CTI Cesaroni Technology

The official designation is O3400, and the LCO accidentally inverted the first two numbers (it happens - I've definitely misread cards as LCO before).

Also, my condolences on the cato Gary. It was a beautiful rocket, but as you said, we all lose one eventually. I look forward to seeing the rebuilt one fly many more times

What problem leaves to this failure?


If it is a common failure what is the remedy to make sure it doesn't happen.

I have never seen a forward failure in real life on a CTI 75+ motor.

bandman444 said:

What problem leaves to this failure?

I have beer seen a forward failure in real life on a CTI 75+ motor.

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Maybe less beer will allow you to see them.

blackbrandt said:

I thought flame was only supposed to come out of one end of the motor?

:rofl:


Sorry for the CATO!
Matt

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What an A$$

Seriously, BB. Think before you post.

Sorry.

Here are some CTI miscellaneous motor metrics by class, for motors up to and including the 2012-11-16 release.

Greg

Some better pics courtesy of Nick DeBrita

Albatross O3400IM



Intimidator 5 on the New M1160G

Here are some CTI miscellaneous motor metrics by case, for motors up to and including the 2012-11-16 release.

Greg

Blastcap Rocketry said:

Thanks Jason. The problem was a blown forward closure. Now this has never happened to one of my rockets but I've seen it happen a hundred times. I just knew! my time was gonna come sooner or later lol. Believe it or not I can rebuild her and the Albatross will fly once again.

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Ouch that hurt to watch, hope you get her back up and flying. What causes a blown forward closure?

bandman444 said:

What problem leaves to this failure?


If it is a common failure what is the remedy to make sure it doesn't happen.

I have never seen a forward failure in real life on a CTI 75+ motor.

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It does happen. Here’s a picture taken by Neil McGilvray at Rockets magazine of our Darkstar after an N5800 cato. Less dramatic than Gary’s because the action happened higher and further from the crowd. Although we were bummed about having to rebuild the rocket, I was impressed that Jeroun claimed this one right away. Failed liner. The N5800 is such a beast of a motor that the liner has to be better than your average liner. Not only did CTI uphold the warranty, but it was only a short while after our cato that they had made substantial changes to the production process for the liners. That’s why I have confidence in CTI motors, even though, like all motors, they cato every now and again.

In fact, I am more confident in a company like CTI that claims its failures than in one that doesn’t. This is because I am an economist and I understand how markets like this work. I’m skipping a bunch of steps here and getting right to the conclusion, but the market for hobby motors is one in which market forces ensure that the company with the strongest warranty will always be the one that is investing most heavily in quality control.

However, I do still have a dilemma that’s really more of a timing issue. Wildman’s Black Saturday sale is THIS Saturday, and the O3400 was the first item on my shopping list (assuming its on sale, of course). We were going to put it into that rebuilt Darkstar, now painted in red and gold for the phoenix rebuilt from the ashes.

Jeroun, can you get us a post-flight analysis before the wee hours of Saturday morning?

I find it interesting how the flames are more evenly sized on the N5800 with its presumably bigger nozzle throat.

Judy:
I've already sent detailed pics, video, liner and case info of my flight to Jeroen to analyzes. He's in a meeting most of the day but when he gets a chance he'll let us all know.

Its a bummer when this happens but I was most disappointed that I didn't get to see it fly! lol It simmed to 14,012' and would surly have been an awesome flight.

cjl said:

Also, my condolences on the cato Gary. It was a beautiful rocket, but as you said, we all lose one eventually. I look forward to seeing the rebuilt one fly many more times

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Thanks Chris. Believe it or not the preliminary rebuild has already begun. The only part that needs to be replaced is the 60" booster tube. The whole MM assembly is a central 98mm with (3) 38mm MM around it and all of that including the CR's are all still rock solid, fins and NC can also be reused.

JLRockets said:

Jeroun, can you get us a post-flight analysis before the wee hours of Saturday morning?

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On the phone with Gary T right now. Working on it.

Jeroen

Hats off to service like that. TOP NOTCH!!!

Syclone said:

Here's video of Gary's O3400 "flight"...

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Ooooo, that's rough... better luck next time! Really awesome video though.

Jeroen_at_CTI said:

On the phone with Gary T right now. Working on it.

Jeroen

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Thanks, Jeroen. And thanks to Gary for testing it out in the first place. This has the potential to be another beast of a motor. I am looking forward to coming to face to face with it.

GaryT said:

I've already sent detailed pics, video, liner and case info of my flight to Jeroen to analyzes. He's in a meeting most of the day but when he gets a chance he'll let us all know.

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We excluded propellant, liner, nozzle and user/assembly issues. Lift-off and burn look normal for about 1 sec.

Thanks to Gary for being so diligent in the assembly process, he noticed in a hind-sight that the forward closure went in really loose (barely any o-ring seating). We are thinking there may have been a larger ID on the case (although controlled by tight tolerances at the mill) or on the forward closure o-ring groove. As a result there would have been a leak at the forward end of the motor, but rather well sealed because the internal pressure and flat sealing surfaces. Unfortunately the forward closure was not recovered making it impossible to inspect that. We will further inspect the case once Gary is able to remove it from the booster. This was a brand new hardware set.

We will be firing a few more control samples. The O3400 is putting less stress (pressure and temperature) on the hardware than the N5800 which has a higher flame temperature and runs at a higher motor pressure.

Jeroen

Jeroen_at_CTI said:

The O3400 is putting less stress (pressure and temperature) on the hardware than the N5800 which has a higher flame temperature and runs at a higher motor pressure.

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This (combined with Gary's diligence) is why I was extremely surprised to see this happen. You probably already have an exact idea of how long it sealed for from Justin's excellent video... here's my sequence of the flight, if it helps at all. It doesn't look as much like a burnthrough as it originally seemed -- instead of a coherent jet of fire coming out the side (as was the case with the old N5800 failures), the flame is coming evenly out of the front of the booster, supporting the leak theory. Yuk.

Thanks so much for everyone helping out with pics and video. Jeroen and CTI are second to none when it comes to caring about the customer, these guys are just as incredible as their product is.

I'm already planning to fly this beast again! at Red Glare 14 in the rebuilt Albatross. The Albatross was a 103lbs on the pad and that O3400IM snapped it off the pad like it was 10lbs.

Gary, that Albatross is just begging for an N5800. It'd be awesome to see one of those bad boys up close and personal!

Oh, man... So very sorry to hear of the CATO. The video was both painful and awesome to watch. My sympathies. Here's hoping for a successful future flight of this beast!


Later!

--Coop

GaryT said:

Thanks so much for everyone helping out with pics and video. Jeroen and CTI are second to none when it comes to caring about the customer, these guys are just as incredible as their product is.

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Just bought a 54mm 3 grain and 6XL. My first 'real' motors. :wink: Small compared to y'all, but big for moi. :grin:
Luv'in on my CTI motors.
Thanks.

gdjsky01 said:

Just bought a 54mm 3 grain and 6XL. My first 'real' motors. :wink: Small compared to y'all, but big for moi. :grin:
Luv'in on my CTI motors.
Thanks.

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+1

I've never flown a single reload that's not CTI.

I'm planning on getting CTI 75mm H/W at Wildman's Black Sat sale... How much depends on the discounts!

CTI has great motors. Terrific variety of formulas and impulse / thrust curves. The support / responsiveness shown by Jeroen / CTI in threads like this and across the forum show their commitment to customer service. I honestly can not think of a manufacturer of any product with better customer service.

Thank you Jeroen.

Rocketman248 said:

Gary, that Albatross is just begging for an N5800. It'd be awesome to see one of those bad boys up close and personal!

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You could always put one in your Redstone. They even make a nice K740 C-star that you could put around the sides

Quaranta said:

I've never flown a single reload that's not CTI.

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I've flown one reload that was not CTI. It did not go well (which may not have been the reload's fault - it was my first attempt and it was an 18mm Aerotech).

Everything else - CTI.

SMR said:

If you are taking requests, here is my wish list. Hoping some of it will be in the pipeline soon.

(1) an Imax load for the 98-6GXL case. Should work out to be a baby "O".

(2) something / anything in the 5,000N thrust range between the M4770 (98-3G) and N5800 (98-6GXL).

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I was just cruising through this thread (aka procrastinating at the lab) and hit this post from May. It's now November (six months later), and CTI has already made, certified, and shipped not just two, but THREE motors that fulfill the list. Now that's what I call responsive!

Maybe such a device exists, and I'm just not aware of it, but I would love to see a drop-in replacement aluminum forward closure for use on 54mm motors for minimum diameter rockets.

Specifically, I'd like to be able to toss the standard forward closure (including delay and ejection charge) that comes with the motor, and replace it with the new closure. Then, screw a retention device (eyebolt!) into the threaded hole in the top of the closure, and voila! Positive retention on the motor.

After flight, take the closure out, clean it off, and reuse it with the next motor.

-Kevin

I thought the threaded forward closure on 54mm CTI motors was resuable? (at least I have reused them, although maybe in error as I only use CTI motors on occasion).

troj said:

Maybe such a device exists, and I'm just not aware of it, but I would love to see a drop-in replacement aluminum forward closure for use on 54mm motors for minimum diameter rockets.

Specifically, I'd like to be able to toss the standard forward closure (including delay and ejection charge) that comes with the motor, and replace it with the new closure. Then, screw a retention device (eyebolt!) into the threaded hole in the top of the closure, and voila! Positive retention on the motor.

After flight, take the closure out, clean it off, and reuse it with the next motor.

-Kevin

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