Differences, pros and cons to true leaf switch pushbutton designs

[RandyT]

This comment, as well as a couple others in a recent thread, deserve their own space, as they don't really relate to the topic of the thread where they appear, and is something where some real discussion would well serve those who might be interested.

Also, since the happs are locked in place at the sides loosely, the button can rock a bit from side to side... resulting in a bit of sloppy 'play'.   The Leafs have very little space between the center shaft and the button shell, so theres less side to side slop.

No Steve, this simply isn't true.  You are extrapolating, incorrectly, rather than comparing.  I have 25+ year old leaf buttons in cabinets behind me.  There is considerably more wobble in those plungers, specifically due to the fact that they are supported by a single shaft.  The shaft, and the hole it slides in, wears more quickly and is actually a bit large to begin with to prevent binding.  This does make them very free moving, but "plunger wobble" is part and parcel of the early leaf button design, and made more apparent due to the extra plunger height most of them have.

On the topic of sound, the "vibration" heard in newer button designs is a result of the longer spring.  Most folks like a lighter actuation, so the springs are tuned to do not much more than provide as much force as is required to return the plunger to the "home" position.  Any more, and it adds unwanted resistance to the button.  This results in a spring that tops out in size at a point that still allows a little vibration in the "home" position.  Because the spring is larger, there is more of it to resonate.  As I have mentioned before in these forums, it takes just a little stretch of the spring to remove virtually all of that resonance, at the expense of a slightly firmer button.  As for a button sounding "hollow", most early leaf buttons were mounted in thin metal panels.  Banging on these switches to the point where they bottomed out was tantamount to hitting a drum head.  Modern, long body pushbuttons sound no more "hollow", once screwed tight to a panel with the switch side enclosed.  What could be creating this misconception is that many poorly installed leaf switches never actually allowed one to bottom them out, as doing so would hyper extend the metal parts, and that created a huge amount of resistance.  These types of installations are likely the main reason why operators disliked the leaf switches.  Bend them too much as a result of not having the correct distance between the plunger and the switch and you'll be tweaking them every other week.  One cannot reasonably use the sounds (or operation) of an improperly installed switch as a reference example for one that is.

And as a side note, if anyone out there is making a video pinball controller, and you are not using a decent leaf switch pushbutton for the flippers, you are doing yourselves a huge disservice.  You'll understand why when you fix that situation .

RandyT

[VanillaGorilla]

I have 4 original arcade cabinets in my home:

Scramble
Dig Dug
720 degrees
Defender
(I also have my MAME rig)

ALL of them have leaf switch buttons, my MAME rig has both. ALL of them are different!

Scramble : short plunger leaf buttons in a wood panel
Dig Dug : TALL plunger leaf buttons in a metal control panel
720 Degrees: short plunger leaf buttons in a metal panel
Defender: TALL plunger leaf buttons in a wood control panel.

They all feel slightly different;
In terms of noise, Dig Dug is definitely the loudest of the bunch, followed by 720.
Dig Dug also has the wobbliest plungers of the bunch.
Scramble, and my MAME cab are the quietest.
720 has the worst feel (I think the leaf switches themselves are wearing out and getting 'spongy')
Defender the best feel (The leaf switches are screwed down directly to the underside of the panel with no 'holders', IDK if that is making the difference).

I dont think its possible to make a blanket statement about how old school leaf switch buttons feel, except to say that they feel decidedly different than micro switch based buttons. To compare old school leaf switches to the modern-day replacements (CLASSX, Rollie) is an exercise in futility. They all feel very good, and any difference is splitting hairs.

There is no doubt that blindfolded, I could tell the difference between leaf and micro. If I had to do the same with the different leaf switch buttons, I could probably only discern the difference between the tall plungers and short plungers, because that part of the button is obvious as far as travel is concerned.

Leaf switches feel great, old style or new style. There is much less fatigue when rapidly actuating a leaf switch button. There is no denying the superiority in rapid actuation over micros. Gotta love that 'bounce'.

Its clear to me, that the taller the button, the more noise they seem to make. Only micros are louder. My Scramble and my MAME rig are whisper quiet, but in the end, the noise level is my least concern. Tall or short, old or new, the ones outfitted with leaf switches win handily over micros every time. Please note that my area of interest is the classics (pre-fighter era).

Im sure some of the younger guys prefer micros, or sanwas (which I have not really tried, except for a few excursions at the arcade in recent years playing a few fighters), because that is what they cut their teeth on. They may actually be superior in that context, as that is what the machines of that era were outfitted with.

I think it makes sense to use the same type of switches that were installed as original equipment on the games that you prefer, if authenticity is your goal.

Thats my 2 cents.  

[RandyT]

I dont think its possible to make a blanket statement about how old school leaf switch buttons feel, except to say that they feel decidedly different than micro switch based buttons. To compare old school leaf switches to the modern-day replacements (CLASSX, Rollie) is an exercise in futility. They all feel very good, and any difference is splitting hairs.

There is no doubt that blindfolded, I could tell the difference between leaf and micro. If I had to do the same with the different leaf switch buttons, I could probably only discern the difference between the tall plungers and short plungers, because that part of the button is obvious as far as travel is concerned.

This is about the only place where I'm inclined not to fully agree.  

I have here an original Defender (with the direct panel mounted switches, special injection molded tall bodies, 3 blade parts, actuator ahead of the contacts), an original Galaxian (very shallow metal switch holder, 2 blade parts, stacked body, actuator ahead of the contacts) and a criminally poor example of a Twin-Cobra conversion (standard white plastic switch holders and molded, normal height, 3 blade part switches, actuator directly above the contacts.)  I could tell, blindfolded, exactly which button was associated with each.  

The best feeling buttons out of the group belong to the Galaxian.  It's also the one with the least apparent amount of damage compared to the others.  It's switch is smooth, and has very little overshoot, which means very minimal flexing of the lower blade and consequently, very little deformation.  The next are the Defender buttons.  The fire button on this one is obvious from below the panel, as it's the only one bent so far away from the button as not to touch it (by about .050") at rest.  There is literally 3x the throw in the button as is required to close the contacts.  It still has a decent feel, because the button is positioned past the contact points, but still more resistance than the Galaxian.  It would have suffered far less damage, however, had the button had about 1/3rd less throw and had the switches positioned differently.  The fire button with the bent leaf actually feels better than the rest, which to me indicates a design which could have been better.  And the one which is the perfect example of what not to do is the Twin Cobra conversion.  All of the buttons on this machine are stiff and cause severe fatigue because they have so much resistance.  The throw on the buttons is 4 to 5x the gap of the switch, and the buttons are directly over the contacts.  This makes for buttons with a high force requirement, which has resulted in literally grinding the contacts of the switches down to almost nothing, and many attempts by it's previous owner to tweak the switches to keep them working.  Its a mess...it looks like a mess and it feels like a mess.  The majority of microswitch buttons out there would run circles around this particular attempt at a leaf installation.

And without turning this into a sales pitch, any modern attempts at incorporating leaf switches will have similar properties associated with the implementation that will ultimately, and similarly, affect them in either a positive or negative way.  As such, not all of these will be equal either, and need to be considered based on the individual implementations.  

Leaf switches have the ability to be one of the best solutions out there for a broad range of gaming purposes.  But like microswitches, there are many varieties and many implementations which are going to play a big role in their durability and suitability for any particular purpose.

[Xiaou2]

No Steve, this simply isn't true.  You are extrapolating, incorrectly, rather than comparing.

 You were correct. I should got my lazy butt down to the basement to test them physically again.

 Anyways, what I noticed now is that the Happs seems to have more friction if it hits the sides when pressed.  Where as the leaf button, even when pressed at the edges, has very little frictional increase at all.   

 In fact, I was able to press the happs button down on the very edge opposite of the switch actuator, and press it down fully... yet the micro did not activate.  This shows that a happ button has a design flaw.  Although, this probably may never happen in real play.. due to hitting the center of the button... it still shows the mechanical differences.  The leaf button, even when moved around, will never fail to activate the switch.

  I have 25+ year old leaf buttons in cabinets behind me.  There is considerably more wobble in those plungers, specifically due to the fact that they are supported by a single shaft.

 Ok, well, I just tested and observed some ancient leaf buttons myself.. and I noticed something you may not have.

 The Leaf seems to have a slight more wobble on the top side (when not depressed).  However, if you depressed it fully, then wiggle the bottom part of the shaft.. you will notice very little play.    HOWEVER, if you depress a switchless micro fully, then wiggle the actuation clips, you will notice about 3x the horizontal travel found in a leaf.

 The micros start out fine, but as depressed, can angle a lot more because the clip holes are 2x the size they should be to keep the actuators from angling.  Of course, this is needed, otherwise you couldnt get the actuation points thru the bottom of the button to lock them in place.

 Very interesting indeed.

On the topic of sound, the "vibration" heard in newer button designs is a result of the longer spring.

 

 If you want to really compare sounds, take the springs out of a micro, and grip it upside-down in your fingers.  Then tap the button with your other hands fingers, and note the resulting hollow-echoing sound.  Then do the same with a leaf.  but, you can even leave the spring in the leaf, as it doesnt really play any factor.

 The happs is 2x as loud, and the tone is deeper, with an echo to it.  This is the nature of acoustics of a much wider chamber.

 The spring noise was merely a part of the equation, but the truth is, even with no spring, the happs are louder.

  As for a button sounding "hollow", most early leaf buttons were mounted in thin metal panels.  Banging on these switches to the point where they bottomed out was tantamount to hitting a drum head.  Modern, long body pushbuttons sound no more "hollow", once screwed tight to a panel with the switch side enclosed.

 Well, I still disagree.  If the sound of your game is up and you are not concentrating on the sound, then you are not going to even notice.  However, turn the sound down minimally.. and or off.   Compare two mounted in an enclosed wood box.  You will clearly hear the difference.  The metal CP comparison really makes no sense... as you could just as easily mount a micro to a metal CP.

  What could be creating this misconception is that many poorly installed leaf switches never actually allowed one to bottom them out, as doing so would hyper extend the metal parts, and that created a huge amount of resistance.  These types of installations are likely the main reason why operators disliked the leaf switches.  Bend them too much as a result of not having the correct distance between the plunger and the switch and you'll be tweaking them every other week.

 

 Well, this was also an interesting thing to read.  I never may have realized the old arcade leafs were using an improper spacer depth.  Not sure, cause its been so long.  But its something to note for future reference.

And as a side note, if anyone out there is making a video pinball controller, and you are not using a decent leaf switch pushbutton for the flippers, you are doing yourselves a huge disservice.  You'll understand why when you fix that situation Wink.

 So True.

 
 Thanks for the arguments.  Was a good to make further observations and discoveries.

[taylormadelv]

I tend to prefer the action on micro buttons and I tend to have much less "hand fatigue" with micros for some reason but there are exceptions. The original leafs in my Stargate are perfect. Some of this is due to the fact that they have been broken in over the last 30 years but the fire button on my Stargate is perfect and obviously it gets pushed a lot and I never have any hand fatigue with my Stargate for some reason.
Now with Gravitar and Asteroids Deluxe, that's different. I do not like the leaf switch action on those games for some reason and I replaced those leafs with translucent IL's and I am very happy with the firing action on those two games. I did get significant hand fatigue when firing in Asteroids Deluxe, even though the leaf is very very close to Stargate but not identical.
In terms of aesthetics, the translucent leaf buttons with the tri-spoke on top look fabulous when illuminated but you have to live with the leaf and how to install that leaf in your CP. Translucent IL's were the answer for translucent micros but the tops are perfectly clear and don't look quite as cool as the translucent leafs IMO.

[Xiaou2]

Now with Gravitar and Asteroids Deluxe, that's different. I do not like the leaf switch action on those games for some reason

 Probably the same reasons as we have already covered:

1) Leafs not being floated, and instead, and being pushed too far, to full extension
2) Leafs holders incorrect, and thus the depth of switch is incorrect.

 The age of the button should not be really be a factor.

[Xiaou2]

Leaf Mod Idea...

 To help counter Leaf over-bending, and that bottoming-out crash... heres an idea I had came up with some time ago.  Ive yet to build and try it, but it seems sound enough...

 This design uses a stiffer spring mounted under the leafs.  Even if you press the leaf past the float point, the help of the spring underneath should be good enough to provide protection against over-bending... as well as add a nice cushy feel instead of a solid stop crash.  It will store up energy as well, returning it to the rebound.

 Also, sitting on the leaf buttons wider shelf, is a pink line.  This line represents a small rubber washer.  Even if you bash the button to the point where it would hit the shelf... the rubber washer would absorb the forces better, as well as make the buttons quieter.

 This could be a little deeper, and thus a mod to the shell would have to accomodate its extra depth.  Also, the material could be something other than rubber.  Something soft like silicone maybe?  not sure.

 The designs a little off yet, but still it drives home the idea.


(design not to be used without my permission)

[RandyT]

Leaf Mod Idea...

Interesting, but ultimately, it's over-engineered.  There's nothing that the extra spring at the bottom could do, other than increase cost and complexity, that can't be incorporated into the button spring/leaf switch design.  The rubber pad, or any other soft material in the button body, will at minimum eventually break down and not do what you want it do, and at worst, jam up the button action when it does.  Something durable enough to do this without breaking down will be harder and while it will quiet down a "bottom out", it won't do much else.

The best solution to the leaf switch issue, IMHO, is one that allows a reasonable throw without being long enough to damage the switch, adjustable tension through a few methods easily performed by the user to suit their tastes, and a simple low-cost approach to doing so.  If you can keep an open mind and ask questions before you jump to conclusions about what is and isn't possible, I'll send you a CLASSX™ button to play with so you'll have a frame of reference as to what is already being done, and then we can discuss further if you'd like. .

[boardjunkie]

As far as leaf switch button "wobble" or slop goes, there was the snapped together (no e ring) types that were superb. Shorter throw than the e ring style, and the top side of the button (which is what you push down) had 3 molded in "nubs" that kept it centered and slop free. They, to me, are the best of the best...I'm real picky about buttons and leaf switches.

This type:
http://www.diypinball.com/images/DSC_2057.jpg

You can simulate this on e ring buttons by placing 3 small dabs of epoxy midway down the top section of the button top. You may need to file or sand them slightly to get the perfect fit. I've done this, and it works.

Another thing I like to do with regular e ring buttons is put a nylon washer/spacer ahead of the e ring. This shortens the throw and gets them pretty close to operating like my favorite ones.


It looks like this:
http://www.flickr.com/photos/62937081@N00/5545046534/#

The nylon washers are available at home depot and lowes type places.

[Xiaou2]

Interesting, but ultimately, it's over-engineered.  There's nothing that the extra spring at the bottom could do, other than increase cost and complexity, that can't be incorporated into the button spring/leaf switch design.

 Yes, it would increase costs.  But Imop, it just might give an advantage over other designs.

The rubber pad, or any other soft material in the button body, will at minimum eventually break down and not do what you want it do, and at worst, jam up the button action when it does.  Something durable enough to do this without breaking down will be harder and while it will quiet down a "bottom out", it won't do much else.

 Well, as said, it could be as simple as a mild rubber washer.  Such a thing in a home environment would probably take like 5yrs to wear out.

If you can keep an open mind and ask questions before you jump to conclusions about what is and isn't possible, I'll send you a CLASSX™ button to play with so you'll have a frame of reference as to what is already being done, and then we can discuss further if you'd like

 I always have had an open mind.   Id love to check out your buttons/products.