FAQ

Frequently Asked Questions

What do you need to provide a quote?
3D Data along with information on the process you need, quantities and finishing information.

What type of data do you need for quoting?
Preferred formats are STP or IGS files for each part. We also accept assembly files with all parts in STP or IGS. We work with all types of data and for 3D Printing quotes we can accept STL files as well.

How do I send data to request a quote?
Just click the Get a Quote button at the top of our website to reach a simple to complete form. We ask some simple identifying questions such as your name, email, phone, where you are located and a few others. Then enter a project description including service you are requesting, quantities needed, finishing desired and anything extra like paint or threaded inserts. Multiple CAD files can be attached. ARRK receives these into our ftp server so very large files arrive safe and secure.

How is the cost calculated for SLA or 3D Printing?
ARRK takes the volume or size of the part along with type of material and finishing requirements and plugs that information into a quote logarithm. Price is based on size, material cost, build time and finally finishing type.

How large a part can you fit into your machines?
Our largest machines can fit 30″x28″x28″ building in a single piece. Or we can section the part and build something in the 6′-8′ range.

What is the smallest size part you can do?
The smallest size for printing in SLA is .5mm x .5mm. The reason is this is due to the small size of the laser and minimum thickness it can build a part.

What types of finishes can ARRK provide?
ARRK can do a support removal only where we only do a light sandblast. We also have what is called an Engineering Review finish where we sand the part down to a smoother surface. This is our standard finish. We have an engineering review finish along with a primer and finally a high end finish with primer and paint to match customer’s preferred color.

What materials does ARRK CNC?
We can cut from a wide range of materials including ABS, polycarbonate, acrylic, nylon, delrin, polypropylene, PEEK, model board to various grades of aluminum, brass, stainless steel to name a few.

What are your CNC tolerances?
ARRK NA holds standard overall CNC tolerances of +/-.005 in. or =/-.13 mm. Plus standard print tolerances example: .X =/- .030, .XX =/- .010, and .XXX =/-.005. We understand tighter tolerances are sometimes needed please contact us to advise so we can review these on individual project basis.

How large of a part can be CNC machined?
Size on some materials is limited to the sheet or block size available. However, with some materials such as ABS, polycarbonate the sheets and blocks can be bonded prior to machining for larger parts. Another option often used on bondable materials is to split the file machine the large sections and solvent bond them. These bonds are very strong as the solvent actually welds the material.

Why do I want to use urethane castings as opposed to SLA?
Urethane materials more closely simulate a production process whereas the SLA process yields a cosmetic looking part, but also more fragile. Urethane process can also become more cost effective at higher quantities.

Can urethane castings be in color?
ARRK can color match most of our urethane casting materials to match Pantone and RAL colors. We can even match provided color samples.

How many parts can you get from a silicone rubber tool?
You can mold between 10-20 parts per mold depending on the size and geometry and material used. Some companies may be able to mold more parts, but ARRK has always found that parts start to change after 15 parts per mold due to the harsh conditions of the urethane molding process.

How long do you keep the silicone tools before you throw them away?
Typically, ARRK keeps molds for 3 months or until the maximum number of parts has been reached.

What is the largest size part ARRK can cast?
We can cast parts up to 3 or 4′ in size in one piece. Please provide us with the geometry and exact dimensions of your part so ARRK can determine the best way to produce what you require. We also bond large sections together should you have an extremely large part.

Can ARRK produce undercuts using the cast urethane process?
Some undercuts can be produced easily due to the flexibility of silicone rubber tools which is cost effective. For difficult geometries, ARRK produces inserts in a number of materials that are placed in the silicone rubber mold to provide the details necessary. Please send ARRK your data so we can recommend the optimum way to cast your parts.

What is the maximum amount of parts you can produce using the urethane casting process for production?
We have some customers who have ordered up to 1000 parts using the silicone rubber molding process. Usually, anything after 300 pcs might be reason to switch to a plastic injection process. However, there are many factors so please check with your ARRK representative to calculate the crossover between Rapid Prototyping and Injection Molding.

Why order tools from ARRK?
We have a global network of tooling and injection molding facilities at our disposal. Projects are managed by highly experienced Tooling Engineers working with you at every step of the process. ARRK is a publicly traded company so therefore we take security and confidentiality seriously. Our Tooling Engineers are located stateside and are available for meetings during your normal business hours.

What information do you need to provide a tooling quote?
ARRK needs 3D CAD, 2D drawings (if available), specified material, color, finishing, any special tolerance or quality certifications, as well as intended tool life. If ARRK will be the molder, we need to know the part quantities to be quoted. Please check with ARRK’s Tooling Engineers with any additional questions or clarification.

What types of steel do you use for your tools?
ARRK only uses high grade steel for our tools. We match the steel grade to your tool life requirements. Although we can use aluminum material, steel has many advantages our customers prefer over aluminum. Steel has a longer life and better ability to be modified are just some of the reasons to choose steel over aluminum. Please check with ARRK’s Tooling Engineers with any additional questions or clarification.

What quality certifications do you have?
ARRK has fully owned ARRK facilities globally as well as several partnered suppliers with quality certification of ISO9001, ISO13485, ISO14001, IATF16949, AS9100, and BS OHSAS 18001. ARRK Tooling Engineers use the correct facility that is best suited for your project.

What is different about using ARRK, or using a China company direct?
ARRK NA’s Tooling Engineers are located in the United States providing North American customers direct access for all stages of their project during your normal business hours. ARRK facilities and suppliers hold the highest standards of security and confidentiality. They are certified and audited to comply with ARRK’s Non-Disclosure policy making sure your project data and parts stay controlled within the ARRK organization.