BLOCK-HEAD® Air Bearing Spindle Specifications (metric)

(at 10 bar)

The BLOCK-HEAD® family of air bearing spindles (named for their short, blocky shape) combine rotational accuracy with extremely high stiffness comparable with that of heavy-duty ball bearing headstocks. These spindles are suitable for accurate support of overhung loads, and their unique combination of accuracy and stiffness makes possible direct machining to optical tolerances and finishes.

BLOCK-HEAD® spindles have been used successfully from less than 3.5 bar up to 14 bar, and have shown no signs of instability. They will operate equally well in any position, over a wide speed range, and in a variety of environmental conditions. Add-ons such as motors, chucks, mounting plates, and custom tooling benefit from the correct nature of the BLOCK-HEAD® design. Accessories can be close-coupled, tightly-held, and non-distorting.


 
Load Capacity
Radial
Axial
Tilt
Stiffness
Radial
Axial
Tilt
Error Motion
Radial
Axial
Tilt
Total Weight
Rotor Weight
Rotor Inertia 
Maximum Speed
Air Consumption

Model 3R BLOCK-HEAD®

Ultimate Working
280 N 140 N
760 N 380 N
16 N-m 8 N-m
88 N/micrometer
260 N/micrometer
0.18 N-m/microradian
< 25 nanometers
< 25 nanometers
< 0.3 microradian
32 N
14 N
0.0011 kg-m2
15,000 rpm
< 55 L/min


Model 4R BLOCK-HEAD®

Ultimate Working
440 N 220 N
1780 N 890 N
45 N-m 23 N-m
120 N/micrometer
350 N/micrometer
0.45 N-m/microradian
< 25 nanometers
< 25 nanometers
< 0.1 microradian
85 N
34 N
0.0052 kg-m2
7,500 rpm
< 55 L/min


Model 4R 2.25 BLOCK-HEAD®

Ultimate Working
560 N 280 N
780 N 390 N
17 N-m 8.5 N-m
140 N/micrometer
175 N/micrometer
0.19 N-m/microradian
< 25 nanometers
< 25 nanometers
< 0.1 microradian
71 N
31 N
0.0054 kg-m2
7,500 rpm
< 55 L/min


Model 4B BLOCK-HEAD®

Ultimate Working
440 N 220 N
1780 N 890 N
45 N-m 23 N-m
120 N/micrometer
350 N/micrometer
0.45 N-m/microradian
< 25 nanometers
< 25 nanometers
< 0.1 microradian
80 N
34 N
0.0052 kg-m2
7,500 rpm
< 55 L/min


Low-Profile 4R & 4B BLOCK-HEAD®

Ultimate Working
440 N 220 N
1780 N 890 N
45 N-m 23 N-m
120 N/micrometer
350 N/micrometer
0.45 N-m/ microradian
< 25 nanometers
< 25 nanometers
< 0.1 microradian
71 N
22 N
0.0028 kg-m2
7,500 rpm
< 55 L/min




 
Load Capacity
Radial
Axial
Tilt
Stiffness
Radial
Axial
Tilt
Error Motion
Radial
Axial
Tilt
Total Weight
Rotor Weight
Rotor Inertia 
Maximum Speed
Air Consumption

Model 10R BLOCK-HEAD®

Ultimate Working
1780 N 890 N
10700 N 5350 N
680 N-m 340 N-m
350 N/micrometer
1750 N/micrometer
11.3 N-m/microradian
< 25 nanometers
< 25 nanometers
< 0.1 microradian
680 N
320 N
0.254 kg-m2
1,800 rpm
< 85 L/min


Model 10B BLOCK-HEAD®

Ultimate Working
1780 N 890 N
10700 N 5350 N
680 N-m 340 N-m
350 N/micrometer
1750 N/micrometer
11.3 N-m/microradian
< 25 nanometers
< 25 nanometers
< 0.1 microradian
650 N
320 N
0.254 kg-m2
1,800 rpm
< 85 L/min


Model 10R-606 BLOCK-HEAD®

Ultimate Working
2670 N 1330 N
4450 N 2220 N
320 N-m 160 N-m
525 N/micrometer
875 N/micrometer
6.8 N-m/microradian
< 50 nanometers
< 50 nanometers
< 0.1 microradian
460 N
190 N
0.191 kg-m2
1,500 rpm
< 110 L/min


23R BLOCK-HEAD®

Ultimate Working
6670 N 3340 N
66700 N 33400 N
5650 N-m 2830 N-m
700 N/micrometer
7000 N/micrometer
170 N-m/microradian
< 25 nanometers
< 25 nanometers
< 0.1 microradian
9800 N
6200 N
1.73 kg-m2
Application Dependent
< 280 L/min



Load capacity and stiffness are approximately linear with air pressure.

Ultimate load capacity is measured when metal-to-metal contact is made across the bearing surfaces. Working load capacity is half of the ultimate load capacity. Rotor weight must be included as part of total spindle load.

Axial and tilt loads are supported by the same bearing surfaces. Consequently, a load applied in one mode reduces the other mode proportionally.

High speed or high inertia applications require rotor containment. Maximum speed is dependent on application. Consult Professional Instruments for further information with regard to speed.