-----Original Message-----
From: Brian Chapman <cornbeltroute@...>
To: STMFC@...
Sent: Sun, Jul 12, 2009 1:13 pm
Subject: [STMFC] Re: Critiquing Pre-production Models?










Thank you for the interesting comments. . . .

I have a self-interested reason for asking the question, and I believe prototype
modelers have a self-interested reason for making suggestions (we both want
accurate models).

I have formed a business association with a friend who is an experienced
pressure resin-caster. He has a new laser cutter with which he's getting up to
speed and new spin-casting equipment, too (resin and metal casting capability).

Myself, I use 2D CAD/CAM and 3D software to draw model items precisely (the 3D
software works wonderfully to ensure that the master parts to be cut fit
together accurately). I am experienced, too, at creating double-sided
photo-etching artwork. The 2D drawings generate G-code to operate my CNC mill
and CNC lathe. Within the next year I expect to upgrade my CAM mill software to
3D cutting capability. Also, I expect to use the 3D software to test 3D printing
capabilities, too.

The laser can vector cut with a cutting beam about .003" diameter. Often, I have
cut with a .005" diameter end mill (about twice the diameter of a human hair) on
the CNC mill (brickwork looks fantastic, in my biased opinion). So, between the
two of us, we not only believe we're well equipped to create fine-scale models,
we're anxious to get going on our devised plan of operation. But. . . .

I am a rivet-counter nit-picker type of personality. From a variety of sources
(outstanding multiple photos and manufacturer brochures, modeling articles), for
example, I have been able to 2D and 3D draw (and test cut many parts) of a P70
PiggyPacker. There is one area of the vehicle, though, for which I have no
information. And, perhaps none can be had (after searching laboriously, I have
been unable to find an existing P70 vehicle).

I hate to commercially issue this intermodal lift vehicle without that
information, it grates on my sensibility for accuracy. OTOH, intermodal modelers
might wish to have the option to purchase it since it might be the most accurate
model to be had. A dilemma. How would prototype modelers here suggest that a
manufacturer in my, uh, boat, proceed?

Along this same line, I've been highly intrigued by Ray Breyer's comments about
the short NYC offset side twin hopper. (Hey, Ray, are drawings available?) I
have Karig's "Coal Cars" book, CBC cyclopedias, tons of articles with hopper
drawings and construction methods. I'd like to give the car a shot (and not just
in HO scale).

But, how to overcome the inevitable drawing and/or cutting errors? Are modelers
here on the list saying, "Have at it, after you've released the kit, we'll tell
you what's wrong with it"?

I had some idea that I might be able to upload screen shots of the 3D art and
invite critiquing before moving on to CNC cutting, but pilfering by another
model manufacturer is the likely result of this approach, I take it. Perhaps,
then, lists such as this one, populated by individuals with extraordinary
knowledge about historical freight cars, must remain untapped. Is this so?

BTW, I do wish to say that I'm a passionate hobbyist. A love for the hobby goes
hand-in-hand with my desire to produce prototype models with all the accuracy it
is in my power to create. The question I am attempting to answer for myself,
though, is how best do I do this?

Thanks much,

Brian

Brian Chapman
Evansdale, Iowa




------------------------------------

Yahoo! Groups Links