2015Camera Stage/Donkey Box forum
Bayonet connection play between XCS post and Pro junction box camera mount
What the thread found
- Rotating the junction box 180 degrees can eliminate or significantly reduce play in the bayonet connection between XCS posts and Pro junction boxes.
- Play in the bayonet connection may result from tolerance differences between junction boxes and posts from different manufacturing periods or manufacturers.
- The locking collar from an older junction box can be swapped onto a newer one to resolve play issues.
- Pro did not change bayonet tolerances but modified the threaded ring approximately 8-9 years ago to add three additional threads for docking capability.
- XCS modified their Pro-style mounts after Pro added extra threads, causing compatibility issues where the locking ring may bottom out on the post and prevent full tightening.
- Adding a retaining ring that raises the junction box by an equivalent thread height can resolve play caused by inadequate thread engagement on the post.
- Safety pins on the junction box side, whether pressed-in or screw-type, can affect fit quality; tightening screw-type pins may improve seating.
- Wrapping threads with PTFE tape and inserting small pieces into the mating pin holes can help tighten the connection.
- On 2-inch posts specifically, the newer locking ring may contact the post surface before full tightening is achieved.
- Regular inspection and tightening with the post tool and plastic hammer helps maintain connection integrity over time.
Depends on
- Some experiences are anecdotal and lack definitive root cause analysis.
- The 180-degree rotation fix remains unexplained by those who implemented it.
- Solutions mentioned were not tested systematically across all post and junction box combinations.
- One user reported difficulty reproducing the manufacturer's explanation regarding tolerance changes.
- PTFE tape and pin hole modifications are described as temporary or supplementary fixes rather than permanent solutions.