David Palmeter said:
Graeme Price said:
David Palmeter said:
Another question for Forrest, Noel or anyone who has built G Scale power poles:
How do you attach the cross bars to the poles to keep them from popping off if you bump the wires? There isn’t much glue surface and pins or tiny brads would seem to be fragile. Use both?
I hid my power pole by disguising them as my irrigation system or to be more accurate disguising the irrigation risers as power poles. I used the 4mm risers for my sprayers as the poles and glued cross arms made of strip wood with a round groove in one side to increase the gluing area then “twitched” a thin piece of copper wire to add strength to the joint (when painted black the wire was virtually invisible). This worked well for a few months till the lady of the house’s feline decided to mark his territory by rubbing up to the cross-arms and snapping them off (moral of story do not get a cat). The wires were strung and secured with brass dressmaking pins with a glass beads threaded over them and sealed with an poly urethane electronic conformal coating, they carried 5V to run some LEDs.
Without the cat’s intervention I think they would still be functional today 5 years later.
Graeme, some good ideas, do you have pictures (pre-feline), particularly of the crossarm setup? Thanks!
Unfortunately no I do not. The railway is no longer in existence, it is in pieces in my shed at my new house waiting to be resurrected in a new form.
This would be a simple task to cut them out of 3/8" acrylic on the laser and include the hole(s) for the crossbar(s) and guidewires, if desired. The crossbar would then include holes for the wire/fixtures. Then 1.5 or 2mm screws/nuts can be used to hold it together. (Cheap on the bay from China is any kind of quantities.) I’m building an entire trestle this way. The two pieces of acrylic can also be cut to “interlock” like Lincoln Logs requiring a shorter screw.
Tell you what…,
You tell me what you want (give me a preliminary design), I’ll put it into CAD, and cut them from ~3/8" smoked acrylic for $1/each plus shipping. But you need to think in 2D. For example, the top of the pole can come to a point/curve in 2D and will be flat in the third dimension. Also, the pieces can interlock, but any holes also need to be along that side requiring one pass of the laser without lifting the pieces from the tray. (I think you get the idea.)
You can get the screws/nuts/bolts in stainless steel cheap on the bay from China. For two pieces of acrylic, get 25mm long and if three pieces get 35mm long bolts/screws.
Todd Brody said:
This would be a simple task to cut them out of 3/8" acrylic on the laser and include the hole(s) for the crossbar(s) and guidewires, if desired. The crossbar would then include holes for the wire/fixtures. Then 1.5 or 2mm screws/nuts can be used to hold it together. (Cheap on the bay from China is any kind of quantities.) I’m building an entire trestle this way. The two pieces of acrylic can also be cut to “interlock” like Lincoln Logs requiring a shorter screw.
Tell you what…,
You tell me what you want (give me a preliminary design), I’ll put it into CAD, and cut them from ~3/8" smoked acrylic for $1/each plus shipping. But you need to think in 2D. For example, the top of the pole can come to a point/curve in 2D and will be flat in the third dimension. Also, the pieces can interlock, but any holes also need to be along that side requiring one pass of the laser without lifting the pieces from the tray. (I think you get the idea.)
You can get the screws/nuts/bolts in stainless steel cheap on the bay from China. For two pieces of acrylic, get 25mm long and if three pieces get 35mm long bolts/screws.
Thanks for the offer, Todd. I like the look of all wood but if that test doesn’t work, I’ll get back to you, acrylic and stainless should be very sturdy.
I don’t know if this would be of any use or interest here, but I found this article from 1993 while sorting through some of my old notebook binders:
I applaud the work the guy did, but the wires do not look realistic in the first picture, they are too thick and defying gravity and have anti-gravity kinks.
You can get the sag by lightly pressing on the wires back and forth after strung with a fair-diameter dowel. Too small in diameter will make visible kinks and will stretch the wire too much (force per unit area).
Done right it’s great, but we will see the amount of effort required!
Greg
I too am in the planning and even some construction of a 1:24ish Vic inspired large micro layout. Unlike Vics pizzas which are the inspiration, mine will be in a 20 X 10 room. When I saw this thread I got excited then Greg ruined it. I think I will stick with under the bench 12v bus wires. But great post and a neat idea.
Somehow I missed the whole second page. I like Noel’s idea to fix Greg’s foreseen problem of scale wire not carrying enough juice to be of much use. Using a 14/2 bus wire under the bench to sections that are then over head wired with the telephone wire seems very doable as Noel has proven. Since I am using LED they don’t draw a lot so this may very well work out nce.
use 48 volts on the poles, then you can use finer gauge wires… put $2 DC to DC inverters in the transformer housings, bringing the voltage down to about 3.5 volts and drive the leds directly.
doable…
Greg
Thanks Greg. We are back to having me excited. This maybe a dumb question but I am an electrical idiot. How easy is it to get a 110ac to 48v DC inverter. I was going to use a 12v garden light system. How would I achieve 48v. Is there some normal converter? Would you carry the 48v from the source over the 14/2 same as using it for a 12v DC bus.
The DC to DC step down is easy and understand that part no problem.
Devon Sinsley said:
When I saw this thread I got excited then Greg ruined it.
Not uncommon Devon …apparently that same problem used to happened on the other train sites that used too exist. However as I write this I’m badgering , being unfriendly and the attack dog as it’s called these days.
Devon Sinsley said:
Thanks Greg. We are back to having me excited. This maybe a dumb question but I am an electrical idiot. How easy is it to get a 110ac to 48v DC inverter. I was going to use a 12v garden light system. How would I achieve 48v. Is there some normal converter? Would you carry the 48v from the source over the 14/2 same as using it for a 12v DC bus.
The DC to DC step down is easy and understand that part no problem.
https://www.trcelectronics.com/48-volt-dc-power-supplies
I “guess” this is what he is suggesting Devon ?
Just a question about the size of the layout and the number of LEDs that are being used.
Guessing that an indoor layout would not be that large than in size then perhaps consider a 12 or 24V DC ring main for lighting.
Ring main means both ends of the +ve and the -ve are connected to the output of the power source forming a ring.
Then the LEDs will be across the +ve and -ve lines the number which will form the load, the same voltage will be present at all points on the line.
If larger items need to be run then consider higher voltages, higher voltages will mean smaller diameter wire.
Personally I am planning to run only LEDs on my new layout so I will be able to get away with lower voltages and smaller diameter wire and a ring main.
Devon,
Think of electricity as irrigation or your garden hose;
Voltage (V)= pressure (PSI)
Current (I) = water flow ie amount of water flowing onto the ground per minute
Load = number of things on the system eg sprinklers delivering an amount of water per minute, the extremes are; no end to the hose = a short circuit (water pouring everywhere, a blocked hose = open circuit (no water at the end of the hose).
Switches = taps/faucets or water diverting devices.
This is an analogy I used when teaching my apprentices over the years, to help them get their head around the magic of electricity as they could all relate to the garden hose connected to a tap/faucet with a trigger nozzle.
I understand doing the ring thing to reduce voltage drop along the line. But why not several rings, or circuits. That way the load on each circuit can be kept low and the wire can be kept thin. Then one could model a small power substation, where all the diverging lines come together. Rural substations can be as small as a small house.
So, start with a 48v supply, you can probably find a transformer, AC or DC does not matter, but I’m going to recommend a bridge rectifier and a cap to produce DC, you will see why. This is easily available and I can help you shop.
I picked the voltage, because this is about the limit for outdoor voltages by code, that don’t need special insulation, grounding, etc, it still qualifies as a “low voltage” circuit.
So, the idea here is the highest safe voltage on the pole wires, this allows you to use the finest wire. You should be able to approach prototype wire sizes.
Now, run the wires into the buildings like you see in real life, small insulators on the roof, etc.
Here is the key to keeping it cheap and simple: once in the building, a small DC to DC inverter/regulator (this is why I specified putting DC on the poles). These are cheap, small, and adjustable. You can set the output voltage at around 3 volts and you won’t need any energy-wasting resistors, just connect your LEDs to the output. Simple, cheap.
Here’s 6 of them for $10.75 and you could run up to 15 LEDs from just one… you can indeed find them cheaper direct from China if you wait a month and a half.
I’d be happy to work with you on this project.
Greg
David Maynard said:
I understand doing the ring thing to reduce voltage drop along the line. But why not several rings, or circuits. That way the load on each circuit can be kept low and the wire can be kept thin. Then one could model a small power substation, where all the diverging lines come together. Rural substations can be as small as a small house.
Valid query …Greg ??
Yes, of course the fewer loads on the line, i.e. splitting up, would reduce loads.
But how far do you want to go? If you want to follow the prototype, many homes come off the intermediate lines, the 3 wire, approximately 5,000 volt lines on telephone poles.
In any case, my suggestion is easy to do, inexpensive and not too complex, and will allow you to make power poles that look prototype.
You can go as wild as you want, I see the challenge is getting it to look prototype and to carry sufficient power that one “line” can power many buildings, including perhaps some light animation.
Oh, Devon, the 48 volts can be a couple of simple transformers with a full wave bridge rectifier. The reason I say couple is you need about 35 volts AC, and it might be easier to get a 24 volt and a 12 volt transformer and hook them together… 36 volts with a full wave bridge and a filter cap will be cheap… there is no need to get a fancy regulated supply… the DC to DC regulators will handle that…
Greg
Greg
OK, since there have been distractions and “noise” and more in-depth explanations, Devon and I have been communicating by email…
I will report that this can be done inexpensively (Devon found a 48v power supply for $27), and I have shown the link for the DC-DC inverters that will step down the 48 volts to 3 volts regulated for the LEDs.
Also, theoretically, the system could power 1,000 LEDs total.
Finally, after asking about gauge, I did some rough calculations, and for this type of power pole, the utilities often use 0 gauge (aught gauge) which is about .324" and changing to 1:29 brings it to 29 gauge wire, and I had guessed 30 gauge would be about right, so all of this will allow a completely prototype looking distribution system, that, like the prototype, can power hundreds of homes.
Greg
Don’t forget the distribution or service transformers for additional prototype fidelity. (https://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-smile.gif)
Yeah, no way to do that easily with real components. Thought that through.
The idea is using LEDs and designed for efficiency, so try to keep power-wasting resistors out of the circuit, and also to keep it simple a system to not worry about voltage drop along the lines.
That all equates to a regulated voltage in the buildings… so a transformer on the pole would not solve that issue, still need regulation. Now, if we could get the DC to DC regulators to fit in a scale size transformer “can” that would work, but too small.
So, there will be “dummy” transformers, but they will just feed the voltage through.
Greg
As Greg mentioned we have discussed this pretty thoroughly. I agree with Greg on using “dummy” pole mounted transformers with simple wire passing through them and then having real working transformers in the buildings. I powered an LED that has a resister and at 12 volts is just way to bright. With the adjustable DC to DC transformer in the building each building could be custom adjusted to a level of brightness that is appropriate.
I even have a plan to make a mold for pouring clear resin insulators in different colors for the poles. My father is one of the nation’s leading experts on glass insulators and was one a prominent collector. So he has helped me with deciding what would be the appropriate style. Should be fun once we get to wrking on it.
Devoning again?