HSMAG can produce rotary scales for many application areas. HSMAG can produce rotary scales on the flange, outer or inner diameter.
HSMAG produces rotary scales from 3 mm to 2.1 m outer diameter.
HSMAG produces rotary scales as true angular divisions. At a circumference of 360 mm and a number of 360 poles the universal magnetizing tool from HSMAG writes a north or south pole for each mm equaling exact 1°. There is no gap or mating place at any point of the scale.
The HSMAG magnetization process allows for several tracks and pole lengths from a minimum of 0. 1 mm. Scales can be produced for high accuracies up to <0,005°. For such high accuracies, the eccentricity errors of the scale need to minimized.
Due to the digital creation of the scale pattern, only a low programming fee instead of high tooling costs for magnetizing tools is required enabling engineers to experiment with different pole patterns.
Rotational scale accuracy
Using a flexible manufacturing process HSMAG offers scales for arbitrary lengths with different pole lengths. HSMAG uses different accuracy classes for rotary scales
G006 +/- 6 arc seconds maximum deviation of a pole boundary of the ideal position
G010 +/- 10 arc seconds maximum deviation of a pole boundary of the ideal position
G060 +/- 60 arc seconds maximum deviation of a pole boundary of the ideal position
G100 +/- 100 arc seconds maximum deviation of a pole boundary of the ideal position
G600 +/- 600 arc seconds maximum deviation of a pole boundary of the ideal position
Rotary scale material
HSMAG uses different materials for rotational scales
Ferrite ring – Using a sintered ferrite ring, HSMAG can magnetize many different patterns on the ring. While ferrite is cheap, once a tool is created, the accuracy of the ferrite is limited. Typically, the magnetized face has been ground before magnetization.
Ferrite ring on a hub – The ferrite ring is glued on a hub to provide a more accurate positioning of the scale.
Plastoferrite ring – Using plastics filled with ferrite, HSMAG can magnetize different patterns. Due to the production process, the accuracy of the rings is more limited than with other materials. Due to high tool costs, this material is only relevant for higher volumes.
Elastomer on a hub – Gluing a ferrite filled elastomer on a hub enables many geometries and different scale width on a big variety of hubs. This method can be used for prototypes and scales well for high volume production.
Vulcanized rubber on a hub – For harshest applications, vulcanizing ferrite filled rubber on a hub provides the best environmental performance while having high costs. Industrial and automotive applications are typically using vulcanized rubber.
HSMAG produces rotary magnetic scales with one or more tracks. A reference point or index can be written in the second track, which is used as the zero point for the control.