The document outlines an improvement plan for defects found in a Y-tray assembly. Four main defects are described: 1) The Y-tray bridge was too narrow, 2) Screws were protruding at the bridge, 3) The X guide rails were rough, and 4) A rivet core was preventing X motion. Root causes and improvements are provided for each defect. The plan also details eight improvements that were implemented, such as adding jigs and gauges to checks dimensions and prevent issues during assembly.

1. Y-TRAY IMPROVEMENT PLAN
Prepared: Engineering team

2. Contents:
1. Defect:Y-tray too narrow at bridge
- root cause
- improvement
2. Defect:Screws protruding at bridge
- root cause
- improvement
3. Defect:X guide rails rough on sides and top
- root cause
- improvement
4.Defect:One rivet core was still in the assembly preventing X motion
- improvement
5. Implemented improvement

3. Defects:
1. Y-tray too narrow at
bridge
Root cause:
During screw tighten the part
tend to pull inside toward the
middle slot where there is no
force to resist it.
Improvements:
- Put a gage block in the
middle during installing the
screw to prevent the part
from pull inside.
Gage
block

4. Defects:
2. Screws protruding at
bridge
Root cause:
- Burr not properly remove
during lasercut
Improvements:
- Implement proper buffing
jig
Before
After

5. Defects:
3. X guide rails rough on sides
and top
Root causes: Y-tray rib
tolerances max 3.2mm and min
2.8mm. Actual part (3.1mm-
3.2mm)
Improvements:
- Control the tolerances on
nominal minus.Change from +/-
0.2mm to + 0.0mm/-0.2mm

6. Defects:
4. One rivet core was still in the assembly preventing X
motion
Root cause:
Cosmetic standard not updated to defect criteria
Improvements:
-Provide training,update cosmetic standard and visual check the
riveting if any balance rivet core stuck at the tray before test the
x-carriage.

7. Implemented improvements
1. 100% in process dimension and angle checking by
technician,operator for bending process
2. For IPQA in process checking every 2 hours change to every
1 hours

8. 3. Implement positioning jig at lasercut to prevent
missing hole as shown in Figure 1
Figure 1

9. 4. After assembly 100% checking
using the sliding jig as shown in
Figure 2
Figure 2

10. 5. Implement buffing jig to prevent countersunk hole undersized
as shown in Figure 3
Figure 3

11. 6. Implement Go/ No Go gauge to prevent
oversized/undersized bending height as shown in
Figure 4.
Figure 4

12. 7. Implement Go/ No Go gauge to prevent
oversized/undersized rib height as shown in Figure 5.
Figure 5

13. 8. Implement jig to prevent oversized/undersized total
length for bending as shown in Figure 6 .
Figure 6

14. Thank You