We often need custom cable and connector assemblies engineered specifically for our machine automation applications. Is it best to just make these ourselves, or should we go outside? If we go outside, how do we find a good source that we can count on?
—from June ’07 Control Design
Most people feel a molded cable is best. We agree, so this answer will assume you prefer a molded cable assembly.
If you use a single-ended cable, it’s possible to stock molded cables in several lengths that can be cut down if necessary to reach the required length for your application. Determine how many different lengths you might need. Can 80% of these needs be accommodated by cutting down a few different stock lengths? If yes, you can keep those items in stock, and cut to length for most of your needs.
If you require double-ended cable assemblies, you can stock a few different lengths of single-ended molded cables and apply a field attachable connector on the opposite end—the end going in the least hazardous side of the application—after cutting to your desired length.
Can you plan in advance for the cables you need? If you can, and if you have significant quantities, there are many cable manufacturers that can help you. If your required quantities are small, you’ll need to find a cable manufacturer that can produce smaller quantities.
We have a system we call Open Variant, an automated production cell that lets you select from a variety of cable and connector options for both ends of the cable and select your desired length, but doesn’t require large quantities.
If you need custom-length assemblies and can’t plan in advance, then you really have no option other than to stock your own cable and field-attachable connectors.
Ted Brunk, national sales – connectivity
Form a Business Relationship
Typically, it would be cost-effective to have this work done by a manufacturer that specializes in this area, but some connector manufacturers won’t touch a custom job unless the volumes are high enough, or they have a strong partnership with the customer, and know that in time it eventually will be profitable. Other factors to consider are UL certifications and safety issues arising from improper in-house design and development.
A good way to find a reputable connector assembly company is to go online to any of the industry publications. Most have a directory listing of manufacturers. Once you find a few, call them to see what their custom capabilities are, and perhaps visit their facilities to see if they can show you work in progress. Begin to form a new business relationship. Then make your decision.
Ronald Bezz, national sales and marketing
Cables Are Like Porsches
As with any skill set, given time and trial, your machinists can build cables, but you’ll be taking them away from the expertise and skills they were hired for. Building the cables only answers half the problem. They also need to be built correctly. This means using the correct wire, no internal shorting, correctly soldered connectors, secure strain relief and hooding, and accurate testing to make sure they meet all the required specifications.
Think about it this way: If you own a Porsche you could try to figure out what might be wrong and attempt to fix it yourself, take it down the road to the neighbor who moonlights as a mechanic, or have a certified Porsche mechanic fix it. Considering high-end machines and computers can approach or exceed the cost of a Porsche, this analogy is appropriate.
So how do you decide which company to choose? First and foremost, base your decision on the longevity of the company. You want an established stable company because it will have perfected its techniques and cabling procedures. Do you really want a newly established company using you as its guinea pig, while it learns how to correctly build cables?
Ask co-workers and peers which companies they recommend. Read reviews of these companies online. Take a look at the company’s web site. Do they offer a great variety of cables? If so, then they should be able to handle any unique cables you request from them. If you need a larger quantity of a certain cable, the right custom cable company should have the partnerships in place with their factories to have your unique cables professionally molded. Ultimately it will come down to whether you think the company trustworthy enough to build your product to your expectations in a reasonable timeframe.
Dave Maher, sales
Pacific Custom Cable, www.pacificcable.com
Proper Tooling Ensures Reliability
This is a question I’m sure many companies struggle with. On the surface, assembling cables appears to be easy. Just crimp or solder contacts to wire, perform some mechanical assembly and off we go. Not so fast.
There are many different connector systems available that perform differently, and are assembled and tested with a variety of tooling. Tooling can be expensive, and sometimes can exceed the cost of the cables. The performance of your cables can drastically affect your application. Proper crimp tooling is essential to ensure reliability. Cables can fail immediately or over time due to improperly crimped terminals. There is nothing worse than sending a technician on an expensive service call to fix a $10 cable.
Partnering with a qualified cable assembly shop is the path most companies choose these days. Some require a very high volume of assemblies, but many of them don’t. Some will design cables from the ground up and most will help with design suggestions and improvements.