The Rotary Beam Engine is unique in that the rotation of the flywheel and  crankdisk are at right angles to the up and down rocking motion of the beam.  This engine incorporates a 3/4" aluminum base and pedestal, and brass for the flywheel, linkages, piston and connecting rods. Aluminum is also used for the cylinder and beam stand while mild steel is used for both the crankdisk and beam. Small details like affixing the pedestal to the base from the underside and pocketing one end of the base for the crankdisk give the finished model a clean symmetry that displays well. It runs well on as little as 3-4 psi of air and the rocking motion of the beam being converted into the  rotary motion  of the inline crankdisk/crankshaft/flywheel is fascinating to watch.

The single acting cylinder simplifies construction, and with the valving being integrated with the crankshaft, the need for a more complicated eccentric/linkage/valve assembly is avoided. These factors, which are also featured on the "Simplex" engine make it a ideal first project for the novice, or an enjoyable weekend or two project for the more experienced machinist. Some soft soldering of brass is required in fabricating the connecting rod and crank arm.

For a listing of material and fastener requirements click here.

Overall dimensions are apprx. 2" W x 4" H x 3-3/4" L

The plan set consists of 8 pages of drawings and 4 pages of construction notes for $10.00 (US postage paid). Please see the general info. page and order page for more detailed information on plan sets.

As a side note...I originally saw this concept on a rather crude model being auctioned off online (see the pictures below). The design was intriguing enough to try and copy, though in a somewhat more "engineered" and precision fashion.  I hope you will agree that this design and plan set achieves that end.

To view or download a video clip of this engine running, click on the "Video" button below. (5.6MB, apprx. 52 seconds, .wmv format)