# Checking track power



## mickey (Jan 28, 2009)

Finally got most of my track (floating sectional) in and ready to go. I have soldered jumpers on all sections and clamped all turnouts plus jumpered around them. So I get ready for my first test of the track and pull out my Bachmann 2 truck Shay and it goes around but not very fast. I checked at the PS and at full have 18v. Then I spot check and get 18v everywhere. The track was cleaned with the green pad so it's good. Any other suggestions? Plan to try the Connie tomorrow to see how it does.


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## Gary Armitstead (Jan 2, 2008)

Shays are supposed to be slow.


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## Greg Elmassian (Jan 3, 2008)

OK, some basic electricity: 

V = I * R voltage = current times resistance. 

Clearly you have voltage drop, even though you don't say it runs faster in one spot than the other.... I'm going to assume this is the situation, not what Gary said, all shays go slow. 

OK back to V = IR .... you measured 18 volts everywhere.... so what gives? 

Well you must have some extra resistance somewhere, but look at the equation... the Voltage loss = current times resistance.... even if you have a lot of resistance (bad connections, joiners, etc.) if very little current is flowing then I is very small... so then V (drop) is small.... and guess what, your meter draws VERY little current. 

But when you run your shay, now you are indeed drawing significant current, so V (voltage drop) is higher because I (current is higher) 

Bottom line, other than checking basic connections, measuring voltage NOT under load is meaningless.. 

You need a load on the "far side" (away from your power feeds) drawing a couple of amps.. THEN you can measure the voltage across the rails, working away from the feeders, and you will see where it drops... 

Greg


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## Dan Pierce (Jan 2, 2008)

You can build a car with power pickups and add a power resistor and and tie your voltmeter to it. 
As you roll this car around you can see the effects of a power drop every time you cross past a rail joiner/clamp. 
Add a switch to shut off the resistor and this car will just be part of your rolling stock.


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## mickey (Jan 28, 2009)

Same speed everywhere. So I guess I could get my stationary rollers and set it up at the far end then measure with it running in place. Thanks Greg, will try that right after church along with other engine. Dan, for future I may just do that.


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## chuck n (Jan 2, 2008)

Are you measuring the 18v with the engine on the track and running, or just on the track itself, without any load. What kind of power supply are you using?

Have you disconnected the track from the power supply and measured the voltage at the back of the PS? What gauge wire are you using to connect the PS to the track?

For another post, last weekend I measured the speed of my Bachmann 2-truck Shay on my layout without any cars. My layout is 87' around. At 12.3v it took 110 seconds to complete one lap (scale speed 11mph). At 14.1v it took 84 seconds (scale speed 14mph). One lap took 57 seconds at 18.7v (scale speed 22mph). How long is your track and how long does it take to make a lap? Slow is a relative term. Your idea of slow may be my idea of OK. As Gary said Shays are slow.

Chuck

PS is you can't easily measure the circumference, measure out 10 feet of track and time the engine going over that segment.


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## Gary Armitstead (Jan 2, 2008)

Posted By chuck n on 19 May 2013 06:57 AM 

Slow is a relative term. Your idea of slow may be my idea of OK. As Gary said Shays are slow.

Chuck

PS is you can't easily measure the circumference, measure out 10 feet of track and time the engine going over that segment.


Thank you chuck. At least my statement wasn't a wholesale "right-off"!


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## mickey (Jan 28, 2009)

Posted By Gary Armitstead on 19 May 2013 08:21 AM 
Posted By chuck n on 19 May 2013 06:57 AM 
 
Slow is a relative term.  Your idea of slow may be my idea of OK.  As Gary said Shays are slow.
 
Chuck
 
PS is you can't easily measure the circumference,  measure out 10 feet of track and time the engine going over that segment.
 
 
Thank you chuck. At least my statement wasn't a wholesale "right-off"!








 




Gary, please don't get your feeling hurt, as I did not intend any sort of blow off. I know they are slow, but can be run faster. I've had it run faster with same PS but on smaller indoor temp layout at Christmas. Your post just did not seem to me to give me much more than dummy you should know they are not fast. So I decided to just not assume that was intent and wait for other comments.


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## noelw (Jan 2, 2008)

Might check your power cord for a line drop to your power supply too, if running faster indoors and not out on the layout. You can still have 18 volts on your track with no load...


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## Gary Armitstead (Jan 2, 2008)

Posted By mickey on 19 May 2013 08:35 AM 
Posted By Gary Armitstead on 19 May 2013 08:21 AM 
Posted By chuck n on 19 May 2013 06:57 AM 

Slow is a relative term. Your idea of slow may be my idea of OK. As Gary said Shays are slow.

Chuck

PS is you can't easily measure the circumference, measure out 10 feet of track and time the engine going over that segment.


Thank you chuck. At least my statement wasn't a wholesale "right-off"!













Gary, please don't get your feeling hurt, as I did not intend any sort of blow off. I know they are slow, but can be run faster. I've had it run faster with same PS but on smaller indoor temp layout at Christmas. Your post just did not seem to me to give me much more than dummy you should know they are not fast. So I decided to just not assume that was intent and wait for other comments. 
Mickey,

My feelings are FAR from hurt.







It WAS a legitimate comment. When I run at Russ Rutalj's layout (he is an MLS member), I have noticed how much slower his Bachmann 3-truck Shay runs in comparison to his Bachmann 4-4-0 "Pacific & Palisades" loco. Bear in mind that he runs on battery, not trackpower. BUT when BOTH engines are running "dead-head" (just the engines alone, NO cars pulled), the difference in speed is remarkable. BOTH engines weigh the same. Same "speed number" on the Airwire T5000, BTW. My little Berlyn Work Goose #6 pratically gets run-over by ANYTHING on the same track. But that's the gearing. Slow or fast, it's ALL relative. This experiment was my point in making my comment. I guess I should have elaborated on that point. My bad.









P.S. I don't know where you thought I had insinuated that you were a "dummy". Crazy what the "printed" word can do to people.


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## Greg Elmassian (Jan 3, 2008)

I made up a heavy load that would connect to the rails and then a simple voltage test will point out weaknesses. 

Some helpful (I hope







) debugging advice here: *http://www.elmassian.com...trong>** 








*


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## Gary Armitstead (Jan 2, 2008)

Greg,

Checked your link. Great tips! Thank you.


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## mickey (Jan 28, 2009)

Here is what I found today. First, quick background: approx 200' all sectional aristo, all 14 ga stranded jumper wire soldered and for now, the PS is next to track connected with a 3 foot section of 16 ga speaker wire. Yes I know but this was just to see how the basic track was prior to side to side and final grading and ballasting. When I put the Shay on rollers at the far end, and cranked it up to the 18 volts, I still got 18 everywhere and the Shay appeared to run at what I normally expected and was drawing under 1 amp. But as I tested more then played with volume, it started to start and stop on the rollers. I touch it and it would start up. So I took it off and put on the Connie. Ran great and no starting/stopping normal speeds. Now it did derail on several of the switches where the Shay had no problems. While clamped with split jaw, I found some connections where track was not flush, causing a bump jump. It was very slight but after taking off the clamp and reinstalling it, all was fine. Which was all I was trying to accomplish, basic track trouble spot identification. Still have some switchs to work the bugs out, but realize now I need to go joint by joint and scrutinize carefully 

Bottom line is I think I have some sort of pickup or whatever issue with the Shay but I can continue the process of track refining. 

Thanks to all for input.


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## mickey (Jan 28, 2009)

Gary, I was not trying to say "you were" referring to me as dummy, just that since I don't know you or have a feel for you, you could be or not, so I just didn't respond since not sure which way to take it. I've seen some of these treads get 'very' up close and personal and I'm not interested in that drama so better to just not assume or answer.


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