1. Problem Description
A customer reported a failure of the solder pot lifting mechanism on an Electrovert Vectra wave soldering machine.
The four lead screws responsible for raising and lowering the solder pot were found in different positions:
Two lead screws were fully extended.
One lead screw was approximately halfway extended.
One lead screw was completely lowered.
The uneven positioning caused the solder pot to tilt, resulting in an estimated 20–50 pounds of molten solder spilling inside the machine.
The machine was taken out of production while the customer cleaned up the spilled solder and prepared to remove the solder pot for further inspection.
Initially, the customer suspected that one or more set screws had sheared, potentially disconnecting the lifting mechanism from the gear chain.
2. Cause of Failure
During troubleshooting, the customer identified solder contamination inside one of the jacking screws.
The hardened solder prevented the jacking screw from moving properly, preventing it from lifting the jacking stand.
This resulted in uneven lifting of the solder pot and ultimately caused the pot to tilt.
The customer was able to restore operation of the jacking stand after identifying and addressing the solder obstruction.
3. Jacking Screw and Leveling Plate Design
Following the incident, the customer raised an additional design concern.
The customer questioned why the jacking screw was not mechanically locked to the leveling plate with an additional retaining device, such as:
A cotter pin
A locking collar
Another mechanical retaining device
The concern was that if the leveling plate became disengaged from the top of the jacking screw, the screw could spin freely without raising the leveling frame.
In this situation, the lifting assembly could effectively lose support at one corner, allowing the solder pot to become unstable and tilt.
The customer requested that Engineering review the possibility of adding a mechanical retention feature.
4. Engineering Review and Response
On March 24, 2025, ITW EAE Product Technology Management reviewed the proposed modification.
Engineering determined that simply adding a cotter pin to secure the jacking screw to the leveling plate would create another potential safety hazard.
Engineering's explanation:
If a tool or another object were accidentally left underneath the leveling plate, securing the plate directly to the jacking screw could cause the entire jack tube assembly to be lifted upward.
This could pull the jack tube assembly out of the lower bearing block and result in a serious mechanical malfunction.
For this reason, Engineering does not recommend simply adding a cotter pin or similar retention device.
Engineering indicated that it was investigating whether a different method could safely secure the leveling plate to the jacking screws without introducing additional mechanical risks.
5. Troubleshooting and Inspection Recommendations
When investigating solder pot lifting problems, inspect the following components:
Jacking Screws
Check for solder contamination or hardened solder buildup.
Verify that the screws can move freely.
Inspect for damage or binding.
Confirm that all lifting points operate consistently.
Jacking Screw Engagement
Verify that the head of each jacking screw is properly engaged with the top plate.
Confirm that the screw is correctly retained by the top plate during operation.
Check for signs of disengagement or improper positioning.
Brass Internal Threads
Inspect the brass threads inside the jacking tubes.
Look for stripped, damaged, or contaminated threads.
Verify that the jacking screw can operate properly within the threaded assembly.
Leveling Plate and Jacking Assembly
Inspect the leveling plate and associated lifting components for damage.
Verify that all four lifting points are properly positioned.
Check for signs of uneven lifting or mechanical misalignment.
6. Important Engineering Notice
DO NOT ADD AN UNAPPROVED COTTER PIN, LOCKING COLLAR, OR OTHER RETAINING DEVICE TO THE JACKING SCREW.
Engineering has identified a potential safety hazard with mechanically securing the jacking screw to the leveling plate.
If an obstruction is left underneath the leveling plate, an added retaining device could pull the entire jack tube assembly out of the lower bearing block.
Any proposed modification to the jacking screw retention arrangement must first be reviewed and approved by ITW EAE Engineering.
Do not modify the factory lifting assembly without Engineering approval.
7. Safety Considerations
If the solder pot becomes tilted or the lifting mechanism operates unevenly:
Stop machine operation.
Do not continue raising or lowering the solder pot.
Keep personnel clear of the unstable solder pot and lifting assembly.
Follow the machine's applicable lockout/tagout and molten solder safety procedures before inspection.
Have qualified service personnel inspect the lifting mechanism before returning the machine to production.
A solder pot that is not properly supported at all four lifting points presents a significant mechanical and personnel safety hazard.
8. Summary
The Vectra solder pot lifting failure reported by Valcom was traced to solder contamination inside a jacking screw.
The contamination prevented the screw from lifting the jacking stand, resulting in uneven support and causing the solder pot to tilt and spill molten solder.
The customer subsequently requested a design modification to prevent the jacking screw from disengaging from the leveling plate.
ITW EAE Engineering determined that simply adding a cotter pin could create another serious safety hazard by potentially pulling the entire jack tube assembly out of the lower bearing block if an obstruction were present underneath the leveling plate.
Do not add an aftermarket retaining device or modify the factory lifting arrangement without prior Engineering approval.
Keep the jacking screws clean, verify proper engagement with the leveling plate, and inspect the internal brass threads whenever lifting problems occur.