Design Data

Metric to English Conversion Table

1 kW=1.341 hp1 mm=0.03937 in 1 kg=2.205 lbs 1 Nm=8.851 in-lbs1 N=0.22481 lbs1 cc=0.061 in 3 =61,023.76 in 3 3 1 N/µm=5,710 lbs/in 1µm =0.00003937 in 1 bar=14.50 psi1 m

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F - 32) ÷1.81 kg-mm 2 =0.0034 lb-in 2 ‘DN’ = bearing bore diameter (mm) X spindle RPM

‘DN’ Value –

The standard ProMetrix the ‘DN’ value plays a significant role in the overall design of series super precision spindles as shown in this catalog are designed andmanufactured to operate up to a ‘DN’ value of 600,000 utilizing steel ball. For spindles operating to higher ‘DN’ values consult SETCO’s Design Team. ProMetrix series superprecision spindles. From the initial design stage to the finished product the ‘DN’ value determines bear- ing precision, bearing mounting arrangement, machining tolerances, bearing preload, type and method of lubrication, material and heat treat process, balancing requirement, vibration acceptance level, and final inspection method that a spindle is processed. The ‘DN’ value is calculated as follows (using the largest bearing in the spindle): ProMetrix series super precision spindles in this catalog to specific applicationrequirements. This information is provided as a guide for a quick and simple means of approximating machining application requirements. Consult a cutting tool manufacturer specialist to obtain best results for final machining requirements. The Design Data section contains machining data tables and equations to calculate approximate power, speed and feed rates. The Flowchart for Selecting Optimum Spindle Sizing, on page 31, provides a step-by-step procedure to calculate the required spindle speed and power. The Spindle Selection Chart on page 5 of this catalog is provided to assist in proper spindle sizing selection for a specific application.

Spindle Sizing - Power / Speed Requirements

For proper spindle sizing, the machining power and speed requirements must be known or determined. The optimum spindle size for a specific application is dependent on the operating speed of the spindle and the power that needs to be transmitted by the spindle to accomplish the machining operation.A major factor in selecting the proper spindle for a specific machining application is the amount ofpower required to do the work. This power requirement, as recommended by SETCO, is defined as the Unit Power technique. The Unit Power technique utilizes published machining data, based on the machining operation, for recommended cutting speeds and feed rates as determined by the material and geometry of the cutter, material and hardness of the workpiece and the machining operation being performed. The tables, on page 30, provide approximate cutting speeds and feed rates for a specific machining application. After determining the recommended cutting speed and feed rate, the equations contained in the flowchart on page 31 provide a simple and easy method to calculate the power required to accomplish the machining operation.Information provided in the Design Data section, pages 30 and 31, has been compiled to assist in applying the
For grinding applications it is recommended that a grinding wheel manufacturer be contacted to determine the proper safeoperating speeds and power requirements to ensure that the grinding wheel is not operated above the maximum rated speeds. 29