deck the table with vows of folly

...or something like that.  Happy belated Woolfnoot, by the way.

 Today's avoidance of writing the various lathe articles consists of me writing up this nice and easy and safe article about tweaking my drill press.

 Once upon a time, I bought a Craptsman floor-mount drill press, cheap.  And while it is more evidence that 'You get what you pay for', it has been much better than no drill press, especially for the money... and at the time, I did not know a knee mill was about to fall into my lap.

 One of the things that bugged me was that - somehow - the table rim and the table were at different heights on opposing corners, despite the surface evidence that the whole shmear had been decked with a five inch fly cutter while they rotated it with the mounting spud.  As should be, in fact, but why then was it not flat?  On one corner, the rim was higher than the table, on the opposing corner it was lower than the table, and on the other two corners, the table and rim were about the same.  I mean, how do you even do that by sweeping it with a five inch fly cutter??  And the table itself had a curve in it. (aha, your first clue, padawan)

 I decided long ago that this was some kinda post-post-cooling, precipitation-having, slow crystal forming, meta-magi-lurgical phenomenon, and tried to work around it.  But man, it has bugged me ever since.

 The other day, as I was feeling The Urge (to putter / work in the shop) but not feeling the confidence to work on the lathe gibs (which are non-replaceable) my eyes alighted on that drill press table, and I decided it was time to Do Something About It.  It occurred to me that if there was some kind of thermal stress issue in the casting at the plant, then by now it should be as relieved as its gonna get without a long time in an oven, so I theorize that if I only skim off a few thousandths (which is all that seems to be required) any remaining internal strain shouldn't warp it too much.

Honestly I did not like this setup, but it worked

 Long story short, I fixtured the table in the mill vise using the mounting spud between two vee blocks, because we very much want the table surface square to the mounting spud, otherwise if you rotate the table, things go up and down, no bueno.

 I milled it with a cheap Enco (RIP) fly cutter holding a cheap Enco lathe holder for triangular inserts.

 The inserts were, amusingly, TiN coated, which really only helps you when machining aluminum, and a little on gummy stainless alloys.  But the profile works best on ferrous alloys not aluminum.  D'oh!

 In any case, HSS was a non-starter because cast iron is so abrasive.  All the speeds and feeds charts have blank spots or "not recommended".  So it was a cheap triangle insert tool or nuthin'.  The ones I had available have a quite rounded nose, and this seems to have contributed to a nice surface finish.

Enco's finest!

 I used 300 SFM based loosely on the chart and not having the foggiest what sort of iron I am dealing with.  

 The first pass fixed the high spot but failed to pick up the low spot.  I rotated the table in the jig on its mounting spud by 90º and made a second pass which covered all but a tiny low spot on one rim edge that did not seem worth re-running the whole table again.

 The widest I could go on the fly cutter was about a four inch swath, the twelve inch table thus requiring three cuts.  Or is that three passes per cut?  I am not a machinist.  In this case, 300 SFM worked out to nearly 300 RPM.  Ugh; that is not fast.  And it meant that, if I wanted a nice surface finish, the feed rate had to be glacial.  Ahem.  I don't have a working table feed.   So between arthritis in hands and shoulder joints and stuff, I had to take breaks after each cut.  So three breaks per pass, six breaks total, a meal break, and a couple of hours total to slowly turn a crank handle do the machining, not counting maybe ten minutes to make and check the setup.

(this video seems to be running faster than it should?)

 

Surface finish?  Single point cutters for the win!

 Between both passes, about .009in was removed. The overlap between cuts passed the fingernail test.
 

 Mucking about with the indicator on the mill showed the surface flatness to be no worse than the mill's table ways at least. ;)

 I also put it down on the plate for yucks, and I could not get my thinnest (.0015) feeler gauge under the edge anywhere, so that's a good sign.  I think it's good enough for a drill press table.

 Oh, I could go around and break all the newly-machined corners - somehow - but none of them seemed eager to cut my finger so I'll just let time take care of that. :)

 I think we're done here.