As explained in the recent post Rebuilding of Sparks yard, a new control panel will be needed. This is the procedure I follow to make my control panels.
Below is a preliminary design drawn with Microsoft Visio. Having a drawing available now would also be a good time to go over the operating scheme of this yard.
The original momentary center off toggle switches that could route in
either direction have been replaced with 6 red push button switches to select
the route. The green LED's show track
selection or turnout position as they did on the old panel. All traffic will enter through the first turnout in the
closed position and pass through the yard track selected. After going around the loop
there is one more siding along the return track. The siding turnouts are also controlled with the red push buttons. The control of that
first switch is automatic using sensors just like it was before so will
align itself when a train approaches to exit the yard. The sensors can
be over ridden by a pair of red push buttons. The toggle
switches will be used to control which tracks will be in use for the
automatic sequencer I am planning to include using Infrared sensors.
The original control panel was made from a pattern which I kept. This pattern was made from a scrap of hard board is seen in the photo below. Using this ensures proper size and alignment of the mounting holes. The new panel is made from this same pattern.
Once a design is finalized, a printout of the drawing is stuck to the acrylic sheet and taped around the edges. After drilling, the printout is removed and the acrylic sheet is cleaned up and polished with a product that removes any small scratches.
A sheet of .030 white styrene sheet is cut to match the size of the acrylic sheet. Using the acrylic sheet as a pattern holes are made in the styrene sheet to match the ones in the acrylic sheet. Then another copy of the drawing without the switches and LED's is used as
the actual display. Using the acrylic sheet again as a pattern two or three of the switch holes are cut out from the drawing using a hobby knife. The drawing is then sandwiched between the acrylic and white sheets and switches are installed in these holes so that everything stays aligned and then all the other holes can be cut out.
Since this panel was made the same size as the original, it will fit right into the original housing. Almost all of the control wiring can also be reused with a few more added. The red and white bottle shown in this photo is the product I use to polish out any small scratches on the acrylic sheet.