Liquid Fueled Rocket Engine.

[britishrocket]

Hi Ron,

I just re-read one of your earlier posts and realised you are looking at spinning a nozzle. I had thought about that too but I have no experience with spinning in the lathe. I was wondering if you'd had any success in that area with regard to nozzle production?

[jt8d]

Hello Carl, 

Although I'm no help,  here is some info I've found regarding metal spinning.  

John Carmack in 2008 switched to stainless steel spun chambers employing film cooling.  He had good success relying solely on film cooling.  Here are some quotes from his 2008 blog regarding spun chambers. 

"We recently had a chamber fabricated by spinning seamless pipe down onto a two part tool. The first article did not come out perfect, with the throat not getting down to the desired radius and being somewhat non-concentric, but it was good enough to start our testing with, and we expect future ones to be better."

"We have moved from 304 to 310 stainless for the injectors, and our next batch of chambers will also be spun from 310 seamless pipe."

"We used a new spun chamber from AMS for this engine, and Phil polished it for best smoothness. This chamber is more concentric, but it is still a 3.5” throat, and AMS doesn’t think they will be able to spin the tube all the way down to 3.0”. We will see how the next couple go, but machining out of billet may turn out to be a better option."

Also of interest, on practicalmachinist.com a gentlemen shared his experience of spinning aluminum on a lathe to form a venturi.  

www.practicalmachinist.com/vb/general/would-like-some-guidance-making-venturi-270383/

Barry