CNC Rotary Table is a precision work positioning device used in CNC machining centers to precisely position the component in the desired angle to do the multi-face operation in a single setup. Rotary tables can be interpolated as 4th axis with machines X, Y, and Z axes to enable machining of profiles such a cam machining, blade machining, helical grooves, etc. which is out of reach with a standard 3 axes machining center.
Based on the application one can use only the Rotary Table with some work holding fixture or will have to use some accessories like Dead Center or Revolving Center Tailstocks, Face Plate Tailstocks, Manual or Power Chucks etc.
There are some basic points which needs to be checked for correct sizing of Rotary Table.
Rotary Table selection guidelines
- Rotary Table Selection based on Component Size
- Check for the swing required on the component
- Check for Center Height of the Table
- For the Multi-spindle Table check for the center distance between the spindles.
- In vertical condition, if the length of the component is more than 100 mm it is recommended to use the tailstock support
- The larger component can be used provided load and clamping torque is within the capacity of the Rotary table. For larger swing use height Block.
Rotary Table Selection based on Clamping Torque
- Check for the machining forces required to do the operation.
- Check for the distance from the center where operation is to be carried out.
- Calculate torque applied during machining ( Torque = Force x Distance)
- Machining torque should be with in Clamp torque capacity of the Table
- Check for the type of clamping required (Hydraulic or Pneumatic )
Selection based on Component Weight
- Check the dead weight of the component and fixture.
- The dead weight of component & fixture should be within the capacity of Load capacity of the Rotary Table.
- With tail stock support Load capacity of the Rotary Table in vertical condition will become same as horizontal load capacity.
Selection based on Indexing Accuracy
- Check for the accuracy requirement on the component.
- If accuracy specified in mm, check for the diameter at which the accuracy is required.
- Convert Indexing Accuracy of the Rotary Table specified in arcsec to mm at the diameter where the operation is to be carried out
- (A = Tan Ө x R),
- Ө = Indexing Accuracy (Ex: +/- 15” (30”sec))
- R = Radius at which the operation to be carried out
- A = Accuracy in μ
- NOTE: Higher accuracy of +/- 5” can be achieved by using an additional high-resolution encoder mounted on the table axis.
Selection based on Machine Capacity
- Check the Machine Strokes and ensure once the Rotary Table is mounted on the Machine Bed, the component falls in the machining area.
- Also, check for the Tool change position. While tool changing the tool should not foul with Rotary table.
- The total weight of the Rotary table including the work holding should be with the capacity of the machine load capacity.
Selection based on fouling with machine guard
- Check for fouling of Rotary table Sheet Guard with Machine guard after mounting on Machine bed locating on the center tenon slot.
- If there is fouling we can use the Rear Motor mounting Table, provided there is sufficient space between the Machine table and Machine sheet guard when the table is on the extreme right-hand side.
Selection based on controller feasibility
- Check if Machine Controller is capable of taking the 4th Axis Rotary Table and 5th Axis Rotary Table for single-axis table and 4th and 5th axis for two-axis tables.
- We can also suggest a stand-alone controller if the machine is not capable of handling the 4th axis, provided the component does not need continuous interpolation with machine axes for performing the operation
- In some cases, controllers are capable of 4 regular axes and the 5th axis can only do indexing.