I posted this on rec.games.pinball in 2004:
My purpose with this posting is to help other Demolition Man Pinball
machine owners out. There were a few things about this machine that
bothered me - things that didn't seem to work quite right. This could
be just MY machine, but I wanted to share these tips anyway... just in
Problem #1: The Retina Scan ball gate does not always capture the
On my machine, many times a strong right-flip into the retina scan
would cause the ball to go through the gate, hit the metal plate
(which sends the eyeball rolling), and then bounce back out towards
the flippers. The gate was NOT catching the ball consistently! I
analyzed this in great detail by repeatedly sending the ball through
the gate manually. The ball would go through the gate, the gate would
swing down. The ball would hit the metal plate, bounce off, and hit
the (now closed) gate. The impact would cause the gate to swing open,
and fling the ball back to the metal plate. The ball would bounce
back off the plate and through the open gate and towards the flippers!
Hard to believe, but that's what was happening (anyone else have this
problem?) This bothered me because... well, shoot... the ball
*SHOULD* be held behind the gate!
No amount of adjusting the gate wire helped this problem. I needed to
devise a way to minimize the ability of the gate to "bounce up" when
hit from the opposite side. I thought of something that might work...
a common part of any pinball guy's supplies (if you don't have any,
you need to get some!): weather stripping tape!
I bought mine at an auto parts store, when I needed to create a better
seal for my truck topper (which was leaking water between the bottom
of the topper and the top of the truck bed edge). It's black, and
comes in a big roll. The tape is about an inch wide and the foam is
about 1/8" thick. GET SOME! It can be used on the back of targets,
OK? You need it.
I cut a VERY THIN piece of this tape - probably about 1/8" wide - and
stuck it to the bottom of the bracket that holds the gate, on the
"north" side (away from the flippers). This foam tape is forgiving
enough to allow the ball to pass THROUGH the gate (the gate rises as
the ball passes through, compressing the foam tape), but resilient
enough to prohibit the gate from lifting up very high when "bounced"
from the other side! It works like a charm - nearly 100% of the shots
to the retina scan now STAY in the retina scan, as intended! Best
part? You can not even tell this tape is there!
Problem #2: The upper left flipper hits the ball up the side ramp
("skill shot" ramp) with so much force, the ball flies off the end of
the wireform (coincidentally, this wireform *should* drop the ball
into the "retina scan" area!)
This may be the result of a clean playfield, ramp, and shiny balls.
Too much speed and spin! But that's a good thing, right? Still, I
don't like the ball flying off my ramps. First thing I did was step
down the upper left flipper coil. I should have the details on that,
but I don't. And that didn't really help much anyway. What DID help
was bending "up" the end of the wireform! I wrapped a rag around the
end of the wireform, clamped on with my big locking pliers, and
muscled a bend upward. There now is just enough height on this
wifeform to "catch" the ball so it does not fly out. Bending
wireforms in this manner is fairly common practice to keep the ball on
track (CV's "acrobat" wireform being notorious), so this shouldn't be
too enlightening to some.
Problem #3: The left loop shot ("Start Multiball") does not catch the
This problem is common to many machines; the worst of which I've seen
is Indiana Jones "Start Mode" scoop. The fix here is the same as it
is there... and it involves... WEATHERSTRIP TAPE! Cut off about an
inch square piece and stick it to the right wall of the VUK. This
cushions the impact of the ball, allowing it to fall gently into the
VUK properly instead of bouncing out into the rollover lanes. After
performing this "fix", the left loop shot was made nearly 100% of the
time (before it felt like maybe 60%). However, I noticed the kick out
from the VUK didn't always send the ball down the rollover lanes any
longer, it now (mostly) bounced and dribbled down the left loop. I
didn't like that, so I put another piece of weatherstrip tape on the
back wall of the VUK. Now, it kicks out over the rollover lanes as
Problem #4: Or is it a problem? I was wondering: how often does your
ball launcher send the ball to the upper left flipper vs. the rollover
lanes? It seems to me, the design was to send the ball to the upper
left flipper, because that is where the skill shot is (shoot the ball
up the side ramp = skill shot). Well, my machine sends the ball to
the upper left flipper most of the time, but I also get frequent
visits to the rollover lanes (I'd say 60/40). I'd like to fix this
problem, and I believe bending the right metal guide at just the right
point (towards the end, near the VUK) is the key. I made an
adjustment at one time that corrected the ball launch so it would
always make it to the upper left flipper, but then an orbit shot from
the lower left flipper got hung up on the VUK and would always end up
at the rollover lanes! I couldn't do without the right orbit shot
(that's just not right!) so I changed it back. Now the orbit shot is
fine, but the ball launch is as I mentioned, 60/40 left loop/rollover
lanes. I think I just need to fiddle with this more, but I'd like to
read your thoughts.
In closing, making these 3 "tweaks" has improved my game play
experience greatly. I wanted to share these with you in hopes that
you could benefit from them as much as I have!
Now, flip away!