BLOCK-HEAD® Spindles

The BLOCK-HEAD® family of air bearing spindles (named for their short, blocky shape) combine rotational accuracy with extremely high stiffness comparable to 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 at air pressures from 50 psi to 200 psi, 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. Read more about why BLOCK-HEAD® spindles are the best in the world.

Attachments 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.

The model 3R BLOCK-HEAD® air bearing fits well in high-speed applications like dicing saws or I.D. grinders. Its sub-millionth-inch accuracy and high central stiffness enable controlled material removal even in tough or brittle materials.

The combination of reasonable load capacities with 7,500 rpm maximum speed makes the model 4R a first choice for most high-accuracy applications. The stator’s generous mounting surfaces provide for an extremely rigid assembly, while the compact structure allows an installation where conventional spindles will never fit.

The model 4R 2.25 combines the familiar mounting features of the model 4R with a larger diameter bore. Increased radial load capacity and clearance for fixturing make this spindle a useful tool in the optics industry.

The rectangular stator of the model 4B allows the choice of six different mounting surfaces, two of them offering lowest-possible centerline height. Although it is more challenging to integrate a frameless motor with a model 4B, a belt-drive arrangement is ideal for many low-to-moderate-torque applications.

Low-Profile 4R & 4B air bearings are used in applications where overall height is limited. The smaller thrust plates also have a lower moment of inertia, allowing more rapid accelerations and shorter settling time in servo applications.

High capacity and ultra-high stiffness make the model 10R ideal for turning or grinding heavy workpieces, or as an ultra-rigid toolpost pivot. When integrated with a high-power motor, the model 10R forms the heart of a state-of-the-art optical-surface generator.

The model 10B combines high capacity, high accuracy, and high stiffness with the convenience of mounting on six different stator faces. Long used in the world’s finest asphere generators, the model 10B is an all-around workhorse for heavy workpieces.

The model 10R-606 has a clear axial aperture 6.06” diameter, and high radial capacity thanks to a large shaft. Originally designed for lens alignment, it offers ultra-high accuracy in an uncommon configuration, yet it shares the external dimensions of the standard model 10R.

Designed to support a liquid-mirror telescope lens, the model 23R is an example of the large-scale, special-purpose air bearing Professional Instruments Company builds to solve a customer’s particular problem. When ultra-high accuracy is paramount, regardless of load, our design services will offer you a solution.