Quoted from SantaEatsCheese:I am obviously not an engineer but will brainstorm with the crew a few ideas. Letters correspond to following image.
A: Does the plunger have to be made solid? It seems to me like if it were hollow it increase surface area and allow for air to come in. We only focus on cooling the outside of the coil.
Yes it must be solid or you will have an incredibly weak flipper. You need that moving mass to produce enough force to launch a ball. Remember Force= Mass x Acceleration
B: What if we changed the material the coil sleeve was made out of and expanded it so that it acted as sort of a heat sink on its own?
The coil sleeve is there to reduce friction. Even if you used one of the old metal coil sleeves, there is no where to reject the waste heat to in that configuration. It will just heat up to the same temperature as the coil.
C: We focus on cooling this, but what about giving the coil itself more space and airflow to dissipate heat? The paper wrapper is there to stop shorts, but does it have to be paper? What if a small heatsink was attached to this. Imagine the photo in reference 1 with a coil in the center, and the whole thing except the outside being made out of metal. This would give much more surface area for air flow and to dissipate heat. The scale is way off but you get the idea. Could something like this be 3-d printed out of plastic, have it still be effective, and just snap over a coil? If you could get something like this to rotate around a coil it would be nifty.
If you move the coil outward from the playfield to gain more clearance, you will need longer flipper shafts. Adding heatsinks with fins increases the surface area and increases the effects of convention (both natural and forced). Being in a cabinet, there is very little air movement, so convection is mostly natural based on the buoyant force of hot air rising. Many plastics in general are poor thermal conductors and would not make good heat sinks.
D: The coil stop has direct contact with the coil. Could this be turned into a heat sink? Would it be possible to make a hollow coil stop letting air flow through the middle?
The coil stop is only in contact with the plastic end of the coil. The plastic is acting as an thermal insulator and would do a poor job conducting heat away from the windings.
E: Can we use the magnetic field that is driving the coils to spin a fan on its own without an external power source?
The duty cycle of the coils means that the fan in this configuration wouldn't run after the coil is deactivated, so it wouldn't be effective.
F: This mount is one of the few areas to come into contact with the coil… could a small heatsink be attached to this?
Just a few ideas I could never engineer that are fun to speculate about. [quoted image][quoted image]
The mount has minimal contact with the coil, so its ability to conduct heat would be minimal.
