Point Jumpers and Track Feeders

Some time ago I wrote up how I did point jumpers on my Atlas O code 148 turnouts.  For N scale I'm using Atlas N code 55 turnouts.  My rule of thumb for track is simple - if it doesn't have a wire soldered to it, it's going to be unpowered sooner or later.  Turnout points are electrically connected by a contact under the hinge point, and by contact with the stock rail.  They are exposed to dirt, ballast glue, paint, scenery materials - in short they are almost begging to have electrical issues if you don't take measures to make sure they're powered.

My solution for N scale is the same as for O scale - solder a jumper wire between the point and it's closure rail.  Even though it's a bit trickier to solder a jumper wire to a code 55 point without melting ties, resistance soldering and solder paste make it doable without too much trouble.

Resistance soldering runs a high electrical current from one probe to the other, and anything in between gets hot.  Assuming you pinch the wire and rail with the probes, this tends to put the heat exactly where you want it - right where the wire meets the rail.  The rest of the rail gets heated from there, so if you wait long enough the entire section of rail will get hot.  Since that would melt the plastic ties, you need to get the job done before that happens.  In other words, timing is important.  And since how long it takes depends on how fast the joint and solder get hot, power is important too.  You can do it with regular solder, but it's easier with solder paste.  I'm using Iso-Tip silver bearing solder paste (http://www.iso-tip.com/products-page/smart-paste-series/).  Solder paste is basically a mixture of solder particles and flux.  For the resistance soldering station I'm using the American Beauty 250 watt unit that micro-mark sells.

Here's what I do.  First, scratch up the surface you want to solder a little (I use one of these things http://www.micromark.com/scratch-brush,8058.html).  The scrub it with a toothbrush and some 90% alcohol.  Clean fresh metal makes for an easier joint.  Then I strip a section of stranded #18 wire and cut off about 1/2" pieces of single strands.  Same treatment for the wire - scrap it up a little with some fine-ish sand paper, wipe with a paper towel damped with alcohol.  Put a dab of solder paste on a scrap, and use a toothpick to put a little bump of it in the web of the rail at the spot you want the solder joint to be.  I do it between two ties, one tie away from the point hinge (so there are three ties between the two soldered spots).  Using some tweezers you can now set one of the single strands of wire across the point, with each end mushed into the solder paste a bit.

For the soldering I use the tweezer handpiece, with the tips bent a little to make it easier to get contact where I want it.

Squeeze the jumper wire and rail web between the tweezer tips right at the solder paste blob.  After some experimenting I've found that setting the 250 watt unit to 90 and using the foot switch to hit the power for 1/2-3/4 of a second is about right - you get a nice solder joint and don't melt anything.  You'll need to experiment a bit to find the right power and timing for whatever soldering unit you have, so practice on some flex track you don't mind wrecking before you start mangling turnouts.  You may mangle a turnout too, but get the worst of it over on the flex track.

And a closeup of that - note that this attempt was before I went with the longer jumper to put the joint between ties, but it does give you the idea of what it looks like with the wire mushed into the paste.

A closeup of pinching the jumper into the solder paste jut before soldering

Finally, assuming everything went well, clean any residual flux from the paste off with the toothbrush and alcohol.  Here's what the end result looks like if you got everything right.

A nice point jumper

Closeup of a nice point jumper

Note that you will almost certainly not get it right the first time - the power and timing are critical for one thing.  It takes a little practice.  In the above photo you can see a little fuzzy in the background my practice turnout (kind of destroyed) and a piece of flextrack I used for practice as well.  Both for soldering point jumpers (you can practice on flextrack just soldering the strand into the web), and for track feeders.  You will destroy some flextrack and quite likely a turnout or two getting the process right.  Use a magnifier to inspect the joint - sometimes a joint can look OK to the naked eye but when you look closer it's not so nice.  Here's one example of what happens when you get the power and timing off (this one looks a little questionable to the naked eye, but with a magnifier it's pretty ugly).

Bad power and timing, jumper too short

Also notice in that photo that I was trying to solder right over the tie - not surprisingly that makes it more likely that you'll end up melting the tie, which is why I ended up going with a slightly longer jumper to put the solder joints between ties.  It is possible to re-flow and fix joints like that one if you get it right the second time, but if you keep re-flowing eventually you'll wreck the turnout.

You might expect that adding a jumper like that on each point would stiffen up the pivoting action of the points.  Surprisingly, it doesn't - the points still slide side to side with no noticeable additional resistance, and then stay where you leave them - there is no tendency to spring back.

I did consider other ways of powering the points.  Here's one I got as far as trying - soldering feeders to the bottom of the point hinge pins.

A rejected approach

There are two problems with that approach.  The first is that the hinge pin itself does get hot enough to melt the tie a little, and it's at possibly the most critical spot in the turnout to not melt.  The other problem is the wire needs some space to move, and I could quite see how I would keep it unrestrained after gluing ballast down.  I think the point jumpers are better all around.

Enough of point jumpers, on to track feeders.

In O scale I did my feeders after the track was laid using the resistance soldering unit with the single tip probe to solder the flattened end of a #18 wire onto the back side of the rail base.  Very inconspicuous, and easy to not melt ties in O scale.  For my N scale layout though, I couldn't imagine doing that without melting a lot of ties, and also the pressure required on the probe would probably mush the track into the foam roadbed a bit (3/8" homabed in O is a lot less susceptible to mushing than the blue foam insulation I'm using for the N scale layout).  So I decided to solder the feeders to the bottom of the rail before laying the track.  I decided to use #22 wire for feeders - it's big enough to carry the necessary current for the relatively short distances from the bus (~12"), and it's small enough to fit between the ties without touching them.  Also I was able to find scotchlok connectors that are rated for #22 solid on the tap, and #14 solid for the bus.  I used the scotchlok connectors on my O scale layout and liked them, so in part selecting wire size depended on finding the right connector.

The process of soldering a feeder on is simple.  Cut out a bit of the pastic to expose the bottom side of the rail if there's not already a convenient exposed spot.  Scratch it up with a needle file.

Scratch up the rail for soldering

Strip a little bit (3/32 or so) off the end of the #22 feeder, and bend it over 90 degrees with some pliers, squeezing just hard enough to flatten the end a little bit (but not so much that it gets brittle).

A bit flattened on the end that will touch the rail

If you put the track on a little block (like you see in the photo with the file above) with the spot for the feeder just a bit off the end of the block, it makes it easy to use the soldering tweezers.  Put a dab of solder paste on the rail where you scratched it up, mush the wire into it, squeeze the tweezers down, and hit the power.  I find the same setting of 90 for 1/2-3/4 second works for me here too.  It's a little harder to not melt ties a little when soldering right up next to them like this - even if you're fast with the power, the residual heat from the wire, the joint, and the tweezers themselves can melt a little.  On the plus side, a little melting here is nowhere near as bad as it would be right at the point hinge.  On turnouts after I add feeders to the stock rails I also solder one onto the frog power eyelet using a regular old soldering iron and solder.  I'm still not sure if I'm going to power my frogs but it's a lot easier to solder the feeder at the bench than it would be with the turnout glued down to foam.  Finally, of course, clean up the joints with alcohol and a toothbrush.

Feeders soldered on

If you get a good solder joint it's pretty strong.  If you get a cold joint the wire may pull off as you shift the turnout around on the roadbed.  So inspect those joints carefully!  I'm willing to count on the internal connections in the turnout to power the rest of the rails (closure and the two little stubs off the frog), a decision I might regret later but for now it seems like a good trade off in retaining the strength and unmeltedness of the turnout vs. potential electrical trouble.

One final bit of soldering, this time rail joints.  On curves I've found it much easier to maintain a smooth continuous curve in the rail across joints if the rail joint is soldered.  Doing this requires a little test fitting and thinking, to make sure you get the soldered joint in the right place without having to cut out more ties after you curve the flex track.  I use the resistance solder unit again, but with the carbon jawed plier handpiece this time.  I tried mushing solder paste into the rail joiner, sliding the rails in, and soldering, but it turned out to be virtually impossible to get the rails to butt up end to end (not all the paste would squish out from between them).  In the end it turned out to be easier and better to use traditional solder.  As always, scratch up the rail surfaces that you want the solder to stick to and clean them off.  Slide the joiner on centered on the joint.  Keeping the joint straight is a little tricky but not hard - I lightly clamp the track half off the edge of my bench with the back edge pressed against a ruler to keep it straight.  Brush on a little good quality liquid flux (much better than paste flux).  If you use too much flux you'll eventually end up with a glaze of flux on the carbon plier jaws and they won't conduct electricity well enough to solder with - if that happens a little sandpaper will clean the glaze off.  Squeeze the pliers onto the top of the rail and the bottom of the rail joiner.  Be careful not to shift the rail position as you clamp down on it - I brace my hand on my leg (not the same leg I'm using for the foot switch).  Hit the juice.  The foot switch is critical here unless you have more hands than I do.  The power setting of 90 worked well for me here too.  Be ready with some nice thin solder at one end of the joiner, preferably on the outside of the rail.  As soon as the solder flows into the joint a little quickly move it to the other end of the joiner, and as soon as it flows there take your foot off the switch but don't move the pliers!  Wait for the joint to cool a little before you move the pliers.  If your eyeballs are into middle age or beyond, an optivisor definitely helps in all these soldering processes.

Soldering a rail joint

Unclamp everything and use the straight edge to make sure you didn't shift the rail a little with the pliers and introduce a kink while you were trying to do everything at once.  If you did end up with a kink, re-clamp, use the resistance pliers again to reflow the solder and let it straighten out.  You will probably get a little tie meltage, you can either ignore it or if it's to the point of looking bad cut off the offending ties.  If you melt too many of them from too many reflows, consider cutting the joint out, trimming both pieces back, and trying again.  Once you get the track pieces soldered together, you can solder the feeders on the bottom.

I was a little surprised that it actually turned out to be easier to get a good straight clean solder joint on N scale code 55 than it was with O scale code 148.  The bigger rail takes longer to get to the point where the solder melts, and it holds heat longer - that means you have to hold everything still for longer.  And since the rail is stiffer, you need to clamp against a longer straight edge.

That's about it for soldering and track.

A code 40 turnout

Today's project was going to be figuring out the best way to solder point jumpers on to my Atlas code 55 N scale turnouts.  I've tried one or two techniques already, but I'm not totally happy with them.  I was also looking into cleaning up the points.  After a few false starts, I made an abrupt course change and pulled out the Fast tracks code 40 turnout jig I bought a few years ago but never actually tried.

A long time ago, when the first article on handlaying code 40 track came out in the late '70s, I built a timesaver switching layout in code 40.  My first turnout worked marginally, the subsequent ones weren't even that good.  More recently I've built a large curved turnout in code 148 rail in O scale, with much better results.  I was more careful, and I know a lot more about turnouts than I did in the '70s.  I was pretty sure I could build a turnout using the Fast tracks jigs without too much trouble.

Actually building the turnout took longer than I thought it would, but in fact it was in line with what the instructions tell you to expect your first turnout to take.  There is still a fair amount of craftsmanship involved in making a good turnout even with the aid of all the various Fast tracks tools and jigs.  My first turnout has a rather despicable frog.  Although it seems to work quite well, which is a testament to how much the jigs help you get everything properly aligned.

First Fast tracks code 40 turnout

The above photo shows my first turnout.  The wheelsets in that truck are Fox valley, it rolls through the whole thing very smoothly.  I haven't installed the turnout on the QuickSticks ties yet, because I haven't gapped the frog rails yet, which is in turn because I can't seem to find the jewelers saw I am quite sure I have somewhere.

The hardest part of making the turnout is, as you might expect, getting the points and frog to be really nice.  The points were considerably easier than the frog, oddly enough - the opposite of my experience making the code 148 curved turnout with no jigs.  I think the frog is trickier because you can't fine tune the point by filing the gage face of the rail - doing so pulls the actual point of frog further back from the theoretical point of the frog.  I think I also need to get a better optivisor, and better lighting on my workbench.  But most of all I just need practice.

A not so nice frog

You can see from the above photo that my frog actually seems to have two points.  It's pretty nasty, in fact.  I'm sure I can do better with practice.  But the interesting thing is the geometry of the turnout as a whole is so good because of the precision of the Fast tracks jigs that the shoddy frog point doesn't seem to matter.

And just for fun, a side by side of this and an Atlas code 55 turnout.

Fast tracks code 40 vs Atlas code 55

Both are number 10 turnouts.  Note that the closure rail curvature of the Fast tracks turnout is a little different, so the points are actually further away from the frog than the Atlas turnout.  The difference in rail height is the same proportions as comparing HO code 70 to code 100, or O scale code 132 to code 183 - the last comparison pushes home what's been bothering my about the code 55 track.  The code 148 track on the newer half of the O scale No-Name Industrial looks bigger than I want (I prefer the look of the code 125 on the older half), and the thought of code 183 for O scale boggles the mind!

So, what's the point of all this?  Didn't I already decide to build the Palmer Industrial Park layout in Atlas code 55?  And have I not, in fact, bought all the code 55 turnouts and flex track for the job?  Well, yes.  But I've been repeatedly reminded recently of how much better code 40 looks than code 55, and the recent thread on the Atlas N scale forum on code 40 track got me thinking about it again.  I'm also feeling less pressure to speed through the track laying since I got my O scale No-Name Industrial back into operating shape.  I'll need to do a few more practice frogs and switches to see if I can consistently produce a good code 40 turnout, and I'll need to try laying some plain old code 40 track.  I've already tried some ME code 40 flextrack, but the batch I got had very inconsistent tie height - it just didn't seem good enough to be worth the trouble.

Ground throws

I like to use Caboose Industries ground throws for turnout control.  They're simple and reliable.  And they don't require you to hunt around on the fascia for controls.

The way caboose ground throws are designed to be installed is sitting on top of the head blocks, with the pin going down throw a hole in the throw bar.  Here's a 208S ground throw mounted the way caboose industries intended on wood ties on the older section of my layout.

Caboose 208S mounted as designed.

That works great for hand laid turnouts, and it looks OK too even though it's knee high to an O scale person.

Atlas turnouts don't have long head block ties, so some form of extension is needed.  While I was experimenting with that, I came up with what I think is a better approach to get both extended head blocks and less conspicuous ground throws.

Inconspicuous ground throw on Atlas O turnout.

The red paint on the ground throw handle indicates the turnout is reversed. The opposite side is painted green for normal. It's a nice idea I got from a friend that helps orient visitors.

Inconspicuous is achieved by mounting the ground throw at roadbed level instead of tie level. Since I used homabed, I notch out the beveled edge by the throw bar and fill in a wood block to match the roadbed height. The pin sticking down from the ground throw is cut off, and I drill and tap a small hole in the end to accept a small screw. The throw bar on the turnout gets shortened a little - pretty much just clip off the part on the end - so it ends up almost flush with the ends of the ties when you push it so the opposite point hits the opposite stock rail.

Modified ground throw ready to install.

Then attach the ground throw to the throw bar, center the points, center the ground throw handle, and mark where to drill holes to screw down the ground throw.

Center everything to locate holes.

And here it is in working order.

Working but ugly.

At this point you could stop, but it's not pretty. Once I'm sure it's lined up and working correctly, I add the head blocks. Since the ground throw is at roadbed level, they need to go around the ground throw. I clip out a pair of ties from some Atlas flex track leaving the bit of plastic that joins them in place for the time being, and cut off the other end at the tie plates. Here's a pic of it at that stage sitting where it needs to go, but as you can see it doesn't fit down over the ground throw. Yet.

Test fitting head blocks.

Using a burr in a dremel tool, a razor saw, an xacto knife, a mill file, and a rat tail file I remove everything that seems to get in the way of a fit. The plastic bit joining the two ties keeps you honest about alignment at this stage. Here's a shot of it sitting in place after I made it fit.

It fits!

Here's a shot of what the bottom looks like. The notches get around the "hips" of the ground throw, and the cross groove in the middle clears the tops of the #2 wood screws I mounted the ground throw with. Since my wood block ended up just a smidgen above the roadbed level (oops) I filed the entire bottom a little.

Bottom view of trimmed head blocks.

The final step is to cut off the other end of the ties at the tie plates. I used CA to glue them to the ends of the switch ties and the roadbed. Being VERY careful not to get any one something that's supposed to move! It would be nice if the ties were just a bit longer, but you can't get a longer molded plastic Atlas tie without mangling a switch - something I'm not willing to do. And I think the fact that the head blocks are the same material and surface texture makes them blend in better than using wood or raw styrene shapes. Here it is glued up.

Head blocks glued on.

All that's left to do is use some putty around the edges to keep ballast and glue from getting in where they might cause trouble.

The ground throw sticks up above rail height only about 1/8 inch, so it can be pretty close to the track with no concern about pilots or whatever hitting it. Looks better at that height too.

Point jumpers

Rule of thumb:  If it doesn't have a wire soldered to it, it's unpowered (if not now, then soon, and probably at an inconvenient time).

When I first started using Atlas O turnouts this rule was proven once again.  I started having trouble with the Weaver GP38-2 I had at that time occasionally stalling on my Atlas #5 turnouts.  (So far I have left my frogs unpowered).  On unmodified Atlas turnouts there are two ways the point gets powered - through the hinge, and from contact with the stock rail.  If you've painted the track, or ballasted and gotten glue in, or just aged it enough to get dirty either or both can fail.

It turns out the GP38-2 is exactly the right length so when one truck is completely on the (unpowered) frog, the other is completely on the point.  Since I hadn't thought to solder anything to the points, the inevitable happened and sometimes a point would be jiggled just right so it wasn't making contact, and the loco would stall.

My solution was to solder jumpers between the points and closure rails.

I made my point jumpers out of 1" long pieces of #24 stranded wire.  You want to center it on the point hinge, a solder the last quarter inch of each end to the rail leaving the middle half inch free and not saturated with solder.  It's very important to make sure the middle 1/2 inch is free from solder so it maintains it's flexibility allowing the points to move freely.  My switches with point jumpers installed will still stay in either position by themselves with no ground throw holding them there, and still flop back and forth just as easily as ever.

I made a clamp to hold the wire in place and act as a heat sink to keep solder from wicking into the middle of the wire.  I cut three ~2" pieces of 1/16 x 1/2 aluminum.  These will form a sandwich - one piece will go on the gauge side of the rail, the middle piece between the rail and the wire, and the last piece outside the wire.  File grooves on the middle piece to help hold the wire in place on one side, and to help position the clamp on the rail head on the other side.  The exact placement of the grooves isn't critical - you want the groove for the wire to end up about centered on the web of the rail when the other groove is on the head of the rail.  I drilled a hole through all 3 pieces and put in a screw with a wing nut to make it easier to use.  The screw head is glued in place so the wing nut can be easily tightened.

Point jumper clamp.

The rail goes in the left side, the wire in the right side.  The next picture shows it holding a wire in place:

Point jumper clamp in use.

I use a resistance soldering iron to solder on point jumpers and track feeders.  I will admit to a moment of confusion when I just couldn't get a jumper soldered on well with the resistance unit.  Obviously the aluminum jig conducts electricity quite well, so most of the juice was going through it instead of the solder!  Duh!  Putting a piece of paper between the clamp and the rail solved that problem.  I left the paper out of the above pic for clarity.

Here's a turnout with both point jumpers soldered in place.  Even unpainted and sticking out they're a lot less conspicuous than they appear in the top down close-up photo below.   After you paint the jumpers, the rail and fold the jumpers down right next to the rail they virtually disappear.

Finished point jumpers.

The rest of the rails in the turnout are bonded to the two stock rails via copper strips that appear to be soldered to the bottom of the rails.  This is true for the closure rails and the two rails on the other side of the frog.  So once you've added the point jumpers, you can power the entire turnout with just two wires, one to each stock rail.