ewlsey
Diamond
- Joined
- Jul 14, 2009
- Location
- Peoria, IL
I'm working on a Blanchard grinder. I was asked to replace the ring gear on the bottom of the chuck and scrape it in and rescrape the bearing in the saddle. I also rebuilt the bevel gear box that drives the chuck rotation. That's all done and worked fine. But, I found a much bigger issue when I went to put it back together.
The "saddle" as I call it, is the carrier for the magnetic chuck. It slide in and out on ways that are integral to the base casting of the machine. On the back side of the machine (away from the operator controls) is a single way that handles the side load of the saddle. The front side just floats. Someone must have tried to rebuild this way at one time and either botched the job, or didn't understand how the ways are supposed to work. They ended up with about a 1/4" gap around the way that is attached to the saddle, and they glued on a piece of Turcite and blocked the grease passages.
As a result, the saddle rocks back and forth when you move it in and out and only the very ends of the way are bearing. This has caused about .035-.05" of wear in the base casting in a sort of hour glass shape with the ends being more worn. The opposite side, the water cover, is also badly worn with a belly in the middle about .05" deep. Also, some the bolts have broken and the bolt holes have broken out, probably from the ways being so incredibly loose and allowing the hole saddle to bang around.
So, I need to fix it. We bought a replacement way for the saddle, so I can throw out the old one with the crappy Turcite. I can make a new shim that is the correct thickness. I think I can machine the wear out of the water cover and fix the broken bolt holes.
But, I'm not sure how to fix that step in the base casting. It really needs to be built back up to the nominal dimension because the saddle is driven by a rack and pinion and the engagement of the teeth is compromised by the wear in the ways.
The only thing I can think to do is build a form and try to fill the step with Moglace. This is a bearing surface and the saddle will slide on the Moglace. The only repairs I have done with Moglace were static surfaces.
The guys I am working for also mentioned a product called Belzona. They have used it to fix shafts and gear boxes for stamping presses and they say it works very well.
The "saddle" as I call it, is the carrier for the magnetic chuck. It slide in and out on ways that are integral to the base casting of the machine. On the back side of the machine (away from the operator controls) is a single way that handles the side load of the saddle. The front side just floats. Someone must have tried to rebuild this way at one time and either botched the job, or didn't understand how the ways are supposed to work. They ended up with about a 1/4" gap around the way that is attached to the saddle, and they glued on a piece of Turcite and blocked the grease passages.
As a result, the saddle rocks back and forth when you move it in and out and only the very ends of the way are bearing. This has caused about .035-.05" of wear in the base casting in a sort of hour glass shape with the ends being more worn. The opposite side, the water cover, is also badly worn with a belly in the middle about .05" deep. Also, some the bolts have broken and the bolt holes have broken out, probably from the ways being so incredibly loose and allowing the hole saddle to bang around.
So, I need to fix it. We bought a replacement way for the saddle, so I can throw out the old one with the crappy Turcite. I can make a new shim that is the correct thickness. I think I can machine the wear out of the water cover and fix the broken bolt holes.
But, I'm not sure how to fix that step in the base casting. It really needs to be built back up to the nominal dimension because the saddle is driven by a rack and pinion and the engagement of the teeth is compromised by the wear in the ways.
The only thing I can think to do is build a form and try to fill the step with Moglace. This is a bearing surface and the saddle will slide on the Moglace. The only repairs I have done with Moglace were static surfaces.
The guys I am working for also mentioned a product called Belzona. They have used it to fix shafts and gear boxes for stamping presses and they say it works very well.