Idea to Drive a Rotary Beacon

I think it's a great idea. Mine works ok, but I'm keepin' this in mind.

From an ex Long Islander circa 1961-1985. Dix Hills.

Neil Kresge

We have an old Marx rotary beacon that was donated to our model RR club.  I've bought a dimple bulb and red/green beacon for it, but would like to improve its rotation.  Has anyone tried directing the air flow from an aquarium air pump to provide a constant rotational nudge?  I'm going to ask our members whether anyone can loan me a pump for experimentation.  BTW, this forum has been able to provide answers to my questions in the past and is a great resource in my opinion.  Thanks in advance to anyone who can help.

I don’t know about aquarium pump sizes but a flat cooling fan from a recycled laptop/PC might fit within the footprint of the tower. The one at left is only 1” across. These fans use DC power – typically 5V or 12V. 

I’d be curious to hear what you come up with…

Thanks for the tip.  I'm open to any and all ideas.  One fellow suggested the tip has to be very sharp.  I checked, mine was dull, so I sharpened it a bit with a file and it works better, still stops occasionally.  Need to sharpen it to pin or needle sharpness.

Question:  Is the beacon lit?  If so, how is power being supplied to it?

Thanks,

George

It's all about the angle of the fan blades.  They have to be tweaked so they are not too flat or too steep.

Yes, George, the beacon is lit.  The beacon turns by air heated by the lit bulb rising past fan blades in the top of the beacon.

The motor idea would work but you would need gear reduction to ~20-30 RPM plus you would need to support the crankshaft just before the 90 degree bend. The center support tube would probably have to be dedicated to the crank shaft and the lamp wiring routed outside of it.

As for improving the rotation using heat, vibration from trains running can help a lot.

Pete

Originally Posted by G3750:

Perhaps the idea here is to increase the voltage to the bulb to run it hotter which might increase the airflow?  Won't help bulb life but you did say you're open to all ideas.

So when it occasionally stops, presumably you gently tap it to restart. Using the train vibration idea, perhaps some kind of electromechanical vibrator would help. I believe the OP is describing the revised beacon version using the vibrating nipple ring mechanism. I'd think something like that vibrating coil used in the revised beacon and in many other accessories might work.  You'd drive it at a lower AC voltage since you don't need much vibration. It would be small enough to fasten near the top of the tower. I suppose you could wind your own mini electro-magnet vibrator if you like tinkering.

I thought of recycling the tiny vibrating motor from a cellphone. While it would probably work, they are not known for long-life and of course are not used for continuous-duty. 

I only mentioned the vibration aspect because a few were addressing lack of rotation with heat. Tapping won't help, its has to be a steady vibration. No one thing is the answer with the 394. It seems to have a mind of its own.

     Pete

I have been using an small aquarium air pump for years. It always runs the lense. The pump is located under the table and a small nylon tubing is run up to the top of the beacon. I drilled a small hole adjacent to the bulb and fed the tubing through it.

I have a heating duck near the beacon, and the method I described just keeps the lense turning and turnng.

If interested, email me and I wil send you a write up, if I can find it.

It was printed in the TCA electronic magazine several years ago.

Thank you everyone for your input.  I chatted with an S gauger Sunday who said his beacon only turns when the trains run, when they stop, it stops.  Obviously, vibration is good.  I've run mine at full voltage, but would prefer to cut the voltage back to preserve bulb life.  Tinplate guy has already built a pump system that works.  I've replied to him for a copy of his write up.  A couple of fellow club members are checking to see if they still have an aquarium pump I could use.

RonInIdaho

Here's a link to the multi-gauge layout we're building in Pocatello, Idaho:

http://myflyertrains.org/gallery/album106

My idea would be to build a small electrical shed on top the the base unit, have air gaps to the bottom edges for air intake to the fan, install inside of the building one of those PC fans with air blowing up, use a drinking straw painted like conduit coming out of the peak of the roof blowing air up to the fan blades on the beacon, I think it should give enough pressure to turn the beacon light blades and the fan would be quiet enough so no one could hear it. Anyone ever try something like this?

I think it would be easier, and maybe even less expensive to just find one based on the 494 vibrator type beacon
I think part of the problem with the bulb type units are the bulbs.
The original bulbs (#461) were rather high amperage (.25 amps at 14 volts), and the cup was molded in place.

For a while, the only commonly available replacements came from Madison Hardware in NYC. They took 1455 bulbs, and added the dimple. So the bulbs really weren't hot enough, and the dimple usually wasn't very well formed.
Some of the imports that I have seen do not look much better.

From time to time I have run across new old stock American made #461 bulbs, but they are hard to find.

For two of these, I took the tip out of them and used JB-Weld to put a sewing needle into them for the pivot.  That worked much better than the stock pin that's part of the design.

I have also thought about the tiny fan, I have several that are only 3/4" in size, they should fit below the platform with a couple of air holes.  It wouldn't take much to spin the spotlight.

Interesting ideas. I picked up a 394 Beacon tower with dimpled bulb but no light housing for only $5, and improvised it into a water tower. But if I can make a rotating beacon unit somehow, I'll convert it back to that.