Rotor Inspection Gages

Due to high spirals on the lobes, conventional measurement gages cannot be used for measuring rotor major diameters. Gagemaker developed the T-MIC to measure a rotor’s major diameter. The T-MIC’s base spans across two lobes on one side of the centerline and uses a micrometer thimble on the other to measure the diameter. Instead of modifying an existing micrometer, Gagemaker custom builds each T-MIC. Each T-Mic is made to fit a 1″ range of rotor diameters.Gagemaker’s rugged design far exceeds all others on the market today.

Special sizes, metric thimbles, and metric sizes are available; contact customer service for more information.

Gagemaker’s minor diameter micrometer (MIC) gage was designed to measure a rotor’s minor diameter. The spiral lobes on the rotor produce a valley, or minor diameter. The depth of the minor diameter from the major diameter requires a 1” travel indicator stem. Gage range is 0” – 6”, which allows measuring most rotor sizes with only one gage. Ensuring the gage’s durability and long life, Gagemaker’s design uses a heavy duty indicator stem and bearing housing to withstand side loads. Special sizes are available.

Rotor Minor Diameter Gages (Minor MICs)

	Range*	Indicator Travel	Description	Model
	0 – 3” (0 - 76.2 mm)	1”	Rotor minor diameter micrometer	MM-0-3
	0 – 6” (0 - 152.4 mm)	1”	Rotor minor diameter micrometer	MM-0-6
	0 – 6” (0 - 152.4 mm)	1”	Rotor minor diameter micrometer with electronic indicator	MM-0-6E

The lobe height gage, also known as a rotor saddle gage, is the last weapon in the rotor inspection arsenal. This gage sets on top of the spiral lobes of the rotor and measures the variation in lobe height. Sliding the gage along the length of the rotor detects variation in root to crest height of all the lobes. Measurements can be taken at 90° or 180° intervals to provide an accurate dimensional map of the relationship between lobes. This inspection aids in manufacturing the rotor to specification.