SNK RB-350F 5-Axis Column Style Milling Center
Ballscrew Guys called in to address looseness issues in the X-Axis table ball screw inside a SNK RB-350F 5-axis column style milling center. We have done quite a few Shin Nippon Koki machines over the decades. This one has an exceptionally long ball screw, made by NSK. Replacement of the screw was quoted as having over a one-year lead time and six-digit replacement part cost.
Backside of a SNK RB-350F 5-Axis column style milling center. Here the protective covers have been disconnected and slid out of the way. You can see the X-Axis table ball screw is now exposed. We are returning the preload back to the ball screw assembly. The looseness in the ball nut and screw was the main issue with this machine. Milled radius cuts had excessive lines and chatter. Unacceptable for the aerospace client who contracted the parts this machine produced.
The X-Axis table ball screw from inside a SNK RB-350F 5-Axis column style milling center. Here the protective covers have been unbolted and slid back. The ball nut is a splint nut or dual ball nut design. This ball screw type has a precision nut based on two separate halves. Each ball nut half requires an exact sized ball bearing to position on the shaft raceway helix. Then they come together into position on either side of the spacer shim, creating the preload required for machining processes. This proportional relationship must be correct. Otherwise, the assembly will be too loose or worse, damage the ball screw and ball nut internal components.
X-Axis ball nut service to the table ball screw on a Shin Nippon Koki SNK RB-350F 5-Axis Column Style Milling Center. Here one of our technicians is in the process of working the ball nut out of the yoke assembly under the table. Our people typically restore the positioning accuracy of your SNK table in one production shift. At a price that is simply pennies on the dollar compared to buying a new ball screw assembly and waiting for the boat to arrive from Japan. We come to your facility, minimize the downtime, and get your SNK cutting parts again in a timely fashion.