Vintage Craftsman 150 Drill Press - Restore/refurb

[hman]

With that frosted face 150W flood lamp, I'm sure that you are correct. I should have been more specific and said to use an unfrosted (clear) bulb 12.5 or 15 Watt lamp.

However, assuming that you are using a three-wire plug in a properly grounded outlet, as it hasn't tripped the breaker yet, it is most likely alright.

You did say in your initial post that a smaller bulb should be used, and I agree that a 150 watter would be totally unsuitable. But I know that even small bulbs need more than a few volts to even give off a glow. So just for fun, I connected a 5 watt Christmas tree bulb (remember these?) to a precision (DC) power supply I have.

Results were as follows -
10 volts - 0.0003 amp (0.003 watt), no glow visible, even in a totally dark room
12 volts - 0.0011 amp (0.0132 watt), glow barely perceptible in totally dark room
15 volts - 0.0026 amp (0.039 watt), glow visible in dark room, not visible with reading light on
20 volts - 0.0040 amp (0.08 watt), slight glow visible with reading light on.
I'd have gone to higher voltages, but 20 is the limit of the power supply.

If you look very carefully, you can barely see the W-shaped filament glowing in front of the gray panel of the power supply. The brighter yellowish ring-shaped glow near the top of the bulb is a reflection of the reading light. Obviously, the glow would be more visible with just a reading light than with the flash from the camera.

Anyway, I simply don't think a light bulb is a sensitive enough instrument to be very useful in this application. Yes, it's a slightly better than nothing. But I think we're both safety conscious enough to agree that this isn't an area where you want to fool around with half measures. You really need some kind of a meter with a scale.

The best solution, as you'd originally said, is a megohmmeter.

Or else, as I'd suggested, use a voltmeter on its most sensitive scale to look for high resistance shorts (after checking for hard shorts with your method and any kind of bulb). Though not ideal, it's workable. Movement of a scale is much easier to spot than a faint glow.

 

[wa5cab]

I didn't mean to start an argument over this. Two things.

First, in the beginning, as far as I could tell from what you wrote, you didn't own any decent test equipment. And if you did, I had no way of knowing whether you knew how to use it. I could see that you had a lamp socket and some alligator clips. So I suggested that method as it was simple to explain and the only additional component that it required that I wasn't sure you already had on hand was the small standard base lamp.

Second, the nature of inadvertent shorts is to be intermittent, to sometimes behave as low quality semiconductors, and typically to be difficult to find with a low voltage analog ohmmeters and much more so with digital ones. Unless running current through the point of contact welds the two pieces together. Plus high impedance voltmeters can be fooled by shunt capacitance in the pfd range. Using the 120 VRMS AC line guarantees a minimum voltage from the run or start winding to case of 85 V peak at the midpoint and higher than that toward each end.

Anyway, as I said earlier, the fact that it's running satisfactorily would seem to indicate that the report of a bad motor was false. The problem could have been in the external wiring. Or even in some of the internal joints that you opened up and then re-taped.

 

[hman]

I didn't mean to start an argument over this.

No problem. Nor did I think it was an argument. I figured we were simply batting ideas back and forth, with the common goal of a thorough safety test methodology.

Anyway, as I said earlier, the fact that it's running satisfactorily would seem to indicate that the report of a bad motor was false. The problem could have been in the external wiring. Or even in some of the internal joints that you opened up and then re-taped.

I think it was indeed the external wiring (which was snipped off short in several places. My best guess is that the original owner (or his heir?) saw some of the old insulation in bad shape, and decided to cut it away for safety's sake before donating the drill press. But who knows????

Anyway, I think I lucked out in finding everything as good as it was.

 

[hman]

OK, back to the rebuild ...

Quill tensioner: The quill return spring in this Craftsman is quite unlike the ones used in most modern drill presses. Instead of a flat coil in an external "cheek," it has a coiled wire spring inside the hollow shaft of the feed handle. An external knob on the side opposite the hub sets/adjusts the spring tension and a thumb screw underneath locks the setting.


The end of the lock screw is pointed, to improve its gripping power on the adjusting knob. But even with a point, the grip strength of this lock screw was pretty low. I found that pliers were needed to tighten the lock screw enough to get a good lock. The original owner probably did the same, as the mating surface on the tension knob was already marred in several places.

I decided to remedy this situation by adding a series of dimples around the mating surface of the tension adjuster. The photos show my mill setup and the result (which works well). A pointed rod in a Noga-style indicator holder engages the flutes of the knob, creating a makeshift indexer and allowing placement of the dimples at equal intervals.


Vari-Slo assembly: Unlike other parts of the drill press, the Vari-Slo speed control assembly did have some signs of wear. A hole in one of the links was egged out - possibly from the assembly having been displaced from its original location. There was also a part missing - a plastic clamping pad that originally went between the steel adjusting/position locking knob and the soft aluminum face of the adjuster frame.

I found a piece of K&S brass tubing of the right ID to use as a repair bushing, drilled out the hole to fit the OD, and used JB Weld to hold the brass in place and fill the oval around it.


After the epoxy had hardened, I filed down the ends of the brass tube even with the surface of the aluminum casting.


As for the clamping pad, I only had some sketches from the installation manual to guide me. But nothing looked very critical. I turned the end of a piece of UHMW rod to fit into the threaded hole of the adjuster, then turned a 1/8" length to as large a diameter as I thought would fit the available space. After parting off, I cut a flat on the flange, so the pad would fit under the bar of the adjuster.



Final assembly and table tram check: Using my downloaded copy of the Vari-Slo manual, I installed this and the otherwise completed head onto the drill press post. The photos show the completed assembly. Everything works!!! The Vari-Slo does a nice job of setting the spindle speed anywhere from ~300 to ~3750 RPM.

PS - the red object on the right side of the motor is a toggle switch with a Radio Shack shield over it. It's a reversing switch. I really don't have any plans to run the quill backwards, and it has no effect when the motor is running (reverses the start winding!), so it's not too handy for tapping. But there was such a switch on the motor when I bought the DP, so I decided to keep it for authenticity's sake.

As a last hurrah, I checked the table tram. Because the table is not adjustable for tilt, I expected it would be pretty square to the spindle. Wow again! It was off just 0.009" front-to back, and 0.003" side-to-side on a ~9" circle. Even better, pressing downward on the table (say for a heavy drilling job) would improve the squareness as it flexed!


Anyway, that's it for the refurb. I enjoyed it all immensely, and again think I was extremely lucky to find such an oldie in such fantastic shape!

 

[DoogieB]

Great job! With your quality rebuild, the press should give you decades of trouble-free service.

Now you just need to make a table lift.

http://www.hobby-machinist.com/threads/drill-press-table-raiser.24006/

 

[Fairbanks]

Excellent work! Thanks for posting.

Sent from my XT1585 using Tapatalk

 

[wa5cab]

John,

That is very nice work you've done. But I have to give a mia culpa here. Another member, whose ID I didn't look at long enough to recall ten seconds later, posted a similar kudo but somehow two copies showed up. I went to delete the duplicate, then noticed that it had a Like and deleted the first one instead. Unfortunately, I forgot to UN-CHECK the duplicate and it got deleted, too. I can't remember whose post it was but their avatar is a side view photo of a light green Atlas MF(*). So if that individual happens to read this, please re-post.

 

[tomjaksa]

That is not a drill press its a work of art...........

 

[Silverbullet]

Beautiful press, you my friend are very lucky to find that press for such a paltry sum of money. Good luck with a gorgeous drill press. Reading this was like watch two shop teachers correcting a student or apprentice . I look at the vari speed but can't see how it works. Dose it use clutches ,, Phillies,,, that slide open and closed??? Thanks just interested in the how it works.

 

[Sandia]

Very nice job John. Love the retro look of those old presses.