Over this last weekend, I converted one in the set of four Roundhouse Overton
34' passenger cars to narrow gauge. I don't know if this has appeared in the
MRR magazines, but I thought I would share this with my fellow Nn3ers. The
short answer is: it was relatively easy.
According to the Narrow Gauge Data Book, the Overtons are actually shorter than
what most ng lines operated with, but it seems that as most ng railroads were
bought and sold, things got mixed, rebuilt, and for me that's good enough reason
to have something that is close. For the price (around $6), these are easy
conversion and if need be, two can be chop into one longer unit (maybe even
three into two).
General Description of Roundhouse's Overtons:
The cars, out of the box, require some assembly: rod and truss are to glued in,
three brass weights are to installed, and the trucks are to be assembled and
installed into the frame. The bottom black frame is removable with two of the
three brass weights installed between the frame and the bottom the car body. An
inner clear plastic box (i.e.,. the windows) is removable from the car body for
the final brass weight to be install in a small recessed cavity on the
underside.
Unfortunately, the interior floor level is only 1-2 mm below the windows: so
much for real seats. The roof, as well as all parts, are simple friction fits
and can be pulled apart quite easily.
Overview:
Judging by the average width of the cars in the NG data book (just a little over
8 feet), the cars need to skinnied by about 0.1". Your mileage and accuracy
will vary. There are three main items to modify: the frame, the body, and the
roof. Then the installation of Nn3 trucks and Nn3 couplers. Last but not least
are the weights and windows of which you may decide to throw away and replace
with your favorite materials. Although the following is a *general*
description, it will help greatly if you have a disassembled car in front of
you. I cannibalized a Micro-Trains undecorated gondola car for trucks, pins,
and the couplers, but new ones can be purchased.
The Frame:
There are at least three ways to skinny up the frame. I'm sure others will find
more methods or better reasons to modify the car in other ways. I opted for the
simplest method with less chance of error or mis-alignment in reassembling.
There just happens to be a 0.1" gap between the two main beams, the exact amount
needed to be removed. This requires one cut and some sanding until the waste
material is flush with the inside each beam, although this results in one big
fat beam when glued. (Most of my friends wouldn't know the difference ;-)
Using ACC, the floor halves were firmly jointed while making certain both pieces
were level to each other. New holes for the truck pins were drilled to match
the existing holes from the MT frame. No additional cutting nor trimming of the
bolster was needed for free pivoting of the truck (about +/- 30 degrees).
Other ways to reduce the width of the frame is to remove 0.05" from both outside
edges of the frame, but this has numerous interference problems with the steps
and hand rails when cutting. Or one can remove 0.05" from just outside the two
frame beams which involves cutting the frame into three longitudinal pieces.
Again, problems mention before and with reassembling the frame for flatness.
The Body:
When viewing the ends, the car ends have either one door and no windows or one
door and two windows on each side of the door. On the "one door" end, simply
remove 0.05" of material from both sides of the door.
On the other type of end, it's a bit tricker. The windows are relatively close
the corner edge of the car and does not provide amply room to remove 0.05" of
material. However, between each window and the door there is enough distance -
provided that the inner vertical window sill is also removed. Cutting and
removing material at this location also helps to disguise the joint because it
is away from the (more) visible corner edge of the car.
Care, precision, and ample time should be used in cutting car as it is the most
visible thing you can mess up (guess what I did?). The exterior of the car has
vertical clap boarding which can be used as alignment in cutting. The car body
slices should be dry fitted onto the frame for accurate trimming and alignment
before gluing the pieces together.
The Roof:
The center raised roof section, according to most drawings, is the correct
width. Only the lower outside roofs need to be reduced. The roof is normally
held onto the car by two long longitudinal tabs running the inside length of the
car. Fortunately, the outside edge of these tabs mark the new edge of the roof.
Using this outside edge of the tab as a straight edge, a knife blade can score
and cut the roof. Special note: both the tab and the roof will need to be
remove. Unfortunately, one edge is the cutting guide for the other. Therefore,
before the roof is completely trimmed off, use the roof edge itself to score a
line along the tab. (This is where you need a real roof in front of you, trust
me.) Complete the newly cut roof edges by rounding the edges with a sanding
block.
The Couplers:
The couplers were attached by drilling and tapping into the platform using MT's
drill bit and tap from their coupler kit. The screw, when completely inserted,
stops flush with the upper visible surface of the platform (hmmm, like MDC was
thinking ahead!). A dab of paint is all that's needed to hid the screw end.
The knuckle is just a bit lower than normal (as compared to another MT car - I
don't have a coupler height gauge yet) by about one half of a coupler "hose"
diameter. With minor tweaking of the hose height above the rail, it works just
fine.
Miscellaneous:
The weights need to be trimmed to fit, but even with all the supplied weight, it
is still less than the recommend NMRA standards for standard gauge N scale.
Again, do as you see best.
Final thoughts:
Although I have not painted nor decaled it yet, it rolls, pulls, and pushes just
fine. An enjoyable project for an evening (perhaps not including painting) once
you get the hang of it. On the other three unmodified units, I might try
different narrowing technics just to ensure I'm not missing the obvious. Good
luck, worth the price of trying.
Addendum, Nov 4, 1997:
Many moons ago I wrote a short article on how to convert over the N scale
MDC's Overton 34 ft passenger cars to Nn3. I thought I would update it
with a new finding.
In my conversion I used freight trucks and it seem to set the car at the
correct height for couples. However, a fellow Nn3 email list member
indicated he had some differences in height (but I can't remember if he was
using different trucks). Last night I received several Nn3 passenger
trucks (MT #904) and tried them out and discovered several big problems.
First, the 904 trucks raise the car by at least one millimeter. Although
the wheels look to be bigger in diameter (it was late last night and my
eyes weren't working too well), the truck itself has a higher upper surface
which when the bolster pivot point sits on it, the car body height is
raised. The solution is to remove the (raised) bolster block.
Unfortunately, the 904 trucks are longer, requiring you to move the pivot
point back about 1.5 mm, otherwise the trucks interfere with the steps.
This requires new mounting holes for the truck pins. And now that the
trucks are moved back, the outer wheels hit the remaining bolster beam, so
it too must be completely removed.
To make matters even move frustrating, to compensate for the taller trucks,
you must also remove material away from the bottom the main (longitudinal)
beams. This is a trial and error by filing away material - careful, too
much and the car will sit too low !
If you're with me so far, you'll find that the car looks funny. It's a
short car with two (very) long trucks under it; about half the car length
has trucks. Also, the rod and truss can not be installed as supplied.
More work. . .
On a personal note, I'll just use freight trucks and not stare too hard as
my trains passes by.
Tobias Giles
Mtn. View, CA
USA
More Notes:
Garth Hamilton adds the following notes:
In my conversion I used the 904 trucks and took the 1mm from the bolster block
and then trimmed the edge of the truck and the back of the stair frame to
allow the truck to swing with out any difficulty. The interference is not
very large and chamfering the upper end of the truck will allow it to clear.
Another alternative is to use the Nn3 passenger trucks cast by RLW as they
are slightly shorter in length.
Garth Hamilton
Ontario, Canada
nn3@ve3ho.com