Drill Press Restoration

I wanted a drill press, and I wanted one where there weren’t any corners cut in its making. As far as machine tools go, this is synonymous with “old” and “made in America.” I lurked around on Craigslist for a month or so until I found a good deal. I contacted the owner and the very same day I was in my truck headed up to Ogden. From what I could pick up, the owner was a man in his late 70’s who was moving and getting rid of his woodworking equipment that he’d had for the last 30-60 years. For $100 I bought his workbench, radial arm saw, Westinghouse bench grinder, two vises, and his Rockwell Delta Homecraft drill press. His shop was in a basement and all of the tools were bolted to the work bench. I had no use for the work bench so I demolished it in the basement and loaded it into my truck in pieces, along with the rest of the tools.

Old_Full_View
The machine as I bought it.

Once I had the drill press back in my shop, I did some inspection to see just what I had bought. Based on some internet research, the machine is a Delta Homecraft 11-120 11” Drill Press that was manufactured in Milwaukee, Wisconsin in 1953. It even came standard with a Jacobs chuck. Old Wisconsin steel with a chuck from Connecticut is exactly what I wanted. I checked the runout on the spindle and chuck by chucking a 1/4” endmill and setting a dial indicator perpendicular to the rotational axis of the spindle. 0.0055” of runout. Not perfect, but good enough for a drill press with a three-jaw chuck.

Old_Motor_Head

Knowing that it was at least in good working order, I decided to give it a bit of a restoration. I took the entire machine apart and vigorously cleaned every surface with acetone and a wire brush.

IMG_7036
Disassembled and dirty.

I masked over the important surfaces and primed and painted all of the castings. While doing my internet research I came across a forum post that said “All drill presses should be gear grey or gloss black, period.” I disagree. The original machine was gear grey but I don’t like that color. Instead, I painted it a similar color to a Nardini lathe that Paragon Machine Works had when I worked there. I’ve come to call it “machine green.”

Masked_Table_Head
Masking the surfaces I wanted to preserve.
Priming
Priming the body pieces.
IMG-7049
The final color.

While I was waiting for the paint to dry, I took a wire wheel on an angle grinder to the more rusted out pieces of the machine. I then coated them in Fluid Film, which is the superior surface corrosion inhibitor. Don’t bother with anything else, it’s not worth your time or money.

Pole_Before_after
Removing rust.

I disassembled the spindle and quill and cleaned them both thoroughly. Grease is a mixture of oil and wax, and when those two separate after many years the result is ugly and sticky. The bearing that the spindle pulley rides on was full of this junk, so I cleaned all the waxy residue out with acetone and a pick and checked all of the surfaces for wear and damage. Luckily there was none.

Spindle_Trio
Left: Cleaning the spindle. Right: Cleaned arm.

The motor is a General Electric 1/6 HP 3A 115VAC motor made in the USA. I took it apart to see what kind of wear there was and what I could replace to make it last longer. There really wasn’t much wrong with it other than some decaying insulation on one wire.

Motor_Before
Dusty, half-ass old wiring. Not allowed in my shop.

This motor is a repulsion-start induction motor, which I think is pretty cool. Generally, an AC motor requires more than one power phase to start. This is why its extremely common to see start capacitors on newer AC motors. The discharge of the capacitor on starting creates another phase that allows the motor to start. However, this motor does not have a start capacitor. Instead, it uses brushes to bring itself up to speed, and then a centrifugal switch engages and shorts the brush circuit, directing power to the main armature. A brilliant and elegant solution that will last nearly forever, since the brushes are only in contact with the commutator for fractions of a second on startup.

Motor_pics
Magnets – how do they work?

Once I cleaned it out and reassembled the motor, it was good to last another half of a decade. That said, it’s less powerful than I’d like for it to be, so I may swap it with a Century 1/3 HP motor I have lying around. Time will tell.

Not only did I not like the original on/off switch, it was extremely unsafe. In the event of an accident, it should be easy to find and actuate the power switch. The original switch was both hard to find and difficult to use.

Old Cord
Left: Switched neutral? No hot? Right: Mystery solved: ground taking the place of neutral, neutral taking the place of hot. Disgusting.

To fix this, I wired in a new switch. The original motor/machine was not grounded, which I did not really like. After consulting an electrician friend, I added a grounding wire to the machine when I added the switch, as well as a new power cable. I put ring terminals on the motor connections because I was bothered by the half-assed job done by the original owner. The result is a much safer and a much easier to use machine than the one I bought.

Switch_Trio
Peace of mind.

With the paint dry it was time to reassemble. I packed every moving part with Phil Wood Waterproof Grease and put the whole thing back together. Not too complicated.

I replaced the motor mounts with new zinc plated carriage bolts and nylok nuts. Do it once, do it right.

new motor bolts
Slowly but surely bringing this old machine up to code.

I stoned the base and the table to knock off the high spots and remove some of the rust. Always worth it, if not just for the looks.

Stoned Table

I didn’t like the table adjustment screw so I welded some 1/4″ round bar onto a hex head screw, cut some threads into the end, and attached a brass ball knob from McMaster Carr.

Knob_Trio

As a finishing touch I turned down a hex head brass screw on my hobby lathe to make it look nice.

CustomBolt
If ya got it, use it.

Now that I had the machine ready to go, I needed a place to put it in my crowded shop. The bench that the original owner had it on had nice casters, so I kept those and welded a table to sit on top of them.

Tableprocess
Left: completed base frame and some math used to get there. Right: Underside of tabletop made from 1/4″ plate.

This way it is on wheels and can be moved out of the way if need be. My metal supplier had a sale on ¼” plates so I got some and welded them together to make the top surface. Welding the ¼” plate tested the very upper limits of my 110V FCAW machine and I learned a lot about how to control the heat and minimize warping. All in all, the table came out level, plumb, and true. It seems like very welding challenge I’ve encountered can be solved with a cleverly devised tacking sequence. Someday I may make a cabinet to go under the drill press, but for now I will leave it empty. To match all of the other tables in my shop, I left the legs bare.

Table3
The completed table.

Finally, some before and after shots of the machine. I’m pleased with the result.

B_A_headon
To the untrained eye, the machine on the left looks like a piece of junk. Patience and time are all it takes.

B_A_profile

B_A_side

B_A_motor

B_A_table

B_A_knob
The original geometry of the table clamp was awkward so I re-clocked the lever and lengthened it to get the appropriate torque at the right place in the stroke. Now the operator can clamp the table tightly without having to move to the back or side of the machine.
unnamed
Checking the runout by chucking a 1/4″ endmill and measuring with a Starrett dial indicator.
IMG_7134
The machine’s new resting place.

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