Composite sprocket

1. A composite sprocket comprising:

a skeleton having a connection interface and an outer portion having a rough tooth structure;

an overlay formed on and over the outer portion of the skeleton and comprised of a precision material and forming a high precision tooth structure over the rough tooth structure;

the skeleton formed having a low precision with tolerances of plus or minus 0.060 inches;

the overlay formed having the high precision with tolerances of plus or minus 0.015 inches;

the connection interface is a hub is configured with a mating feature to facilitate rotational movement of the sprocket about an axis;

the overlay is further configured to cover an inner surface of the hub to form a high precision mating feature.

2. The sprocket of claim 1 , wherein the skeleton is comprised of a castable metal material.

3. The sprocket of claim 1 , wherein the skeleton is comprised of iron and is formed by a rough casting without metal finishing.

4. The sprocket of claim 1 , wherein the skeleton is comprised of extruded aluminum.

5. The sprocket of claim 1 , wherein the precision material of the overlay is a castable polymer material.

6. The sprocket of claim 1 , wherein the precision material of the overlay is a castable urethane.

7. The sprocket of claim 1 , wherein the overlay material contains a textile reinforcement material.

8. The sprocket of claim 1 , wherein the skeleton has a tensile strength greater than about 9,000 psi.

9. The sprocket of claim 1 , wherein the sprocket is configured to rotate about a center axis and move a belt, where the high precision tooth structure engages ribs of the belt.

10. A composite sprocket comprising:

a skeleton having a connection interface and an outer portion having a rough tooth structure, wherein the connection interface and the rough tooth structure have a first tolerance; and

an overlay formed on and over the outer portion of the skeleton and forming a high precision tooth structure over the rough tooth structure, the high precision tooth structure have a second tolerance and the overlay configured to cover an inner surface of a hub to form a high precision mating feature;

the first tolerance is greater than about plus or minus 0.030 inches;

the second tolerance is less than about plus or minus 0.010 inches.

11. The sprocket of claim 10 , wherein the skeleton have a first tensile strength and the overlay has a second tensile strength, then the first tensile strength is greater than the second tensile strength.

12. The sprocket of claim 11 , wherein the first tensile strength is greater than about 9,000 psi and the second tensile strength is less than about 6,600 psi.

13. The sprocket of claim 11 , wherein the skeleton is comprised of cast iron.

14. The sprocket of claim 11 , wherein the skeleton is comprised of iron and the first tensile strength is about 65.5 to 172 Mega pascals (Mpa) tensile strength, yield.

15. A composite sprocket comprising:

a skeleton having a hub and an outer portion having a rough tooth structure; and

an overlay formed on and over the outer portion of the skeleton and comprised of a precision material and forming a high precision tooth structure over the rough tooth structure;

the hub is configured with a mating feature to facilitate rotational movement of the sprocket about an axis

the skeleton is comprised of iron and is formed by a rough casting without metal finishing;

the precision material of the overlay is a castable urethane;

the skeleton formed having a low precision with tolerances of plus or minus 0.060 inches;

the overlay formed having the high precision with tolerances of plus or minus 0.015 inches;

the skeleton has a tensile strength of about 65.5 to 172 Mega pascals (Mpa) tensile strength, yield;

the overlay has a tensile strength less than about 6,600 psi;

the tooth structure comprising 9 teeth;

the overlay configured to cover an inner surface of the hub to form a high precision mating feature.