Quote, Merzo: "Someone does not document Isayev "KTDU 417 engine?"
Forgive if I am wrong, but, is not this engine just the same as the Orbital Manouevering Engine intended for the Manned Lunar mission? To my eyes, it looks to be very much the same engine, but without the external coverings it would have had for the manned lunar mission.
If my thinking is correct, (and I admit I may well be wrong), then the published images of the OME I mention might be good enough to use as references for the build Merzo is so skillfully executing.
Regarding the styrofoam balls: unless one uses either white (PVA) glue or silicon-based adhesives, almost any other type of glue/adhesive (example Uhu, or Bostik) has a huge disadvantage for styrofoam: it dissolves into a chemically burning sticky messy lump in seconds. And it will damage skin and eyes (minor chemical burns) if in contact with skin for longer than a very few seconds. It is, in effect, a very very weak form of napalm, so to speak.
Kind and Respectful Regards my friends, Uyraell.