end of stroke/switches question

FlashbaxArcade

Active member
Joined
Jun 2, 2009
Messages
1,521
Reaction score
11
Location
Burleson, Texas
ok my buddy has a BK2K that is acting up and we are lost! the upper right flipper is very weak at times(sometimes chattering)

things done:

-repl both right flipper coils(lower and upper), didn't work
-checked for cold solder joints at coil and cut back wires and resoldered, nothin
-seemed a little better when we were adjusting lower end-of-stroke switch but not 100%
-repl both lower flipper switches(EOS and other?)
-finally he was messing with the upper flipper EOS and seem to temp fix it til new switches come in again.

so here's my question. i am still fairly new to pinball being a long time video arcade guy so hoping to get a detailed explanation of how EOS works and why? also, what is the other (first switch on lower flipper) do? there is only one switch(EOS?) on the upper flipper, so how does all these work together?

they all looked ok at the beginning of all this trouble-shooting.

thanks in advance,
Kelly Ray
 
The lower right flipper has 2 switches on it.

8082426238_6f7e9b9748.jpg


In this photo of my BK2K machine, the upper switch is the End of Stroke (EOS) and the lower would be the Lane Change switch. The EOS is normally CLOSED, and the lane change is normally OPEN.

When the flipper activates, the pawl OPENS the EOS switch telling the machine to switch current to the "hold" side of the coil. The plastic spacer on the EOS switch then CLOSES the lane change switch, telling the machine to switch the lane change lights.

Here is a photo with the EOS open and lane change CLOSED:

8082432365_89e7ca15a7.jpg


On the UPPER right flipper, there should only be one switch, the EOS.

I would make sure both of these EOS switches gap open correctly (about 1/16th of an inch) when the flippers are activated.

Chris
 
The lower right flipper has 2 switches on it.

8082426238_6f7e9b9748.jpg


In this photo of my BK2K machine, the upper switch is the End of Stroke (EOS) and the lower would be the Lane Change switch. The EOS is normally CLOSED, and the lane change is normally OPEN.

When the flipper activates, the pawl OPENS the EOS switch telling the machine to switch current to the "hold" side of the coil. The plastic spacer on the EOS switch then CLOSES the lane change switch, telling the machine to switch the lane change lights.

Here is a photo with the EOS open and lane change CLOSED:

8082432365_89e7ca15a7.jpg


On the UPPER right flipper, there should only be one switch, the EOS.

I would make sure both of these EOS switches gap open correctly (about 1/16th of an inch) when the flippers are activated.

Chris

thanks for the pix and description, good stuff, it helps!!!

he thought he had fixed the problem but then the lower flipper was getting too hot. i believe it was not gapped correctly or not at all so that current was always going thru the coil, burning it up??? then the coil/plunger seemed like it was swelling a bit and binding the flipper.

a tech told me that when the coil fully engages(or flipper button pressed and held) then the gap on the EOS should be about 1/8 inch. are they that sensative to the gapping or does it just need to be somewhere in that range as long as it isn't touching for sure???
 
The gap does matter, but 1/16-1/8 should be fine. Just as important is that you adjust the switch so it only opens at the END of the stroke. If it opens too early you will lose a lot of flipper power. The coil getting hot indicates that the EOS switch may be mis-adjusted and not opening at all (the EOS switch is what changes the coil from high (smack the ball) power to low (hold the flipper up) power.

my $0.02
/Tim

thanks for the pix and description, good stuff, it helps!!!

he thought he had fixed the problem but then the lower flipper was getting too hot. i believe it was not gapped correctly or not at all so that current was always going thru the coil, burning it up??? then the coil/plunger seemed like it was swelling a bit and binding the flipper.

a tech told me that when the coil fully engages(or flipper button pressed and held) then the gap on the EOS should be about 1/8 inch. are they that sensative to the gapping or does it just need to be somewhere in that range as long as it isn't touching for sure???
 
The gap does matter, but 1/16-1/8 should be fine. Just as important is that you adjust the switch so it only opens at the END of the stroke. If it opens too early you will lose a lot of flipper power. The coil getting hot indicates that the EOS switch may be mis-adjusted and not opening at all (the EOS switch is what changes the coil from high (smack the ball) power to low (hold the flipper up) power.

my $0.02
/Tim

ahhh, good analogy on the EOS, high smacking the ball to low! that makes sense now and appreciate clearing those things up.......im learnin slowly :)
 
Just fixed my weak flipper on my Firepower. Took me a while and turned out to be a bad pin on a connector. I assume BK2k is the same and the connection from the coil to the cabinet switch and to the relay on the board needs to be good or else the flipper will be weak. You can isolate weather it's the coil/flipper or connectors by grounding out the coil. Take an alligator clip and attach one end to a cabinet rail and touch the other end to the coil lug with the non banded side of the diode (you'll blow a fuse if you touch the banded side of the diode). It should fire. If that's good then look at the connectors or the cabinet switch.

Also make sure there is up and down play on the flipper so it doesn't bind. You should be able to pull the flipper up on the playfield a little. If it's tight against the playfiled it'll cause problems.
 
Back
Top Bottom