Liftmaster K158A0068 Photo Interrupter Cup 158A0068, 29-10344
The LiftMaster K158A0068 is a replacement photo interrupter cup used on select LiftMaster commercial door operators. In operators that use optical feedback, the interrupter cup passes through or works with a photo sensor so the control system can read movement. If the cup is damaged or out of position, the operator may not receive clean feedback.
This is a small part, but it can affect travel tracking and operator response. Common service reasons include a cracked cup, stripped mounting point, missing cup, broken tabs, or a cup that no longer rotates correctly with the shaft. A dirty or failed photo sensor can create similar symptoms, so the surrounding components should be inspected.
K158A0068 is commonly cross-referenced with 158A0068 and 29-10344. Match the original part number, shape, and parts diagram before ordering. Similar optical wheels or cups may look close but have different slot spacing or mounting geometry.
Compatible With
Common Compatible Models and Applications
- Select LiftMaster commercial door operators using a photo interrupter cup
- Commercial door operator optical feedback assemblies that specify K158A0068
- Operator applications where the parts list calls for 158A0068 or 29-10344
Additional Model Families to Verify
- Various LiftMaster commercial door operator generations when confirmed by original parts diagram
- Related photo interrupter sensor assemblies should be verified separately and are not automatically included
Important Compatibility Notes
- This is the interrupter cup, not necessarily the sensor.
- Inspect the photo sensor and wiring if feedback errors remain.
- Match the cup shape and part number before ordering.
Features and Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Photo interrupter cup |
| Part Number | K158A0068 |
| Application | Commercial door operator optical feedback / position sensing assembly |
| Compatible Operator Type | Select LiftMaster commercial door operators |
| Related Numbers | 158A0068, 29-10344 |
| Notes | Verify cup style and parts diagram |
Also Known As / Related Part Numbers
- K158A0068
- 158A0068
- 29-10344
- 2910344
- Photo interrupter cup
- Photo interuptor cup - common misspelling
Technician Note
If the operator still shows travel or movement feedback symptoms after replacing the cup, inspect the photo interrupter sensor, sensor gap, wiring harness, connector condition, and control board input before replacing more parts.
Before Ordering
- Confirm the original cup part number is K158A0068, 158A0068, or 29-10344.
- Check the cup for cracks, missing tabs, or loose fit.
- Inspect the sensor for dirt, damage, and alignment.
- Verify the operator parts diagram before ordering.
- Do not bend or modify the cup to fit a different sensor assembly.
Professional Advisory
Travel feedback problems can cause a commercial door operator to stop incorrectly. If the door movement is unpredictable or the operator will not complete setup, have the system diagnosed by a qualified commercial door technician.
Important Ordering Warnings
- This part does not automatically include the photo sensor or control board.
- Similar interrupter cups may not have the same slot pattern or mounting fit.
Product Questions and Answers
What is K158A0068 used for?
It is a photo interrupter cup used in select LiftMaster commercial door operator feedback assemblies.
Is 29-10344 the same related part number?
Yes. 29-10344 is commonly listed as a related number for K158A0068 / 158A0068.
Does this include the photo sensor?
No. This item is the interrupter cup. The sensor and wiring are separate unless a different kit specifically includes them.
What symptoms can a damaged interrupter cup cause?
Possible symptoms include travel errors, movement feedback faults, unexpected stops, or failure to complete setup on compatible operators.
Can I use a different-looking cup if it fits the shaft?
No. The cup shape, slot pattern, and sensor alignment must match the original design.
