Posted: 6/13/2025 12:52:16 PM EDT
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I have a used PM-25 mill in my garage waiting to be setup. The previous owner cleaned it up a bit, but there's still spots of surface rust on the bed that do not feel flat. I'm going to shoot PM an email asking if there's anything they can do to help while I'll be near the factory, but I expect doing it myself will wind up being the answer. Lacking anything abrasive that's also flatter than sandpaper stapled to a board, what are my realistic options? - find someone local to surface grind it flat & smooth? - find a chunk of flat metal to use as a scraper and see if a tempered glass shelf & some dyechem can mark the bed properly? - grab a sharpening stone, knock down the high / rust points and drive on? |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Mills are designed to make things flat. Stick a fly cutter in it and skim them bed.  I've used a random orbital sander with some less-aggressive grit paper on it, along with paste wax to remove rust from cast iron beds before. You could do the same with a little hobby mill. Thats not exactly a 0.00001 tolerance machine. If you dont like the sander idea, hand scrape and stone it. |
well, skimming the bed with a fly cutter would be a nice shortcut to tramming it, no?  - edit - yeah, no.. it was a nice idea though.  I might have some razor blades, and definitely have 0000 steel wool & oil. No orbital or other non-finger powered sander, though there is a pawn shop or two nearby. I like options, and it seems I have some. |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
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I prefer steel wool over scotchbrite. Scotchbrite is easy to over do and remove material. Use 000 or 0000 steel wool and a bit of light oil. For anything like dings and such, norton stones work great. A very light touch. If you hate $$$ buy the precision ground stones. |
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| The precision flat stone, while nice and requires them in pairs, just an ordinary fine India 6" stone with a bit of WD-40 or Sprayon LU711 works pretty well to remove the high spots from all sorts of usual dings, rust, etc. Just use the stone diagonally in both directions to find and remove the high spots. You should wind up with a just visible cross hatch pattern when done. |
If I were a hedonist, I'd be a hermit.
You need a good airgun if you don't have one already.
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The single edge razor scraper trick is impressive. I tested on a few spots and it lifted this weird brown paste that a few seconds ago was surface rust. There was still a little color, but it was much smoother. I'm going to keep all the other answers in my back pocket until I get a chance to razor the entire bed. |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
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Originally Posted By mnd: Clean up the rust with WD-40 and steel wool, use a precision ground flat stone to dress the surface. Any more than that and you're into machine rebuilding and that's a steep learning curve. |
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Originally Posted By Spaceboy: This is the answer and you should also also stone the bottom of your vise before bolting it down. But you do know before bolting your vice to sweep the head in. Originally Posted By Spaceboy: Originally Posted By mnd: Clean up the rust with WD-40 and steel wool, use a precision ground flat stone to dress the surface. Any more than that and you're into machine rebuilding and that's a steep learning curve. I would also agree. I did a good size shop worth of machines after the shop shut down for months during the China flu. It worked very well. |
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The vise is already mounted and (at least in theory) the head trammed... but that was before I lifted it, bounced it around on a trailer for 6 hours, and got it onto a furniture dolly here. I'll validate it as it sits - maybe I'll be lucky and it will still be aligned... Either way, I'll clean/clear more of the bed once it's in place and the traveling spacer / block of random wood comes out from between the spindle and bed. |
Disclaimer - OP is bad at knowing things, and might catch on fire.
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
Vet - Op MMAMA
Every other species kills off their stupid......we cater to them. -- spin-drift
Nobody ever called 911&said I just did something smart. -- TheFlynDutchman
I'm not lazy, I just really enjoy doing nothing.
Joined:
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Originally Posted By Amish_Bill: The vise is already mounted and (at least in theory) the head trammed... but that was before I lifted it, bounced it around on a trailer for 6 hours, and got it onto a furniture dolly here. I'll validate it as it sits - maybe I'll be lucky and it will still be aligned... Either way, I'll clean/clear more of the bed once it's in place and the traveling spacer / block of random wood comes out from between the spindle and bed. Although not ideal, you can check it beside the vice. Or you can run an endmill side to side and front to back. If there are swirl marks that make a cross hatch pattern on the passes then the head is probably pretty close. |
I can explain it to you but I can't understand it for you.
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Originally Posted By Spaceboy: But you do know before bolting your vice to sweep the head in. What does this mean? |
Ellen; Clark, I think it'd be best if everyone went home... before things get worse.
Clark; WORSE? How could things get any worse? Take a look around here, Ellen. We're at the threshold of hell.
Clark; WORSE? How could things get any worse? Take a look around here, Ellen. We're at the threshold of hell.
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Originally Posted By texashark: What does this mean? Originally Posted By texashark: Originally Posted By Spaceboy: But you do know before bolting your vice to sweep the head in. What does this mean? Sweeping the head, or more commonly known as sweeping the table, is a precise way to ensure that the spindle of the head is perpendicular to the table. The basic procedure is as follows: 1. Move the table so that the spindle is near the middle of the table. Eyeball close is good enough. 2. Install a mandrel or clamp a dial indicator to the spindle so that the indicator will sweep nearly the entire width of the table. Flat button indicators with the large button installed tend to work the best for this. 3. First, check the indicator difference between the front and back. Move the head until both the front and back read the same. Snug the locking bolts. 4. Second, check the indicator difference between the left and right. Move the head until both the right and left are the same. Snug the locking bolts. 5. Make a full sweep of the table, and note any change to the front and back, and left to right as the head locking bolts are tightened. Some final adjustment may be required as this tightening process is done. |
If I were a hedonist, I'd be a hermit.
You need a good airgun if you don't have one already.
You need a good airgun if you don't have one already.
I'm not lazy, I just really enjoy doing nothing.
Joined:
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