D1091 – Manual Collet – Light machining spindle

The D1091 is a small air turbine-driven spindle for light machining duties, with a maximum speed of 100,000rpm. It is fitted with a manual collet system, with sizes from 0.5mm to 5mm diameter available. Due to its compact size and air-cooled body, installation into any precision machine tool is simple. An optional speed sensor can be supplied for accurate turbine speed feedback.

Specifications of D1091 spindle

Max. operating speed100,000 rpm
Collet bore sizes0.5 to 5mm
Turbine air consumption113 nl/min
Bearing air supply pressure5.6 kg/cm*2
Bearing air consumption39 nl/min
Axial failure load - push75 N
Collet tool runout - max0.01mm
Dynamic runout at tool10 μm
Motor typeAir turbine
Speed sensor (Tacho) - OptionalHall effect
Radial failure load at collet face35 N @ 100,000 rpm
Axial failure load (push)75 N
Body diameter41.3 mm
Weight (approx)1.1 kg


Have a question about the Air Bearing Spindles product range? Here we answer a selection of frequently asked questions.

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This should be carried out at intervals recommended by the machine manufacturer. You are strongly advised to refer to the appropriate Westwind collet maintenance booklet (available free on request), and to use the Westwind collet maintenance kit available through your machine supplier. However, as a general rule we would recommend a maximum of 5,000 hours between removal/cleaning/re-setting, although some end users maintain their collets every 100 hours.

Westwind recommend the use of distilled water with the addition of chemical agents to prevent algae or bacterial growth. Each spindle needs an uninterrupted flow at between 16-20ºC. Many spindles used in production are fitted with temperature sensors that shut the machine down before damage is done.

By clean air we mean the supply should be filtered to better than 0.01 microns and 99.99% free from oil and water as a liquid or vapour with a PDP (Pressure Dew Point) @ 7°C. Westwind are able to supply suitable filter units. Please note that in all cases we strongly recommend that the compressor system is backed up by a reservoir tank to maintain a steady pressure and to minimise the effects of an air failure.

Westwind spindles, when correctly installed and supplied with clean adequately filtered air, give many years’ service with the minimum of attention. Routine maintenance is limited to changing the air filter elements so that the air supply remains uncontaminated. Guidelines can be found online for spindle and collet maintenance.

No, you do not need to add lubricating oil to the air supply of the air bearing spindle.  This does not work like a ball bearing spindle. You should not add oil, as air bearings, being non-contacting, do not need a fluid lubricant.