The Bridgeport Torq-Cut 22 is a smaller CNC vertical machining center. It comes fitted with a grease lubricated and belt driven spindle capable of running up to 7,500 rpm.
Read MoreHitachi Seiki HT-250 Spindle Repair
The Hitachi Seiki HT-250 is a CNC turning center. It comes equipped with a grease lubricated and belt driven spindle capable of running up to 5,000 rpm.
CHALLENGE
Our customer stated that the rear bearing is bad and was vibrating at 1,500 rpm. When this Hitachi Seiki HT-250 spindle arrived at Northland Tool and Electronics we completed a full breakdown and evaluation. Upon inspection we found a few issues to be addressed. First, the rear roller bearing may not have been preloaded correctly. The rear roller housing bore and shoulder have pre-existing damage from someone trying to remove the rear roller outer race. It was oversized +3/+7(ISO is +2/-18). Second, the front housing was oversized +20/+30 (ISO is +/-10) and has pre-existing damage. Third, the rear jacking screws for removing the outer race were broken off and stuck. Lastly, the shaft lathe taper and face could use a cosmetic kiss grind and there was light damage to the front cover.
SOLUTION
The following actions were performed on this Hitachi Seiki HT-250 spindle:
- Clean, inspect overall dimensions
- Grind, chrome plate, and finish grind the front and rear housing
- Kiss grind lathe taper and face
- Replace bearings, o-rings, and assembly screws
- Stone out damage on the front cover
- Install 4 new jacking screws in rear housing shoulder for outer race removal
RESULT
After reassembly of all components, adjusting bearing preload, and undergoing break-in and testing procedures, this spindle passed our final quality inspection before being returned to our customer with a 1-year warranty.
Does your spindle need repair? GET A QUOTE TODAY
More Case Studies
Repair History - Here are examples of similar spindle repairs that may contain additional information that will help you. If you have additional questions, please contact us.
Spindle contamination is a critical issue that can significantly impact the performance and longevity of your machinery.
Read More