Hand laid turnout question

[peteski]

I'm still san mill.  The letter to Santa will again include a Sherline CNC rig.  Must not have been good enough in the last few years...   

So currently when I rip stuff, its either with the cabinet saw or (something this narrow) my band saw.  And for straight, I can rip though most fast.  But in spite of what premium blade maker Timber Wolf claims, I've recently trashed a new 3/16 x 12RK Swedish silicon steel blade in one day, cutting some impregnated plastics and 3/16 AL bar stock. 

FYI: the glass/epoxy PC Boards are machined using Tungsten Carbide drill bits and routers.  I imagine that for ripping you should be using TC blade.  Silicon Steel is not quite up for the task. 

[narrowminded]

Definitely a job for carbide tools.

If you're going to get into machining your post brings to mind a few generalities for things you'll likely encounter or be tempted to use.  It might be counter intuitive but some common plastics, especially PVC, is harder on a cutter than steel or SS.  It dulls a cutter in very short order.  On the other hand, ABS and especially Delrin are very easy on cutters and machine nicely.  Delrin can be a little tough to grip but doable whereas some like polyethylene can be very difficult to grip.  For free machining metals it is tough to beat brass, nickel silver, and then aluminum.  Some bearing bronzes, although they look much like brass, can be very difficult to machine, especially internal such as drilling and reaming.  There are "free machining" bronzes but they will never be brass for ease of cutting but also should be used for bearings, not brass other than very light duty.  The harder, stronger alloys of aluminum (6061 is common for machined parts) machine better and are also more corrosion resistant than the softer, purer grades of aluminum like 3003 or even 1100.  Those can be gummy.  And calling 6061, 2024, or 7075, some of the more common aluminum alloys, "harder" is true but as compared to other aluminum, not steels.  7075 is probably the highest strength alloy that's readily available at an industrial metal supplier, is pretty hard, and has strength around that of a medium carbon steel but still not quite as hard as steel.  It still cuts quite readily. 

That's some quickies off the top of my head.  Hope they help.

[ednadolski]

alternatively, one could copper clad the entire textured surface and then just etch back to the tie plates using a photo resist process prior to tinning.

Interesting thought.... one could readily make a trial of it by etching a few sets of the Fast Tracks PCB ties using the same materials from a DIY PCB etching kit.

I wouldn't be too concerned about the mechanical strength of the cladding, presuming that (a) one does not excessively overheat too many ties; (b) avoid too many sharp curves with heavy rail (C40 would of course look best); and (c) use proper rail gapping to avoid expansion issues.

Ed

[narrowminded]

Interesting thought.... one could readily make a trial of it by etching a few sets of the Fast Tracks PCB ties using the same materials from a DIY PCB etching kit.

I wouldn't be too concerned about the mechanical strength of the cladding, presuming that (a) one does not excessively overheat too many ties; (b) avoid too many sharp curves with heavy rail (C40 would of course look best); and (c) use proper rail gapping to avoid expansion issues.

Ed

My concerns are just that, concerns.  I know you have experience with hand laid track which I don't so if you think it would be worth a trial I'll defer to your experience and maybe I will try it. I wouldn't etch them but just machine the pads as they need to be cut somehow and might just as well use the mill and do it all in one setup.  I also might cut plastic ties with the beds cut to capture the rails for gauging as it wouldn't look right to have every few PCB ties one way and the rest just flat.  

I'll have a very small module to do for myself with the mine locos I've been working on so it would be a manageable size project to run them manually at home.  If it proved viable I could get them done in a small production quantity at a reasonable cost in one of my buddy's shops.  I still think I will make my first one or two switches following the Fast Track method (with a few variations already) to gain experience and maybe then.... should I do it?  The whole deal?

[SandyEggoJake]

Let's be clear - this concept is mostly a thought exercise...

The issue with milling the copper back to the tie plates is that it is not amenable to retention of possible molded details nor high throughput.  Far easier to electroplate the surface and etch back to just the desired tie plates.  Might even be possible to electroplate just the tie plate areas?  That could save several steps and reduce loss from etch failures.

So I've found two producers of Copper Clad Laminate (CCL) and both seem interested to explore development of a textured surface "prepreg" board.
Apparently, these CCL sheets are a very cheap commodity and there is next to no margin for the standard FR4... and excess capacity.   So to say they are eager to explore alt uses is an understatement.   

They don't even seem concerned when I told them my max initial would be far below their standard 5,000 sheet order size.    They even cut to size.... or actually sheared (like those by Clover House).

The conversation as advanced with one group to the point of them asking for
a) ideal thickness of finished boards and b) thickness of required copper lamination.

For A) I propose N:7" rail bed so that they align with standard precut wood ties and the Fast Tracks standard PCB ties, and can thus used in their jigs.   Apparently ~0.04" /1mm thick.

For B) thickness of copper - I have no idea.  I suspect something similar to what is on the Fast Track ties?  For what it's worth, I've yet to figure out a way to measure the foil on their laminated sheets.  Basically they ask as they don't know if it would be best to use electroplating or hammered sheets. 

To develop a pattern on the pre-preg, we are looking at several options.  Of course, I've not heard any price yet.  So I have little confidence this will be a reality. 

But thinking the detail would be just on the top and would include wood grain and tie plate / spike heads.  Obviously would leave flat where the rail goes -- width to base of ME55?

@narrowminded yes I love the proto:87 PE tie plate concept.  But I have never tried it given they are made to fit c:40 and my desire to use c:55 (the FreeMoN standard).  I was told by another FreeMoN guy who tried their plates and found they wouldn't fit ME55 as stock.  I even wrote proto:87 to see if they had interest to make a slightly wider PE tie plate to fit other codes.  In fact I tried twice.  Never got any response. 

Obviously would be easy to design and run a fret of c55 plates... but I stopped when I read they recommend to use CA for construction with their tie plates - not solder. 

 

[ednadolski]

yes I love the proto:87 PE tie plate concept.  But I have never tried it given they are made to fit c:40 and my desire to use c:55

FWIW I tried those tieplates a while back and found that they simply are too small to work with individually, at least for me.  Once painted, they are virtually invisible without strong light and magnification.  (I never tried the turnout tieplates but they seem problematic to me)

Ed

[ednadolski]

I even wrote proto:87 to see if they had interest to make a slightly wider PE tie plate to fit other codes.  In fact I tried twice.  Never got any response. 

Obviously would be easy to design and run a fret of c55 plates... but I stopped when I read they recommend to use CA for construction with their tie plates - not solder.

Not too surprising, since there is such a small market for those things even in HO scale.  Ease of design is not the issue, there simply is no ROI for anyone to produce them.

Ed

[SandyEggoJake]

Agreed.  But I designed a C:55 tie plate any way.  Figured if I ever professionally print any of my PE designs and have some excess space, might toss a few frets of such on the margin. 

[ednadolski]

Found this old pic of the C40 rail with wood ties and P87 Stores N-scale tieplates.  Only thing holding them in place is the paint