Worth Knowing: Selection Criteria for Rotary Indexing Tables

Be­fore pur­chase fol­low­ing ques­tions should be con­sid­ered:

1. Mode of op­er­a­tion

• Ro­tary In­dex­ing Ta­bles sin­gle-axis
• Ro­tary In­dex­ing Ta­bles mul­ti­ple-axis

2. Work­piece and fix­ture sizes

• geom­e­try
• weight
• mass mo­ment of in­er­tia

3. Type of axes – ac­ti­va­tion of Ro­tary In­dex­ing Ta­bles

Ro­tary In­dex­ing Table di­rectly in­te­grated ma­chine con­trol (as one or more ma­chine axes)​

• Ad­van­tages
  No ad­di­tional con­trol nec­es­sary
  Si­mul­ta­ne­ous op­er­a­tion (Turn & Burn) pos­si­ble
  Cost-sav­ing and highly ef­fi­cient man­u­fac­tur­ing so­lu­tion for mod­ern ma­chines
• Dis­ad­van­tages
  Ap­plic­a­ble only on ma­chines pre­pared for it

Ro­tary In­dex­ing Table in­te­grated by sep­a­rate con­trol (com­mu­ni­ca­tion via M-com­mand of ma­chine)

• Ad­van­tages:
  Uni­ver­sal so­lu­tion for all Ro­tary In­dex­ing Ta­bles
  Quickly ap­plic­a­ble on other ma­chines (WEDM, SEDM, EDM drilling)
• Dis­ad­van­tages:
  Ad­di­tional, sep­a­rate con­trol nec­es­sary
  For po­si­tion­ing or ro­ta­tion only, si­mul­ta­ne­ous op­er­a­tion (Turn & Burn) not pos­si­ble

4. Se­lec­tion of mea­sur­ing sys­tem ac­cu­racy

Ac­cu­ra­cies of Ro­tary In­dex­ing Ta­bles are pro­por­tion­ally de­pen­dent on the ac­cu­racy of di­rect mea­sur­ing sys­tems (an­gle en­coders, en­coders). They are avail­able in var­i­ous classes of ac­cu­racy (higher ac­cu­racy = higher price).

The di­a­gram shows that for small work­piece di­am­e­ters, lin­ear po­si­tion­ing er­ror (straight dis­tance) is low; for larger work­piece di­am­e­ters, larger de­vi­a­tions may oc­cur.  
 
Stan­dard an­gle en­coders with an ac­cu­racy of +/-5" or +/-10" are used (other ac­cu­ra­cies on re­quest).
 

Ex­am­ple

Max­i­mum po­si­tion­ing er­ror is de­pen­dent on sys­tem ac­cu­racy and work­piece di­am­e­ter.

Work­piece radius	50 mm	100 mm
Mea­sur­ing sys­tem ac­cu­racy +/- 5 sec­onds	+/- 0,0012	+/- 0,0024
Mea­sur­ing sys­tem ac­cu­racy +/- 10 sec­onds	+/- 0,0024	+/- 0,0048