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1. Q: Are all carbon fiber parts brittle and therefore extremely
fragile? |
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....A: This is a common misconception.
No, Dream's properly made carbon fiber parts are not fragile.
Please see the videos on this
page as a vivid illustration of just how rugged Dream's
advanced composite parts are. Also keep in mind that Dream's
composites are inherently resistent to moisture/humidity, are
non-corrosive, have a low CTE (low thermal fatigue) and are quite
chemically resistent. Because we cook each part in one of our
ovens, the parts are also stable at higher temperatures. |
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2. Q: Do all carbon fiber parts vary in mechanical performance
from part to part, making them impossible to use in high-performance
opto-mechanical systems? |
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....A: We've heard this comment
and the next (3.) many times over the years. Most of the time
it is coming from companies that are using conventional materials,
like metals, to produce their products. They lack a deeper understanding
of composites in general, but also process controls and the specific
materials and methods that we use to fabricate our parts in-house.
Dream started as an advanced
composites company with a keen eye on optical systems. We
are the only company that has a deep understanding of optics
and a deep understanding of composites. Bringing the two together
has allowed us to focus on methods that are highly consistent
from part to part. A 16
pound bio-medical product that we have been producing for
the past 2.5 years varies in resin (epoxy) content by less than
1.5% (25 grams of epoxy). |
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3. Q: Do all carbon fiber parts vary in Coefficient of Thermal
Expansion (CTE) from part to part, making them impossible to
use in high-performance opto-mechanical systems? |
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....A: As stated above Dream has
always had optical systems in mind for the composties. We are
not a general composites company that is trying shoehorn our
composites into precision optical systems. We can produce a part
today, then again two years from now with extreme consistency
in the part, both mechanical performance (question 2. above)
and CTE (question 4. below). They typically coincide with each
other (mechanical and thermal), although mechanical properties
and thermal properties are two completely different attributes
of a part. We document each part that is made. Logging all data.
Without proper data there is no quality assurance. |
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4. Q: Do all composite parts have resin-rich areas that will
have a wildly different CTE than other areas, therefore causing
the part to distort, which will in turn cause either optical
alignment errors and/or focus shifts? |
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....A: From day one Dream has always
used the following; vacuum bagging, paid especially close attention
to fiber orientation & resin content, high-temperature epoxy
that is specifically engineered for an ideal match to opto-mechanical
systems, and Dream has detailed Quality Assurance and Quality
Control (QA & QC) methods in place. It is therefore technically
impossible for Dream's advanced composite parts to have a wildly
different CTE. Full vacuum is applying roughly one ton of pressure
per square foot on the part. A part with 6 square feet of surface
area has roughly 6 tons of pressure being applied across that
surface. Unlike a press that inherently will have "hot spots"
(higher pressure and subsequent lower pressures), properly executed
vacuum bagging will produce the same pressure across the entire
part, regardless of it's shape. |
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....Dream has been producing advanced
composite parts for opto-mechanical clients since the company's
inception in 2003. Our methods have changed very little since
the beginning. Our materials have not changed at all. We have
always used the same high temperature epoxy, cooked in one of
our composite ovens. Although ignorance tries to argue that what
Dream has done, can't be, our
products and the 3/4 decade of shipped parts and finished
instruments prove otherwise. |
