Saturday, 23 June 2007
Other materials we have ordered include PVC, PE (polypropylene), HDPE (high density polyethylene) and UHMWPE (ultra high molecular weight polyethylene).
PVC and PE are used in SkyRipperSystems commercial Hybrid motors. HDPE has been used in hybrid design. UHMWPE might offers advantages of more material being ejected, and therefore higher thrust. Presumably, this is all to do with the density of the plastic. Some of these plastics may be very difficult to machine or drill. This is why Chimera will be doing some experiments.
Saturday, 16 June 2007
Tuesday, 12 June 2007
Monday, 11 June 2007
Everything about a hybrid motor can be made, but we cannot make anything unless we have materials. The main two materials needed are aluminum for the case and plastic for the reload. It is proving very hard to find the right sizes of materials. Why?
1. There are lots of people who will supply aluminum tubing, but very few in the right alloy, right temper, right outside diameter, and right wall thickness. And they will only make tubing to our size requirements if we buy hundreds of meters (literally).
2. There are lots of people who will supply various kinds of plastic rod or tubing, but not in the right diameter (to fit in the case exactly) and with the right wall thickness for the burn. And they will only make tubing to size if we buy hundreds of meters (literally).
I've found some suppliers that can supply small quantities, even having quite a range of sizes, but, as yet, no match - nothing fits exactly.
You see, while I think we make make values, end closures and much else, we cannot machine four feet of aluminum tube to a specific outside diameter, let alone an inside diameter. And I don't believe we can take plastic rod and reduce its thickness, nor can we drill the large hole in it for the gas to pass through. The plastic will likely buckle. Even if we did manage it, we don't want to have to do this for every reload we make. What we want, is a reliable source of the fuel, and then build the motor and values etc., to fit that.
So... as far as I can see the main Chimera challenge now is to get a reliable source of these two materials, in the right specifications, in the right sizes. It's a hunt for suppliers.
Monday, 4 June 2007
So, for Chimera projects we shall be focussing on nitrous oxide (otherwise known as laughing gas or NOS). This is not to be confused with NOX which is a generic term for any single nitrogen atom molecule oxide. NOS got its name from the company that first made nitrous oxide for boosting internal combustion engines.
Sunday, 3 June 2007
The introduction to Hybrid Technology is written by Bill Colburn, the Co-Inventor of the Urbanski-Colburn Valve for simplified hybrid motor construction. Bill also designed, constructed and tested the first Hypergolic Hybrid Motor in June of 1951.
Bill also built the first N2O Hybrid motor using 2 inch tanks (laboratory demonstration tanks), the fore-runner of the consumer High Power Rocket Motors now supplied by both Aerotech and Hypertech. Bill wrote the first Hybrid Propulsion Manual aimed at the field of Experimental Rocketry. This re-written manual is included as part of the SORAC Hybrid Manual.