Get a Grip! Choosing the Right Robotic Gripper

If you need robot tool­ing to pick up, manip­u­late, and place your product/​part, chances are you’re going to use a robot­ic gripper.

Arguably the most com­mon type of end-of-arm tool­ing (EOAT), robot­ic grip­pers are found in vir­tu­al­ly every indus­try and con­text from food pro­duc­tion and clean­room envi­ron­ments to foundries and dis­tri­b­u­tion cen­ters. These grip­pers come in a vari­ety of types, sizes, and con­fig­u­ra­tions — fric­tion, encom­pass­ing, hydraulic, pneu­mat­ic, elec­tric, mag­net­ic, etc. 

Fric­tion vs. Encompassing

There are two main types of grip­pers – fric­tion and encom­pass­ing – which are bro­ken down by the way they pick up mate­ri­als. Fric­tion robot­ic grip­pers hold the part through force alone, while encom­pass­ing grip­pers sur­round the part. Which one is right for you? It all depends on the mate­r­i­al. Gen­er­al­ly speak­ing, fric­tion grip­pers are bet­ter suit­ed for hard­er mate­ri­als, and encom­pass­ing grippes are well suit­ed for flex­i­ble or soft­er mate­ri­als, like bags or boxes.

Angu­lar or Parallel?

Many grip­pers come with two or three jaws – except for vac­u­um grip­pers which often come with rows of suc­tion cups for grip­ping. Par­al­lel grip­pers, the grip­pers with two jaws, close onto either side of a prod­uct and lift it up. An angu­lar robot­ic grip­per moves more like a human hand, with the ​“fin­gers” wrap­ping around the prod­uct. In a major­i­ty of cas­es, com­pa­nies will choose the par­al­lel design because it is eas­i­er to design for and more prac­ti­cal than the angu­lar option.

Of course, it isn’t just about how many jaws or fin­gers the robot EOAT has – it is also about the size and shape of them. The length of the jaws can have an impact on cycle speed and effec­tive­ness. Longer jaws many be nec­es­sary depend­ing on the work cell and appli­ca­tion (exam­ple: remov­ing a part from an injec­tion mold machine). In addi­tion, grip­pers are com­mon­ly con­struct­ed with two or three fin­gers (actu­a­tors) for grasp­ing an object. Inte­gra­tors con­sid­er the size and con­struc­tion of the part being manip­u­lat­ed to deter­mine how many actu­a­tors are best. 

Use of Force

Once you decide whether your appli­ca­tion needs a fric­tion or encom­pass­ing grip­per, there are sev­er­al dif­fer­ent kinds to choose from, and once again, it is all about the part mate­ri­als and weight. These grip­pers are pow­ered in many ways, and the wrong kind of force could dam­age or ruin your prod­uct. Oth­er fac­tors you could con­sid­er when choos­ing your grip­per cost and space constraints.

The most pop­u­lar type of grip­per for robot­ic sys­tems is the pneu­mat­ic grip­per. These grip­pers are com­pact, light­weight, and capa­ble of apply­ing a sig­nif­i­cant amount of force. These grip­pers do not have the bulk of motors or gears, which can make a grip­per sig­nif­i­cant­ly larg­er, so they are ver­sa­tile enough to fit into tight work cells. Some­times, pneu­mat­ic grip­pers are com­bined with oth­er ele­ments, like suc­tion cups or mag­nets, to bet­ter grip materials.

If you need more force than a pneu­mat­ic grip­per can pro­vide, it is time to move on to the hydraulic grip­per. These grip­pers can deliv­er plen­ty of force, but they can be a mess for your fac­to­ry because of their oil, pumps, and reser­voirs. Anoth­er clean­er option is an elec­tric robot grip­per, which eas­i­er to main­tain, while also pro­vid­ing the same amount of force as the hydraulic options.

These grip­pers can be larg­er than pneu­mat­ic grip­pers because they do include motors, but with the help of micro­proces­sors, they are much more adaptable.

Choos­ing Your Gripper

Robots​.com’ inte­gra­tion team works with each cus­tomer to deter­mine which robot­ic grip­pers is best suit­ed to the appli­ca­tion, work cell design, and most impor­tant­ly, the part/​product. Some prod­ucts, for exam­ple, will be dam­aged if too much force is applied while oth­ers can han­dle sig­nif­i­cant amounts of force. As men­tioned above, a num­ber of fac­tors, such as tool­ing cost, force nec­es­sary, part weight, and accel­er­a­tion /​deceleration rates are con­sid­ered when select­ing a robot­ic grip­per solu­tion. Our staff works dai­ly to ensure that you are com­plete­ly sat­is­fied with the qual­i­ty of your parts and systems.

For more infor­ma­tion about robot­ic grip­pers, call the Robots​.com Sales Depart­ment at 877−762−6881 or con­tact rep­re­sen­ta­tives online.