CTI advice needed

[Andy Greene]

So , I have been flying Estes 640/7w motors in my Argent and plan to use my CTI 29/140 3g case for the first time at the next launch.
I spoke with a vendor that will be on hand and have yet to do the rest of my homework, and looking for some advise on 3g motors or 2g with a spacer that will keep me close to the G40/7w .
Thinking maybe a G54 long burn or G33 - anyone have any input or advice they are willing to share ??

 

[djs]

The G40 is 100 newtons.. i'm thinking the G68 White might be a good replacement, although a bit faster. 3G motors are all 125+ newtons, so while it would work, it might be a little more "oomph" than you're expecting.

 

[DavidMcCann]

G54 is a nice long ride. With 159 Ns, it's going to go a bit higher than the G40W that has 113 Ns total impulse.

H133BS is a sweet little 3grain thats 163 Ns Just enough for an L1

 

[Andy Greene]

Yeah - with only single deploy , its gonna require a calm day to go that big. sigh.......
Just trying to avoid the haz mat costs of ordering one single use motor for 1 flight.

 

[DavidMcCann]

Get some aerotech cases. most of the 29/40-120 are no hazmat. the 29/120, 180, 240, and 360 all all non has except a few.

also- The F20, F23, F27 and F42 2 packs do not require hazmat if shipped USPS ground (ask for it) https://www.wildmanrocketry.com/ShowProducts.aspx?Class=82&Sub=85&Sub1=86


or there are "loadable" single use motors that ship no hazmat, all you have to do is assemble them- https://www.siriusrocketry.biz/isho...s-hdw-36/aerotech-29mm-loadable-motor-sys-40/

 

[dhbarr]

Shout out for the two no-cert no-haz Loki, as well.

 

[DavidMcCann]

Shout out for the two no-cert no-haz Loki, as well.

You know I'd be all over that.... but he's not into 38mm yet. Though I do know a way to fly 29mm Loki

 

[Steve Shannon]

The G40 is 100 newtons.. i'm thinking the G68 White might be a good replacement, although a bit faster. 3G motors are all 125+ newtons, so while it would work, it might be a little more "oomph" than you're expecting.

G54 is a nice long ride. With 159 N/s, it's going to go a bit higher than the G40W that has 113 N/s total impulse.

H133BS is a sweet little 3grain thats 163 N/s Just enough for an L1

Impulse units are Newton seconds, not Newtons, which is thrust, and not N/s, which doesn't make sense at all. It's the area under the thrust curve where one axis (usually the vertical one) is thrust and the other axis is time. A motor that burns with an average thrust of 80 N for 2 s has 160 Ns of impulse.

 

[DavidMcCann]

And that's why I shouldn't post and drink. No idea where that / came from

 

[Steve Shannon]

And that's why I shouldn't post and drink. No idea where that / came from

Isn't it funny how those things happen! I was sure you knew the difference; I shouldn't have pointed it out. I'll buy you a beer sometime and we both won't post afterwards.


[emoji1010] Steve Shannon [emoji1010]

 

[DavidMcCann]

Haha. No worries. Good to catch it before someone new sees it and it becomes a thing.

 

[Andy Greene]

I will get with the local vendor and figure it out next weekend on sight - thanks for the reply fella's .
I really dont want to buy another case, the reason I went with the Cessi case was the ease of assembly vs the A/T case -
At least from a newbies standpoint - lol

 

[djs]

, the reason I went with the Cessi case was the ease of assembly vs the A/T case -

You are correct on this- CTI motors are easier to assemble than AT. However, if you have not done it before, it would be helpful to find someone with experience on site that can walk you through it.

FYI- A favorite CTI motor of mine is the F59 White thunder (29mm 1 grain). It packs a good punch, and is a motor that I use for trial runs on new rockets.

 

[Andy Greene]

I would certainly seek advise and assistance to ensure I do it properly. The advice and input is appreciated from all here,
Thanks

 

[BDB]

Though I do know a way to fly 29mm Loki

Do tell...

 

[rharshberger]

Do tell...

Indeed....

 

[Buckeye]

Is "Cessi" a new thing? I never heard that nickname before.

 

[Steve Shannon]

Is "Cessi" a new thing? I never heard that nickname before.

This thread was the first I'd heard it used also. I don't think it'll stick.

 

[bill_s]

The weight is increased, so you'd need maybe 120 N-s to be equivalent, but the G54 is definitely a step beyond that, one of the reasons to choose the 3 grain, unless you're going to certify, after which you can also fly the G106 Skidmark, which is spectacular. I've flown it and the H42 4-grain in my closest rocket (yet) to the Argent.

 

[r12ski]

Whenever I have a question of either a) What's a good motor for rocket "x", or b) I have motor "y", what rocket can I fly it with I go to rocketreviews.com

You can look up a kit or motor and it will list all the flights that have been logged with it.

I usually look for comments like "perfect motor combination for this rocket" or "this reload was made for this kit". Or,conversely "delay was too long", etc.

Then, get into the habit of logged your own flights. It is a great tool.

In fact, just today I was looking up info on a kit and saw my own flight log listed and it reminded me of that flight. I wish I could say I remember every launch but at least I can easily keep track of my notes.

 

[Andy Greene]

Its been a bit , but last time I checked rocketreviews had very little info on the Argent - I will revisit it and see. Maybe I need to add mine- I have had several perfect flights with the G40-7W Single use motors.
Thanks for the reminder. :wink:

 

[Andy Greene]

This thread was the first I'd heard it used also. I don't think it'll stick.

I edited the original post- sorry for my newb terminology ..........

 

[Steve Shannon]

I edited the original post- sorry for my newb terminology ..........

It made me think of Nessie, aka the Loch Ness monster. It didn't offend us; we were just confused. [emoji15]