Re: 10K Gallon AC&F Type 11 tanks


feddersenmark
 

Rob, The link to the photos is in message #67493. I thought you said
you were considering using .001-.008 brass, so that's why I
suggested .005 styrene. I should mention I use clear styrene, as it
is more dense and doesn't "melt" as easily and the rivets hold up
better. I had no problem with a snug fit of the collar. Email me for
details. Mark





--- In STMFC@yahoogroups.com, Rob Kirkham <rdkirkham@...> wrote:

Thanks for the tips Mark - I'll track down that article of yours.
For all
the criticism one sees of things MM, it still remains the magazine
I most
enjoyed - and it was for articles like that.

I am using the brass shim stock rather than the .005" styrene for a
couple
of reasons: 1) I don't like the way the rivets settle back down
into the
styrene after a while and am not very skilled at filling them from
the back
to prevent this. That's mostly on account of a lack of patience as
it
doesn't seem difficult! 2) the thinner brass will give (in my
opinion) a
lesser step up from one panel to another - more in scale with the
prototype
appearance I think. .005" styrene (which is my usual material)
felt too
thick for that purpose on this particular model.

I have been wondering about the dome collar. I am concerned about
getting a
really nice snug fit. I'm willing to use filler if need be, but
hope it
isn't necessary.

Do you have a link to your Naperville photos?

Rob Kirkham
----- Original Message -----
From: "feddersenmark" <feddersenmark@...>
To: <STMFC@yahoogroups.com>
Sent: Monday, April 28, 2008 11:26 AM
Subject: [STMFC] Re: 10K Gallon AC&F Type 11 tanks


Rob, I wrote an article for the July 1988 Mainline Modeler that
describes how I constructed domes for a two compartment GATX car
made
from two Tichy cars. The technique can be used to construct almost
any diameter dome out there. You should be able to easily scale
the
diameter of the dome from the AC&F drawing. Why not use .005
styrene
for the wrappers rather than brass? Much easier to work. I did not
describe how I created the dome collar, but it is very
easy...contact
me off list if you need help. You may also want to look at the
photos
of the 2007 Naperville meet..four tank cars I did are shown.
Mark






--- In STMFC@yahoogroups.com, Rob Kirkham <rdkirkham@> wrote:

Guys - thanks for the input. Here is what I have done:

Using the AC&F drawing at p.219 of the Kaminski Tank Cars book, I
took a
pair of callipers to the individual panels and found (taking
overlap into
account) that the actual sheets of steel were the same width or
so
close I
couldn't detect the difference. I then assumed from each rivet
row
centre
line to the edge of each sheet was 1.5". That led me to subtract
3" from
the overall cylinder length (3.855" - .0344") and divide the
result
into 5
equal length sections, each .764" long - the space between centre
lines of
the rivet rows.

On the cars I am modelling (CPR OCS) the courses, working from
one
end to
the other, are as follows:
a - overlaps the tank ends and the next course toward the
centre -
so two
rivet rows - one either side of the course - add 3" or .0344".
b - overlapped at both sides by adjacent sheets, so no exposed
rivet rows -
subtract 3" or .0344"
c - the course with the dome - overlaps the adjoining course on
both sides,
so two rivet rows - add 3" or .0344"
d - like b
e - like a

In the result, courses a, c and e are modelled .798" wide, and
will
be
wrapped around an unriveted cylinder which models courses b and
d.

The execution is less than perfect because its hard to trim the
riveted
sheet brass (.001" or .0008"? - I can't measure that fine very
well) so
close to the rivet rows, so I will have to work on fixing that
some.

Thanks to Garth's observations about the dome, I have so far
avoided the
next error - a too large dome. I had missed that fact, and was
thinking I'd
use the Type 21 dome off P2K. Now its back to the drawing board.
Fortunately, my plan is to make the centre course without a hole
for the
dome, and cut it to fit once in place on the car, using the dome
itself as a
cutting guide and the riveted collar to hide the joint.

Too bad the drawing lacks a dome diameter! Help! I'll probably
do
something with proportions from a photo to model it.

Rob Kirkham


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