Hi, my name is Faye Stenack and I have been the office manager at ProtoCAM for four years. I remember the first time I walked in the front door at ProtoCAM and found myself totally amazed at the complexity and variety of parts that were produced on the stereolithography machines. I felt like I had just stepped into another world that I never knew existed. Instantly, I knew this was the right job for me and where I wanted to work every day...that has not changed. I am still excited to be a part of the ProtoCAM team. We all have the same objective which is to provide quality parts and service to our customers in a rapid fashion.

I recently had the opportunity to attend the MDM East 2008 Trade Show in New York City at the Jacob Javitz Center. I was astounded by all the different companies that exhibited and the products they displayed. It was quite an eye-opener and a wonderful experience. It was so nice to finally meet some of our existing customers that you usually only get to talk with via e-mail or on the telephone. The positive comments that were shared proved to me that we are doing a good job and listening to the needs of our customers and giving them the quality and service they deserve.

ProtoCAM is a very people-oriented environment and I would encourage you to give us a call or send us an e-mail with your concerns or requests. I feel confident you will become one of our satisfied and valued customers that keeps coming back project after project, too!

ProtoCAM will be exhibiting at Atlantic Design & Manufacturing tradeshow next week, June 3-5, 2008 at the Jacob K. Javits Convention Center, 655 W. 34th St. (West 34th Street at 11th Avenue), New York, NY.


ProtoCAM's booth is number 201 - please stop by and visit us there.

Click the coupon below to view important show information and register for a complimentary expo hall admission - a $55 savings.

When screwing your prototypes together, using the proper technique is critical. Tapping the hole is an option, but the threads can wear relatively quickly in certain prototyping materials. Using self tapping or thread forming screws should be avoided with most prototyping materials, because these fasteners can crack or damage the prototypes. Threaded brass inserts work well when the prototypes must be assembled and disassembled multiple times.

ProtoCAM can assist with the installation of threaded brass inserts into our stereolithography prototypes, as well as SLS nylon prototypes, Polyjet parts, and cast urethanes. There are two types of inserts that can be used in our prototypes, standard and expandable threaded brass inserts. Choosing the correct insert for your application is critical. Please make sure the holes are designed per the tables below.

Standard Inserts

The standard threaded brass inserts work well with all types of prototyping materials, especially SLA prototypes. The inserts are installed into the prototype with an adhesive. Keep in mind that these inserts are only held in by epoxy glue, and should not be used for high torque applications. Recommended minimum wall thickness around the insert is 0.060”. For high torque applications, it would be best to contact ProtoCAM's engineering staff for recommendations. See the chart for the design guidelines when using the standard threaded brass inserts.

Expandable Inserts

The expandable threaded brass inserts works great with durable prototyping materials, such as urethane castings. These inserts are pressed into an undersized hole. As the machine screw penetrates the insert, it expands slightly. This expansion allows the insert to bite into the sidewalls. Recommended minimum wall thickness around the insert is 1/2 the hole diameter, or a minimum of .060”. These inserts provide a slightly higher pull out force, when compared to the standard inserts. For high torque application, it would be best to contact ProtoCAM's engineering staff for recommendations. See the chart below for the design guidelines when using the expandable threaded brass inserts.

Ryan Schmidt
Engineering Manager
rschmidt@protocam.com

One question that I get asked on a regular basis is "How large a part can you build?" Rapid prototyping machines have a fixed size, and many of them have a relatively small area where they can build parts (their "build envelope"). Our largest machines, the SLA-7000s, have a build envelope of 20" x 20" x 23", but this doesn't limit the size of the parts we can deliver. By sectioning your CAD model into 20" x 20" chunks, we can build parts of any size.

When we receive a large part for quotation, we cut it into sections in a way that minimizes cost. The typical factors we consider are total height of the platen (if you don't know already, we use height and volume to estimate cost, and we adjust that based on part complexity), number of platens, and number of cuts. We then price it based on the machine's run time and finishing/gluing time, so you get a quote with the information you need to know -- how much it will cost you, and how quickly you can have it.

Once you give us the job, we go back and cut the part again, this time adding lap joints for strength. This step allows us to produce a part that is very strong along its seams, and that can be positioned back together accurately. For parts with complex cutting requirements, this step may be responsible, partly, for any additional lead time (beyond our typical 2-day turnaround) that you were quoted.

After the parts are cut in CAD, they are prepared for build in the 3D LightYear package, a proprietary software package built for stereolithography machines. This step comes up with the set of instructions that the SLA machine uses to build. (Conceptually very similar to the G-code used to run CNC machinery.)

Once finished, the parts are drained, removed from the perforated metal platen, separated from their supports, rinsed of excess resin, and cured in a UV oven. After this step, the lap joints are sanded so the parts can be fit together. Once the fit has been adjusted optimally, the parts are bonded with one or both of the glues that we've settled on using after years of experience. This leaves the seam with excess material and sometimes slight discoloration. The seam is then sanded until it is smooth to the touch. This process is repeated for each piece that needs to be glued together. Often times, our choice of glues leaves the seam stronger than the part.

With this proven process, we can deliver you prototypes of any size, from dashboards to wind tunnel models to tractor seats to chair backs. Large parts require extra care when shipping, but we have great experience doing that, from customers local to us in the Lehigh Valley to those on the other end of the country in California or Washington.

If you have any questions, drop me an email, give me a call (610)261-9010, or leave a comment here on the blog.

Labels: CAD, cutting, large parts, prototypes

What is Durometer?

When new products are being developed, one of the most difficult tasks is to determine the material. Materials are typically selected based on several criteria:

• Association - use material that has been used with similar products.
  
• Mechanical properties - Flex Modulus, Tensile strength, Impact, HDT, etc.
  
• Color - Part needs to be clear – Knowing the color can help to narrow the search
  
• Durometer - measure of hardness in polymers, elastomers and rubbers.

I would like to discuss durometer. Durometer can be a very fast way to narrow your search for a material. Durometer is a value that indicates the hardness of a material, defined as the material's resistance to permanent indentation.

There are several scales of durometer, used for materials with different properties. The two most common scales, using slightly different measurement systems, are the ASTM D2240 type A and type D scales.

The A scale is for softer materials

The D scale is for harder materials

Durometer works together with association.

The chart below relates Shore A and Shore D values with production grade and some common materials

In the Rapid Prototyping industry there are a number of resins that can simulate different production and common materials.

The chart below relates Shore A and Shore D values with Rapid Prototyping resins. The chart is only a guide to help direct you to a material that closely represents your final product.

Durometer is a tool to use when selecting a material for a new product design. It’s one of many tools that can aid in the design and material selection process. Once a design is complete and a material has been selected – ProtoCAM will be glad to produce high quality prototypes.

Ed Graham
Engineering Manager
egraham@protocam.com

As a new employee of ProtoCAM, I'd like to take a minute and introduce myself. My name is Tracey Collins and I have been working at ProtoCAM since November of last year. Some of you may already have spoken to me or received quotes from me.


Working at ProtoCAM has been challenging and fascinating at the same time. The environment is very diverse and fast paced. I love to see how we take someone’s idea and convert it into something you can hold in your hand! One of my favorite things about working here is how well we work together as a team. From start to finish, we all work closely to make your dream a reality. We start the process with a request for quote. Our engineers carefully process your request and then give them to either Faye or myself to format into a formal quote. When we receive your order, either Faye or I will follow through with creating the work order to your specifications and make sure everything is set for production. From engineering to finishing, we all work very closely together to make sure that the process goes smoothly and without interruption.

Even though the pace is hectic, we always find the time to smile and keep the atmosphere fun. The owners help with that too. For instance, the first day of spring Ray made a run to the local Italian Ice shop and we all enjoyed our first Gelati of the season. I’m really looking forward to this summer’s company picnic which will be held at a Reading Phillies baseball game. It will be nice to meet all the family members that I hear so much about.

Whether it’s watching your parts get built or meticulously hand finished, it gives me a wonderful sense of pride to be an integral part of supplying people with such high quality prototypes. I look forward to seeing your idea become a reality!

Tracey Collins

ProtoCAM recently installed Somos® ProtoGen™ O-XT 18420 resin in our SLA-3500. This resin is a general purpose white resin that has ABS-like mechanical properties that offers superior chemical resistance and dimensional accuracy. The resin has high temperature capabilities (208ºF) and produces durable parts that are humidity tolerant.

ProtoCAM also recently installed Somos® Water Clear® Ultra 10122 in our two Viper SI SLA's.
This resin is optically clear, colorless and rigid. This resin also has ABS-like properties and produces accurate parts that simulate acrylic in appearance. This is ideal for applications requiring optical clarity such as lenses, bottles, and light pipes. The resin produces transparent parts right out of the SLA machine, but post processing is required to obtain true optical clarity.

Ronald Belknap
Managing Partner
rbelknap@protocam.com