This is what happens to your mill vise when you use water-based cutting fluid or an oil-water emulsion and then don't remove it from the "inaccessible" nooks and crannies.
It turns out there are no corrosion inhibitors in either window cleaner or the green soapy stuff, who knew?? This mess was under the fixed jaw, which most people never remove. Factory really didn't want it removed either, as the two bolts were fixed with both fancy super-aggressive double-sided lock washers, and thread locker. I used a torque wrench and my skinny little arms.
I assume this was caused by using mild soapy water as cutting fluid for plastics - well, there's not a lot of choice there. I don't think shop air would have got the fluid out of there, and I don't use shop air as much as other people, I prefer the shop vacuum, so as not to drive chips & dust into places they don't belong. So what do I do, disassemble the vise each time I cut plastics? (possibly yes) The only other cutting fluid I use is Tap Magic EP Extra, which is oil-based AFAIK, and shouldn't have any water in it. The good news is that all that horrible rusty crap came right off with brass bristle hand brushes and less than an hour of effort. Brass bristle because these surfaces are precision-ground and I don't wish to cause the slightest bit of surface abrasion by using steel bristles. I should have taken 'after' pics, because there was no pitting from the rust, I got pretty lucky.
At the end of the day, having the fixed jaw be perfectly aligned with anything else - even with the moving jaw - isn't all that important, because the fixed jaw is the only reference you trust, and you tram it with the table whenever you take it off. When you're squaring new work, you don't trust the moving jaw anyway; for the first squaring cuts, you place a bit of brass rod or the like between the moving jaw and the work; this only allows the work to align with the fixed jaw, rather than imperfections of saw cuts in the work causing the two jaws to fight each other. Then you put that face against the square jaw, and so forth and so on. So all the fixed jaw has to do is A) not move at all - not even 1/10,000 of an inch - and B) be perfectly parallel to the axis of table motion, ie; parallel with the table ways. Every time you take the vise off the table, or move it or whatever, you have to re-align the vise's fixed jaw with the table ways. It's not deep' you just mount an indicator on the spindle and move the table back and forth, observing the change in reading caused by the vise being at an angle to the axis of motion. Then you gently bash the vise with your deadblow hammer in the right direction and check it again, lather rinse repeat until there is no change in the reading. This is called tramming.
(see YouTube for detailed instructions)
Pro machinists gripe about this slightly, because time is money, but it takes me only five minutes to tram the vise or the head, and I'm not making a dime. Professional machinists also prefer to keep the machine in tram/square, and find other ways to cut angled features (vs. putting the head at an angle) if they can. It's kind of a philosophy of precision; once you've got the machine exactly right, you may be reluctant to take it out of tram again. ;)
Me being a bodger who rarely holds a thou, never mind a tenth, and being unafraid of the shop time taken to tram, I don't hesitate to use every feature of the mill if it will make my life lower-effort. ^_^
(If you ever move the head in any of its three axes, you will end up tramming the head afterward as well. That requires an additional inexpensive little doodad but it's not much bigger a deal than tramming the vise.)
I wish I'd taken photos of the bottom of the vise, as there are some interesting convenience features there which I do not use but I feel I ought to discuss. Some day...
It turns out there are no corrosion inhibitors in either window cleaner or the green soapy stuff, who knew?? This mess was under the fixed jaw, which most people never remove. Factory really didn't want it removed either, as the two bolts were fixed with both fancy super-aggressive double-sided lock washers, and thread locker. I used a torque wrench and my skinny little arms.
I assume this was caused by using mild soapy water as cutting fluid for plastics - well, there's not a lot of choice there. I don't think shop air would have got the fluid out of there, and I don't use shop air as much as other people, I prefer the shop vacuum, so as not to drive chips & dust into places they don't belong. So what do I do, disassemble the vise each time I cut plastics? (possibly yes) The only other cutting fluid I use is Tap Magic EP Extra, which is oil-based AFAIK, and shouldn't have any water in it. The good news is that all that horrible rusty crap came right off with brass bristle hand brushes and less than an hour of effort. Brass bristle because these surfaces are precision-ground and I don't wish to cause the slightest bit of surface abrasion by using steel bristles. I should have taken 'after' pics, because there was no pitting from the rust, I got pretty lucky.
At the end of the day, having the fixed jaw be perfectly aligned with anything else - even with the moving jaw - isn't all that important, because the fixed jaw is the only reference you trust, and you tram it with the table whenever you take it off. When you're squaring new work, you don't trust the moving jaw anyway; for the first squaring cuts, you place a bit of brass rod or the like between the moving jaw and the work; this only allows the work to align with the fixed jaw, rather than imperfections of saw cuts in the work causing the two jaws to fight each other. Then you put that face against the square jaw, and so forth and so on. So all the fixed jaw has to do is A) not move at all - not even 1/10,000 of an inch - and B) be perfectly parallel to the axis of table motion, ie; parallel with the table ways. Every time you take the vise off the table, or move it or whatever, you have to re-align the vise's fixed jaw with the table ways. It's not deep' you just mount an indicator on the spindle and move the table back and forth, observing the change in reading caused by the vise being at an angle to the axis of motion. Then you gently bash the vise with your deadblow hammer in the right direction and check it again, lather rinse repeat until there is no change in the reading. This is called tramming.
(see YouTube for detailed instructions)
Pro machinists gripe about this slightly, because time is money, but it takes me only five minutes to tram the vise or the head, and I'm not making a dime. Professional machinists also prefer to keep the machine in tram/square, and find other ways to cut angled features (vs. putting the head at an angle) if they can. It's kind of a philosophy of precision; once you've got the machine exactly right, you may be reluctant to take it out of tram again. ;)
Me being a bodger who rarely holds a thou, never mind a tenth, and being unafraid of the shop time taken to tram, I don't hesitate to use every feature of the mill if it will make my life lower-effort. ^_^
(If you ever move the head in any of its three axes, you will end up tramming the head afterward as well. That requires an additional inexpensive little doodad but it's not much bigger a deal than tramming the vise.)
I wish I'd taken photos of the bottom of the vise, as there are some interesting convenience features there which I do not use but I feel I ought to discuss. Some day...
~≈{👁}≈~
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