Photo Etched Turnout Details: N Scale Code 40 No. 10 Turnout

[ednadolski]

Here is a project that I am starting as a follow-on to some of my previous efforts at photo-etching.   This time it is a detail fret for a #10 turnout designed for Code 40 rail, with tieplates designed to take the HO-scale P:87 spikes.  I've tried to include some learnings from my previous stuff:

 - No PCB ties.  Plan is to solder the rail to the fret and use Pliobond to glue the fret to the ties.  So the ties will be functional from the POV of maintaining the gauge.
 - Build either at the bench or on a layout, as desired.
 - A layered photo-etch frog, assembled by soldering the layers together. It is designed to NMRA clearances, hopefully this will saves some filing/fitting work with the smaller rail.  (I'll still have to file the point/stock/guard rails as usual.)
 - A jig to aid in getting the ties laid out into the proper locations.
 - Spikes are intended to be optional/cosmetic, but might work out as an alternative to Pliobond to hold the rail in place.  It still may be advisable to Pliobond the critical areas (ie., under the frog/guard rails to maintain gauge.)
 - A few additional/optional detail parts such as rail braces, bolt strips, and joint bars.  (I'm not sure how easy or hard it will be to glue these onto code 40 rail...)
 - Including some extra tieplates, for indulging those  ( ) times when reason fails and I feel compelled to try to build some sample track from individual, nano-sized tieplates and spikes. (Hopefully that will not last too long when it strikes.)

At this point all I have is the .dwg, tho it's just about ready to send out to the etcher:





I'll be updating this thread as the parts arrive and construction commences.

Cheers,
Ed

[svedblen]

Yet another interesting turnout build!

A question about what I assume is the jig for laying out the ties. Why the "pegs" protuding into the tie "holes" and not just a simple square for each tie? Probably something I have misunderstood here 

[ednadolski]

Why the "pegs" protuding into the tie "holes" and not just a simple square for each tie?

Actually that's a pretty good question.  My thought there is that the ties themselves being wood cannot be made quite as precisely as the photo-etched metal, so if some are on the slight larger side of the tolerances then there is a chance they could bind in the jig if the holes were made to an exact size.   A few like that should not be too much of a deal, but if most were then it could be hard to lift the jig away after the ties were glued into place on the roadbed.  The 'pegs' or 'tabs' still should be enough to ensure that the ties come out in their proper positions.

Ed

[svedblen]

...if some [ties] are on the slightly larger side of the tolerances then there is a chance they could bind in the jig if the holes were made to an exact size.

I follow you that far, but I still don’t understand how the tabs, which as I see, it make the tie hole overall narrower, would help with an oversized tie. Or have I misunderstod the use of the jig? Don’t you first lay down the jig and then the ties into the holes in the jig, at which point the ties end up on top of the tabs?

[ednadolski]

I follow you that far, but I still don’t understand how the tabs, which as I see, it make the tie hole overall narrower, would help with an oversized tie. Or have I misunderstod the use of the jig? Don’t you first lay down the jig and then the ties into the holes in the jig, at which point the ties end up on top of the tabs?

It's hard to tell from the image, but the tabs align to the (nominal) dimensions of the tie, and the ties fit in between them. The rectangular holes are somewhat larger.   A sufficiently oversized tie could still kind of drag against the edges of the tabs, tho I'm thinking not by too much (hoping, actually.... it's first time I've tried to do anything like this, so judging the tolerances is a bit of a guess  ).

So it will be important to use the scale-sized ties.  Some folks use 1/16" stripwood to make ties, but that comes out to a scale 10" wide which is too large.

Ed

[svedblen]

Thanks. I look forward to seeing how it all works out.

[ednadolski]

I sent the drawing out to the etcher, but it looks like the ETA is going to be slow:  5 weeks.... 

(I just hope there are no further delays....)

Ed

[chrismears]

This is such a cool idea. I’m really looking forward to updates.

I wonder if one could half etch a spike into the tie plate so the rail could clip into them?

[ednadolski]

.
I wonder if one could half etch a spike into the tie plate so the rail could clip into them?

It’s not really possible to etch an undercut, since the process removes the metal from the surface inwards.  I have seen ‘spikes’ rendered as bumps or nubs on the surface of the tieplates, but they can’t be more than half the metal thickness, and tend to look more like bolt heads or rivets (and easily disappear after painting/weathering).

Ed

[Doug W]

This is such a cool idea. I’m really looking forward to updates.

Me too!

[chrismears]

It’s not really possible to etch an undercut, since the process removes the metal from the surface inwards.  I have seen ‘spikes’ rendered as bumps or nubs on the surface of the tieplates, but they can’t be more than half the metal thickness, and tend to look more like bolt heads or rivets (and easily disappear after painting/weathering).

I hadn't considered that--thank you for the detail. In my "never etched anything before" head I was also counting on being able to control the depth of the etch on each side which is really more of a milling activity than an etching activity. I can see how those rounded spikes would work for track where the rail is attached using chairs, such as in European practice, but that it might not render the way we'd need to for American N. Thanks again. This is always superb work and always a joy to learn from and follow along with.

Chris

[Sokramiketes]

I hadn't considered that--thank you for the detail. In my "never etched anything before" head I was also counting on being able to control the depth of the etch on each side which is really more of a milling activity than an etching activity. I can see how those rounded spikes would work for track where the rail is attached using chairs, such as in European practice, but that it might not render the way we'd need to for American N. Thanks again. This is always superb work and always a joy to learn from and follow along with.

Chris

Some etching houses can vary the depth of cut.  PPD is one.  For example, you could have them etch .005" rivets or surface detail, then do another pass to etch through .020" stock.  Or simply cut more on the front than back. 

[ednadolski]

Woohoo!  Etchings have arrived!



Time for construction to begin!


Ed

[basementcalling]

Woohoo!  Etchings have arrived!



Time for construction to begin!


Ed

Is that enough to do 2 turnouts, or just 1, and do you mind sharing what the etching cost to have made?

[peteski]

Interesting. That looks like stainless steel, not nickel silver.