Hello,
I am looking for mechanical design advice regarding an automatic textile tape handling problem in a custom-built machine.
I designed a device that automatically flips a textile edging tape (mattress edge tape / “kedra”) during winding onto a spool. The system works mechanically, but the flip is unstable and only succeeds intermittently.
I am attaching a short video showing the issue.
Machine setup
The tape sometimes completes the flip correctly, but most of the time it remains partially twisted.
Success rate is roughly 5–10%.
Observed behavior:
What has already been tested
Current questions
I would apprecite advice from people experienced with web handling or textile machinery:
I am looking for mechanical design advice regarding an automatic textile tape handling problem in a custom-built machine.
I designed a device that automatically flips a textile edging tape (mattress edge tape / “kedra”) during winding onto a spool. The system works mechanically, but the flip is unstable and only succeeds intermittently.
I am attaching a short video showing the issue.
Machine setup
- Tape width: 15 mm
- Profile: asymmetric
- 10 mm flat flange
- 5 mm corded edge (round bead)
- Material: polyester textile
- Speed: approx. 33 m/min (≈16000 m / 8 h)
- Application: tape winding onto spool
- Pneumatic rotary actuator: SMC CDRB2 series
- Rotation: 180°
- A guiding wheel (“flipping wheel”) rotates and forces the tape to turn over.
- After flipping, the tape immediately passes through a rubber measuring roller (length counter).
The tape sometimes completes the flip correctly, but most of the time it remains partially twisted.
Success rate is roughly 5–10%.
Observed behavior:
- rotation starts correctly,
- but before the twist fully settles, the measuring roller (high friction rubber surface) stabilizes the tape in a wrong orientation,
- resulting in a permanent twist downstream.
What has already been tested
- changing actuator speed (flow control valves),
- different guide rods,
- larger flipping wheel radius,
- adding intermediate rollers,
- testing a funnel-shaped guide,
- experimenting with asymmetric guiding geometry.
Current questions
I would apprecite advice from people experienced with web handling or textile machinery:
- Is it better to stabilize orientation using passive geometry (guides/funnels) rather than adding another active flipping actuator?
- Would increasing flipping radius or using a geared reduction from the rotary actuator typically improve flip stability?
- Are asymmetric guides commonly used to eliminate rotational degrees of freedom in narrow textile tapes?
- Is placing a high-friction measuring roller immediately after a flip generally considered bad practice in web handling systems?Link to the movie with the issue
