CTI Classic — what’s it like?

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ThirstyBarbarian

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What is CTI’s “Classic” propellant like in terms of flame, color, smoke, and sound? Many of the long-burn CTI motors are made with Classic propellant, and I was wondering what it’s like. Their really long-burning Mellow propellant is useful for certain kinds of flights, but the show is not very impressive — almost no visible flame, thin smoke, and a hissing sound. So I’m wondering if Classic is more like that or more like their White propellant, which I like.
 
[video=youtube;QLyDdMXuEsc]https://www.youtube.com/watch?feature=player_profilepage&v=QLyDdMXuEsc[/video]
 
[video=youtube;QLyDdMXuEsc]https://www.youtube.com/watch?feature=player_profilepage&v=QLyDdMXuEsc[/video]

Thanks! It looks like a decent flame. The smoke seems a bit thinner than White. You can never tell if the video accurately captures the sound — I feel like most rocket videos sound weak compared to real life.
 
I don’t think of classic propellant as a big show. I only use it for a very specific flight profile. For example, I have an L730, which is a 54mm 6XL classic. I’m going to put it in a 2.6” Madcow DX3 DD and try for 15K feet.

Since the classic is a mellower propellant, it’s not going to slam my rocket with a ton of G force (which I consider hard on the electronics) and it has less of a chance of CATOing. Since it’s an L, it still has a decent amount of roar and smoke. Other than that type of flight I don’t use them much.

I believe some people use them when they want to be accurate for a scale project (something with a small amount of smoke like a Mercury) or an Estes upscale. I think the point of the classic is to look like the Estes BP motors, but I could be wrong about that.
 
The flame is a good length and visibility, but it's definitely not as loud or smoky as the WT loads.
 
Here's my darkstar on a J210 classic. If you skip ahead to 2:20, you can see what it looks like. Also, if you skip to the very end, you can see a crappy picture of the rocket going up from the pad.


[video=youtube;2PL11uiPDaU]https://www.youtube.com/watch?v=2PL11uiPDaU[/video]
 
Here's my darkstar on a J210 classic. If you skip ahead to 2:20, you can see what it looks like. Also, if you skip to the very end, you can see a crappy picture of the rocket going up from the pad.


[video=youtube;2PL11uiPDaU]https://www.youtube.com/watch?v=2PL11uiPDaU[/video]

Thanks. That looked like a nice flight!
 
I did my L1 on the motor linked earlier. It's not an impressive propellant by any means, and far from White in terms of looks and sound. I also feel like it has less flame and more smoke than it seems to there. I do like the burn time though...
 
White:
[video=youtube;iof8ZQedKoc]https://www.youtube.com/watch?v=iof8ZQedKoc[/video]

White Thunder:
[video=youtube;0a6s7V5--Ck]https://www.youtube.com/watch?feature=player_profilepage&v=0a6s7V5--Ck[/video]

Sort of hard to tell from the videos, but White Thunder is a punchier, faster burning motor with a lot of white smoke and more roar. I think it's the equivalent to the AT White Lightning, if that helps.

White is a slower, longer burn with less smoke.

White's like a glass of chardonnay. White Thunder is a shot of bourbon.
 
White:
[video=youtube;iof8ZQedKoc]https://www.youtube.com/watch?v=iof8ZQedKoc[/video]

White Thunder:
[video=youtube;0a6s7V5--Ck]https://www.youtube.com/watch?feature=player_profilepage&v=0a6s7V5--Ck[/video]

Sort of hard to tell from the videos, but White Thunder is a punchier, faster burning motor with a lot of white smoke and more roar. I think it's the equivalent to the AT White Lightning, if that helps.

White is a slower, longer burn with less smoke.

White's like a glass of chardonnay. White Thunder is a shot of bourbon.

++1
 
Good descriptions that match the thrust curves well.

Unfortunately, I couldn't detect any noticeable difference in the videos lol
 
I think [White Thunder is] the equivalent to the AT White Lightning, if that helps.
Not really, it has considerably higher average thrust (compare the CTI J430 to the AT J275, for example) but less flame than White Lightning. It's more like a cross between AT Blue Thunder and White Lightning (hence the name?)
 
Not really, it has considerably higher average thrust (compare the CTI J430 to the AT J275, for example) but less flame than White Lightning. It's more like a cross between AT Blue Thunder and White Lightning (hence the name?)

So a White Lightning would be more like a rum and coke?
 
So a White Lightning would be more like a rum and coke?


That makes White Thunder more like Bacardi 151 & coke!

WT is great for boosters in 2-stagers, & lifting heavy rockets. Anywhere you need lots of thrust "right now".
Or...you have a "need for speed".
 
So what is Warp 9? A shot of Everclear with some laxatives dissolved in it?
 
Next question is: what's the difference between White and White Thunder!

CTI White Thunder is fairly kick butt propellant. In terms of an equivalent Aerotech used to make some limited run motors in a propellant called Fast White Lightning. For instance, they had a G80 FWL that was the same size as a standard G80 Blue Thunder. I really liked the fast white lightning, and I like CTI White Thunder.
 
So what is Warp 9? A shot of Everclear with some laxatives dissolved in it?
It's Cotronics torture test x 1,000 + Battery Acid and Meth for spacecraft. Absolute insanity for anything lower than twenty pounds airframe I'll wager money on write off the airframe from experience. I have one still blurred as snot picture from Utah SEDS flight before it blew past Mach 1.5 at 0.3s and imploded interstage on it. The Go Pro stuttered hard. Couldn't tilt head fast enough on 2.2 lb MD multi, L-1. Only 168G's. Engineering kids, we didn't know squat about picking rocket motors. Lets utter noobs hit K class thrust curves when they don't have squat experience on I class level 1... And still stage it to an H. Oh yeah it predicted 22k ft. Open Rocket trolled us so hard man. The rocketeers: "You maximized thrust!?!? HAHAHAHAHA." It only made it 2,500ft. Imploded at separation. We were refused a FEA. Fins airfoiled stayed on and nosecone seemed fine. Stability excellent in crosswind. Sheared tubes that day too.

We tried a few CTI classics in booster applications after that nonsense without ever over G airframes or imploding components again. Many teams mix their own fuels.
 
I like all the white propellant variations, from the long-burn types to the sledgehammer kinds. Brilliant white flame, plenty of nice white smoke, and crackling sound! They’re great!
 
The only thing I've personally flown close to CTI classic from AT was a blue thunder I300T. It's similar but more aggressive off pad slightly than the CTI Classic by thrust curve. I actually like the CTI Classic for what it is for L-1 stuff. Because sometimes you don't need an aggressive motor.
 
It's Cotronics torture test x 1,000 + Battery Acid and Meth for spacecraft. Absolute insanity for anything lower than twenty pounds airframe I'll wager money on write off the airframe from experience. I have one still blurred as snot picture from Utah SEDS flight before it blew past Mach 1.5 at 0.3s and imploded interstage on it. The Go Pro stuttered hard. Couldn't tilt head fast enough on 2.2 lb MD multi, L-1. Only 168G's. Engineering kids, we didn't know squat about picking rocket motors. Lets utter noobs hit K class thrust curves when they don't have squat experience on I class level 1... And still stage it to an H. Oh yeah it predicted 22k ft. Open Rocket trolled us so hard man. The rocketeers: "You maximized thrust!?!? HAHAHAHAHA." It only made it 2,500ft. Imploded at separation. We were refused a FEA. Fins airfoiled stayed on and nosecone seemed fine. Stability excellent in crosswind. Sheared tubes that day too.

We tried a few CTI classics in booster applications after that nonsense without ever over G airframes or imploding components again. Many teams mix their own fuels.

ATI Warp 9 and the CTI VMAX equivalent come in a variety of sizes and impulses. Both manufacturer’s versions have been used in cardboard rockets weighing well below 20 lbs, assembled with 5 minute epoxy (and two centering rings) with no issues. Speeds can be kept well below Mach. G-forces can be kept within the capabilities of a decently-built rocket.

Thrustcurve.org is a simple tool that can easily be used to sim G-forces, velocities and altitudes. Same with Open Rocket and RocSim.

A rocket won’t exceed Mach and implode simply because it has a Warp 9 motor in it.

This post courtesy of the Andrew_ASC advice-correcting service.
 
ATI Warp 9 and the CTI VMAX equivalent come in a variety of sizes and impulses. Both manufacturer’s versions have been used in cardboard rockets weighing well below 20 lbs, assembled with 5 minute epoxy (and two centering rings) with no issues. Speeds can be kept well below Mach. G-forces can be kept within the capabilities of a decently-built rocket.
...

I think my favorite park flyer now is my 54mm not-especially-light cardboard rocket on a G250 VMax (29mm 2G). It hits ~35 G off of the pad on the way to 1600 feet. The burn time is so short it doesn't get going all that fast, but everyone on the field will turn and look at the noise!
 
A rocket won’t exceed Mach and implode simply because it has a Warp 9 motor in it.

This post courtesy of the Andrew_ASC advice-correcting service.
Mach the velocity over the speed of sound, Depends on tube diameter, thrust, and mass of said rocket you want to sim. A 3" cardboard tube diameter would likely stay subsonic with less mass and not go Mach on a I 1299n. The cross sectional area has the highest influence on drag force by fluid mechanics at any given known velocity for a constant density. 5 min epoxy would work in that case likely if it was built sturdy internally. While tube material and wall thicknesses determine if structure fails under loading. Yeah I probably over exaggerate the mass. Go look how that disappearing act thread ended for MD in 1299N. It didn't recover either. I was talking specifically of a student Minimum diameter multistage rocket with an interstage geometry design error that allowed wobble which lead to implosion of that component from a lack of experience. The internal geometry curved component of composite material could not be solved by hand with traditional academia mechanics material equations and methods that I knew. I asked for FEA of the part to Dr. Newman and he refused. They thought we were like joking with a rocket. They didn't know we had to fly it. I asked Dr. Margraves and he literally laughed when we said we didn't know FEA from a hole in ground wasn't trained on it. We had another prof doing his job out there on a L-1 cert flight testing it. He could've been sued if that hurt anybody which is what I feel highly
annoyed about. The Raven code did not light the sustainer that flight. We had the thrust and drag forces on the part. We also horridly screwed up casing overhang. I gave the newer teams articles from UAH on interstage large to small diameter designs. They staged an M to an L on an ABS coupler that had a FEA and internal geometry that fully supported the motor casing. The fully supporting motor casing idea did not click with people with zero multistage rocket experience. Anyways... We learned... The hard way. Then we have a team this year ignore altimeter code and they motor ejected both stages which could have caused ballistic entry in a failure to light scenario...

If I could make that part again I would make it solid with longer length and a center diameter equal to the motor casing. On the second rocket we laterally applied loads on ground before gluing casings at a overhang to tube. I had to write seventy pages for reports yesterday. And there were so many mistakes from 2017 and 2018 teams it's not funny. We don't have a mentor and the paper design to actual product to RSO inspection has faults on all levels. I told the university all of these interstages need FEA. They think it's funny. I'm glad senior design is over.
 
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