Having convinced myself I could make a fireman move, I decided to install one in a loco. I was going to go straight to my ‘best’ loco, but thought maybe I’d better start with a not-so-good one.
So I decided experiment with my stock-standard Big Hauler. The dimensions turned out favourably so I could just glue a servo under the front ‘footplate’. I had to raise the tender footplate to get the shovel to firebox height.
I didn’t need any pin-in-slot arrangement to make him move in and out, so he just turns. I took the easy way out and left the driver on the right side so the fireman can be right handed and I didn’t have to do any surgery except rotate his right hand and shorten the shovel handle.
I used a picaxe to drive the servo and two LED’s in the firebox. In the future I’ll add a sound recording card with shoveling sounds, triggered by the picaxe each time he goes to the tender. The picaxe gets its 5V supply from the Hobbyking ESC, so it’s the simplest possible cct – just the picaxe and a filter capacitor.
Naturally everything was great on the bench, but when I ran it around curves and the tender moved relative to the loco, there were places where things ‘fouled‘ with the loco. I think I’ve fixed it all now except when he’s in his rest position. If it becomes a real problem, I’ve written the Picaxe program so I can put a magnet on the loco and reed switch on the tender to indicate they are too close. The program will then move the fireman to a ‘safer’ place.
This shows the fireman in his ‘rest’ position (turned max to left). However on sharp left hand turns the shovel hits the firebox, so I may change his rest position.
The video here gives a better idea of what happens. The sound is added on the video, until I add the sound card, but I’ll replace the Bachmann sound unit when I do, so it might be a while yet!
[size=12pt]Here’s the video link[/size]
[size=12pt]http://youtu.be/NLm1s7qcjGs[/size]