In these two photos are the large black powder motors available in the 1960s. The bottom two are Coasters. The yellow one an E with 3.5 pounds of max thrust and 2 of average thrust and blue one a F with 40 pounds of thrust.
Coaster was in Euless, TX which is one of the mid-cities here between Fort Worth and Dallas.
Centuri out of Phoenix made motors which in the '64 catalog was a lone F11-3 with 11 pound-second impulse. In 1965 they offered the Atlas E motors (E3.3, E3.1, and E2.8) and F11 and F25. In the 1967-68 catalogs (
www.ninfinger.org), the motors were renamed Mini-Max. Designations were D2, D1.5, D3.9, E1.3, E3.5, F10 and F14. Lee Piester had purchased Coaster in the mid60s and moved production to Phoenix.
In 1969 the Mini-Max line was E7, F55, and F94. In 1971 they were E15, E62, F16, and F97.
Centuri had also purchased the Enerjet line from Irv Wait and Rocket Development Corp. Enerjets superseded the Mini-Max line in 1971 with the E24, F52, and F67. Enerjet had its own catalog with those motors in 1972.
The F94-4 in my collection has a serial code, but no date. Neither does the E15-8.