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1.
What technologies and processes are available at Harvest Technologies? |
We use many different processes to quickly produce prototype
parts. Some of the common direct-use technologies are SLS (Selective
Laser Sintering), SLA (Stereolithography), CNC machining, FDM (Fused
Deposition Modeling), Thermojet, and 3D
Printing. Some widely used indirect processes are RTV tooling &
urethane casting, metal casting, sheet metal fabrication.
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2.
What materials are available at Harvest Technologies? |
There are many materials available via different rapid
prototyping technologies. The
choice is usually dependant on the particular application you are
using the part(s) for such as concept models, functional prototypes,
presentation models, casting patterns and end-use parts. Materials
vary greatly in strength, durability, rigidity, flexibility, fine
detail, optical clarity and surface finish. Some of the rapid prototyping
materials that are currently available are epoxy, nylon, ABS, polycarbonate,
polypropylene, steel/bronze and wax.
If you are unsure which material is best for your particular
application, Harvest Technologies will gladly assist with recommendations
based on your requirements.
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3.
Which process(es)
and material(s) should I use for my project? |
Each rapid prototyping technology is well suited for most
applications, but not all. This
is why Harvest Technologies offers you multiple choices. You should choose the process and/or material
that best matches your needs for dimensional tolerancing, durability, rigidity or flexibility,
temperature range, feature detail, surface finish and price for
each project. Your priorities
for performance and aesthetics should determine the selection, not
a service provider's desire to maximize their profitability. If you are unsure which material is best for
your particular application, Harvest Technologies will gladly assist
with recommendations based on your requirements. back to top |
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4.
What are SLA and SLS and how do they work? |
These rapid prototyping technologies each build 3D
objects-prototypes, patterns, parts and tooling- layer by layer.
In SLA a laser photocures epoxy resin
and in SLS a laser sinters (or fuses) thermoplastic powders to form
an object. back to top |
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5.
How large or small of a part or feature can you build? |
There are a variety of rapid prototyping technologies
with different platform sizes. SLA build envelopes are as large
as 20X x 20Y x 23Z and SLS as large as 13X x 15Y x 18Z. Building
parts larger than this can be accomplished by assembling and fusing
multiple sections together. back to top |
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6.
What is the dimensional accuracy of SLA & SLS? |
Dimensional accuracy in rapid prototyping can vary between
processes and materials, but in most cases can be adjusted to fit
the needs of the customer. In general, tolerances for SLA are +/-
.005" and tolerances for SLS are +/- .3% with a minimum of
+/- .005" on features and parts 1" or less in size.
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7.
How do you make metal RP parts and tooling inserts? |
An SLS metal part is made as follows: (A) build a "green”
part on the machine by fusing powdered steel particles with a polymer
binder material; (B) in a furnace cycle the binder is burned away,
the steel particles are lightly sintered and molten bronze wicks
into the resulting pores forming a fully dense steel/bronze object.
Most other metal parts are created by casting in temporary tooling
created from a pattern master made on a rapid prototyping apparatus,
or by machining objects from a block of bar stock.
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8.
How durable and functional are RP materials? |
Rapid prototyping materials range from highly durable and
fully functional to weak and brittle. Many SLS, CNC machined and
cast plastics and metals are comparable to or equal to production
materials in strength and functionality. The more fragile materials
are more commonly used as concept models or consumable patterns
for casting.
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9.
Can these materials be used for end-use parts? |
Depending on the application, you can certainly and this
is becoming more common. Typically small complex parts that don't
have stringent cosmetic and/or dimensional tolerancing
requirements, as well as parts that are difficult or impossible
to tool conventionally are the best candidates for rapid manufacturing.
Normally this is cost-effective for quantities of less than 1000.
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10.
Can RP parts function in waterflow and
airflow testing and are they resistant to solvents? |
Several of the RP materials can be used for waterflow and airflow testing without leaking. Some of the
materials must be infiltrated or coated to achieve this and some
are classified as solvent-resistant. Of course the specific solvents
and time of exposure are key to a material's
performance.
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11.
Can RP parts have functional living hinges? |
SLS DuraForm PA and fine nylon, as well as the elastomeric Somos 201, can flex enough to function as a
living hinge. At Harvest, we have perfected techniques for certain
rapid prototyping materials to further enhance the flexibility and
repeatability for “living hinge” applications. However,
some hinge geometries do better than others.
Crimped hinges that concentrate stress in a small area tend to not
do as well.
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12.
How smooth of a surface finish can you provide? |
Almost all rapid prototyping materials can have surface
finish and cosmetic improvements made to them. Both SLS and SLA
can be sanded, filled and painted to look like injection-molded
plastic. Surface texturing can even be applied if time and budget
allows. Most parts, however, do not require high level finishing,
and are simply sanded and bead blasted. This creates and nice surface
finish that is excellent for engineering purposes.
At Harvest, we provide a sanded, improved surface finish
on all of our parts at no additional charge.
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13.
Can you make parts in different colors? |
Most rapid prototyping technologies do not allow for much,
if any, color options in the actual building process. However, prototyped
parts can usually be dyed or painted, even color-matched in some
cases, to a customer's specifications.
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14.
What RP materials have high heat tolerance? |
Most rapid prototyping plastics with higher heat tolerance
are from the SLS and CNC technologies. SLS plastics have a melting
point of 184 C (365 F) or more, and Ultem,
an amorphous polymer, has a Tg-Glass Transition
temperature of 215 C (419 F). There are some temperature resistant
SLA materials, but they tend to have very little elongation and
are thus somewhat brittle. At
Harvest, we are experimenting with some new materials that will
have very high heat tolerance.
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15.
Are there any non-toxic RP materials that can be sterilized for
medical use? |
The SLS DuraForm PA can be sterilized via autoclave and
has received USP level VI certification
for brief in-vivo exposure while serving as surgical devices. There
are also some material options with cast
urethanes (RTV) that are FDA approved.
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1.
What is rapid prototyping (RP)? |
In general, rapid prototyping (RP) is defined as
using a technological process to produce 3d objects in a short period
of time--usually days rather than weeks. Most RP machines create
3d geometries by growing them layer-by-layer, but high-speed CNC
machining--a deductive process--also meets this
criteria in certain applications. back to top |
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2.
What is rapid tooling (RT)? |
Rapid Tooling (RT) is general
terminology for using a technological process to rapidly produce
mold inserts for injection molding of plastics and casting of metals.
Most rapid tooling is created in 2-4 weeks rather than 4 or more
weeks, and is best-suited to limited run quantities of 1 to 100,000.
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3.
Where can I get more information about rapid prototyping and rapid
tooling? |
Please look under Process & Materials
on this website and you will find more information. We will also gladly offer assistance in answering
your questions and/or providing you with additional data and samples.
If we don't have an answer readily available, we can usually get
one or provide you with a referral in a short time. back to top |
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4.
How do I get a quotation from you? |
To provide an accurate quotation we need to have STL files
for all parts that are to be built, detailed information about the
performance requirements of the parts and a good understanding of
your expectations. Although we do not prefer to give estimates without
this type of data, we sometimes can give you a ballpark idea of
what to expect based on drawings. back to top |
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5. How much does rapid prototyping and/or rapid tooling
cost? |
Unlike commodity goods and services RP and RT pricing cannot be factored by size, weight or billable
hours. Additive-layer rapid
prototyping systems factor a combination of machine hours, material
consumption and post-processing labor to quote production of a 3D
object, be it part, pattern or tooling. The greatest economy is
found in building batches of parts rather than one at a time. Many
times it doesn't cost a lot more to produce several parts than just
one. CNC machining quotes are primarily based on programming time,
part complexity, build time, materials and post-processing labor.
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6.
What are your lead-times? |
Our standard lead-time delivery for SLS and SLA jobs is
4 working days, but quantity, size and post-processing can affect
the lead-time. CNC machining, casting and rapid tooling usually
takes around 10 days to 3 weeks for delivery of the first articles.
We always strive to accommodate those who need an expedited delivery.
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7.
Why does pricing vary from service provider to service provider? |
There are many variables in quoting rapid prototyping:
the technology used, sizes of machines,
materials, build styles, quality levels, etc. As a quality-focused
service bureau, we have been pricing our parts the same since the
mid 90's when we started. Our customers appreciate this consistency
and the fact that we don't raise prices when we're busy, or drop
them when we're slow. We strive to provide our customers with the
best value, and are willing to work with them to meet their objectives
without breaking the bank. back to top |
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8.
What file format is needed to build a part or tooling? |
Generally the STL format is required for rapid prototyping
technologies and IGES is the preferred format for CNC machining.
Virtually all up to date CAD software allows the user to output
these formats. If you are unable to do so, we can assist you either
with in-house translation software, or by outsourcing from a CAD
service provider. back to top |
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9.
How do I send electronic data files to you? |
The most commonly used methods of sending data to us are
as follows: - Our Website RFQ System (http://www.harvest-tech.com/rfq/)
- E-mail (harvest@harvest-tech.com) - FTP (Browser: ftp://ftp.harvest-tech.com/incoming/)
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10.
How do I output STL files from my CAD software? |
In today’s design environment, there are many
CAD software programs and each one has its own specific way to output
STL files. It is essential that you select a fairly high-resolution
setting when outputting STL files so the rapid prototyping machine
will build models that properly produce the geometries you desire.
If you are unable to output an STL file from your software, seek
assistance from your CAD software vendor or we can assist you in
outsourcing CAD services from one of our vendors. back to top |
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11.
How can I be sure that my design and intellectual property is secure
with you? |
We work with confidential data, most of which is
not fully protected by law, on a daily basis.
It is essential that we operate in a secure and restrictive
manner. We are willing to sign a non-discloser agreement (NDA)
and/or non-compete documents when required
by customers. We operate with the understanding that your trust
and confidence must be assured for us to be in business.
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12.
What industries and applications does Harvest Technologies serve? |
We work will all types of product industries – any
type of company that designs and/or manufactures a physical product. However, most of our rapid prototyping services
are sold to the following industries: design & engineering,
R & D, consumer products, electronics, aerospace, automotive,
robotics, appliances, telecommunications, orthopedics, healthcare,
dental, foundry, oil & gas, petrochemical, toys and plastics.
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