G Scale Rail Cross Section.

electricity_bill

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If you swap the figures in columns B & C, it gets a lot closer to being believable!

Cheers

David
David

I think you are correct. Just got the digital caliper out and confirmed that they appear to be reversed!!! The only difference between the two rail type is the shoulder chamfer at the base of the web.
 

Gslearner

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Hi,

There seems to be some uncertainty about the dimensions given in the G Scale Rail.jpg above.

Please, with respect to the LGB rail data, could somebody with a micrometer:

A) Check the dimensions given in the table, either confirming or giving corrections; and
B) Add the vertical distances between the top of the base section and the underside of the bearing channel,
the height of the base section, and the depth of the bearing channel.

The idea behind item B is to have enough information to be able to calculate rail x-sectional area.
This relates to conductivity.

Best regards
Gslearner
 

Greg Elmassian

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Let me try to head you off at the pass...

Your difference in conductivity vs minute differences in section thickness is trivial.

In general even the differences between steel, brass, aluminum and stainless steel is trivial in practice.

Your issues will be how well you connect your power wires to the rails, and the joiners/fishplates between sections of rail. Those are where you get resistance.

Also, since this is only be important in high current situations, your feeders can be of significant resistance/loss.

Greg
 

phils2um

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The idea behind item B is to have enough information to be able to calculate rail x-sectional area.
Let me add what was not explicily pointed out by Greg above. The resistivity of any of the solid cross-section metal rails mentioned here is so low as to be insignificant. You you will only need to do one calculation based on the dims for any one of the rails in the G Scale Society table to prove it to yourself!

As Greg mentioned - all the potential (pardon the pun ;)) conductivity/voltage drop issues will involve the selection of feeder size and length and how well the electrical connections are made between the feeder(s) and the rails and between the individual sections of rail between the feed(s).
 
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Greg Elmassian

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Now to something interesting, the higher resistance metals actually have some benefit in DCC, and it is about the skin effect, not more current or lower resistance, but less "Smearing" of the signal.

Very interesting. I have stainless rail, and the skin effect is more pronounced which keeps the integrity of the signal. The effect is minimal, but it's there even at DCC frequencies.

Greg
 

Gavin Sowry

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Now to something interesting, the higher resistance metals actually have some benefit in DCC, and it is about the skin effect, not more current or lower resistance, but less "Smearing" of the signal.

Very interesting. I have stainless rail, and the skin effect is more pronounced which keeps the integrity of the signal. The effect is minimal, but it's there even at DCC frequencies.

Greg
Don't matter what the rail is made of, all has the same skin effect, which is two black lines, 45mm apart, whenever you touch or step on the track!
 
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maxi-model

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Don't matter what the rail is made of, all has the same skin effect, which is two black lines, 45mm apart, whenever you touch or step on the track!
My old cat has tested your assertion...........The only black marks found were the ones she was born with, they did start life a narrower gauge :D

Cat sat on the track 001.jpg

As to the merits of steel used in some GM products (or proportions for that matter, Vega all steel, Corvette steel chassis, GRP body) - I had as a company car, back in 1988, an Opel Manta GTE. A fireman acquaintance of mine, at the time, stated, "We have never had to cut anybody out of one of them". Reassuring given my driving style then. Why ? Nothing to do with their relatively low production numbers. The only reason they stayed in Opel's range so long was so they had a model eligible and suited for use in both national and world rallying events. It was what is known as an "homologation special". Its unitary body was pressed from heavier gauge steel than the other versions. Resulting in a stronger shell that could resist rough handling better, with the addition of a neatly designed roll cage for bracing and increasing torsional rigidity.

I think that little revelation will have somewhat derailed this thread. Every pun intended. Max
 

Greg Elmassian

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the analogy was about knowing the very basics of skin effect, not the details.

Like the cat!

I don't want to derail the thread, but there is actually a small advantage to DCC with higher resistance rails, weird but true. I'll start a new thread if there is interest.
 

Gavin Sowry

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Ahh, you should read up on skin depth then. You know Ford vs. Chevy but you don't know vega vs corvette. Only if you are interested.. but you are a battery guy right?
Track power.
 

Greg Elmassian

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good man! There is a slight advantage due to the lesser depth of the skin effect on stainless track vs brass track.

Turns out the skin effect is non trivial on DCC frequencies, so the "thinner skin" actually helps keep the integrity of the DCC signal better. In most cases no one would notice, but it's just interesting that the poorer conducting metal turns out to be beneficial in this case to signal quality.

Greg