Common Issues for Torch Cables

May 20, 2018

Understanding how well welding torches perform or how it’s design stacks up against others in the industry is important. Looking at common issues and best practices for torch cables will help to bring greater quality and productivity.

Under­stand­ing your weld­ing parts will help to reduce down­time and over­all wear while also increas­ing pro­duc­tiv­i­ty. Robot torch parts can come in a vari­ety of styles and build. Over time, there are some parts that have proven to be more effec­tive and more con­ducive to pro­duc­tiv­i­ty and user-friend­li­ness than oth­ers. Being updat­ed and knowl­edge­able on this infor­ma­tion will ensure opti­mal pro­duc­tion on your weld­ing pro­duc­tion line. This arti­cle will bring to light issues that relate to torch cables, lin­ers, tips, and noz­zles includ­ing how they fail and best prac­tices for them. 

Installing Welding Torch Cables

One of the most crit­i­cal com­po­nents of a well-made robot torch cable is the out­er jack­et pro­tect­ing the cable. 

Out­er Jackets

The durable out­er jack­et is a very impor­tant to help pro­tect against abra­sion, cut­ting, and offer increased resis­tance to fail­ing if it ever catch­es on a clamp or fix­ture in the weld­ing cell.

The out­er jack­ets that have proven to offer incred­i­ble resis­tance to abra­sion and cut­ting are irra­di­at­ed with elec­tron beams or com­posed with a cross-linked poly­ester. Even if the out­er jack­ets are dam­aged, the dam­age won’t extend with these cable mate­ri­als because the cable doesn’t have a grain run­ning in one direc­tion. How­ev­er, the out­er coat­ing of a robot torch cable comes with trade-offs. These types of coat­ings are stur­dy, but they are less flexible.

If there were to be a cut or abra­sion on cables using neo­prene, it would read­i­ly extend and increase the chances of fail­ure for the robot torch cable. This would be one rea­son to make this mate­r­i­al less desir­able for a robot torch cable. How­ev­er, the advan­tage to neo­prene is that it is more flexible. 

Pro­tec­tive Sleeves

A pro­tec­tive sleeve on top of the torch cable out­er cov­er will pro­tect the cable and cable strands from rub­bing against the arm when the arm is in motion.

Cables that fea­ture cor­ru­gat­ed, Kevlar, or leather pro­tec­tive sleeves for robot torch­es are impor­tant to fur­ther pro­tect the torch cable espe­cial­ly if your weld­ing torch is rotat­ing or bending. 

Elec­tri­cal Connections

The elec­tri­cal con­nec­tion of the torch cable is a crit­i­cal piece in main­tain­ing con­sis­tent and reli­able pow­er from the cop­per to the torch neck and ulti­mate­ly to the con­tact tip and weld­ing wire.

Under­stand­ing if your torch cable can stand up to the man­u­fac­tur­ing demands also includes ensur­ing that the elec­tri­cal com­po­nents are up for the chal­lenge. These elec­tri­cal con­nec­tions are seen in two com­mon man­ners: a crimp of the cable at the end or a cone and a cone nut.

Crimp con­nec­tion: pro­duces a more sta­ble and reli­able elec­tri­cal con­nec­tion. A pad crimp will pro­vide even pres­sure and a strong and con­sis­tent elec­tri­cal con­nec­tion and current.

Con­nec­tor Cone and Cone Nut: This used to be the way to pro­vide the elec­tri­cal con­nec­tion as it allowed for rota­tion­al move­ment and also because it could be tak­en apart, short­ened, or mod­i­fied as need­ed. How­ev­er, peo­ple real­ized that this was not need­ed so the crimp con­nec­tion was seen as more ben­e­fi­cial and being used with greater success. 

Cable Strand­ing

Look­ing for cable strand­ing is one of the most impor­tant fac­tors to help deter­mine your cable qual­i­ty. Mul­ti-strand cables will last longer and resist tor­sion more than a sin­gle-strand cable.

Cables can be designed to rotate and with­stand tor­sion­al loads which is a crit­i­cal eval­u­a­tion fac­tor to look at when using a through-arm set­up. Eval­u­at­ing the need for cop­per or alu­minum and a mul­ti-strand or sin­gle strand are oth­er fac­tors to consider. 

Welding torch cable failure

Pic­ture Cred­it: The Defin­i­tive Guide to Robot­ic Weld­ing Torch­es by Abi­cor Binzel

A robot torch with 5 inde­pen­dent­ly strand­ed cables will work less to pro­duce a strong elec­tri­cal cur­rent when there’s tor­sion on one anoth­er and cause less fric­tion when trans­fer­ring to the out­er shield. The solu­tion would be a mul­ti­strand design and build that will last longer than a sol­id, or sin­gle, strand cable.

Through-arm torch cables com­mon­ly fail because of over-rota­tion of the cable while in oper­a­tion on robot axis 4 and axis 6. The greater amount of rota­tion, the greater the impact on the integri­ty of the cable build. The strands inside the cable can break and cre­ate heat in areas of the cable it is not designed for.

If a robot torch cable is capa­ble of rotat­ing +/- 210 degrees con­sis­tent­ly while in oper­a­tion, then it should be con­sid­ered a qual­i­ty torch cable for through-arm.

Infi­nite or End­less Rota­tion torch­es are becom­ing more main­stream as there is no wor­ry about what the cable is doing because the wrist manip­u­lates the front end of the torch inde­pen­dent of the robot cable. There are nec­es­sary ser­vo motor adjust­ments that are nec­es­sary to accom­mo­date this torch tech­nol­o­gy, how­ev­er it pro­vides a greater val­ue out of the life of their torch cable. These torch­es would specif­i­cal­ly ben­e­fit oper­a­tions in the oil and gas, auto­mo­tive, irri­ga­tion, pipe, or agri­cul­tur­al industry.

Com­mon Issues with Over-Arm Cables:

Unsched­uled down­time and cost­ly repairs can occur when weld­ing torch cables are not prop­er­ly adjust­ed and placed. It is impor­tant to under­stand the nec­es­sary length for your over-arm cables so that they can give you the most life. To achieve prop­er length, make sure the robot can achieve full move­ment with­out the torch cable hang­ing from the side.

Too long of a cable and it will get caught, expe­ri­ence a lot of rub­bing onto tool­ing, and quick­ly wear out. Long cables can also expe­ri­ence exces­sive heat and tor­sion­al force from it mov­ing too vio­lent­ly, caus­ing failure.

Too short of a cable will lim­it the rota­tion axis 4 and axis 6 pro­vid­ing for access issues, incur more stress, and fail prematurely.

Besides the cable length, it is also impor­tant to look the place­ment and sup­port of your wire feed­ing unit. This unit can be placed at spe­cif­ic loca­tions or angles to help cre­ate fur­ther effi­cien­cies with the robot torch cable. The sup­port can help the cable main­tain a sta­ble arc instead of hang­ing in a way that com­pro­mis­es the cable’s integri­ty and wire feeding.

Ben­e­fits of Through-Arm Cables:

There is less mar­gin for error on cable length with through-arm cables so choos­ing the cor­rect length is the most impor­tant step. It is crit­i­cal to keep the dif­fer­ence between the torch body and the wire feed inter­face to no more than 5 mm.

How Cables Fail:

  • Abra­sion: When a cable rubs up against the part and even­tu­al­ly fails. A cable abrades when the robot puts a torch cable through the same cycle over and over mul­ti­ple times.
  • Cut­ting: When the cable comes in con­tact with a sharp edge to a part over and over .
  • Caught: If the cable isn’t installed prop­er­ly, the cable can get caught on a fix­ture or part and halt production.

In sum­ma­ry, it is impor­tant to ensure your torch cable has a prop­er out­er jack­et; A pro­tec­tive cor­ru­gat­ed sleeve; Has either a strong crimped or coned con­nec­tion; Is a sin­gle strand or mul­ti-strand; Is at the cor­rect length for your robot; The cable is set-up for the prop­er +/- torch cable length; and The wire feed­ing unit is placed properly. 

For more infor­ma­tion on cables, con­tact Robots​.com experts online or at 8777626881.

Source: https://​cdn2​.hub​spot​.net/​hubfs…

Let's talk!

Request your quick quote today.