Landscape Bridges : custommodelrailroads motorized double track Rolling lift bridge

• Building instructions 2 10" Rolling lift bridges with a 5x5" pier connector = 25" river
• Base... Most of the area is taken by the swing bridge protection pier. The Rolling bridge has a 4" fixed bridge span built into the river bank which actually contains the motor and the lifting portion of the bridge... this will have to be built removable to allow maintenance and adjustments of the string that raises the bridge.
• Bridge... custommodelrailroads Rolling_Lift_Bridge $150 plus $115 for the motor stuff per bridge = $530 plus tax and shipping
Our bridge has a 75' (10.25") lift bridge span and a 30' (4.0") fixed bridge span. The total length is 110' (15") including the abutments. The two track bridge requires a space 15" long and 5" wide. The distance from the bottom of the base to the bottom of the track is 3.5".
The bridge will have to be built with the base and abutment raised more than designed to make room for the deep resin river- thus the connecting plastic will not be there - just more added difficulty to an impossible project.
• Location Location Location ...Imaginarily next to the somewhat bashed Milwaukee swing bridge
• Wiring ... all contained in the fixed base ... somehow need to run wires out to the end to light-control the red/green LED. The rolling will make this difficult as there is a large moving-changing separation between the base and the bridge. Ran the wires along the top of the bridge - next to the tracks and then into the base and out the side. They lift up and then go back down ok.
• Belong together... base and two bridges and the connecting pier : into one complicated conglomeration
• ...

• Custom Model Railroads (CMR) motorized double track rolling lift bridge
• Engineering marvel
• Laser cut acrylic - No sprues or hanging chad - prepackaged into sorted ziplock baggies.
• Tab and Slot construction assists positioning the pieces.
• The string is 'special', not something you will get at Jo-ann fabrics
• If you plan to motorize the bridge - go ahead and buy their solution, it seems expensive to me, however, after buying parts that do not fit - work together it gets very expensive to DIY...
• my parts list
• RRP 8719 19t 5mm pinion .8 module
• Traxxas 4472 spur gear 72 tooth 32 pitch
• Futaba S3003 servo - glue the spur gear to the round servo 'arm'
• [Radio shack -Adafruit-Sparkfun ] arduino board and shield, 2 RGB LEDs, wires, 330 ohm resistors (red 2), 270 ohm (green 2), on/off/on toggle switch, rolling pin switch (2)
• the bad uglies
• Counter weight support top needs to be cut away before the support is glued in place... very delicate and would not get this far if it was factory cut.
• part #20 the bronze bushing might be larger than 1/4" - if so drill out the small hole and make it fit (supplier sent a different bushing and did not inform CMR - that gave them fits)
• When my second bridge was ordered they sent a pair of bushings in a separate package, it was delivered before the bridge was shipped... ask and you shall receive. It might have been shipped for the first bridge as the second one had the holes cut out larger so the bushings in the package fit.
• ...
• Assembly opinions
• Laser cut acrylic ... requires Plastruct or Tenax-7 to glue : acrylic requires MEK to be glued-melted togerther ... MEK and acetone diffuse through your skin and attack your liver.
• Tab and Slot construction ... Assure the pieces are fully seated because the MEK will not melt parts it cannot touch.
• Acrylic is brittle and shatters when the bridge is dropped onto the floor... especially when it has ~7 ounces of added weight in a concentrated area.
• ...
• You Tube videos : You Tube video of unpacking the bridge
• Base
• You Tube video of building the bridge base Part 1
• You Tube video of building the bridge base Part 2
• You Tube video of building the bridge base Part 3
• You Tube video of building the bridge base Part 4
• fixed base part 1 of 3
• You Tube video of building the fixed base part 1 of 3
• You Tube video of building the fixed base part 1 of 3
• You Tube video of building the fixed base part 1 of 3
• rolling lift part 1 of 3
• You Tube video of building the fixed base part 1 of 3
• You Tube video of building the fixed base part 1 of 3
• You Tube video of building the fixed base part 1 of 3
• Final assembly and Motorizing
• You Tube video of Final assembly part 1 of 2
• You Tube video of Final assembly part 2 of 2
• ...