Im an engineer too! Just kidding I'm just an elevator mechanic. For what it's worth I like this design as well. Also I like the old saying in the trade- mechanics fix engineer's mistakes. Time will tell if it applies here.
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Quoted from DiabloRush:The thermal expansion coefficient of aluminum is roughly 50% greater than stainless steel. Hence, in this system, as it heats, it will get slightly looser.
I've done some extended play testing on my Godzilla with this setup. While I didn't measure coil temperatures, I did feel them. After 90 minutes of constant play, the coils were slightly warm. Considerably less hot than what I remember before the upgrade.
Also note, I only needed a stiffer return spring in Godzilla. The reason is discussed, above (orientation of the flipper mech is worst-case in GZ for rebound). All my other games did not require a stiffer spring; they're all stock. In all these games (except GZ with the stiffer spring), I had to slightly lower the coil power to achieve the same flipper response. That suggests these are more efficient at energy transfer, and as such, less likely to overheat.
The heating performance could be further tested. I'll see if I can round up some thermocouples and instrument one of my games for comparison to stock setups.
Are you saying The flipper bats are acting as a heat sink to the coil? You still have a flipper link that is plastic separating the plunger that gets hot to the mechanical linkage of The flipper bat.... I would say the the heat transfer still ends there at the plunger, or maybe you weren't flipping as much because the system is "much more accurate"???? Or do you have metal links between the flipper plunger and The flipper pawl? Or are you saying using metal bushings Bridges the heat to The flipper shaft from the from The flipper Mech where a plastic bushing couldn't do so?
Quoted from DiabloRush:No. This has little to do with the thermal conduction through the system. A more efficient mechanical system will require less electrical energy for the same amount of movement. It has to do with the efficiency of the coils ability to turn magnetic energy into mechanical movement. Any mechanical losses will add to this.
Ultimately, it's an energy balance here. The system will equilibrate at the temperature that balances energy input and output. Some amount of energy (heat) is lost into the coils. This heats them up. They lose this energy (via heat transfer) via radiation, convection, and conduction. The temperature equilibrates to balance between these (like any system at equilibrium). Typically, thermal systems can take a while to reach this equilibrium (months, in the case of the JWST; an hour or two for a flipper coil; it all depends on the thermal mass versus input/output rates).
There's some second-order effects here, so its a bit more complex (for example, resistance generally increases with temperature, compounding the coil heating). None-the-less, more efficient mechanicals will drive the temperature down. By how much would require a bit more detailed calculation and evaluation. I haven't done that.
So you turned up power by 10 points on the flipper due to Increased flipper weight, and have less heat... Unless you are adding some heat sink tricks thru conduction which is what I was getting at.... the metal flipper bushing conducting heat the the flipper shaft, the friction within the coil remains un-changed, it's same plunger. Where is friction lost here? How can the flippers coil be cooler? Isn't there less friction between the nylon bushing and metal shaft vs. metal shaft the metal bushing?
Quoted from flynnibus:I don't understand this thermal tangent at all. 1) The coils are not thermally coupled to anything you are dealing with in this system. You are insulated through the linkages.. made of nylon no less. So the entire topic is not about the materials of your flipper solution but simply about the movement of the plunger in the coil and its transfer of kinetic energy.
2) Slop in the flipper movement is a loss of transferred kinetic energy to the intended load, not a new load. The slop is periods where the plunger is getting less resistance as it's pushing against less when it's pushing against nothing or off axis. There isn't any 'compensation' for this loss where the coil is being driven harder to make-up for it.. the lost kinetic transfer is just lost to the inconsistent movement. The coil was driven the same.. the magnetic field was the same.. it's just how consistently that linear movement is applied to the intended load.
I think the only real concern is if you are having to crank the coils to get the stronger magnetic pull to move a heavier mass at the same speed it did previously. Then of course you are making the coil work harder.. and risking increasing heat loads.
And so far.. the adjustments being talked about are within the kind of normal operating ranges people use anyway, so no biggie.
It would be more of an issue on games where adjusting the coil driving power isn't an option.
That's what I was getting at too, but you were way more elegant in speech.
Quoted from nicoy3k:Can we get cliff notes as to why these are better? I feel like flipper bats fall in the “if it ain’t broke” category…
Metal doesn't flex like plastic.
This CNC stuff is way better than other CNC stuff
Screws on top are ugly/screws on top look nice
Flipping response improved.
Grease? Fuck it. Just grease it.
If you can afford a pinball machine stop being cheap you can afford these.
Engineers know a lot about seemingly nothing.
Quoted from DiabloRush:TL;DR version:
Load matters on a coil. More load, higher power and temperatures. 'cause, physics.
How do I know? Inductive reasoning.
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detailed and boring version:
What you need to add to this discussion is back EMF generated in the windings due to the mechanical load. If there's greater mechanical resistance to plunger movement, it will generate additional current in the coil via back EMF. So it's not quite accurate to say "the coil was driven the same". Actually, the coil sees higher currents (drive + back EMF) when there's greater resistance in the plunger. The load is said to "induce" a current in the coil (and this effect is also the principle for the common component known as the inductor).
Stated another way, there's no free lunch. Electric motors and coils obey the laws of conservation of energy just like everything else. The power to drive a motor (or a coil) is not just a function of motor speed. It depends on the resistance of the load.*
More load = more work (force x distance) = more power input from the windings. Given that power (the product of voltage x current) into the coils must increase, so too will the heat generation as defined by coil resistance. It just so happens the way nature balances the energy in coils and motors under varying loads is via back EMF. It must be this way, as shown in Maxwell's laws for EM.
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*to cite the dreaded automotive example, this is why an electric car going a constant speed on a flat stretch of road uses less power than the same car at the same speed going uphill. The difference here (at the same motor speed) is the load. Higher load = more power = more current = higher motor (and battery) temperatures.
So basically without the flex of a plastic flipper the mechanical load is increased in a metal flipper due to less physical absorption of mechanical energy so there's more back EMF so the metal flipper bats will actually increase the coil heat rate. LOL this is so dumb.
Quoted from punkin:Thanked him for poking fun at you.
[quoted image]
Actually poking fun at the shill for not being capable of answering direct questions, and replying with googled up jargon.
Quoted from DiabloRush:What direct question did you want answered? I hope you're not referring to me? None of my replies have been "googled". I teach this stuff, often. Not that it matters, but an Engineering Ph.D. (from Berkeley '91) + 35 years experience. My day job is slightly more complex engineered systems.
Let's try a new question.
Does a standard plastic stock flipper give more back EMF than an aluminum one?
Is so how can it given the plastic flipper flexes and absorbs some mechanical energy reducing the mechanical load?
If the metal flipper with no flex creates more back EMF (which given your description on the matter it should??) how can you say the flipper coils were cooler in Godzilla even though you bumped up the power? Isn't there greater mechanical resistance when a metal bat flips the ball versus plastic?
Quoted from DiabloRush:Sure. Now, the amounts here are small in relation to the total, but still an effect. I'll answer these 1 by 1.
If that flipper is flexing, then yes. It takes some energy to flex the flipper. This will be pretty small, and second order, but yes. Slightly more. I could give you the relevant equations for elastic energy storage in solilds, if you feel you need these.
Flexing doesn't reduce load. It increases it. It takes energy to flex a material, just as it takes energy to compress a spring.
It's the opposite of what you state. Lack of flex means LESS energy is wasted in compressing flipper material. More efficient = less energy for a given amount of ball movement.
GZ is not the system to be talking about here, as I put stronger flipper return springs in that one game (only; no other games needed them). The only reason I bumped power on GZ was to compensate for the stronger return springs. And to be fair, I don't have quantified date from GZ. Only my play testing that showed mildly warm coils after about 2 hours of play. Note, in all my other games I reduced flipper power to get the same ball power/movement pre-upgrade. These games didn't require stronger flipper return springs (to damp flipper release bounce).
No. As a system, the PPP is more efficient. Less slop. Less resonance. It's slightly heavier (not much, about 7 grams). Heavier does require more power and presents a higher load. My testing (need to lower coil power) suggests that the gains in efficiency from a more precise mechanical design outweighs any extra power needed due to slightly higher mass.
Thanks for the direct answers. I'm having trouble understanding how the coil plunger itself isn't stifled more getting pulled into the coil as a stiff metal bat hits the ball versus a plastic one with some flex. Which bring us into the back EMF confusion I have. But with no energy lost in flex you get a snappier hit. But then there the extra mass of the flipper to deal with.
Quoted from punkin:Aaaahhh, you are poking fun at yourself without realising it.
As well as being fucking rude to the OP and calling him a liar and a shill.
He's told you he is qualified and has written books on this shit, but that seems like more hard work than you have ever done, so it's 'googled up shit' because you can't grasp his area of expertise, and despite him saying he is just a customer who wrote a review of a product he liked, you are once again calling him a liar and a 'shill' because, like, who ever heard of someone just being honest, eh?
Man even the internet can kill ya down under!
Quoted from punkin:Thank you, it shows me how to be a better person by hanging out with better people than my self.
Pinside. Providing the ultimate experience of individual enlightenment in your life. But apparently only if there's people who are trollin'
You're welcome? 
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