Saturday, June 30, 2007

Minisshot Nozzle Update



The nozzle ring is nearly completed. The 24 ring to casing screw holes and the 6 shell to ring holes all still need to be tapped. I'll probably have that task completed before the weekend is over. Indexing and drilling the 24 retention screw holes was more time consuming than I was expecting. The Mid-bulkhead design has 48 screw hole locations, so that will be even more challenging in that regard. I was worried about the alignment between the shell and the ring. It looks good though, the holes line up very well. I'm also pleased that it came in right at the predicted weight of 365 grams. Just for fun I looked at McMaster-Carr to see what six titanium machine screws for the shell to ring connection would cost; over forty dollars after shipping. Too expensive! The shortest ones that they had were a bit too long anyway. I may try and stop by Luky's Surplus Aviation Hardware in Burbank next week and see if I can find some there. Their prices and selection are awesome, finding the exact one that I want will be the hard part. I don't think that it's absolutely necessary, but those six screws will be exposed to significantly more heat than the ring to casing screws.

3 comments:

Magnus Gudnason said...

This is some nice nozzle you got there.

I like the design a lot, pretty cool.

So when is the static test?

Randy Dormans said...

Thanks Magnus. The static test is going to be a while yet as several components still need to be machined (hopefully in the next couple of months) It's a pretty cool motor design, it sims to around 50,000ft on only about 25lbs of propellant. I'm not sure if you're familiar with the sugarshot project or not, but you can see more about the motor design here http://www.sugarshot.org , this nozzle is for the minisshot flight.

Magnus Gudnason said...

Yes I´m familiar with the sugarshot, Have viewed about 80-90% of all the info on the site :)

I´m very much thinking about going on a trip and see the eXSShot launched...