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Thanks, lio, for the feedback, there are some very good questions in there, let me address that point by point:
"Mass" setting:Flipper bats are pretty light-weight (just the the actual bat itself is certainly lighter than a pinball - together with the metal rod that is attached to it it might weigh about the same as a ball but the weight is distributed very unevenly).
The first assumption we have to make is that the flipper is modeled as a rigid body, i.e., doesn't deform as it moves. (The rubber is obviously a different story, its elasticity is modeled through a separate parameter.) This seems pretty reasonable and makes the simulation much more efficient.
The theory/physics of rigid bodies is pretty well understood, and it turns out that, as long as the body rotates around a single axis, the distribution of mass enters only into a single parameter called the moment of inertia. Now I didn't expose this directly since it would be even more abstract for most people than the mass parameter, but it doesn't matter, the two are in a simple linear relationship. Here's some theory if you are interested: http://en.wikipedia....ment_of_inertia
So this means that, no matter how the mass in the whole flipper bat/armature construction is distributed, there is always a proper choice for the mass parameter which will model this distribution exactly.
Even better is that there is a relatively easy way to measure this parameter from a real table; we only need to measure the time the flipper needs to perform its forward stroke empty, and how long it takes with the ball on its tip. I'll link again to the derivation I made to estimate this parameter: https://bitbucket.or.../FlipperInertia (see the bit at the end about the Judge Dredd video).
In reality you obviously don't make the bats heavier to affect their interaction with the ball - to make flippers stronger/faster you can basically only:
You don't adjust the weight of the bat, no -- but it is certainly there and is a physical parameter which needs to be taken into account for realistic results. Note that this is separate from the stronger/faster adjustments that you mention, which are mostly controlled through the Strength parameter in the new physics.
(-replace worn parts)-Replace the coil that drives the flipper with one that has more or less (magnetic) force to pull in the metal rod of the plunger and link assembly into the coil shaft which is translated into the rotational motion of the flipper bat.
This corresponds to adjusting the solenoid force and translates directly into adjusting the Strength parameter in the new physics.
-Replace nylon with brass coil sleeves or vice versa (even though I don't know how exactly the material choice influences gameplay)
I don't know enough about the physics of solenoids to understand exactly what this does, but I assume that this will again translate to a weaker/stronger solenoid and therefore an adjustment of the Strength parameter.
-How much of a noticeable hit the bat takes in "end position" from an incoming ball depends on the strength of the lower power coil that takes over once the end-of-stroke-switch has been triggered (even though different manufacturers handle this differently)
I model the hold coil in the following way: if the bat is within one degree of its end position, the coil force is reduced to one third. It might be interesting to play around with this parameter and see what it does. On the other hand, I don't want to overload VP users with dozens of physics parameters. So I'm not sure. Also there are so many different ways this is handled in real flippers; sometimes it might just be a timed pulse of the high-power coil which then goes into the low-power coil, or it's actually a switch at the end of the stroke.
What I'm curious about though is how large the area at the end of the stroke is where the hold coil takes effect. Is it really only at the very end? Is there a larger zone? This is hard for me to find out since I don't have a real flipper handy.
-A more light weight bat (if in reality there would be any real weight difference) would not move slower with a ball on it than a heavier one in my feeble physics understanding.
-"Return Strength Ratio" setting:In my opinion this should not be tied to the coil strength as in reality it is just gravity along the playfield slope and a return spring that pushes/pulls (depending on manufacturer) the flipper back into its' start position.So in reality you could insert a stronger and/or longer/shorter spring for more return speed/force regardless of the coil force.
Yes, this is true. I basically only reused this field since it was already there in the old physics.
However, it doesn't really matter: you have two values which you want to set, and whether you do this by setting both absolutely or setting the first one absolutely and the second one relatively to the first makes no difference. It may not be as meaningful physically, but the achieved result is exactly the same.
One could also make the point that on modern tables with very snappy flippers, the return spring will also tend to be stronger since having a very fast flipper with the sluggish return of a 70's EM flipper would feel odd. So there is a kind of correlation.
Edited by mukuste, 23 April 2014 - 08:25 PM.
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