BATMAN There are a lot of very smart capable housebound modelers here on this forum, we should turn this working wig wag thread into a group developement project. Suggestions of gears, piano wire, cams and such will give people ideas. I have often thought of using Ngineering stainless tubing and an aquarium pump as a means of propulsion. An intermittent puff of air could get the thing rockin. Being the dummy in the crowd, I'll sit back and take notes.
There are a lot of very smart capable housebound modelers here on this forum, we should turn this working wig wag thread into a group developement project.
Suggestions of gears, piano wire, cams and such will give people ideas. I have often thought of using Ngineering stainless tubing and an aquarium pump as a means of propulsion. An intermittent puff of air could get the thing rockin.
Being the dummy in the crowd, I'll sit back and take notes.
tstage I wish the NYC had used wigwags. Obviously they are better suited for warmer and drier climates where snow and freezing rain is less likely to occur. I just find them fascinating to watch, as well as unusual. I also have a soft spot for ball signals.
I wish the NYC had used wigwags. Obviously they are better suited for warmer and drier climates where snow and freezing rain is less likely to occur. I just find them fascinating to watch, as well as unusual. I also have a soft spot for ball signals.
i grew up in northeastern Wisconsin in a town with a lot of grade crossings ... every one protected by wigwags.
I was thinking, I could get some of those motors and play around with them. But not sure what I would do with them, so I don't want to really spend the money. Wait - 10 motors for 70 cents?
Mel, if you have a sketch that makes them move back and forth, the issue is probably only with keeping track of the steps - that's the only way you will get them to stop in a specific position. The problem with those motors is being only 2 phase they can only stop in 180 degree incrememnts. Depending on the gearing, that may be almost no different, to be a step off, or it may be very noticable when the wig-wag is supposed to hand perfectly vertical when stopped. But say it's 6 steps from center to one end, you'd have to go 6, then -12, then another 6 and it should be back at the original start position. If not, it's missing a step, maybe because they are coming too fast for the motor to react.
I suspect you could do this with a servo, if you can get a linkage inside the pole.
I'm also thinking the best way to get it to stop vertical is to actually couple the mechanism loosely. Like the moving part ends in a C shape, with a vertical pin from the wig wag itself in the center of the C. Freely pivoting, with a decent amount of weight on the signal - maybe make that of metal. That way there is some leeway in just where the mechanism stops yet the wig wag will hang perfectly vertically.
I leave the construction of such a fiddly bit to someone who can see better than I can.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
RandyWhen I gave up on the stepper motor I worked on a servo drive rod for awhile and it’s doable but tedious. I haven’t totally given up but it’s pretty far back on the burner at this time.Another thing about the stepper motor, the movement was too jerky. Mel My Model Railroad http://melvineperry.blogspot.com/ Bakersfield, California I'm beginning to realize that aging is not for wimps.
Yeah, I'd expect a 2 steps per rotation motor would be fairly jerky. I wonder what they are out of - they look like some sort of disk drive stepper, or maybe CD player, but they have to be smoother than that for those functions. I wonder if they have a half step option of some sort, and just have a more complex drive need than indicated by the seller.
If an idea presents itself (I have no real use for a wig wag myself), maybe I'll order some and play around. I'm no stepper motor expert, but I think even the one that somes in many Arduino kits (I have one of those) aren't driven in the way it first appears you would wire it up.
If you've ever stood at a RR crossing at night and noticed how the alternating red lights at the crossing signal seem to make what is lit up around you seem to "move" slightly because the angle of being lit differs slightly. I wonder if it would be possible (and technologically easier) to create a trompe l'oeil ("fool the eye") wigwag signal by having a mast with two wigwags one at each of the extremes of their back and forth movement, but have the lighting alternate between them. If done right perhaps the eye would "see" movement. And maybe the effect would be enhanced if the round discs of the two wigwags were transparent or translucent rather than solid, with only portions painted.
It might look strange when sitting still but mostly you'd only tend to notice it anyway when a train is crossing and it is lit up. What I have in mind is something akin to the sense of motion you get from one of those flip books for kids that as you flip the pages, seem to show motion.
Dave Nelson
That's not a bad idea, Dave, and might be worthwhile pursuing, although I'm not all that interested in such things for my railroad.
However, I have been following this thread, because back in the mid-'50s, my dad worked for a small company called Activated Advertising. They made moving ads for window displays and also as novelty items for the home.I remember a Christmas ornament that we had from them, which was made of white bead-type styrofoam. It had a square styrofoam base, with a styrofoam arch attached to it, and within the arch was a styrofoam bell, which, once set in-motion manually, would swing back and forth pretty-much until it was manually stopped. I recall it as being about a foot tall-or-so.
The activation was done by two magnets, one in the base, and one in the bell, with their poles aligned in opposition. I've been trying to visualise how this might be used to power a wigwag, and am wondering if the very small rare earth-type magnets available nowadays might work for such a device.Perhaps this mention of a long forgotten novelty might give some of our more creative Members the incentive to try both your suggestion and perhaps investigate this idea, too.
Wayne
BATMANI have often thought of using Ngineering stainless tubing and an aquarium pump as a means of propulsion. An intermittent puff of air could get the thing rockin.
I never thought of that! A simple vane inside the box, and a pair of watch hole jewels for the bearings, and little what, 36-gauge leads to the LED in the swinger? Some pretty simple escapement theory would control your pump or valve, too... come to think of it, all you'd need would be some adjustment to vary the pulse timing of the pump as you watch the wig-wag, to get a good swing amplitude at resonant frequency, then a periodic adjustment if it changed time a bit...
Firing up the pump to control air admission is probably waaaaay too much overall latency with the long required piping length, so you might be looking at some sort of small proportional air valve near the base, and a metering nozzle (perhaps just flattening the tubing appropriately?) at the business end. You could probably run a bunch of these off a small air compressor and 'reservoir' tank... or run the aquarium pump continuously and just valve its airflow as desired.
I'm not positive, Tom, as I was only a kid at the time, but I seem to recall wigwags on at least a couple of crossings, here in southern Ontario, on Central's CASO tracks.
The New York Central was also part-owner of my hometown TH&B, in Hamilton, Ontario, and there's a good chance that some of the many crossings there were wigwags, too.