It's a 14-inch model, oftentimes referred to as a DP220, after the part number that's rather prominently cast into the head.
From what I have gleaned over at Old Wood-Working Machines, based on the badge designs on the pulley cover and motor, the absence of a serial number, etc., I have narrowed it down to about a 1939-1940 model.
As much as I loved the cool patina, I decided to go through and clean things up because a few of the parts that were supposed to move and slide weren't moving and sliding like they were supposed to.
I probably wouldn't have spent the asking price of $200 on it, except that I really wanted to get my hands on a nice positioning table/vise like the one that came with this drill press.
I think I have finally had my fill of crappy made-in-China Harbor Freight tools.
I'm tired of: parts being bent, right out of the box; dovetail slides that are tight on one end and loose on the other; misaligned holes; brittle, under-designed rivet-pins; you name it.
From here on out, I'm sticking to vintage steel made by people who believed that a tool ought to last you awhile.
Of course, 70 years of use is going to take its toll. The spindle on this drill press has less slop in it than my 5-year-old made-in-China Delta drill press.
But the Acme nuts on the X/Y/360 positioning table had about .025 inch of backlash, so I went ahead and fabricated a couple new ones for it.
Theoretically I could have machined these Acme threads on my lathe, but I was hoping to actually reduce the backlash, not increase it.
So I opted to spend $75 on a 1/2-10 left-hand Acme tap and do it that way.
Partly I wanted the tap for the Acme nuts on this cross-slide here, but I also wanted to fabricate some replacement Acme nuts for my Atlas lathe.
As luck would have it, both my Atlas lathe and this "Mastercraft Tools" branded positioning table have nearly identical Acme nuts. I have seen very similar Atlas-made positioning tables on Ebay, so it wouldn't surprise me a bit if this one wasn't made by Atlas, as well.
But who knows, right?
So I managed to reduce the backlash on the positioning table from .025 down to .002-.004, depending on where you are on the mating Acme screw. "Close enough for government work," as they used to say, back in the day.
I had similar results fabbing up new Acme nuts for my Atlas lathe, except that I went from a rather unnerving .035 backlash down to .002-.004.
A lot of machinists will tell you that backlash is no big deal on a lathe since you're almost always pushing out the slop between the part you're cutting and the screw threads.
And that may be fine when you're cutting steel, but ebonite and plastic just don't push back hard enough, so you either have to lock down your gibs on the final pass or risk having your dimensions meander along the cut.
But backlash in a drill press slide table is more problematic, particularly when you're using a home-shaped spade bit that wants to chatter. Things being misaligned .025 might show with careful observation.
I was a little torn about what material to use for the Acme nuts. I have a hunch the originals were probably 360 free-cutting brass, which makes a fair bearing, except that it wears pretty badly.
On one hand, it seems that it would be better for the nut to take the wear, except that there's also a risk that sandpaper grit and such can embed into a softer metal easier and chew up the Acme screw along the way, anyway.
So I ended up going with 954 aluminum-bronze. Hopefully that will prove a good choice, but time will tell.
Maybe somebody else can check and see how they're holding up in another 70 years.
