In response to my post, Time to kill the knob, the ever-insightful Trevor Marshall asked
… but if we get rid of the knob, what do we replace it with? Are you thinking along the lines of a miniature backhead? I assume it would have to be something hand-held…
Yes, exactly. The knob killer will be based on a small tablet like an iPod. Think about an app with two main screens – one for the engineer and one for the fireman – as in the diagram below. You swipe between them to change roles, or you give an iPod to each crew member. Both views include the steam and air gauges that the engineer and fireman share on a real locomotive.
On the engineer side, I see four sliders – reverser, throttle, train brake and independent brake. There is also a button (slider?) for the cylinder cocks. Opening the throttle and pushing the reverser all the way forward makes the train go, but also uses steam.
On the fireman side, I see a water glass, a slider (button?) for the injector, a button for the blower, and a slider that opens the fire door. When the fire door is open, you can see the fire, and feed it by tapping on the dark spots. Using the injector or feeding the fire depletes the amount of water or coal in the tender.
This all runs on an iPod or Android tablet because they are fantastically flexible devices, with very high reliability, and amazingly inexpensive! Users of WiThrottle have already noted that the wireless performance of their phone is much better than radio throttles. My friend, Mark Dance, is quick to point out that any time we choose consumer devices over something that has been custom built for the model railroad hobby, we benefit from orders of magnitude more research and development into reliability and cost efficiency. The result is that WiThrottles can be cheaper and better than radio throttles.
Trevor goes on to point out,
In defence of the knob and toggle approach, it does allow us to control speed and direction without having to look at the throttle – in the same way that an engineer on a real railroad doesn’t have to look at either the throttle or the reversing lever in order to operate his locomotive. It’s done by feel, while keeping one’s eyes on the track ahead.
There is already a snap-on knob for smart phones. I believe it works with the same material that styluses use to interact with the smart phone screen. It would be straightforward to 3D print a cover for the phone or tablet that works the sliders in the same way. As in the bottom half of the diagram below, it would have holes for the gauges. Where appropriate, the knobs would ride in notched slots, and the user would have to push the knob in to move it.
If your fireman didn’t show up one day, you could open the front cover of the throttle and swipe across to the fireman view to maintain steam. Or, I guess we could invent an auto-fireman mode, for less fun.
Oh, one last thing: to ring the bell? Shake the device. To sound the whistle, hold it above your head and raise and lower it.