The CNC-251R is old model and indeed new model is CNC-250R, drawing #CNC250R-001-03.
Differences are as follows
Old CNC-251R: thru-hole: 52mm, gear ratio: 180:1, center height: 185mm
New CNC-251R: thru-hole: 70mm, gear ratio: 90:1, center height: 185mm
| Table Size-X | 10" | 254 mm |
