Bore 1 in
Stroke: 2 in
Length: 15 1/2 in
Width: 6 1/2 in.
Height: 7 1/8 in.
Design: Mill Engine
A governor kit is available which greatly adds to the engines appealvespecially when running under steam. The book "Building the Victoria" is highly recommended to anyone making this engine.
CAST IRON. Baseplate, pedestal, pulley, crank, cylinder, valve chest and cover, front and rear cylinder covers, piston, 7 in. flywheel.
BRASS. Slide valve, eccentric strap, valve operating block, glands, corned bush, crossheads, crankshaft bearings.
STEEL. Crankshaft, connecting rod, eccentric sheave, eccentric rod, clevis, crankpin, piston and valve rods, all materials for valve gear and crosshead guides.
SUNDRIES. Detailed drawings, gaskets, "O"ring, gland packing, fixings pack,
The design of the victoria is fully detailed on the Victoria page, here I will concentrate on the changes required to combine two engines.
The two engines although generally built at the same time are machined as mirror images. One with the crankshaft bearing on the right hand side and the other on the left hand side. The two engines are connected together by a long common crankshaft with a crank on each end. The cranks are mounted at 90 degrees to each other, this ensures the engine can self start. It also smooths out the power output as when one piston is changing directions, the other is still on its power stroke. The two flywheels are often machined separately and the grooves machined into the rim, to indicate rope guides. Some engineers instead join the two flywheels together with hidden bolts and machine the rope guides in one go. (See Sidebar for more information)
The pedestals are not required for this version.
As both engines are only connected by the crankshasft care must be taken to carefully align both engines prior to fitting to the base.
The design is very similar to a full size mill factory engine. A few differences are apparent due to the size difference. The real engines were big enough to run a complete factory full of for example weaving machines. The power was very large. For efficiency the engines were almost always compound engines with the exhaust of one cylinder feeding into the second cylinder. This increases steam efficiency but leads to the engine unable to self start. Depending on the size of the engine they will have notches cut into the perimeter of the flywheel so an engineer can put a pryer into a notch and inch the engine forward, repeating until the engine is in a starting position. This is called barring. Larger engine will have a small steam engine to turn over the main engine, this is called a barring engine. The red model above has these barring notches cut into the flywheel for aesthetics as the engine is not compound and thus will self start.
Mill Factory Rope Drive
On real mill engines the power was transferred from the on steam engine to each floor of the factory by ropes running from the flywheel machined with as many as 40 rope grooves to pulleys for each floor, power was then transferred to overhead shaft drives and pulleys to each machine. Ropes were used as they were much more effective than belts. Belts slip more than ropes which run in V grooves. Multiple ropes were used to connect each pulley to the main flywheel so that if one broke work could continue uninterrupted until the next scheduled maintainance period.
A Barring engine is used to turn a large engine into its starting position.