I'd been tossing a few ideas around in my head on how to solve a couple of problems with the spinning cup atomiser: first one is that you get a flat disc-like plane of spray at right angles to your tuyere/air inlet that is hard to blow in the right direction. Most of my experiments were able to direct the flow into a 90 degree cone with a large amount of airflow. The second issue is that getting the fuel into the cone via a hollow pipe has technical problems getting a good seal, a 270 degree bend in the fuel pipe to enter the mouth of the spinning cup has fuel boiling problems and dripping caused by the spray being intercepted. I dug out my old faithful "Flame" brand motor tool test bed and fitted one of the early spinning cups back on it. This time the fuel tube places fuel on the outside of the spinning cup where a kitchen scouring pad lightly rubs the spinning cup outside. The pad catches the fuel from the tube and ensures good contact of the fuel with the spinning cup: without it most of the fuel bounces off a boundary layer of air on the cup surface and bounces right off again uselessly. The second even more important thing which I found out by accident today is the pad allows fuel to be atomized in one narrow arc instead of a flat plane. In theory you could mount the spinning cup/cylinder at right angles to the tuyere pipe with the fuel spray going into the furnace. There's a few issues to be sorted out but for a Sunday afternoon experiment, I think it's a pretty good result. So this is the old spinning cup assembly used, it shows the fuel tube location before the scouring pad strip is wrapped around the cup.