Dual-drum tumbler for "DoubleShot" mission designed & built to pre-mix 32 lbs (15 kg) of KNO3/sorbitol powder. Each 8 gallon fibre drum is filled 1/3 capacity for maximum blending efficiency. Rotation speed is about 32 RPM. After blending, propellant remains in sealed drums until ready to be loaded directly into melting apparatus: Please contribute to the "Sugar Shot to Space" project with a donation and help make the dream of reaching space with the first amateur rocket using amateur propellant a reality!