Faller Rainbow 140436 - Construction Log and Motor Replacement & Automation Project
Motor Replacement & Automation Project
Aim of Project:
1) To replace the standard Faller 16vAC motor with a low-voltage geared DC motor.
2) Create a Circuit Board to automate the model and attempt to replicate the real-world ride.
3) And while I'm at it, I might as well add some LEDs.
The original AC motor will be replaced with a 20mA Mclennan 90:1 Gear Ratio DC Instrument Motor #1271-12-90.
The Circuit Board will contain a programmable Picaxe 18X chip and an L293D motor driver IC.
The original motor rotated at a fixed 15rpm at 16vAC.
I chose this particular DC motor because it is bi-directional and rotates at 30rpm @ 12v and 15rpm @ 6v.
This, in combination with pulse width modulation will hopefully give me the most flexibility in getting a realistic and variable speed from the motor.
Once I had removed the original motor, I needed to remove the section on the front of the motor housing (upper circle)(*). I then had to slightly widen the hole left behind.
I also had to remove the brass coloured sleeve from the main arm (lower circle).
* The section I removed connects to a mechanism inside the arm that acts as a stabilizer and prevents the seating platform from wobbling as the arm rotates. Unfortunately, some time ago I accidentally disconnected the arm from the motor and somehow disturbed this mechanism and it hasn't worked since.
Otherwise, I would have attempted to glue this section back onto the new motor so that it can reconnect with this stabilizing mechanism.
The motor is simply superglued into place inside the original motor housing.
To attach the arm to the motor, I had to carefully enlarge the slot inside the centre of the arm to accept a 4mm diameter shaft
instead of the 2.7mm diameter shaft of the original motor. Again, the arm is held securely in place with superglue - there's no going back now!
Unfortunately, the new motor is 12mm longer than the original, so I will have to come up with means of hiding it.
I've glued pieces of grass mat and gravel mat to a roughly 12" square piece of 6mm MDF.
Four Fast-Flash Rainbow LEDs have been mounted behind the four lighting boards. Two white LEDs have been placed inside the Cash Desks.
The photos above & below show the decoration that I've added to the motor housing in order to hide the new, longer motor.
All the wires from the motor, reed switch & LEDs have been threaded down a hole drilled through the gravel mat and MDF.
The controlling circuit will contain a programmable Picaxe 18X chip and an L293D motor driver IC.
Flow diagram (Click on image for larger version).
Circuit Board mounted to the underside of the MDF.