Hey there! I totally get the frustration of dealing with intermittent issues when you're under pressure to just keep things running. Documenting these tricky servo motor vibration problems without fancy vibration analysis tools is definitely challenging, but here's a practical approach you can use:

1. Create a simple tracking log - Use a spreadsheet or notebook to record every occurrence. Include: date/time, shift, who reported it, what the vibration felt/sounded like (describe it in plain terms), and any immediate actions taken.

2. Track environmental conditions - Since you suspect humidity spikes, start recording the humidity levels when issues occur. You can use a basic hygrometer or even check weather data for your area. Note temperature too, as it often correlates with humidity.

3. Use your senses as tools - Describe what you hear (buzzing, grinding, humming), feel (hand vibration intensity), and see (motor movement, visible shaking). Be specific - 'feels like a washing machine off-balance' is actually helpful!

4. Take photos/videos - Your phone can capture visual evidence of the vibration. Even better, record audio of the sound. This creates objective evidence you can show supervisors.

5. Correlate with production data - Note what the machine was doing when vibration occurred (startup, specific speed, load conditions). This helps identify patterns.

The key is consistency - document every occurrence, even if you just 'make it work' temporarily. Over time, this data will reveal patterns and help build your case for proper diagnostic tools or permanent solutions. It's frustrating to document when you're pressured to just fix things, but this evidence is what gets management to listen and invest in proper solutions!