jmkasunich
Aluminum
- Joined
- Mar 3, 2007
- Location
- Cleveland Ohio
I have a new-to-me 1969 B'port. Came with an Albrecht chuck, 6F-B power feed, Acu-Rite AR-5 scales and model 200S DRO, and a slotting head, all for a bit under $2K. Evaluation is on-going, but I've found a few things that should be fixed.
I'm doing all the basic maintenance - cleaning everything including oil lines and oil passages, new felt wipers, new lube metering units, new filter on the lube pump, etc.
The table gets tight at the ends, as expected for a 50 year old machine. Table ways show at least some flaking everywhere, and no gouges or scoring. Measuring the male (table) dovetail over 5/8" rods shows a variation of 0.002" from ends to center. The hard chrome on the top of the saddle is worn at the ends, but faint traces of flaking are still visible and there is no scoring, peeling, etc. I'm not planning to mess with the saddle-to-table fit.
The knee-to-saddle is in worse shape - probably due to 50 years of chips landing on the ways and sneaking under the wipers. The chrome on the top of the knee is worn in the center to the point that the flaking almost disappears in spots (first photo). Careful measurement says that the flats are worn about 0.0008" deeper in the center than the ends. Measuring over 5/8" dowels shows the center about 0.002" looser than the ends.
The bottom of the saddle is pretty ugly. (second photo) On the flats, the center relieved section has no wear, but all flaking is gone from the contact areas and they are pretty badly scored. The dovetails are in better shape, with traces of flaking still present.
A professional rebuild is out of the question for a variety of reasons. Although I'm a hobby guy and like working on machines a full rebuild is well above my skill level and is also not going to happen. However I don't want to put the saddle back on the way it is.
I have some scraping experience - I can scrape flat to a surface plate, but I've never done dovetails or scraped for alignment. Since the flats of the ways are by far the worst part, I'm thinking I want to scrape them "fairly" flat. I'd rather do too little than too much, because I want to preserve alignment
My current plan is to scrape only the flats on the bottom of the saddle, using a surface plate as a reference. They won't fit the knee ways perfectly - over the 12" length of the saddle the knee ways are about 4 tenths hollow, so the saddle will bear more at the ends. But somehow it feels wrong to scrape the saddle to fit the curvature of the knee ways. And I'm not re-doing the top of the knee - stripping the chrome and re-scraping those ways is more than I want to tackle.
Looking for input - does this seem like a reasonable course of action? To me it seems like it falls somewhere between "just put the damn thing back together and use it" and an obsessive-compulsive "make it perfect" rebuild.
Second question is more specific. Third photo shows the oil grooves in the bottom of the saddle. They seem very inconsistent, especially the one on the bottom left. Seems like it should get closer to the edges of the way. Not sure if its just a coincidence, but the blue seems to show that the worst wear is in the areas outside the ends of the oil groove.
Will I do any harm if I make the oil grooves longer, so they end maybe 1/4" from the edge of the way? Is 1/4" the right number?
Any other suggestions for stuff I should address while the machine is apart?
Thanks,
John
I'm doing all the basic maintenance - cleaning everything including oil lines and oil passages, new felt wipers, new lube metering units, new filter on the lube pump, etc.
The table gets tight at the ends, as expected for a 50 year old machine. Table ways show at least some flaking everywhere, and no gouges or scoring. Measuring the male (table) dovetail over 5/8" rods shows a variation of 0.002" from ends to center. The hard chrome on the top of the saddle is worn at the ends, but faint traces of flaking are still visible and there is no scoring, peeling, etc. I'm not planning to mess with the saddle-to-table fit.
The knee-to-saddle is in worse shape - probably due to 50 years of chips landing on the ways and sneaking under the wipers. The chrome on the top of the knee is worn in the center to the point that the flaking almost disappears in spots (first photo). Careful measurement says that the flats are worn about 0.0008" deeper in the center than the ends. Measuring over 5/8" dowels shows the center about 0.002" looser than the ends.
The bottom of the saddle is pretty ugly. (second photo) On the flats, the center relieved section has no wear, but all flaking is gone from the contact areas and they are pretty badly scored. The dovetails are in better shape, with traces of flaking still present.
A professional rebuild is out of the question for a variety of reasons. Although I'm a hobby guy and like working on machines a full rebuild is well above my skill level and is also not going to happen. However I don't want to put the saddle back on the way it is.
I have some scraping experience - I can scrape flat to a surface plate, but I've never done dovetails or scraped for alignment. Since the flats of the ways are by far the worst part, I'm thinking I want to scrape them "fairly" flat. I'd rather do too little than too much, because I want to preserve alignment
My current plan is to scrape only the flats on the bottom of the saddle, using a surface plate as a reference. They won't fit the knee ways perfectly - over the 12" length of the saddle the knee ways are about 4 tenths hollow, so the saddle will bear more at the ends. But somehow it feels wrong to scrape the saddle to fit the curvature of the knee ways. And I'm not re-doing the top of the knee - stripping the chrome and re-scraping those ways is more than I want to tackle.
Looking for input - does this seem like a reasonable course of action? To me it seems like it falls somewhere between "just put the damn thing back together and use it" and an obsessive-compulsive "make it perfect" rebuild.
Second question is more specific. Third photo shows the oil grooves in the bottom of the saddle. They seem very inconsistent, especially the one on the bottom left. Seems like it should get closer to the edges of the way. Not sure if its just a coincidence, but the blue seems to show that the worst wear is in the areas outside the ends of the oil groove.
Will I do any harm if I make the oil grooves longer, so they end maybe 1/4" from the edge of the way? Is 1/4" the right number?
Any other suggestions for stuff I should address while the machine is apart?
Thanks,
John
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