Monday, August 27, 2012

Four Easy Steps For Preloading Guide Wheels in Linear Motion Systems


ADJUSTING ECCENTRICS Preloading guide wheels is simple, essential and very necessary as it greatly improves the life and performance of a guide wheel-based linear motion system — also cuts maintenance costs and maximizes functionality. In today's #MotionMonday post we highlight four easy steps for adjusting eccentric guide wheels. Using a socket wrench + an open end wrench, follow the instructions below:
  1. STEP ONE Begin by placing the carriage on the track assembly.
  2. STEP TWO Using the open end wrench, tighten the eccentric wheel clockwise until it makes contact with the track. Find where it's snug then tighten using the socket wrench so the nut is flush with the wheel plate.
  3. STEP THREE Slide the wheel plate back and forth to check whether there is any noticeable variation in rolling resistance.  If there is, loosen the wheel plate for desired tension by using the open end wrench. Check for tension by manually sliding the wheel plate back and forth on the track.
  4. STEP FOUR To lock the wheel in the adjusted position, tighten the eccentric wheels fastener with the socket wrench in place.

WHY PRELOAD? This is a common practice when you're putting together the structural parts of a linear guide system. It's widely used in bolted joint assemblies, according to Leslie Lui, a Bishop-Wisecarver research and development engineer. A properly preloaded guide wheel lasts much longer because it reduces variations in resultant loading on the bearings.

Proper preloading comes with other benefits, too. It cuts down on vibration and noise since the carriage won't tile or shift on the tracks. And when outside loads are applied, a preloaded carriage in a driven system will see much less displacement on the tracks. This practice also enhances the repeatability and linear accuracy of the carriage on a driven system.

DIY EMPOWERMENT End users can easily adjust the preload for guide wheels, unlike other linear slide systems that are factory set, such as profile rail. Guide wheel-based systems, however, are easily customized.

NEED MORE INFO? If you'd like to read more about this process in great detail, check out the full article posted on our website. We've also included a short video demonstration below for your viewing pleasure.