The outer-sleeve is the foundation for the outer belts.

Outer belts bow outward, pressing against the inner surface of the outer-sleeve and creating ample surface area for no-slip scrolling contact.

Inner-belts create the assembly's stability, so a patterned balance of outer belts is not needed.

Note: An outer-sleeve can increase the diagonal rigidity of the assembly. (e.g. 4 belts per 4 orbit rollers is fine.)

Fig.66

Outer belts can be placed:

• On top of Inner belts
• Pressed against sleeve
• Between Inner belts
• etc.

Note: As speed increases, centrifugal forces increase the outer-belt's grip on the inside of the outer-sleeve.

The bowing effect of the outer belts can be created in several ways:

• Magnetic/Static
• Spongy
• Springy (steel, plastic)
• Inflatable (hose)
• etc.

(Link: Construction)
(Link: Outer Sleeve/Casing)