FUNCTION OF A roller straightener:A staggered roller straightener simultaneously applies tension and deflection to a wire bending it beyond its yield point causing a redistribution of any internal stresses to improve its orientation and straightness. A properly applied straightener can reduce wire distortion and improve mechanical predictability but a wire straightener that has been poorly maintained or incorrectly adjusted can turn a little problem into a much bigger one. To prevent these big problems from happening a daily and bi-monthly preventive maintenance program as well as training users to be aware of certain problems that can be caused by straightener issues is recommended. The following lists offer the fundamental production and maintenance activities and problem indicators that will elevate your straightening capability.
roller straightener Problem Performance indicators:Although a straightener in need of maintenance can cause a broad variety of problems, the following lists some specific issues that have been found to signal the existence of probable straightener problems that suggest that remedial countermeasures need be applied.
- Presence of wire and/or insulation damage including scrapes, cuts and scoring
- Insulation tripping problems including cut or nicked strands and scraped core
- Termination defects including strands out of core crimp, missing terminal
- Wire accumulation control: Wire cannot be effectively stacked in a wire tray
- Straightener adjustments (either to increase or decrease deflection) has no obvious effect
- Wire shows evidence of being crushed or extruded
dAILY INSPECTION ACTIVITIES
- Assure that all straightener rollers are in place and roll smoothly without binding or gritty feel
- Verify that both the horizontal and vertical straightener planes as well as the associated mount are securely mounted and does not wiggle when pushed.
- Sight down the wire line to assure alignment between the entry guide, the vertical and horizontal planes, and the exit guide. All should be relatively straight.
- Observe no evidence of a build up of insulation dust or excess lubrication on the straightener or guides
bI-MONTHLY MAINTENANCE RESPONSIBILITIES
- Assure that all rollers are tight and exhibit only circular movement. Roller must be replaced if any lateral or random movement is observed.
- Confirm that the socket of all hex bolts are not rounded and in good condition
- Slowly spin each roller to insure that they turn smoothly. ANY roller that appears frozen or difficult to spin, has a gritty feel or has a variation in torque must be replaced.
- Verify that roller grooves are “V” shaped” with no sign of rounding or ledges resulting from wear. Note: The careful examination of the roller groove is critical and is best done with some form of magnification. Undetected wear in a single roller can compromise the performance of the entire straightener.
bI-MONTHLY MAINTENANCE pROCEDURE:
- Unscrew each shoulder bolt and remove all rollers, washers and spacers
- Wipe shoulder bolts clean and inspect for any evidence of hex socket rounding, bending, scoring or other distortion. Do not attempt to repair damaged bolts, replace as necessary
- Verify that the number of washers and spacers are the same on each roller. Note: The presence of different quantities of washers and spacers on a roller set is indicative of potential roller misalignment or unauthorized disassembly.
- Wipe mounting bracket, adjusters and roller bars clean, Assure that all guides are round and not grooved or cut. Do not attempt to repair damaged guides, replace as necessary
- Wipe clean all rollers with a microfiber cloth. Inspect all roller bearing seals for presence and integrity. Discard and replace those bearings with broken or missing seals.
- Grasp each roller between fingers and slowly rotate. Replace any roller that is frozen, feels gritty, is resistant to spin or has a variation in torque.
- Test that the roller race is tight allowing only circular movement. Detection of any lateral or random movement signals a roller that has failed or will soon fail. Replacement strongly recommended.
- Using an inspection device with at least 2X magnification verify that the entire circumference of each roller groove is “V” shaped” with no sign of wear or scoring. Side by side comparison with a new roller is recommended.
- Re-assemble each roller and shoulder bolt assembly assuring that wire line integrity is maintained internal to the roller plane and in concert with the opposed plane
- Release assembly only after verification that all rollers in all planes are rolling smoothly and the wire is tracking as intended.