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RE: (erielack) Superelevation - cant deficiency



This has been an interesting thread.  I have no home layout, so I have experience with the North
Shore Model Railroad Club (as do several other list members . . .).  As a result, I've been involved
with a couple kinds of roadbed construction.

We started with spline.  We ripped lath strips in half, and spaced them with what seems like
thousands of little blocks, about 1/2" x 3/4" x 1".  More clamps than you can shake a stick at.  We
did risers (initially way too small at 1x2) and we vertically drilled the middle spline for a nail
to secure it to the riser.  There are MANY ways to F*** this up.  It's NOT a good way to go.  For
one thing, we had to learn that we had to saw both "halves" of the lath, as they are not all the
same width, so the kind of "unsawed" side was sometimes deeper or shallower than the rest.  Doing
the hold in the center spline made it weaker right at that point.  You have to get the riser at
exactly the right place in the sweep of the curves or you get a kink.  And when you splice a spline,
you get a short straight, or straighter, section.  Sorry Paul B, I really don't like this technique,
after building and laying ties and rail on several hundred feet worth.

There is another technique too complicated to explain, and it doesn't work well anyway.

Lastly, we did something like Joe's version.  For the last 30+% of the layout, I drew the whole
d*****d thing with AutoCAD, and we printed it out full size.  I broke up the various sections into
pieces that would fit on a 36x96 plot (I didn't have access to a 48" plotter), with match marks so
we could put the pieces together later.  Glue the plot on the plywood and have at it with the saber
saw, being VERY careful at the ends of the various sections.  It is a matter of insufferable pride
on my part that when we got to a closure point of the line, having built it from both ends toward
the middle, the last piece fit in  Just...Like....That.

We supported all this on risers, like Joe, but instead of securing the plywood directly to the
riser, we used a piece of 1x3, which with many many clamps (we already had them remember?) we would
move things around until they were Just Right.  Right in elevation, right in horizontal location,
and right in superelevation.  Once we'd achieved Justrightness, then we'd screw everything together.
Risers were 1x4, generally, with everything on an L-girder "table".   We used a rotating laser level
as a way of establishing grades, which I had figured out on CAD, and labeled the plan as it was
drawn.

We had one interesting learning experience.  One member was responsible for buying the plywood.  He
bought "certified plywood" at Home Depot.  We had about 40' or so of roadbed built when we began to
have some Very Strange Problems.  Most notable was when our chief (not to say only) tracklayer
noticed that one of the (electrically necessary) gaps he'd left had closed up.  He Dremeled it out
with an abrasive disk, and as he put the Dremel down, he heard this very loud "TING!"  He glanced at
the gap, and the rail had moved, audibly slamming together to close up the gap.  It took four times
Dremeling it to get it to stay open.  We started looking at things a lot, and found the shrinkage in
the plywood was so significant it was pulling some risers out of vertical!

Two of us did independent research into plywood.  Picture a Gomer Pyle type at the end of the
plywood production line, saying every couple minutes "Gosh, yup, that there shure is plywood, I'd
know that stuff anywhere!!" and he whacks it with a stamp saying "CERTIFIED PLYWOOD."  That term
means nothing.  What does, is DFPA (Douglas Fir Plywood Association) certification, and "cabinet
grade."  We ripped out the certified stuff, and switched to Cabinet Grade Birch Plywood, certified
by DFPA.  (there is another worthwhile certification agency, but I forget what it is.)  This has all
internal voids filled, and is made with kiln dried wood, so it's dimensionally stable.

Oh, one last thing: we used finger-jointed primed trim 1x4 and 2x3, which was not cheap, but it
doesn't warp.  Well, it's cheap in the long run . . .

SGL

> -------------- Original message --------------
> From: "Joseph A. Braun" <joebraun_@_optonline.net>
> 
> > [Original Message Tupaczewski, Paul R (Paul) Sent: Tuesday, September 30,
> > 2008 9:03 AM
> > >Jeff Mutter told me of a novel approach he uses - strips of
> > >masking tape! To make the track higher, just keep layering on
> > >more masking tape.]
> >
> > I will make this modelling thread totally relevant by declaring that we are,
> > of course, modelling only the DL&W, Erie, and/or EL!!
> >
> > Jeff's masking tape technique for super-elevation is a terrific variant with
> > wide applicability.
> 
> Thanks, guys, but I have to give proper credit....I stole the idea from Bob Willer :-)
> 
> I use 1/4" wide masking tape, layered from the start of the easement transition.  Offset the start
of each successive layer
> to get a smooth transition into the superelevation -- I found between 1 and 2 inches works best.
I use a digital level to
> determine when I have enough superelevation, but usually about 12 to 13 layers does it.
> 
> As an aside, I used masonite spline for subroadbed and homasote roadbed.  The masonite was glued
together using
> industrial-strength hot glue, and goes together quickly.  The downside is that you must sand the
top to get a smooth
> surface.  Unfortunately, that sanding combined with the uneven thickness of homasote, creates lots
of opportunities to
> perfect your shimming technique (and your langauge skills).
> 
> It also makes installing the superelevation challenging.  I initially tried using stripwood as has
been suggested, sanding
> the ends into a smooth transition, but once track was installed, the variations in roadbed created
enough irregularities in
> the track that I had tracking problems with longer cars.  Using the digital level to measure the
actual superelevation, I
> was able to fine-tune the numberof tape layers to accomodate the roadbed irregularities.
> 
> Jeff Mutter
> 
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