This spindle is a heald OD grinder being run up on the test stand. Denton is explaining the specifics of the spindle. View Our Heald Page Here.
Heald 407 Spindle Repair
Our customer sent us a spindle that had front bearing failure from contamination. This spindle also had a rear journal that was -3/-5 microns undersized. We ground plate ground the rear journal. The shaft pilot had 20 microns runout. This was also ground plate ground. The pilot face had 15 microns runout. This was kiss ground. After all the grinding was completed, the spindle was balanced, assembled, broke in and sent to our QC department. The final step was shipping back to our customer. View Our Heald Page Here.
Heald 405 Spindle Repair
This spindle came with front bearing failure from contamination. The pilot had 22 microns runout and was oversized by 13-23 microns. Rear pulley taper had 60 microns runout. Front and rear journals are tapered and undersized by 3-4 microns. We ground plate ground the shaft pilot, front and rear journals. We also kissed ground the rear taper and the damage before the taper. Before the spindle was shipped back to the customer we adjusted preload, balanced, assembled and broke it in. View Our Heald Page Here.
Heald Red Head 411 Spindle Repair
The grease was completely washed out of this spindle causing bearing failure. This can be caused by coolant being directed at the face of the spindle or not removing coolant from the spindle before it cools. As the spindle cools it will draw the coolant into the spindle similar to soldering a joint. Over time this will accumulate in the bearings causing premature failure.
The rear pulley taper had 16 microns run out so we kiss ground it to bring it back to ISO specifications. The front bearing journal is fretted and undersized by -14 microns and was ground plate ground. The front housing was scored an egged by 5 microns so that was also ground plate ground. We adjusted the preload, balanced, assembled and broke in the spindle before the final QC and shipment back to the customer. View Our Heald Spindle Repair Page Here.
Heald Red Head
This Heald ID grinding spindle came in with end play and the pilot had 12 microns of run out. The spindle appears to have been crashed. The spindle required grinding; chrome plate and finish grind to the pilot. The replacement of the high-speed bearings requires perfect adjustment of the preload. If the preload is heavy the bearings will produce heat and fail. If the preload is light the balls of the bearings will “skate” causing vibration and ultimately failure. The final QC checks for this type of repair include preload checks and intensive vibration analysis to insure your spindle is in prime operating condition. View Our Heald Spindle Repair Page Here.
Heald Redhead 413
Heald Redhead 413 Spindle Repair
A bearing manufacturer sent us a Heald Red Head belt driven 413 A-Frame style spindle. The customer wanted to increase the maximum speed capability of the Heald to decrease their machine downtime from changing out the ID spindle heads. They also wanted to increase they rigidity of the spindles used at 18,000 rpm. The existing bearing arraignment of the in the spindle had a maximum speed of 17,000. Our customer wanted to run his spindle at between 8,200 and 18,000 rpm. We replaced the steel bearings with ceramic bearings and implemented design improvements. We were able to increase the maximum speed to 21,000 rpm.
This is possible by insuring all the integral spindle precision parts were measured and gauged making sure they were at proper tolerances. This is critical when increasing the speed of a spindle. The spindle was then tested at the higher rpm, vibration analysis was performed and the top speed was calculated with the data accumulated. The customer received the Heald spindle and has stated the finish and accuracy it provides is far better than before the modification. They have increased productivity with the spindle and have requested ceramic bearings in any future Heald spindle rebuilds done by Northland Tool & Electronics. View Our Heald Spindle Repair Page Here.
Written by Sandy Smith
I can be contacted at email@example.com or 1-800-774-6353
Heald 405 Spindle Repair
This belt driven ID grinding spindle came to us from one of our automotive parts manufacturers. They were having part quality issues and the bearings were starting to make noise. When we disassembled the spindle we found that contamination had gotten into the front bearings. The front and rear housing dimensions were out of ISO spec by 30 microns and the rear pulley taper had run out.
We had to grind plate grind the housing and kiss grind the pulley taper. We then assembled the spindle in our clean room and test ran it at 35,000 rpm. After final QC the spindle was packed and shipped directly to our customer. View Our Heald Spindle Repair Page Here.