Hello, so we have this Adira GHS-0630 shear that we use. When i bring the back gauge bar to 20" then bring it in to 5" i end up losing about an inch. so now i am measuring 4" rather than the 5" programmed. So i have tightened everything and made sure the belts and chain are tight as well.Do i need to re-calibrate the machine or is my encoder going bad? i am at a loss. any help would be greatly appreciated! Thank you!