# MINI-RBS: Calibration Bug? Motor Always runs for 2 Minutes **URL:** \ **Category:** Free discussion\ **Created:** [July 28, 2025, 8:03am UTC](https://forum.ewelink.cc/t/mini-rbs-calibration-bug-motor-always-runs-for-2-minutes/197045 "2025-07-28T08:03:38Z")\ **Posts on this page:** 1\ **Showing post:** 5
**Author:** ![Nicho](https://avatars.discourse-cdn.com/v4/letter/n/ed655f/32.png) [@Nicho](https://forum.ewelink.cc/u/Nicho)\ **Post date:** [July 30, 2025, 7:19am UTC](https://forum.ewelink.cc/t/mini-rbs-calibration-bug-motor-always-runs-for-2-minutes/197045/5 "2025-07-30T07:19:11Z")
Hi ilGaspa, The MINI-RBS controls the curtain’s position using precise timing based on a percentage scale. For example, moving the curtain from 1% to 51% open runs the motor for half of the total calibrated time. However, because the motor takes a moment to start, it may not reach exactly 51%, stopping closer to 49%. This small discrepancy means the curtain’s position isn’t always perfectly accurate and can worsen if repeatedly stopped mid-position. To ensure the curtain fully opens (100%) or closes (0%), we add a 2-minute buffer to these commands. This extra time guarantees it reaches its endpoint despite minor timing variations. The motor usually has built-in limits that automatically stop it at fully open or closed positions. So even if MINI-RBS keeps the relay on, the motor stops itself—eliminating any risk of damage. We realize this solution might seem radical, so we’re considering adding a feature that lets you customize buffer times for full open and close commands. What do you think? We’d love your feedback! --- _[View the full topic](https://forum.ewelink.cc/t/mini-rbs-calibration-bug-motor-always-runs-for-2-minutes/197045)._