Re: 3D printing- want to see one?


Charlie Vlk
 

Bill, Gordon and List-



Gordon is correct..the commercial shops are currently at a level that one
cannot just submit a 3D model and routinely expect acceptable results.



N Scalers like Gordon are on the leading edge of using this technology and
also have rather high expectations.



Complete freight cars, locomotive shells with truck frames to be placed on
commercial mechanisms, trucks, vehicles, scenic details and other goodies
abound on Shapeways.and that is only one place where some very interesting
work is being printed.



Some of the available projects print out very well.I had a replacement roof
and seat pan for a Kato prewar coach that converted it into the CB&Q
"Pattern Dome" cars and I was very pleased with the resolution of the small
roof corrugations, etc.. There was a shrink factor that impacted the
overall length but that was easily compensated for on the model.
Previously a friend who owns a "Prefactory" .a higher end machine that
yields more precise parts than most service bureaus use.who printed a CB&Q
SM-16 composite stock car for me which was done as one piece from roofwalk
to body bolster, with all brake components, freestanding and clear space
between slats and hollow interior. It was done to exact scale so could not
be fitted with trucks and couplers for operation but showed that the process
could yield results that hard tooled injection molding could not easily
duplicate.



I've also had some of Eric Cox's excellent early era truck frames... The
CB&Q No.7 Waycar truck needs only painting; the recommended wheelsets pop
into the frame just like a commercial injection molded part and they roll
very freely. He has an entire range of early (pre-and post-Civil War) wood
and early steel freight car trucks and freight and passenger car bodies and
even link-and-pin couplers.

All this in N Scale.and with resolution superior to resin parts cast from
handmade patterns.



Yes, flat surfaces in certain build orientations are a problem, as are
gently curved surfaces where you get "rice paddy" build layer contour lines.
The build process orientation of the model in the machine can make a big
difference in the results and you do not have much control over how the
bureau does it.. you pay for whatever part they print and sometimes it takes
adjusting parts and combining them in groups to fix non-printing and poorly
printed aspects.



Clearly, the technology is rapidly (sorry for the pun) evolving. It is,
however, at a point that makes it worthwhile for those of us that have an
interest to develop our skills in creating 3D files and begin to try the
process of creating models using Rapid Prototyping Service Bureaus. The
day will surely come when the technology and costs make it reasonable for a
Hobbyist to have a desktop machine in the basement for personal use. When
that happens there will be a community of designers that will be ready to
crank out whatever models that can be created on the screen..and hopefully
we will also develop a way of trading component files that will capitalize
on the modular and common parts of cars and locomotives.



Today the process isn't for everyone, but it is a exciting new aspect of our
Hobby and Bill is correct that it certainly would be worth presentations at
RPM events. It certainly addresses the need of RPMs for specific prototype
models (with variations) that have no reasonable expectation of being made
as hard-tooled commercial products.



Charlie Vlk

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