How Many Drops

You have to test with a typical load, or you will get 18 volts everywhere, even with just one connection to the track.

Ok Rob,  didn't think of that.  What if I run an engine with, say 10 cars on the track.

And let's say I'm 20 feet away from point A. 

Do I check the voltage at that point as the train goes by and what reading would I get, and what reading would tell me to do another drop ?

Paul

That would keep you quite busy!

Use a load like an automotive sealed beam lamp or two that you can clamp on to the rails and is a steady load, and then check the drop in voltage at the track where the lamp is connected. 

With the load connected, you have to check two points for the best indication - at the source and at the load.

The most important thing regarding wire drops is wire size. Use a good size wire and you will need fewer drops.

I think checking each section from voltage loss is a bit "labor intensive." Its easier just to decide on a regular drop/feeder interval and continue it throughout the layout.

I use 14GA buss and feeders on my layout, my drops/feeders are every 10 feet. Any isolated siding or yard gets its own feeder of course. I have no voltage loss anywhere.

Smaller wire will require more frequent "drops/feeder" intervals. I wouldn't recommend anything smaller than 16 GA for a command layout.

Tell me if I'm going to have a problem with the following.

I'm using all Atlas O track, and I bought a whole bunch of Atlas's "Terminal Joiners" thinking, when I saw them, they were a neat way to put power to the track (I'm not opposed to souldering, but they look like a neat way to put power to the track). 

I'm going to use 12 gauge wire for my power and ground.  The wire that is connected to the terminal joiners is 20 gauge.  Since the drop will be no more than 3" from the track to under the table where it will be connected to the 12 gauge wire, I figured the 20 gauge would not be a problem as far as it creating a current bottleneck drop.

Will I be ok ?

I think I'm reading into what you fellows are telling me, that I should just do a drop about every 10 feet just to make sure I have good power everywhere ?  Or should I do the drops when I read a drop in voltage as I go down the track.

Covrettte

Well, I just got off the phone with Bill Serratelli at Atlas O (their O Gauge tech gie) , and he recommended dropping a power line every 8 feet.  He also suggested placing a power drop near all three ends of the switches.  He said to drop a common line from both outside rails instead of just one, for better connectivity.

Just thought I'd pass on his comments.

Corvettte (Paul)

"Atlas joiners are not reliable".  WOW, is that ever an understatement or what!

I find them barely adaquate for mechanical alignment.  Very disappointing. 

As a rule of thumb; do not ever depend on rail joiner to be a long term electrical connector.  Yes it can work, sometimes for a while.  But if you do use rail joiners for power supply and you do have a failure of continuity look first to a rail joiner.

Recently we have been going through a rail joiner shortage of sorts so this statement has had some speed bumps but my normal approach has been to use early 70's code .157" Atlas rail joiners styled for the older skinny rail on the overly fat current Atlas rail.  For the older Atlas code .157" rail I use the Peco code .138" rail joiner from Rails Unlimited.

Do not get caught up in the code (height in thousanths) of the rail, it is the cross section profile that counts.

In each case the joiner is a  snug tight  fit which needs a massaged tapered 4" piece of rail as a tool to prep it's installation.  You can mount the rail piece in a file handle.

Not knowing when I bought so many of Atlas's "terminal drops" that they were not reliable (have read several times elsewhere that they don't work well), I guess I'll just leave them aside and soulder all my drops.

Corvettte (Paul)

You are right.  I marvel at the track joiners they sell with the wire connected!  Why in the world would you connect your drop to the least reliable connection point???

Paul....if you will email me I will send you a fool proof wiring "plan" that I believe will help you.  My email is in my profile...

Alan

Well John,  since this is the first layout I've ever built, and since I've been buying stuff for a lot of years with the antisipation of finally getting around to building my dream layout, AND because I just came across the OGR Forums about 8 months ago,

I DIDN'T KNOW ANY BETTER ! ! ! !

I wish I had come across these forums alot earlier and been able to learn from guys like you, that would have saved me some $$$$ along the way.  So far my mistakes are not too bad.  I'd say the purchase of so many of the "terminal joiners" is the worst mistake so far.  And if that's my worst, I've not wasted many $$$$ yet.

I depend you guys to keep me straight before I make any more mistakes.

Corvettte (Paul)

I've learned plenty of lessons the hard way, no insult intended.

None taken, John.  Just don't go away, we learn a lot from you.

Paul

It's harder than that to make me go away.

Paul, for my drops I use a foot or so length of solid 18 gauge.  After placement I wrap the dangling tail around the body of a permanent marker which I just used to label the drop's block number on the bottom of the sub roadbed. 

This spring coil eliminates dangling loops to catch on the layout monkees and also leaves enough wiggle room for lifting of that track section if needed.  A 4" long drop would not provide a work margin.

Hay Tom,  I never thought of that, leaving enough room to pull up the track to do work on it without cutting the wire.  Good advise.

Paul

Corvette,

I could shed some light on wiring your layout with the AtlasO track system. I worked for Atlas from 99 until this past Sept. mainly with the track products and accessories. You can reach me at steve@MontanaRailPower.com