Quantcast

CO2 ejection systems

The Rocketry Forum

Help Support The Rocketry Forum:

SkidmarkMonster

Active Member
Joined
Oct 30, 2016
Messages
28
Reaction score
0
Howdy y'all. I was just browsing co2 ejection systems and I wanted to know pretty much everything you guys know or feel about these systems. Particularly the peregrine kit by Tinder Rocketry and the CD3 by Rouse-Tech. If any of you guys have used these systems, please let me know your results. and if possible, please show pics of how you guys mounted them. thx
 

jderimig

Sponsor
TRF Sponsor
Joined
Jan 23, 2009
Messages
3,294
Reaction score
711
I use the Peregrine kit for the nosecone chute cannon in my Honest John. Excellent craftsmanship.

I have a blog entry on my site on the use and handy calculations for the use of CO2 systems.
http://marsasystems.com/index.php/blog Scroll down for the entry.

Since this is a cold gas system they work differently than a hot gas system like traditional BP. If you understand that and apply the correct analysis (amount of volume a given size CO2 cartridge can fill at various pressures) then they are very effective. (and cool).
 

SkidmarkMonster

Active Member
Joined
Oct 30, 2016
Messages
28
Reaction score
0
I heard that because its a cold ejection system you don't need to use nomex or dog barf. which is pretty cool cuz that eliminates a lot of hassle. So you said you use it for your Nosecone. Do you just use a standard bp unit in your drogue compartment?
 

jderimig

Sponsor
TRF Sponsor
Joined
Jan 23, 2009
Messages
3,294
Reaction score
711
I heard that because its a cold ejection system you don't need to use nomex or dog barf. which is pretty cool cuz that eliminates a lot of hassle. So you said you use it for your Nosecone. Do you just use a standard bp unit in your drogue compartment?
Yes that is correct, but you need to be mindful of the volume you need to pressurize and choose the CO2 size (8g, 12g,16g etc) correctly. Accordingly leaks and good fits are important. With BP you just keep increasing the charge till it works.

And yes, I use a traditional BP charge for the apogee event to separate the NC in that particular rocket.

Also on that blog you will see a description of a Balls project rocket and you will see a CO2 system used for the interstage separation and will use CO2 for the recovery events as well.
 

SkidmarkMonster

Active Member
Joined
Oct 30, 2016
Messages
28
Reaction score
0
Yes that is correct, but you need to be mindful of the volume you need to pressurize and choose the CO2 size (8g, 12g,16g etc) correctly. Accordingly leaks and good fits are important. With BP you just keep increasing the charge till it works.

And yes, I use a traditional BP charge for the apogee event to separate the NC in that particular rocket.

Also on that blog you will see a description of a Balls project rocket and you will see a CO2 system used for the interstage separation and will use CO2 for the recovery events as well.
I read that for the correct sizing you use a factor of 5. apparently you are supposed to multiply the amount of bp you use in grams by 5 and that's the amount in grams that you're supposed to use for co2
 

jderimig

Sponsor
TRF Sponsor
Joined
Jan 23, 2009
Messages
3,294
Reaction score
711
I read that for the correct sizing you use a factor of 5. apparently you are supposed to multiply the amount of bp you use in grams by 5 and that's the amount in grams that you're supposed to use for co2
I don't like rules of thumb like that unless there is physics behind that. For CO2 use simple gas law then test. Look at my blog post to see how to calculate the pressure that the CO2 cartridge will generate. A 12g cartridge will fill about 6 liters volume to about 1atm which should be enough to separate a section of reasonable diameter. If you have more that 6 liters to fill it won't work. If you have less it will work.
 

FredA

Well-Known Member
Joined
Jan 19, 2009
Messages
2,170
Reaction score
347
All I can say is ground-test the crap out of it....
And not all systems are equal as far as how big of a CO2 cartridge you need - vent-speed is also a factor.
 

jderimig

Sponsor
TRF Sponsor
Joined
Jan 23, 2009
Messages
3,294
Reaction score
711
Also not knowing where you are in your rocket hobby progression, but if you are new then I would NOT start with CO2. CO2 systems have more failure modes than BP. Most if not all CO2 system just start their process with igniting BP. BP deployment systems start AND end with igniting the BP.
 

mpitfield

Moderator
Staff member
TRF Lifetime Supporter
Global Mod
Joined
Jul 7, 2013
Messages
4,903
Reaction score
431
Location
Toronto, Ontario
Yes that is correct, but you need to be mindful of the volume you need to pressurize and choose the CO2 size (8g, 12g,16g etc) correctly. Accordingly leaks and good fits are important. With BP you just keep increasing the charge till it works.

And yes, I use a traditional BP charge for the apogee event to separate the NC in that particular rocket.

Also on that blog you will see a description of a Balls project rocket and you will see a CO2 system used for the interstage separation and will use CO2 for the recovery events as well.
The Tinder Peregrine is 8g-12g only. The Tinder Raptor is 20-85g. IMO the Raptor is a superior design to both the Peregrine and the Rouse-Tech CD3 systems. I own 2 Peregrine systems and I spent quite a bit of time looking over the both the Rouse-Tech and Tinder's new Raptor system. The new Raptor has less moving mass and parts than the Peregrine system and to my way of thinking is better though out than the CD3 The charge gases of the Raptor exit cold, whereas the charge gases for the CD3 exit hot and you have to use a nomex to cover the exhaust port. Also the Raptor has a return spring to ensure the puncture piston moves back from the face of the CO2 cartridge positively.

I would encourage you to download all of the user manuals and have a good look at how they work

Tinder Peregrine http://media.wix.com/ugd/b73de9_c24d1b724ee493a5b1a62877c96cfa96.pdf
Tinder Raptor http://media.wix.com/ugd/b73de9_1cf9c63dfeaa4018908df6f9ba02c0ca.pdf
Rouse-Tech CD3 https://www.apogeerockets.com/downloads/PDFs/CD3_Manual2009.pdf

Then there is the new Hawk CD which does not use a charge and is completely mechanical http://fruitychutes.com/buyachute/c...-gram-p-224.html?zenid=rkyy1e-89Q5uczrPTbJ8z3
 

s3th

Member
Joined
Mar 22, 2017
Messages
14
Reaction score
0
Also consider launch-day temperatures. I did some "worst-case" tests putting the cartridges into the freezer. After punching the seal - nothing happend, no popping of the airframe. The CO2 just froze to a solid block inside the cartridge after some gas vaporated - lessen learned, kapton-heater installed! If you only plan to launch in summer (well, depending where on this planet) - don´t worry. Btw it was a selfe designed system.

s3th
 
Top