glass playfield mod on Youtube that is interesting:
http://youtu.be/etjzCDI3R2s

Also I think wear on glass has to be better than the see through perspex Surf Champ I think.

What are your thoughts, experiences.

[Marty Machine]

I think this has been kept away from, because it's so damn expensive to have a sheet of glass custom cut/drilled to allow for your bumpers, drop-targets, posts and everything else to be mounted.....

Then the thickness of the glass means all the mechanics will no longer 'reach' where they should, so a LOT of routing out underneath the wooden playfield needs to be done for the bumpers and targets can still poke up high enough for the (now) higher level of the glass sheet (which adds 3-6mm thickness onto your playfield).

Then after routing out everything under your playfield (or simply gutting the playfield and running it thru a plane to remove 3-6mm thickness) you'll then need to use shorter screws, or leave enough of the original wood in place around all the screw holes.....

Glass may eventually mark and streak from ball-skid, but perhaps polishing with something SUPER shiney/slippery polish will help prevent marking....
You'd wanna use brand new balls, and clean/polish ALL your underside ball guides and ramps.....everything that can contaminate the ball with carbon dust and grime must be removed so there's less chance of the ball marking the glass... (this also applies to regular upkeep anyway).
Hardened glass may solve the marking problem, but more costly....

Ball-drops from when the ball bounces off items, or simply 'drops' from an upper level down onto the playfield may also cause chipping & marking over time....

Perspex is out of the question, it'll scuff and streak in an hour of gameplay, plus the heat from all the lamps may cause warping problem too in time.

kinda gets messy huh?


I have a design for a glass/top playfield (easily removable for cleaning/replacement) but that's under wraps at the moment

MM.

[Pinprick]

Q: How do you get past the problem of it not being possible to use screws in glass?
(I am assuming that the glass must be tempered to withstand airball impacts)
I imagine you'd need a LOT of precision (cnc) bolt holes?
Also, if you over tighten B & N and break the surface tension of the glass - kablooey!
Forget to incorporate one hole in the layout and you'd be rooted too

[Marty Machine]

Q: How do you get past the problem of it not being possible to use screws in glass?
(I am assuming that the glass must be tempered to withstand airball impacts)
I imagine you'd need a LOT of precision (cnc) bolt holes?
Also, if you over tighten B & N and break the surface tension of the glass - kablooey!
Forget to incorporate one hole in the layout and you'd be rooted too

Yeh, there's all that too, but he did say top use the glass laid on top of the (wooden) playfield, which would still use  the screws -  see my response above, regarding playfield-wood/thickness/screws etc....

MM

[ddstoys]

My Elektra has a clear plastic sheet over the entire lower playfield and it looks tonhave held up really well the top playfield without the Plastic is absolutely stuffed

[Pinprick]

[/quote]
Yeh, there's all that too, but he did say top use the glass laid on top of the (wooden) playfield, which would still use  the screws -  see my response above, regarding playfield-wood/thickness/screws etc....

MM
[/quote]

Aha!  . . . I didn't read Swinks' article properly (sorry).
It still strikes me as a huge undertaking, but if you have any success that would be terrific.

I recently worked on a GnR playfield which had been cleared with two-pack CERAMIC. The finish looked like a sheet of glass and should very durable.

Let us know if you make any headway.

PP

[Dirty daz]

interesting idear, i'm sure it could be made

[Bayview]

If the glass is to have holes & cutouts in it, it will have to be safety glass, i.e: Toughened Glass.
Problem with Toughened glass is, it is not flat. As it is toughened using a horizontal furnace (that has rollers that it moves along on), the glass actually comes out with waves in the glass. This is caused by the heat and the gaps between the rollers, which I guess sort of causes the glass to sag a tiny bit between the rollers.
If you have a sliding glass door in your house. Have a look at a reflection in it, but from an angle (from the side) you will see all the distortions in it.
So it's not flat.
The ball will scratch the crap out of it.
There is also a limitation to holes being too close to each other, cutouts too close to edges etc.
Just my view.
 
Bruce

[swinks]

Hi guys,

Some good points and thoughts, though I wanted to help the discussion & understanding with a quick playfield sketch just for the concept (definitely not a playable PF). Left graphic is a playfield with the components assembled, middle is the 2nd layer panel and right is the glass panel.

1. base layer (12mm thick ply) - Main playfield would be the one that would hold all the cabling mounted to it underneath and also the (led) globe fixtures to reduce heat on translite sandwiched graphic panel, along with the second layer mounting points.
2. 2nd layer (6mm thick ply) - ply playfield sections fasten onto the base playfield (check out middle sketch of timber component layer) that the mechanics could fasten to on top as well as any plastics over the top disguising the inserted panels. Also to this would be the timber sides and lane divider and apron etc. The mechanics would also sandwich the 2nd layer to the base layer as it alot of the time they are mounted to the playfield underneath.
3. glass panel (6mm thick) - which is water jet cut and toughened which just drops in (right hand side graphic). On a quick removal of the top pop bumper assemblies and any other component blocking the removal would then allow a quick glass removal, clean and playfield graphic swap over.
4. in between the glass panel and the base layer is a translite style graphic inlay that can be easily swapped out for a different theme.

I use to make cnc laser and router machines and can see a mass production potential for cutting out components and the need for screen printing is removed as the translite playfield graphics can be printed and sealed. Along with water jetting of the glass the accuracy is up to within 0.25mm so that could be accurate along with automatic bevelling with a 4 axis cutting head.

I do agree there would be some design limitations to a playfield and the edges of the glass are the weak areas if hit by a ball.

In the end I was just trying to think of way to clean a playfield and change out the look relatively quickly and cheaply and remove the need for inserts and playfield touchups. You never know knocking around a few ideas stemming from areas of need could create a next gen pinball concept.

I plan to do this but not for a year or two as have a few machines that I want to restore and learn from.

Also the glass would not be mirrored like the blackhole one.

[Marty Machine]

No doubt it's very do-able, it's just one of those costly things, and i fear the many negatives will raise their head sooner or later.....who knows, until it's done eh?

Other than that, i applaud you for giving it a go......

MM.

[ajlaird]

Certainly a very interesting idea, and I imagine that you will learn a lot valuable to all of us simply by trying.

I say give it a go!