# Displacement Guide Installation Mistakes > Importance of sensor placement and the location of entry and exit rollers to maintain a 90-degree wrap for optimal web guiding. **Last updated:** 2026-03-03 **Source:** https://r2r.tech/videos/displacement-guide-installation-mistakes --- Optimizing Sensor Placement and Roller Position in Displacement Guides This episode is part of the 'Web Guiding Fundamentals' webinar series, focusing on the importance of sensor placement and the location of entry and exit rollers to maintain a 90-degree wrap for optimal control and stability of a displacement guide system. The video discusses how to position sensors close to the exit roller, the effects of web speed on sensor placement, and the consequences of incorrect installation, including bending and oversteering. By following these guidelines, you can ensure smooth operation and avoid unintended consequences like web breaks. 00:00 Introduction to Sensor Placement 00:10 Impact of Sensor Distance on Control Systems 00:23 Effects of Web Speed on Sensor Placement 00:39 Consequences of Incorrect Sensor Installation 01:04 Importance of 90 Degree Wrap 01:16 Avoiding Bending and Distortions 01:32 Oversteering Due to Spread Out Exit Span 01:43 Ideal Sensor Placement Scenario ## Transcript [Music] We don't want to install the sensor too far away or in the next span. This is mainly for control system purposes and stability. When the web guide makes a corrective action, that action is not seen at the sensor immediately. So, if you're running really fast, you might get away with moving these sensors a little further down. But if you're running slow, whenever this web guide moves here, you would see that motion, if the sensor is as close to the exit roller as possible. If you install it here or here, especially when the web stops and there is a small error, the web guide would keep moving and that might cause the web to break or have unintended consequences. So, we don't want to have the sensor further away or in next span. And we don't even we don't also want to have a scenario where you have an angle that is not 90°. If you have a 90° wrap, you have twist. As soon as you introduce something which is deviating more from the 90°, you start creating bending in the web. So these kind of bending is going to act as under steering the web. It's going to cause bending that's going to under steer the web and it also causes distortions and guiding stability. So we don't really want to have any of these conditions. On the contrary, if you have a span exit span that is spread out like this, this is going to over steer the web. It's the bending effect that is causing that and we really don't want to do that. So ideal scenario would be to have a 90°ree wrap in and out. [Music] ## Related Products - Low Profile Web Guides - Wide Web Guides - ODC Sensors - 1DC Sensors - Web Position Sensor - Narrow Web Steering Guides **Tags:** web guiding, web edge sensor, web guide sensor, Low Profile Web Guides, Wide Web Guides, ODC Sensors, 1DC Sensors, Web Position Sensor, Narrow Web Steering Guides --- ## About Roll-2-Roll Technologies Roll-2-Roll Technologies designs and manufactures patented fiber-optic web position sensors and advanced web guiding controllers — the precision measurement and control core of modern roll-to-roll manufacturing. Spun out of Oklahoma State University's Web Handling Research Center and trusted by Fortune 500 medical, battery, and nonwovens manufacturers, our patented sensors work without recalibration at ±0.1mm accuracy up to 760 mpm — typical customer outcomes are 50%+ less downtime and payback under six months. Headquartered in Stillwater, Oklahoma, our team of PhDs, controls engineers, and industry veterans extends the sensor + controller core into complete web guide systems including stepper-motor-based linear actuators (RLA, BLA, LHS). - Website: https://r2r.tech - Phone: +1 (888) 290-3215 - Email: sales@r2r.tech