We have been collecting belt-driven equipment for years, simply because we have a weakness for anything with a pulley on it. The equipment we've collected had been stored in our barns and garages, gathering dust while we waited for an opportunity to use them. That opportunity finally came along in the form of a steel-wheeled wagon we acquired from an acquaintance in Oregon. The wagon provided a perfect base for mounting our assortment of equipment, and for supporting the line shafts to drive it all.
The result is a working display of belt-driven tools that dynamically demonstrates how. various equipment was powered before the electric motor came along.
An advantage of the wagon display is that we can roll it off a trailer and into position, and it's ready to show -no tedious lugging of materials to set up, and no unpacking.
At the heart of the display lies a venerable 1919 Hercules 1-1/2 HP Type E engine. The main drive belt runs from the engine pulley to line shaft pulley. When the clutch lever is pushed, the engine rolls forward, putting slack in the belt and stopping the shaft. Note springs under the engine to tension the belt.
It took us an entire winter to build up the display, as we had to restore each piece of equipment to some extent, mount it on the wagon, then adjust it for proper operation. The line shafts are 1-1/2-inch cold-rolled steel, supported on ball bearing pillow blocks. To improve visibility and give adequate pulley clearance, we placed the shafts on top of steel pedestals, which are bolted and braced to the wagon top.
The power source is a 1919 Hercules 1-1/2 HP Type E hopper-cooled engine with a Webster Tripolar Oscillator magneto. This engine is old but eager, and will run almost everything on the wagon at once, and at about 400 rpm. The Little Wonder feed grinder takes quite a bit of power, so we have to unbelt a few other tools when we use that particular piece.
Putting things together
We had to make several important decisions in the process of setting up the display. One decision was how to position the line shafts. Commonly, line shafts were hung from the ceiling overhead, using special brackets equipped with bearings, oilers and adjusters. We decided it would be more practical to mount the line shafts on pedestals from the bed of the wagon, making them easier to see and keeping the weight low on the wagon.
A second decision was whether to use one continuous shaft or two offset ones. We finally chose to use two shafts, allowing us to use readily available cold-rolled bar stock, which also adds interest.
The final decision was where to locate the gas engine. Mid-mounting on the wagon would have been logical, dividing power equally on each side, but we chose to put the engine on one end of the wagon, with the carburetor and magneto facing out, so the engine would be easy to adjust and crank-start.
One challenge we faced was how to clutch the engine so we could disconnect it from the line shafts for starting, or for making adjustments to the equipment while the engine was still running. We contemplated several options, including a friction clutch or a centrifugal clutch, but finally decided to take advantage of the cart the engine was already mounted on. The cart has four small wheels, so we placed it on a set of angle-iron tracks. The tracks permit the engine to roll back and forth, changing tension on the main drive belt. Springs tension the belt and a wooden lever releases the tension, making for a smooth working clutch.
Once we had the engine mounted and the line shafts in place, we were able to position our various tools and belt them up. Our current display consists of a DC generator, an air compressor, two bench grinders, two pumps, a feed grinder, a blower and a drill press. Since belt tension is important for proper operation, we needed a way to assure that each belt was under tension, regardless of temperature, load or stretch. Our solution was to mount each tool on a platform that slides in a track under spring pressure to keep the belts tight. For platforms, we used Trex lumber, which is a mixture of wood and plastic. The Trex slides easily along the tracks, which are made of unistrut material. The springs are hidden inside the tracks and have adjustable stops to set the tension.
Another challenge we faced was how to handle the two pumps in the display. How should we demonstrate the pumping action, and what type of fluid should we use? We decided to use clear tubing, so visitors could see the fluid and bubbles in motion. Regarding fluids, we came up with two different methods. One pump is a gear-type built for pumping oil, but it has no provision for lubrication of the rotor bearings since it depends on the pumped oil for this purpose. That meant we had to use some type of oil, but we didn't want to have a gallon or more of petroleum in the system because of the possibility of leakage. We settled on vegetable oil flowing in a closed circuit. This works fine, and we don't need to be concerned if we spill any. The other pump is a centrifugal type and has independently lubricated bearings and seals, so we were able to use water and make an open-circuit system.
A recent addition to the line shaft display wagon was an electric motor to drive it on certain occasions. We use the electric motor to check new items as they are installed on the wagon. It will also be used where the noise of the engine is objectionable, such as at street fairs, or when the wagon is on display indoors, such as in a mall or museum.
Our wagon was very popular at shows this past summer, and the bark from the stack of the Hercules engine combined with the motion of the belts and pulleys proves irresistible to crowds. As might be expected, we get a lot of questions about the display and enjoy the lively discussions that follow. Some typical questions:
'What keeps the belts on the pulleys?' Answer: Each pulley has a crown; meaning the pulley is larger in diameter at the center than at the edges. This has the effect of guiding the belt to the center of the pulley and keeping it there. If we get a pulley without a crown, we chuck the pulley in a lathe and machine a crown on it, then the belts give us no trouble.
'Where do you get belts?' Answer: Local industrial chain and belt suppliers can make belts to any dimension. All you need to do is specify length, width and material. If you use a lot of belts, like we do, then it pays to buy belting material in bulk and make your own belts. Belts also show up at swap meets, but of course you have little control on size or length.
'How are the belts spliced?' Answer: We use a material called Clipper lacing. It consists of a row of stainless steel hooks, and is sold in 12-inch lengths. It is cut to length and applied to the belts with a tool called a belt lacer, which does a neat job of installing a row of loops to each end of the belt. Then, a steel wire is run through the interlaced loops, completing the belt.
'Why do you use a chain to link the two line shafts?' Answer: Three reasons: (1) the chain and sprockets take up less room on the shafts than a belt and pulleys, (2) the chain and sprockets cost less than a corresponding belt and two pulleys (if you have to buy the pulleys), and (3) it is educational to show another form of power transmission. Note the chain never slips and never runs off the pulleys.
'Do the belts ever slip?' Answer: If the belts and pulleys are properly sized for the job, then slippage is rare. If a belt tends to slip, we increase tension, cross the belt for more contact on the pulleys (note this reverses direction of rotation), or we apply a belt dressing spray.
'Where do you get pulleys?' Answer: Used pulleys can be found at all the usual used hardware places. New ones are available from industrial suppliers and some Gas Engine Magazine advertisers. We have also made our own pulleys from aluminum and wood. A split pulley is especially valuable, since you can mount it on a shaft without removing all the other pulleys and bearings.
One of our goals was to have every tool operational, so we have some light bulbs glowing on the generator and a block of wood to drill on the drill press. The only tool we haven't done something with yet is the air compressor, which we intend to have blowing up balloons or tooting a whistle - after all, we need some more projects for this coming winter. ...
Contact engine enthusiast Kirk Unzelman at: 4635 130th Ave. S.E., Bellevue, WA 98006. Contact engine enthusiast Mike Intiekofer at: 4472 119th Ave. S.E., Bellevue, WA 98006.