the leading edge clamp and the trailing edge clamp being configured to hold the substrate during rotation of the printer drum for printing on the substrate.

2. The printer drum of claim 1 wherein the axis of rotation is a common central axis of the disks of the first plurality and the disks of the second plurality.

3. The printer drum of claim 2 wherein each disk defines a centric hole and further comprising an axle extending along the axis of rotation and through each centric hole.

 8

4. The printer drum of claim 3 wherein the axle is fixedly connected to the leading edge assembly such that rotation of the axle causes rotation of the leading edge assembly.

5. The printer drum of claim 1 further including a rotation 5 lock for preventing the disks of the trailing edge assembly from rotating with respect to the disks of the leading edge assembly.

6. The printer drum of claim 1 wherein the disks of the first plurality and the disks of the second plurality each

10 define a through hole located between a center of the disk and a circumference of the disk for containing a balancing weight.

7. The printer drum of claim 6 further including a balance weight located in each disk through hole such that a center 15 of mass of the leading edge assembly and a center of mass of the trailing edge assembly lie along the axis of rotation.

8. The printer drum of claim 1 further including a bal-ancing disk interleaved with the disks of the first plurality and the disks of the second plurality, the balancing disk

20 including an adjustably positioned balancing weight for compensating for the weight of a printing plate attached to the printer drum.

9. The printer drum of claim 8 wherein the balancing disk comprises a disk of the leading edge assembly.

25 10. The printer drum of claim 8 wherein the balancing disk includes a central member having a first side and an opposing second side, a first ring rotatably mounted to the first side of the central member, and a second ring rotatably mounted to the second side of the central member.

30 11. The printer drum of claim 10 wherein the balancing weight comprises a first weight fixedly mounted to the first ring and a second weight fixedly mounted to the second ring.

12. The printer drum of claim 1 wherein the leading edge clamp interconnects the first plurality of disks and the 35 trailing edge clamp interconnects the second plurality of disks.

13. The printer drum of claim 12 wherein the disks of the first plurality and the disks of the second plurality are generally circular in shape and each disk defines a relieved

40 section along a portion of a circumference of the disk, the relieved section of each disk providing clearance for the leading edge clamp and the trailing edge clamp during rotation of the leading edge clamp relative to the trailing edge clamp.

45 14. The printer drum of claim 12 wherein the disks of the first plurality and the disks of the second plurality define a continuous substrate support surface.

15. The printer drum of claim 1 wherein the disks of the first plurality and the disks of the second plurality are

50 substantially identical, each disk of the first plurality of disks and the second plurality of disks having a first side and an opposing second side, when interleaved the disks of the second plurality are reversed with respect to the disks of the first plurality such that the first side of a disk of the first