Fun With Pinball

The Restoration and Photographic Study of a 1934 Rock-Ola World's Series Pinball Machine (continued)

The Playfield Frame

Playfield without the Wooden Frame Playfield with the Wooden Frame

The wooden playfield frame needs to be in place before the Plunger Casting and Tilt Mechanism can be installed.  It mounts to the playfleld in several places along its length.  Along the outside edges (not including the lower right corner) are seven #4 x 1-3/4" oval head slotted wood screws that mount through the frame and playfield and into rails inside the cabinet below.  Some games may have matching finish washers under the screw heads.  This game does not show signs of finish washers so I left them off. Note that in the photo above only a few of the longer screws are installed since the playfield was not ready to be installed in the cabinet at this point.

On the inner rail that frames the inside of the plunger lane there are two #4 x 1-1/4" oval head slotted wood screws.  These screws are shorter since they only mount to the playfield and not the the cabinet rail below.

The Plunger Casting and Tilt Mechanism

RWS7 Plunger Casting RWS7 Plunger Casting

The RWS7 Plunger Casting mounts over the bottom of the shooter lane in the lower right corner of the playfield. Windows in the casting help the player measure how far back to pull the plunger and reveal the Tilt Flag when the game has been tilted.

Tilt flag Tilt flag Tilt flag

The Tilt Flag rocks on a pivot wire suspended between two brackets on the bottom of the RWS7 Plunger Casting.  This flag had been removed for cleaning so one end of the pivot wire is straight.  Once installed both ends of the pivot wire should be bent down along the outsides of the mounting brackets.

Installing the RWS7 Plunger Casting RWS7 Plunger Casting

The RWS7 Plunger Casting mounts to the wooden playfield frame with four oval head wood screws: two #4 x 1/2" screws, one #4 x 1-1/4" screw and one #4 x 2" screw that mounts through the playfield and into the cabinet below.

611 Non-Tilt Housing 611 Non-Tilt Housing 611 Non-Tilt Housing

Part 611 is the Non-Tilt Housing that mounts below the playfield underneath the Plunger Casting shown above.

Installing the Non-Tilt Housing Installing the Non-Tilt Housing

The 611 Non-Tilt Housing mounts under the window in the RWS7 Plunger casting with a pair of #6 x 3/8" round head slotted screws.

611 Non-Tilt Housing armed 611 Non-Tilt Housing tripped 611 Non-Tilt Housing with Ball

The Non-Tilt Housing is the motion sensitive device that drives the Tilt Flag in the Plunger Casting.  A standard 3/4" ball bearing is captive inside the Housing. It activates the Tilt Flag if the game is shaken too much during play.  When the game is reset the ball is lifted onto a small shelf and the Tilt Flag is rotated to the non tilt position showing three silver stars.  If the ball is knocked off its shelf the scoop shaped arm is pushed down which rocks the Tilt Flag into the tilt position.

RWS17 Non-Tilt Spring and mounting pin 611 Non-Tilt Housing mounted under the RWS7 Plunger Casting

Once both are installed the 611 Non-Tilt Housing must be connected to the Tilt Flag in the RWS7 Plunger Casting.  A pin passes through holes in the Tilt Flag and through the 672 Non-Tilt lock. The RWS17 Non-Tilt Spring connects that pin to another pin at the bottom of the Non-Tilt Housing.  Together the ball in the Non-Tilt Housing and the Non-Tilt Spring provide the tension needed to trip the Tilt Flag.

I did not have the original pin so I cut a finish nail of about the right diameter and used that instead.  A small piece of heat shrink tubing on one end will keep it in place after final assembly.

Tilt Flag in the latched position Tilt Flag in the tripped position

Tilt Flag in the latched position Tilt Flag in the tripped position

These images show how the pin and spring are installed.  On the left the Tilt Flag is in the reset or latched position and on the right it is in the tilted or tripped position. If you click on an image to enlarge it you can move back and forth between images with the controls at the side of the image to compare the tilted and non tilted positions.

Tilt Mechanism Patent Drawing Tilt Mechanism Patent Drawing

Compare the photos above to these drawings from the patent application.

Tilt Mechanism in Motion

This video shows the how the complete Tilt mechanism works from above and below.  At the start of a new game when the Coin Slide is pushed in the 603 Main Push Bracket pushes the hook at the bottom of the Tilt mechanism forward, seats the ball on its shelf and displays the three stars in the window.  At that point the Tilt mechanism is latched or armed.  If the ball is unseated from its shelf the mechanism trips and the Tilted Flag is displayed.

Plunger and hardware Plunger installed

The plunger assembly parts shown above include the 542 Plunger Knob, an exterior barrel spring, 2 washers: .265" ID x .500" OD x .032" thick, JS5 Plunger Spring, cotter pin and plunger tip.  Note that the original parts list called for a 546 Rubber for Plunger instead of the exterior barrel spring.  The Plunger rod mounts through holes on either end of the Plunger Casting and the cotter pin mounts in the hole in the plunger rod. Many of these parts are reproductions available from Buckwerx.com.

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