LiftMaster MA012 Cam Arm with Magnet for Mega Arm Barrier Gate Operators
The LiftMaster MA012 is a replacement cam arm with magnet for select Mega Arm barrier gate operators. In the Mega Arm assembly, this part works with the operator travel/limit sensing area to help identify arm position during the open and close cycle. A cracked, worn, missing, or misaligned cam arm can create poor arm positioning, travel errors, inconsistent stopping, or repeated adjustment problems.
MA012 is a small but important part in the Mega Arm mechanical control system. It should be treated as a precision alignment item, not just a plastic replacement piece. When the cam arm is replaced, the technician should check the magnet, related sensor/switch area, arm bracket, shear pin, and overall arm alignment. If the operator has suffered a vehicle strike, simply replacing the cam arm may not correct the underlying drive or alignment damage.
Compatible With / Common Applications
- LiftMaster Mega Arm barrier gate operators using MA012 in the travel/limit assembly
- LiftMaster Mega Arm Tower barrier gate operators using MA012 in the travel/limit assembly
- Commonly associated with MADCBB and MADCBB3 parts breakdowns
- Commonly associated with MATDCBB and MATDCBB3 parts breakdowns
- Commonly associated with MASDCBB / MASDCBB3 and MASTDCBB / MASTDCBB3 service paths where MA012 is listed
- Barrier gate perimeter access systems using the MA012 / MA-012 cam arm with magnet
Features & Specifications
| Feature / Specification | Details |
|---|
| Manufacturer | LiftMaster |
| Product Type | Cam arm with magnet |
| Part Number | MA012 |
| Application | Barrier arm travel / limit positioning |
| Compatible Operator Type | Mega Arm and Mega Arm Tower barrier gate operators |
| Related Assembly | Arm bracket, shear pin, magnet, travel/limit sensing area |
| Notes | Alignment-sensitive part; verify by parts diagram |
Also Known As / Related Part Numbers
- MA-012
- LIF-MA012
- LiftMaster cam arm
- Cam arm with magnet
- Limit cam
- Limit nut cam
- MA011 magnet
- MA010 gate arm bracket
- MA013 shear pin
Technician Note
If the arm stops in the wrong position after MA012 replacement, do not keep forcing the operator to run. Recheck cam position, magnet location, sensor/switch function, and arm alignment before cycling the operator repeatedly.
Before Ordering
- Confirm the parts diagram lists MA012
- Inspect the original cam arm for cracking or missing magnet hardware
- Check the arm bracket and shear pin for impact damage
- Check related sensors or switches for alignment
- Confirm the arm travels freely before final adjustment
Professional Advisory
Travel and limit repairs affect how the barrier arm stops. A qualified gate technician should perform alignment and testing, and required safety devices should never be bypassed during diagnosis.
Product Questions & Answers
What is MA012 used for?
MA012 is a cam arm with magnet used in select LiftMaster Mega Arm barrier operator travel and positioning assemblies.
Is MA012 the same as the gate arm bracket?
No. MA012 is the cam arm with magnet. MA010 is the gate arm bracket, and MA013 is a shear pin.
Can a bad cam arm cause travel problems?
Yes. A broken, missing, or misaligned cam arm can cause poor arm stopping, travel errors, or repeated limit adjustment issues.
Does MA012 include the full limit switch assembly?
No. MA012 is the cam arm with magnet. Check the parts diagram if switches, wiring, or additional limit parts are also needed.
Should MA012 be replaced after an arm strike?
It should be inspected after any arm impact. The bracket, shear pin, gear reducer, belt, and related alignment parts should also be checked.
