The Right Positioner for your Application

Under­stand­ing the avail­able posi­tion­er fea­tures and options can help facil­i­tate the deci­sion-mak­ing process to fur­ther improve qual­i­ty, decrease cycle times, and pro­vide excel­lence on the weld­ing line. Here we dis­cuss impor­tant posi­tion­er infor­ma­tion to help bring a bet­ter under­stand­ing of all the options and fea­tures avail­able to manufacturers.

What is a positioner? 

A posi­tion­er allows for 360 degrees of rota­tion and access to a part through the rota­tion and rota­tors. The use of a posi­tion­er can accel­er­ate pro­duc­tion and improve weld quality. 

When design­ing a robot­ic work­cell, it is impor­tant to under­stand the way you manuev­er the work­piece into posi­tion for the robot to work on. Choos­ing the right type of posi­tion­er will depend on the type of prod­uct, the appli­ca­tion and how the part needs to be moved to opti­mize production. 

Posi­tion­er capac­i­ty can vary in style, size, and capac­i­ty and each is unique­ly designed for spe­cif­ic appli­ca­tion require­ments, as seen below. 

Sta­tion­ary Table 

A robot­ic work­cell sta­tion­ary table posi­tion­er is pret­ty basic. This is a fixed table where a work piece can be placed. Once the work piece is placed on the table, the work­cell robot manip­u­lates the piece, and then the piece is moved to the next area. 

Sin­gle Axis Posi­tion­er

The sin­gle axis posi­tion­er is the most afford­able and basic type avail­able. It can be mount­ed as a head­stock on a floor or table top to help accom­mo­date sim­ple and small part weld­ing. A head­stock and a tail­stock can be com­bined to sup­port long part spans and the load or two head­stocks can be used in con­junc­tion with a sin­gle tailstock. 

Inno­v­a­tive Fix­ture Mount­ing Technology

Moto­Mount has com­pli­ant bear­ings on the head and tail­stock which helps to reduce the stress on the posi­tion­er and sub­se­quent tool­ing by allow­ing up to two degrees mis­align­ment in any plane. This tech­nol­o­gy also improves the repeata­bil­i­ty of the fix­ture by up to 75 percent. 

Fer­ris Wheel Positioner

This is a two-sta­tion design that offers the best floor space effi­cien­cy. It is ide­al for medi­um-to large-sized parts that are 3 to 5 m long and they are gen­er­al­ly rat­ed by capac­i­ty. The auto­mo­tive indus­try uses these posi­tion­ers a lot due to the size capac­i­ties, small foot­print, and excel­lent cycle time. 

Fer­ris Wheel Posi­tion­ers was named so as it will turn in an over-under fash­ion. There are two trun­nion axes on each side of a major ​“sweep” axis that are ser­vo-dri­ven. This helps to reduce cycle time by allow­ing parts to turn into posi­tion while the trun­nion sta­tions rotate over or under the sweep axis. The two sta­tions allow the oper­a­tor to be unload­ing and load­ing one side while the part on the oth­er side is being weld­ed. A cen­tral arc screen divides the two sides keep­ing the oper­a­tor safe from spat­ter and arc flash exposure. 

Turntable Posi­tion­er

Turntable posi­tion­ers rotate in a ​“lazy Susan” motion to move parts from the operator’s loading/​unloading sta­tion to the inside of a work­cell. They use a base with axis mount­ed to the floor and a table top where sta­tion­ary tool­ing can be added. An arc screen is used to divide the two work­sta­tions. Small to medi­um sized parts are ide­al for this positioner. 

H‑Frame Posi­tion­er

H‑Frames include an addi­tion­al head­stock and tail­stock on each side in lieu of a table. Anoth­er axis can be added where the head and tail­stock attach to the floor-mount­ed base allow­ing for a part to be turned end-over-end as well as spun with the head­stock while being weld­ed. This can weld medi­um parts with com­plex, mul­ti-sided weldments. 

Mul­ti-Axis Positioner

Oth­er ser­vo axes, head­stocks, and bases can be com­bined to make a vari­ety of spe­cial­ty posi­tion­ers such as ​“tilt-rotate” or ​“sky­hook” posi­tion­ers. This increas­es the flex­i­bil­i­ty to accom­mo­date parts and tool­ing of dif­fer­ent sizes and com­plex­i­ties. These posi­tion­ers can be mount­ed to walls, tracks, or oth­er sur­faces for increased access or agili­ty. A six-axis robot can also be used as a ​“jig-less” solu­tion. Parts that are large, boxy, or tubu­lar are well-suit­ed for these types of positioners.

Fur­ther Recommendations 

• Stan­dard coor­di­nat­ed motion pro­vides fast and con­sis­tent trav­el speeds while ensur­ing reli­able motion between posi­tion­er axes and the weld­ing robot.
• Inte­grat­ed tool­ing pow­er, air, and com­mu­ni­ca­tions helps to eas­i­ly trou­bleshoot and pre­vent cable damage.
• Be sure that the posi­tion­ers in place are designed specif­i­cal­ly for your appli­ca­tion and com­ply with cur­rent specs.
• Option­al Func­tion­al Safe­ty Unit helps to ensure work­er safety.

Robots​.com inte­grates pre-engi­neered robot­ic work­cells from Motoman, Fanuc, ABB, KUKA, and our very own Robots​.com brand. Our own line of work­cells allows for more cus­tomiza­tion and bud­get options. We can inte­grate a new or recon­di­tioned robot into our work­cells, giv­ing a more cost effec­tive solution. 

For more infor­ma­tion about automat­ing with a cus­tomized robot­ic work cell from Robots​.com, con­tact us today at 877−762−6881.