Author Topic: N scale turnout build with proto:87 parts  (Read 8273 times)

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GaryHinshaw

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N scale turnout build with proto:87 parts
« on: July 18, 2012, 08:32:31 AM »
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I've been trying out various turnout systems for use on my layout and I have pretty much settled on hand-laying using commercially available parts from Andy Reichert's proto:87 store.  While there is a lot of great info on Andy's site (if you know where to look) he does not have any end-to-end instructions on how to do an N scale build, so I thought I would document it - mostly for my own future reference.   I make no promise that this is useful to anyone else, since my procedures might be unorthodox, but I hope it is. I especially welcome suggestions for improvement, since I'm just starting the 'big build' myself and still have a lot to learn!

The basic components I use are: 1. a chemically milled 1-piece frog, 2. a set of CNC planed points, and 3. a combined throwbar and point hinge kit; also ties, rail, and a printed template.  I'll spell out what parts these are on the P87 site, because it can be tricky to tell from the site itself.  The N scale components are all listed at the bottom of this page (BTW, that is Ed Nadoslki's work in the first photo on this page, and the whole page was recently reorganized with improved links that I have added below):

1. Frog - Available in all numbers from 4-10, and in code 40 or 55 rail height.  These are actually made as a sandwich of 3 layers that need to be soldered together.  You can get them pre-assembled for $3.95 extra.  (I did, but I'll probably try the kit in the future.)

2. Points - These are actually scale-independent and come in 4 rail codes: 40, 55, 70, 83; and two lengths "11 ft" and "16 ft", though I have no idea what units these "ft" really are.  I got the long points which are about 3-1/2 actual inches long (~25 ft in HO).

3. Throwbar/hinge - This consists of one etched nickel silver fret with 4 point clips and 4 heel block/hinge parts, as well as a few lengths of PC board ties to serve as the throwbar itself.  Figuring out how to actually fabricate the throwbar and attach it to the points is the most mysterious step in the build.

These components can also be purchased as a kit, listed as "N Scale Craftsman Turnout Kit of parts".  This includes enough ties and rail for a complete turnout.  This is the route I took, but I now have my own stock of weathered rail, so in the future I'll order components separately to save a little bit of money.  In round numbers, all of these parts will set you back $15-20 (depending on whether or not you have the frogs pre-assembled).  If that's a budget-buster for you, read no further.  But these parts are very high quality, and they make the final build pretty straightforward.

updated links to proto:87 store site.  -gfh
« Last Edit: December 31, 2013, 07:53:33 PM by GaryHinshaw »

GaryHinshaw

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Re: N scale turnout build with proto:87 parts
« Reply #1 on: July 18, 2012, 09:04:44 AM »
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The first step is to print the template for the turnout size you want to build from the library of pdf files on the site.  Oddly, the only N scale sizes given are #6-10 (inclusive) even though he sells #4 and 5 frogs.  The rail lines on the template indicate the inside of the railhead.

I tape this to my workbench (a glass-top dining room table!) then put down three strips of 3M double-stick tape over the ties on the template:



(Not sure if you can make out the tape here, but hopefully it's obvious.)  Next cut ties to length, per the template, and put them in place over the tape:



The white strips in this shot show where I will use PC board ties.  Those are strips of .010x.060 styrene that serve as a shim to make the PC board ties level with the (Kappler) wood ties.  I use Plioband to glue the PC board to the styrene.  (ACC could also be used, but the bond breaks when the ties are later heated from the soldering.)  Feel free to use more PC ties if you like, especially under the frog.  I blackened the PC ties first with Micro Engineering rail weathering solution before putting them in place.  I also cut gaps where appropriate, and filed off the blackening where the rails will be soldered to the ties.  (The blackening serves as a kind of primer step, making subsequent painting easier, it also inhibits solder from flowing beyond where it's needed since solder does not bond to the blackened surface.)  I also stain the wood ties at this point using Polly Scale Rail Tie Brown, diluted about 40% with water:



Philip H

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Re: N scale turnout build with proto:87 parts
« Reply #2 on: July 18, 2012, 09:28:58 AM »
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Gary,
Nice start!  I really want to get into hand laying at some point, so your idea of a step by step tutorial is welcome.  I also know that Fast Tracks has a great library of Turnout templates in N scale on their web site, and they have #4 and #5, as well as curved and three way . . .
Philip H.
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GaryHinshaw

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Re: N scale turnout build with proto:87 parts
« Reply #3 on: July 18, 2012, 09:35:07 AM »
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Turning to the rail, I start (perhaps unconventionally) by placing the frog, then working my way out from there.  This is different from the Fast Tracks method (for example), but unlike Fast Tracks, I think the one-piece frog makes this a sensible approach.   I blacken the frog before using it.  One surprise I found when I did this the first time was that the blackening agent (selenous acid) caused salts to exude from the layers of the frog, presumably a reaction with the flux residue (but I'm not sure, and I'd love to know).  Here is a shot after ~1 min in the acid bath:



These can easily be brushed off with an old toothbrush, but it's important to do so midstream, so the blackening goes on uniformly.  The total time in the blackening agent is about 5 min.

Now identify where the frog goes on the template: it is important to note that the rail lines on the template should line up with the inside of the 'V' on the point side of the frog, and with the outside of the 'V' on the other side of the frog.  Once this is properly located, mark a spot where there is a gap in the ties and solder a feeder to the bottom of the frog at that point, so the feeder will sit in a gap (be sure to file off the blackening there before soldering - I also notched the ties a bit to accommodate the feeder).  Glue the frog to the ties with Pliobond following the usual instructions of applying it to both surfaces and letting it dry a bit:



You may prefer to solder the frog to PC board ties.  I find there's quite a lot of surface area for the glue joint and that its quite rugged.

GaryHinshaw

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Re: N scale turnout build with proto:87 parts
« Reply #4 on: July 18, 2012, 09:53:20 AM »
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The next step I take, perhaps unconventional again, is to place the closure and frog rails.  This is quite straightforward: just cut the rail to length per the template and glue them in place following the rail lines.  You will have to gently pre-curve the diverging closure rail before gluing, and the length of each closure rail is indicated on the template.  When you put the rails in place, the rail base will obscure the template lines, but try to get this as close to correct as possible, to save having to tweak them in later steps.

The most important factor in this portion of the build is to make sure the closure and frog rails both line up well with the corresponding sections of the frog and that each rail has a straight shot through the frog.  Here's how it looks at this stage:



At this point I don't solder the rails to the PC board ties and I don't vulcanize (heat) the Pliobond joints until I have the stock rails in place and I'm sure that everything is where it should be.

[More when I get time.  Thx for the comments Philip.]

Chris333

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Re: N scale turnout build with proto:87 parts
« Reply #5 on: July 18, 2012, 10:02:16 AM »
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I wonder if you can get their CAD files and then draw the base of the rail so it would be easier to line up.

Scottl

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Re: N scale turnout build with proto:87 parts
« Reply #6 on: July 18, 2012, 12:26:10 PM »
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Gary, thanks for putting this together.  I've been following your experiments with interest and this is going to be a great thread for reference.  I'm about to take the plunge and try one of these turnouts with proto87 parts myself.

Cheers,
Scott

wcfn100

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Re: N scale turnout build with proto:87 parts
« Reply #7 on: July 18, 2012, 12:41:44 PM »
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The next step I take, perhaps unconventional again, is to place the closure and frog rails. 

I think there's a reason that's the unconventional way.  Once you get the stock rails in place the closure rails will have to be readjusted to get everything into gauge.  Not a big deal, but probably time wasted.


Jason

GaryHinshaw

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Re: N scale turnout build with proto:87 parts
« Reply #8 on: July 18, 2012, 02:56:52 PM »
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I wonder if you can get their CAD files and then draw the base of the rail so it would be easier to line up.

Good idea Chris.  I'll ask Andy about that.

Quote
I think there's a reason that's the unconventional way.  Once you get the stock rails in place the closure rails will have to be readjusted to get everything into gauge.  Not a big deal, but probably time wasted.

I just gauge the stock rails to the closure rails, since they are otherwise unconstrained.  The only place that's tricky is around the points.  But if you stick close to the template, the adjustments are almost nil.

-gfh


GaryHinshaw

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Re: N scale turnout build with proto:87 parts
« Reply #9 on: July 18, 2012, 04:00:27 PM »
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The next step is to fit, but not install, the stock rails.  I don't install them yet because I want to have the points in place first and there's a bit of a chicken and egg thing there.  As I'll explain later, I think the way I have the points set up is pretty robust, but it' not serviceable in the sense that I can't remove the points without de-soldering at least one joint.  But that is probably true of any build.

The point hinge also serves as a heel block which sets the space between the end of the closure rail and the stock rail.  Here is a shot of one in place:



This is a stack of two etched plates with two slots that fit over the web of the closure and point rail, respectively.  The side of the plate rests against the web of the stock rail to maintain separation.  This is the one part of the build where all 4 rails have to be adjusted simultaneously.  I did this as follows:

- Insert the heel block on the curved closure rail, as shown.
- Cut a straight stock rail, and hold it in gauge near the frog, and butt it up to the heel block.
- Use a straight edge to verify that the stock rail is straight and parallel to the centerline throughout.  Adjust the end of the curved closure rail, if necessary.
- Adjust the end of the straight closure rail to ensure gauge of the straight track, as shown:



(If you've done this properly, the straight closure rail should also be parallel to the straight route centerline.)

- Cut a curved stock rail and shape it as shown here:



(Photo from this P87 page.)  In principle, when this curved stock rail is placed against the heel block of the straight closure rail, the curved route will be in gauge too...  It was for me.  If it's not, I can't help you.   :|
- Set the stock rails aside for later installation.


tom mann

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Re: N scale turnout build with proto:87 parts
« Reply #10 on: July 18, 2012, 08:10:08 PM »
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Looks nice so far, but the PC board spacing looks a little too far apart.  How strong is the glue?

GaryHinshaw

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Re: N scale turnout build with proto:87 parts
« Reply #11 on: July 19, 2012, 12:46:26 AM »
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It's quite strong.  I actually have some track I hand-laid with Pliobond back in the '70s that's still hanging in there.  But adding more PC ties is trivial, if you prefer.  I would especially recommend that for track on portable modules.  And I'd be curious to hear if anyone has any Pliobond horror stories.


« Last Edit: July 19, 2012, 04:31:35 AM by GaryHinshaw »

GaryHinshaw

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Re: N scale turnout build with proto:87 parts
« Reply #12 on: July 19, 2012, 11:01:31 PM »
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[I'm writing down the last steps even though I didn't take good progress shots of the point construction.  I want to get the words down before I forget them; I'll update the photos with better ones when I get a chance.]

Up to this point, the build has been very simple - the only particular skill required is patience, which suits me fine.  Assembling the points is a bit more finicky.  The concept of the P87 kit is that the points hinge in the heel block shown above and the tips are 3-way planed to nestle into the stock rail without needing to file away any stock rail metal.  The throwbar is a 2-part affair: one bar is rigidly attached to the points and pulls the closed point open, the other (which the switch machine or ground throw attaches to) pushes the open point closed.  The throwbar kit comes with etched clips that mount in the throwbar and contact the web of the point, ensuring good pressure when a point is pushed closed.   Here is a shot of the finished assembly (with an NZT switch machine):



The rigid (pulling) bar is on the right and the loose (pushing) bar is on the left.  Note that the pushing one does not need to rotate with the points, so it can sit between the normally-spaced head ties without any problem.  The hardware is designed to look something like a prototype assembly, as seen, e.g., in this photo from David K. Smith. While that's debatable, I think their mechanical function is valuable.

Before assembling the points, the tips need to be fine tuned.  First, make sure that the inside of the railhead is dead straight; they come with a bit of a vertical and horizontal curve (for whatever reason). They can be straightened by pulling them through your fingertips with the correct pressure.  Next I filed a slight taper to the inner railhead to give them a bit more of a knife-edge.  When you push them against a stock rail, you should barely feel the tip of the point with your fingertip.  This shot shows the degree of taper I ended up with:



Cut the points to length using the template as a guide.

The throwbars are made from PC tie stock.  The etched fret comes with a drilling template for the 4 clip holes.  I made a simple jig to hold a PC tie and the template as shown:

[photo coming]

I drilled these with a #75 bit in a Dremel tool.  The clips will fit in these holes very snugly; a drop of thin ACC inserted from the bottom of the hole will lock them in place.  To assemble the points, I made a jig as shown:

[photo coming.]

The "ties" in this jig are thinner in height than normal ties (~.040" high) so that a PC throwbar will sit slightly higher when placed between them.  (This ensures that the bottom of the point rails make good contact with the top of the throwbar when soldering.)  I also positioned the ends of two closure rails with hinges in the correct location, per the template, so the points can be inserted and held while soldering.  These closure rails can be permanently affixed to the jig.  In principle you should make a left and right jig; in practice, the resulting points are probably ambidextrous.

Now place the two assembled throwbars between consecutive ties, as shown above, with the loose bar between the head ties, and the rigid bar in the next slot over.  Insert the points into the hinges and push the tips against the tips of the throwbar clips.   Solder the base of each point to the rigid throwbar, letting a bit of solder meld with the clip for strength.  The final point assembly should look like this when removed from the jig:



[better photo coming]

You will find that some solder has leaked to the back side of the points obstructing the groove at the base that is supposed to clear the base of the stock rail.  I cleaned this out the best I could with the edge of a triangle file, but I didn't want to get too aggressive for fear of weakening the structure.  As a result, I decide to notch a short section of the base of the stock rail to better accommodate this.  (Purists look away.)

At this point you can cut the rigid throwbar shorter with a pair of rail cutters.  I left enough material so they stick under the stock rails when the turnout is thrown either way.  Otherwise they might catch on the base of the stock rail.  Now place the points in the turnout; hopefully the two throwbars sit comfortably between the ties and the ends of the points sit well in the hinge slots.

This is a good time to figure out an easy way to electrically connect the points to the rest of the turnout.  ;)  (And don't forget to gap the throwbars.)  The last steps are to install the stock rails and guard rails.

ednadolski

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Re: N scale turnout build with proto:87 parts
« Reply #13 on: July 21, 2012, 12:18:42 AM »
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Nominating this thread for inclusion under Best of the Wire.

Ed

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Re: N scale turnout build with proto:87 parts
« Reply #14 on: October 17, 2012, 12:44:53 AM »
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Reviving an old but valuable thread...

Gary, do you realize N scale parts and kits have disappeared from proto87.com? I sent a note to Andy asking about it.

EDIT: Your direct link still goes to an active page, but there are no links from within the home page or catalog index.
« Last Edit: October 17, 2012, 12:47:47 AM by C855B »
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