Resurrecting a Classic Wind Generator


Inside this Article

A restored, 1950s-era Jacobs wind generator
A restored, 1950s-era Jacobs wind generator flies again.
The excavated holes, with rebar cages in place.
Prepping and pouring the footings for the tower: The excavated holes, with rebar cages in place.
Detail of rebar cages.
Prepping and pouring the footings for the tower: Detail of rebar cages.
Tubular concrete forms are filled to form the upper 8 feet of the foundation.
Prepping and pouring the footings for the tower: Tubular concrete forms are filled to form the upper 8 feet of the tower foundation.
The original Gemini synchronous inverter
The original Gemini synchronous inverter in its new home.
The restored Model 45 Jacobs generator
The restored Model 45 Jacobs generator—as good as new!
Assembling the top tower section.
Assembling the top tower section.
The crane lifts the 3,200-pound, 100-foot-tall tower section.
The crane lifts the 3,200-pound, 100-foot-tall tower section.
Mounting the rotor assembly to the generator
Mounting the rotor assembly to the generator. Temporary coverings protect the blades from damage.
The crane lifts the Jake skyward to its new perch.
The crane lifts the Jake skyward to its new perch.
The restored Model 45 Jacobs wind-electric generator
The restored Model 45 Jacobs wind-electric generator, rebuilt and reinstalled at the author’s property.
A restored, 1950s-era Jacobs wind generator
The excavated holes, with rebar cages in place.
Detail of rebar cages.
Tubular concrete forms are filled to form the upper 8 feet of the foundation.
The original Gemini synchronous inverter
The restored Model 45 Jacobs generator
Assembling the top tower section.
The crane lifts the 3,200-pound, 100-foot-tall tower section.
Mounting the rotor assembly to the generator
The crane lifts the Jake skyward to its new perch.
The restored Model 45 Jacobs wind-electric generator

Several decades ago, before modern small-scale wind turbines hit the market, one of the most sought-after wind generators was the pre-Rural Electrification Administration direct-drive machine made by Jacobs Wind Electric. It’s rugged, powerful, and reliable when maintained well. When I was growing up, my father and I flew five different homebuilt wind turbines, and I had always dreamed of someday flying a “Jake.” I kept my eyes peeled in my travels around the Midwest, hoping for a find.

In September 2003, I spotted an old Jake sitting idly on a tower only a few miles from my family’s home in Merton, Wisconsin, and immediately thought to myself, “I need to get this machine running again.” I also had the feeling that, decades ago, I had once read about this particular machine.

Searching through some of my old periodicals, I found an article from nearly three decades earlier describing the history of the machine that I had spotted. In 1976, then-U.S. Representative Henry S. Reuss installed the 32 VDC, 1,800 W, direct-drive Jacobs Wind Electric generator at his summer home in North Lake, Wisconsin. The wind generator was connected to the utility grid through a Gemini synchronous inverter.

After striking a deal with the current owner of the wind generator, I began assembling the necessary equipment to remove the machine from the tower. I devised a ladder arrangement to access the tower safely. Some friends and I constructed a 12-foot-long gin pole, made of 3-inch seamless steel tubing, to remove the wind turbine. Removing a 400-pound wind generator from atop a 72-foot tower can be challenging, but we did it and lived to tell the tale. The next step was to rebuild the generator and put it back into action.

We Can Rebuild It!

Although the machine was in poor shape from years of neglect, that didn’t deter me. From the circa-1976 photos, I could see that the original flyball-type governor had been changed to a blade-activated governor. Both types use the centrifugal force of the rotating machine to actuate. With the flyball governor, higher rpm cause spring-loaded weights to move outward, decreasing the rotor speed by increasing the pitch of the blades through gears. With blade-activated governors, the blades are spring-loaded, and the blade pitch is increased as they move out on their shafts.

After gently heating up the governor casting with a propane torch, I removed the housing from the tapered generator shaft with a three-pronged gear puller. Liberally applied solvent helped remove the gummed-up grease on the blade shafts and spider casting, and a lot of wire-brushing removed the rust. My friend Jim machined new ball joints to replace the badly worn originals. After several coats of corrosion-inhibiting paint, the blade-activated governor was ready for many more years of service.

The Model 45 Jacobs generator (rated at 45 A, 40 VDC) had to be completely disassembled. We steam-cleaned the armature to remove dirt, debris, and other potentially conductive contaminants, and then oven-baked the windings to remove all moisture before varnishing. The insulation resistance (conductor-to-ground) tested “good,” as did the commutator. The commutator bars were polished and undercut, and the windings coated with insulating paint. The armature bearings were replaced with sealed bearings. The stator was wire-brushed to remove the rust and painted with several coats of antirust paint.

Having rotten tips, the Jake’s wooden blades required major refurbishing. Also, the tail vane had broken, causing the tail to overshoot its parked position. This allowed one of the blades to smash into the tail, putting a cut in its leading edge.

The blades were sanded down to the bare wood and any rotten wood replaced. Next, epoxy resin was spread onto every wooden surface and forced into the wood grain with a heat gun. After sanding, a fiberglass mesh, soaked in more resin, was applied to each blade. After three additional resin coats, with sanding between, each blade was given a final hand-sanding. Two coats of marine-grade epoxy paint were applied with a spray gun. Finally, the rotor was assembled with the governor and static-balanced.

Some miscellaneous parts needed attention too. The turbine tail vane and a generator bearing housing were cracked and required welding. A new tapered roller bearing was installed—it supports the entire weight of the wind generator on the tower. Various other Jacobs components had to be purchased to complete the restoration—blade-actuated governor springs, a tail vane spring, a yaw slip ring and brushes, and generator brushes.

The Gemini synchronous inverter was not part of a standard Jacobs wind-electric system. When interposed between a variable-voltage DC power source (such as a wind generator) and an AC grid, it converts DC electricity to AC and interties it—similar to modern grid-tie inverters.

The Gemini was caked with sawdust, so I completely disassembled it and cleaned it with acetone, alcohol, and flux remover. Some friends and I determined that several components needed to be replaced. One rectifier was bad, the voltmeter didn’t work, and the generator-field-excitation circuit board was shot. (We guessed that the damage was caused by a lightning strike.) We ordered parts from various suppliers and eventually got it running again.

Tower Installation

To minimize the view of the tower by the immediate neighbors, I decided to place it among several trees on the property. A pier and pad footing was chosen for the 120-foot-tall Radian SSV self-supported tower. Three 6- by 6- by 10-foot-deep holes held rebar cages. Tubular cardboard concrete forms were centered on each protruding rebar cage for the upper 8 feet of the foundation. Anchor bolt assemblies were positioned and leveled inside the tubes, and the tubes filled with more than 11 cubic yards of concrete. A backhoe filled and compressed the dirt around the footings. Leveling nuts to support the tower were screwed onto the anchor bolts.

If you loved playing with erector sets as a kid, putting together a self-supported tower is about as much fun—just bigger—and you get to play with a crane to boot. The crane operator visited the site to discuss logistics, such as where to bring in the crane, the crane’s location during the lift, the lifting capacity needed, and where to assemble the tower on the ground. Preparation was key to a successful tower lift as well as keeping the costs down: At $150 an hour for crane rental fees, I wanted to minimize lift-day delays.

Friends helped me assemble the tower in two sections—the top 100-feet and the bottom 20-feet—to allow use of a smaller crane. The tower legs were laid out and leveled on concrete blocks. Starting from the top and working down, we put together most of the top section in one day. Without jacks, a scaffold, or an A-frame, putting the tower together on the ground is definitely a three-person job. Once the top section was bolted together, we mounted 2-inch conduit along the length of the section and pulled the electric cables.

The Jacobs generator saddle, slip ring, and brush assembly were then attached to the top of the tower. Finally, the wiring was attached to the slip rings, which allow the wind turbine to yaw, or move into the wind, while transmitting energy to the wiring running the length of the tower.

Assembling the bottom 20-foot-tall tower section onto the footings without a crane required a lot more people power, since each of the three vertical legs weighs 180 pounds. Six people tilted each leg to a vertical position while three other people held ropes attached to the top of the legs, making sure the section didn’t tip over. The cross-braces were mounted, and everything fit perfectly!

Once the crane was set up, the boom was extended toward the top of the horizontal 100-foot-tall tower section. Three slings were rigged to the three tower legs, approximately 20 feet down from the top of the tower. Then, the lifting began.

Once the tower was vertical, the crane operator lifted the upper section over some fruit trees and positioned it directly above the bottom section. Three of us harnessed ourselves onto the legs of the bottom section and guided the top legs into place. They lined up perfectly—we just dropped in the bolts and torqued the nuts. I then climbed up the tower to detach the lifting slings, and waited to mount the wind generator atop the newly placed tower.

Back In the Saddle Again

Then came the moment I’d been dreaming about—getting the wind generator into the air. The crew on the ground attached the generator to the crane, and the 14-foot-diameter blade rotor was attached to the generator. The governor springs were fastened and tensioned, and the crane hoisted the whole assembly to the top of the 120-foot tower.

The challenge was that a Jake generator with its rotor assembly attached doesn’t hang perfectly level from the lifting eyebolt—the weight of the rotor assembly causes the generator to tilt downward at the rotor end. At 120 feet in the air, I had to exert a lot of ergs of energy to get the three mounting bolts to align. Luckily, we had tied a 150-foot rope to the generator before lifting it to the top of the tower. That way, my helpers on the ground were able to pull the rope to help me get the assembly level, so I could attach the generator to the saddle.

With the generator and rotor assembly secure, the final lift was the tail vane. The trick was to properly tie a rope to hold the vane horizontal during mounting, yet still allow the rope to be easily untied from atop the tower once the vane was in place.

Once this was completed, I felt an overwhelming sense of relief. As I stood, harnessed at 120 feet, with the very machine I had read about all those years ago, I thought that perhaps it would have also made the late Representative Reuss proud to see his old Jake ready for action again.

Ironically, from my 120-foot perch, I was able to see several famous landmarks in the region and also the very spot from which I had recovered the Jake. The fact that it was now in place on my property and ready for my family brought back pleasant childhood memories of time spent with my father working on wind turbines. I hope that this experience also will instill a sense of environmental responsibility in my son.

Final Touches

Getting the Jake up on the tower wasn’t the end—we still needed to wire the system. Because this system was eligible for net metering, an interconnect agreement and site inspection was required by the local electric utility, and a sign-off was needed from the local electrical inspector. They gave their approval—almost three years to the day after I first set eyes on the old Jake!

An average wind speed of 11.8 mph should generate about 400 kilowatt-hours per month, providing roughly two-thirds of our electrical needs. Presently, five loads (see “Household Loads” table below) account for about 90% of our home’s electricity use.

With the Jake running, we’re more motivated to see how we can minimize our energy usage by implementing conservation measures and upgrading to more efficient appliances. I am also pleased that since our Jake was erected, it has generated many positive responses from people in the area. In fact, more than one neighbor has expressed interest in installing a wind turbine.

Getting an arguably famous Jacobs Wind Electric system back up and running again was a dream come true. If you see a turbine standing idle in the wind, stop to imagine the possibilities of generating your own electricity and helping to make a cleaner world for our children. Then put your dream into action!


Willi Hampel is a Wisconsin-based professional engineer with more than 20 years of experience designing medical diagnostic imaging equipment. He has more than 30 years of experience installing and maintaining residential wind turbines.

Curtis A. Eggert • 218-829-4394 • Jacobs parts

Mid-State Electronics • 920-787-7383 • Inverter repair

Pantec Studio • 262-692-6157 • • Blade repair

Radian Communications Services Corp. • 309-697-4400 • • Tower 

Sagrillo Power & Light • 920-837-7523 • • Expert advice 

Schober, Schober & Mitchell S.C. • 262-785-1820 • • Legal advice

Comments (1)

Roger Beale's picture

I think that's just great! spending the time and money to get it running again...

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