Quality problems are not always machine problems
When factories see floating screws, stripped threads, missed holes, or unstable torque, the first reaction is often to question the screw locking machine. Sometimes the machine setting is the cause, but in many projects the root cause is screw or product tolerance.
Automatic screwdriving requires repeatability. If screw dimensions, hole positions, product support, or molded parts vary too much, the machine has to deal with a moving target. This is why process evaluation should include both equipment and product conditions.
Screw-related factors to check
- Screw diameter and length consistency.
- Head type and whether the bit can engage reliably.
- Washer condition or attached parts that may affect feeding.
- Surface treatment, oil, debris, or burrs that may affect feeding and tightening.
- Mixed screw batches or different suppliers used in the same production line.
Product-related factors to check
- Screw hole position tolerance and whether holes shift between parts.
- Plastic post strength and whether the post cracks or deforms during tightening.
- Burrs, blocked holes, or unstable pre-formed threads.
- Thin, flexible, or curved surfaces that need fixture support.
- Part deformation caused by clamping, heat, storage, or previous assembly steps.
How automation can reduce tolerance impact
A well-designed automation system can reduce the impact of tolerance, but it cannot ignore it. Fixture support can stabilize the product. Vision positioning can correct small position shifts. Servo torque control can help identify tightening abnormalities. Feeding and bit design can improve screw delivery consistency.
For products with large variation, the solution may need more than a standard machine. Engineers may need sample testing, fixture adjustment, vision guidance, or product design feedback before finalizing the equipment proposal.
What to prepare before evaluation
- Several product samples from different batches.
- Several screw samples from actual production batches.
- Photos or videos of current defects.
- Information about current torque setting and manual process.
- Details about product material, hole structure, and quality acceptance standard.
Quick FAQ
Can vision guidance solve all position tolerance problems?
No. Vision can correct certain position shifts, but if the product deforms, holes are blocked, or screw posts are unstable, fixture and product process improvements may still be needed.
Should factories test real screws before ordering equipment?
Yes. Real production screws should be tested whenever possible, especially when screws are small, have washers, use special head types, or come from multiple batches.
Need a screw fastening proposal for your product?
If your assembly process has floating screws, stripped threads, missed holes, or unstable torque, send defect videos, product samples, and screw specifications. Chisu can help identify whether the issue is machine selection, fixture design, screw tolerance, or product tolerance.
Talk to Chisu Engineers