Jan 252012
 

Custom composite cable

What makes a wire or cable a custom wire or cable?  One would think it would have to be an elaborate cable design, but in reality something as simple as a unique color or printing can make the cable become a custom cable.

Custom wire and cable is not readily available or stocked by distributors or manufacturers. Simply put custom wire and cable is anything that is made to order specifically for a customer. Hypothetically, let’s say you have a commodity cable that you use regularly but now your product design has changed and you need one or two more conductors. You check with your distributor and the manufacture doesn’t offer that construction. You now need to turn to a custom wire and cable manufacturer which is set up to run special construction cable with little or no minimums.

Yes you will pay a little higher per foot than you do with the commodity wire however, you get exactly what you need and the performance you require. Prices between custom and commodity cable can’t be compared as the construction and materials are different and the quantity produced are much lower with the custom cable. In the end it’s all about having choices available to make a better product.

A few benefits of using custom wire and cable include:

  • Engineered specifically for your application
  • Custom configurations
  • Custom colors and/or printing
  • Improved performance

You have choices! When having a custom wire or cable designed you a wide range of options to assist in building the right wire or cable for your needs. Some options include:

  • Gauge sizes, smaller gauges available
  • Insulation and jacket materials
  • Type of shielding and construction
  • Conductor stranding, plating and type

Reverse engineering is used in situations where the origin of a cable is unknown or there is no information about the wire or cable. Engineers in most cased will carefully dissect the wire or cable taking measurements and noting the construction of conductors, cable lay, shielding, fillers and other vital information. A series of tests are performed to determine the insulation and jacket materials. At this point if a customer would like to see improvements in the cable’s performance such as a more flexible cable, or higher flex life it should be mentioned to the engineers so changes can be made to the design.

Custom braided cable

So who uses custom cables? Just about every industry including medical, robotics, aerospace, music/audio and more. Building a better mousetrap often means designing a product that will exceed it’s expected performance and the wire and cable needs to be considered as well.

If you do not know much about wire and cable properties, don’t be alarmed. Custom cable manufacturers have engineering resources  to assist you with every step of the way starting with determining the right materials and construction based on your application and requirements.

If you have questions about custom wire and cable or a project that you need assistance with, contact Calmont Wire & Cable for assistance.  Feel free to post any questions or comments you may have. If you enjoyed this article please feel free to share it.

 

 Posted by at 4:47 pm
Jan 192012
 
Medical cable lumens

Medical cables

Medical wire and cable is different than wire and cable used in other applications. Design engineers need to keep this in mind when specifying their cable. Often time custom medical cables are needed due to bio-compatibility, sterilization and possibly smaller sized device requirements.

When specifying a medical cable one needs to keep in mind several factors such as:

  • Sterilization techniques autoclave, gamma, alcohol?
  • Will this be a disposable cable?
  • Will the cable come in contact with the patient? Bio compatibility.
  • Flexibility requirements.
  • How will the device be used day to day?

Due to time constraints many times engineers will sometimes settle for a readily available off the shelf cable for prototypes or proof of concept, which is fine for the short term. When it comes to field and clinical trials a prototype should be made with wire or cable specifically designed for the application to better measure longevity and functionality. Medical cable applications fall into several categories, handheld medical devices are a large segment of medical cable applications.

Medical Hand Piece Cables

Handheld medical device cableCables for medical hand pieces must carry the power, control, sensor and data to and from the hand piece.  The cable may be as simple as a two-conductor cable, providing power to a cut & cauterize scalpel or a multi-conductor power, control and sensor cable used on an orthopedic surgery device.  Cables for handheld medical lasers likely contain lumens for cooling.  Ablating hand piece cables can also contain lumens for irrigation and suction removal.

The design of medical hand pieces falls into two categories: re-useable and disposable.  See below for information on Disposable Medical Cables and Re-useable Medical Cables.

Disposable Medical Cables

Disposable medical cables are made from the lowest cost materials that will meet the design needs of the device. Conductor cost is dictated more by the number of strands used to make the conductor.  The higher the strand count the more flexible the wire becomes.  A marketing trade-off is often made for disposable cables, i.e. increase stiffness can be tolerated by the need to hold cost down.  7 or 19 strand conductors can be used, where in re-useable cables the strand count can be well over 50.  The use of plating is reviewed and bare copper is the most often used.  Tin plating is used only to enhance solder ability. Crimping the wires is often the cheapest means of terminating the conductor.  Silver plating is rarely used for disposable cables.  Conductor sizes are determined by the current needs of the device.

Insulation and jacket materials are chosen by cost.  Low cost materials such as Poly Vinyl Chloride (PVC) or Thermo Plastic Elastomers such as poly urethane are often used.  Polyethylene can be used as insulation.  Insulation and jacket thickness are determined by the voltage ratings of the signals in the cable.

Shields, when required, are usually of a spiral type rather than braid to hold the cost down.  Spiral shields may lose shield effectiveness during repeated flexing, but the number of flexes for disposable cables is limited.

Jacket colors usually are chosen by the program.  The need for gamma sterilization may limit the color shades available.  Colors can change during gamma sterilization and are usually required to be stable for less than 10 cycles to allow for re-sterilization when repackaging is needed.

Medical grade silicone

Implantable silicone lumen.

Re-useable Medical Cables.

Medical cablesdesigned for re-useable devices have to use materials that will withstand several cycles of sterilization by alcohol based agents or autoclaves.

Conductors are made from high strand count conductors for maximum flexibility and often they are made from high strength copper alloys.  The size of the conductors is determined by the current they must carry to the device.  To withstand the rigors of sterilization, plating’s of tin or silver plating may be required.

Insulation must also withstand the rigors of sterilization and are often either Teflon’s such as FEP, PFA or Tefzel® or Silicone Rubber.  The use of lower cost materials may be made on a case by case basis.

When shields are required, they must be made from materials resistant to many sterilization cycles and are often silver plated copper or silver plated high strength copper alloys.  Shield construction is usually of a braid rather than a spiral, as spiral shields can move during flexing and compromise the shielding effectiveness.

The more popular choice for cable jackets are made from Santoprene™ TPE which is good for up to 100 cycles of autoclave, or Silicone Rubber.

Medical cable applications also include implantable, medical robotics, therapeutic devices, sensors and monitoring equipment.

To find out more or discuss your applications with medical wire and cable please contact Calmont Wire & Cable.

Please feel free to leave your comments; We would enjoy hearing from you.

 

 

 

 Posted by at 5:58 pm
Jan 112012
 

Robotics and automation

Robotics and automation industries have unique needs when it comes to wire and cable. These types of applications many times require extremely flexible cables that have to endure repetitive flexing, twisting, torsion and in some cases harsh chemicals. Custom cables designed for this type of use is highly recommended.

 

Typical applications for robotic cable include:

  • Welding Robots
  • Painting Robots
  • Rotary Tables
  • Pick and Place Devices
  • Conveyor Systems
  • Animatronics
  • Military / Law enforcement

 

The Challenge lies with the wire and cable engineers to design a strong, extremely flexible cable with a long lifespan that can do everything required by the robot. The application mayrequire having multiple cores carrying data and power under one jacket. Robotics wire and cable often times require the following characteristics which are taken into consideration during the design of the cable or wire:

  • Flexibility
  • Long Life
  • High Strength
  • Durability
  • Miniaturization

 

BigDog robot by Boston Dynamics

The materials used to manufacture the cable are as important as the design. Conductors typically used are ultra-fine high strength alloys with a high strand count construction. Cable lay and shielding also play a role with the the type of movement and flexibility needed to meet the requirements of the application. Insulation and jacket materials are also important. Two good options are silicone rubber which adds superior chemical resistance and flexibility and polyurethane which protect against abrasion, oil, notching, microbes and hydrolysis. Smooth surfaces prevent adhesion to adjacent cables.  It is important to have wire and cable specifically designed for this type of use.   Off the shelf commodity wire and cable will fail at some point if not designed for this type of use.

 

 

 


Watch the Big Dog robot by Boston Dynamics

An AMAZING example of robotic technoloy


For assistance with finding the right cable for your application or to have your questions answered contact Calmont.

Your comments are welcome,  let us know what challenges you have faced with your wire and cable needs.

 

 Posted by at 6:06 pm