CTI Single Use Nozzles

I've been getting into EX motors with sugar propellant and would like a cheap source for nozzles to test with and was told this would be the best option. I'm unable to attend a launch till October so I am willing to pay shipping if someone can collect some 29mm, 38mm, and 54mm nozzles from a club launch. I know there is a launch this weekend at MDRA and was wondering if someone there could collect the nozzles because shipping would be less as they are relatively close to me. (I would LOVE to go but crossing the Chesapeake Bay Bridge in the summer is a nightmare) I'm specifically asking for CTI because it is the only hardware I currently own, though I am planning on getting 54mm Aerotech hardware soon so if some single use nozzles from them can be collected as well that would be nice.

Thanks,
Trevor Mushung

As far as I know, CTI nozzles are single use. Mike Fisher at BinderDesign.com can probably make some for you.

As for the Bay Bridge, go to baybridge.com and look at the traffic cameras before you leave. Then you'll know if there is a back-up or not. I have to cross it for every launch, and I've only hit a back-up once in three years. Usually by 10:30 or 11:00, beachgoers are already there. EZ-Pass helps, too.

I've heard of people doing this before, but if you're collecting nozzles that have been fired, you may have a lot of problems with repeatability. Also, I think CTI nozzles are designed to be a little bit erosive, so each time you fire the nozzle, the throat might be a bit different (again- issues with repeatability).

As far as Aerotech, they sell nozzles and other "pieces" of their hardware on the RCS site. Might be easier to buy new, and know what you're getting.

Also, just a reminder that making propellant has lots of opportunities for bad things to happen (read: hospital)...please try to be as safe as you can.

I reuse all sizes of the AT nozzles and phenolic liners. I also reuse 54mm and above CTI stuff. Also keep in mind that there is cross compatibility.
Below is a photo of a spent 75mm liner and nozzle with an Research load for a snap ring case.



Research Rocketry does not always have to be just propellant based research.

Like playing with different nozzle materials...


it can get weird at times like using a billiards ball for a nozzle.



Tony

tfish said:

I reuse all sizes of the AT nozzles and phenolic liners. I also reuse 54mm and above CTI stuff.

Click to expand...

Tony- for general knowledge- are you able to reuse most/all nozzles for AT and CTI? Or do you need to scrap some of them because they are damaged from the burn.

Also, I think the world needs more billiard ball nozzles.

How would one chuck up a billiard ball to turn it down? Drill a hole and use a mandrel? Maybe drill opposite sides and turn between centers?

I've heard of people using the phenolic nozzles and just drilling them out to the size they want. It only works if the post-burn nozzle is smaller than you want it to be I guess, but there are certainly a lot of spent motors at any given launch.

I'm just using these nozzles to experiment with because I don't want to shell out a decent amount of money on a nozzle and have it get destroyed. I'm looking into either getting Binder Design or Loki hardware for proper EX motors once I start flying them next spring but for now I don't have the money to buy them. As for nozzles being too big or too eroded I can do some work on some to clean them up and smooth them out and if they are too far gone oh well it's not a big deal. I'm hoping that if I get some with small throats I can drill them out to the throat diameter I want.

John, if you are going this weekend could you collect the nozzles from the launch? I would love to go but I can't as parents don't want to take me and I have to prep for state championship for archery in 9 days. I can't make it to another MDRA launch till November so that's why I am asking for someone to do this.

Thank you all for the comments and I have looked at RCS but again I'm trying to stay cheap while I learn. I'm also talking with others about the propellant itself and am doing it safely because I know the dangers that it comes with.


Thanks,
Trevor Mushung

djs- It mostly has to do with the throat size. some of them start out with big throats and then get bigger after the burn. I also try to avoid reusing the long burn motors..just because.

ttabbal- yep more reusable stuff at bigger launch events. I've been doing it long enough that people just bring me bags of their spent stuff.

figuring out how to turn down the billiards ball down was easy


Tony

I have a brand new AT M1939 nozzle if anyone wants to trade for a pool ball nozzle

Love it. People saying phenolic nozzles can't be reused, blah blah blah. Then tfish shows up. See you in a few weeks T!

To the op, a couple guys on this forum are good enough to save and send you spent nozzles but most just throw them away after use. Best way is to bring a trash bag with you to the next launch. You may get some cockeyed looks.

DeeRoc29 said:

To the op, a couple guys on this forum are good enough to save and send you spent nozzles but most just throw them away after use. Best way is to bring a trash bag with you to the next launch. You may get some cockeyed looks.

Click to expand...

I'd love to but I mentioned in the first post that I wont be able to attend another launch for a couple months.

Bump?