Curved Buttons are a common Mistake, that people tend to make. Dont do it.
A curve might seem to fit the shape your hands fingers, when your hand is laying Flat...
However... when you use Buttons, your fingers are Bent at a 90 degree angle... just like when you
use your keyboard to Type with.
When you curve the layout, your fingers wont line up with the buttons... and you will often tend
to press the lower buttons "Side-Edge", instead of the CENTER of the button. This wont feel as
good to press... and in fact, many buttons do not slide well.. when you press the very outside edge.
The only exception to this rule... is when adding a lowered 7th button, such as for use as a
Mortal Kombat "Run" button... that could be reached by your Thumb, or you simply slide your
fingers to the "lowered button"... from the nearest end-button.
I also advise that at least One of these buttons is a Pinball Button (long travel leaf switch)...
which you might either place as that 7th button, or possibly on the bottom row.. nearest the stick.
A Leafswitch button works much better for older Rapidfire games... as you can fire much faster, and with FAR
less fatigue. Games such as Asteroids Deluxe, Galaga, Satans Hollow, and most especially, Halleys Comet...
which requires a sustained maximum rate of fire... to be able to collect as many powerups as possible... in the
shortest span of game-time.
To take advantage of a Leafswitch, you have to do a special technique called "Feathering". You press the button
down to the point where both metal leafs make contact... and then you simply "Vibrate" your finger... instead of
pressing the button down further. Since the leafs can make or break contact.. by the thickness of a piece of paper...
those small vibrations can toggle the button on and off, with a rapid speed that no Microswitch is capable of.
Furthermore... the act of vibrating your finger, is far less stressful.. so you could maintain maximum rapidfire rates,
for hours at a time... without Fatigue. On the other hand... standard Microswitches have between 1 to 2 mm worth
of Travel... and there is a significant Spring Resistance that must be overcame. All of that resistance starts to create
Fatigue, fairly quickly... especially if you have to press repeatedly, as quickly as possible. Micros are good for fighting
games... where you need precision timed accuracy... but they are not good for rapidfire games, and games where you
are repeatedly pressing non-stop.. for long periods of time.
Anyway... to be very clear.. when you "Feather", you do not want to press the button all the way to the Bottom
("Bottoming Out" ). Its more like a diving board... where you lightly bounce a mere cm in each direction... rather
than bouncing the board several inches to a foot.. in each direction.
The other Advantage of not Bottoming out these buttons... is that when a button bottoms out, there is some energy
losses from the hard Impact.. AND... that impact causes impact-vibrations that travel back into your fingers. If you
are repeatedly getting these impact vibrations bounced back into your fingers.. your fingers will start to feel
some degree of pain.
Ohh, and one other advantage, is that the Combinations of Leafs and Feathering... is an almost SILENT gaming
experience. As you will only be hearing your Microswitch Joystick clicks.. and not additional clicks from button presses.
Additionally... you might also consider placing pinball buttons on either side of the Control panel, for Pinball Tables...
as that Orientation, will feel a bit more Authentic.
And finally.. you might also consider adding a cut-out section on the bottom of the cabinet, where you can place
Analog Pedals, so that you can place Racing games better on it. Since the pedals would be inside of the
main cabinet (past the flat front face)... the pedals would be out of the way, when not in use.
About the comments on Lightguns... I dont know if a slight tilt is really going to make much difference. That said,
a fully vertical monitor presents other issues. If people are different Heights... then the view will be better/worse.
The angle you stare at the monitor... at close ranges... will also be poor, as it likely wont match your head/neck angle.
This is why the Control Panel and Monitors, have always been Angled, in almost every standard Arcade cabinet.
(as everyone will be different heights, and so the angles help to maintain comfort at any height, and visibility
at any height)
If you cant find actual arcade cabinet angle and dimension specs, and nobody is giving them here... you may
consider making a lifesize Cardboard Mockup. It could save you a lot of regrets, later on. This is also true
of your control panel... if you plan on using many different controllers. A set of physical Mockup test panels,
can lead to a much more comfy design... instead of ending up with a situation, where your arm ends up
partially resting on a Trackball, or other similar comfort / spacing issue(s).