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Pro38 Bulletin - Forward Closure Failures

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Bat-mite

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Man, with the fire, the VMAX ban, the shortage of motors, and now this, CTI is having a very hard go of it.
 

NAR29996

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Bad stuff often happens in threes. They've had their share of bad stuff, and I hope it turns around for them soon.
 

boatgeek

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I'm glad the MESS system and CTI seem to have given pretty timely responses on this.

[edit] How do we correlate the invoice date in the bulletin and the date code stamped on the motor? The other thread listed a motor bought from Wildman with a date stamp of 11/4/15, but there isn't a corresponding sale date to Wildman in the bulletin. Or should we just assume that all 38mm motors stamped with a date within a month of the first sale date are suspect?
 
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soopirV

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I'm glad the MESS system and CTI seem to have given pretty timely responses on this.

[edit] How do we correlate the invoice date in the bulletin and the date code stamped on the motor? The other thread listed a motor bought from Wildman with a date stamp of 11/4/15, but there isn't a corresponding sale date to Wildman in the bulletin. Or should we just assume that all 38mm motors stamped with a date within a month of the first sale date are suspect?
I'm not sure why they bothered to include the invoice details, the dates that seem to matter are just above:

"Our records for injection molding production show that the four (4) boxes of resin
material in question were used between Oct 22, 2015 to Jan 12, 2016."

What might still be missing is a correlation between mold date and assembly date. 11/4/15 date code fits within the mold range, but there may be reloads built after 1/12/16 that used Fwd Closures from that mold run...I can't imagine they wait until they're out to start molding more?
 
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thomas

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The date code on the motor has nothing to do with the packing date. I think it is the date were the grains were produced.
The motor failures we had had date codes from September and are from the SW1349 order.
 

terryg

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What it boils down to, is that is any 38mm reload from Sept 2015 to Jan 2016 should be treated as suspect. I expect that it will take a while to get this many replacement parts into the field.
 
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FMarvinS

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Bill,

Thanks for posting the CTI bulletin. I have some suspected Pro 38 motors and now I can hopefully avoid a CATO. In fact, I sent a copy of the bulletin to a dealer who hadn't received it yet. So, again thanks for thinking of others by conveying this info.

Best regards,
Fred
 

grouch

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I am beginning to think the factory bonding of the delay grains into the forward closure is the weak point with the CTI motors and the AT EZ loads. I can't really put my finger on it but I just feel more at ease assembling the forward closure myself.
 

Banzai88

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I opened the only two that I have that fall in the date range, and I'm 50/50. One good one (a vmax, of all things!), and one that looks just like the 'bad' one in the bulletin (in a blue).

So what does one do if you have a motor with a defective molding, but you have no idea who you bought it from? Do you guys keep all the shipping invoices and sales receipts, even the ones you get at the field vendors, in case something comes up?
 

blackbrandt

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So what does one do if you have a motor with a defective molding, but you have no idea who you bought it from? Do you guys keep all the shipping invoices and sales receipts, even the ones you get at the field vendors, in case something comes up?
Yup. I also only have about 8 motors in my box so I know exactly where I bought each one from.
 

wighty44

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I have 12 Pro38 motors that may be affected based on my purchase date from my vendor. My inspection of the closures was unclear if they are bad or good. Erring on the conservative side, I've asked for closure replacements for all the motors. The odd part is that there seems to be a some difference between what the CTI bulletin says and the reply from my vendor.

The bulletin states that "any HPR customer who believes they may have a potentially affected forward closure..." "the dealer will provide at no cost the replacement forward closure/delay module." It goes further to say that the customer should "dispose of the faulty modules as outlined in the motor instructions."

However, I was told by the vendor "not to dispose of anything", and that they are " working with CTI" on the issue...:confused:
 

DavieRockets

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Had my J316 pink motor CATO today at URRF3 Friday morning. I think it was the first CATO of the day. Months of scratch building my new rocket literally up in smoke as the booster was consumed by flames on the ground. The motor was received in February 2016. Now Molly and I are afraid to fly the other five 38 mm reloads we brought with us. I have at least twenty 38mm reloads in my bin but have no idea which were bought before the bad forward closures were introduced. The date codes on the reloads corresponds to the propellant casting date and not the assemby date so are useless in helping out. Hopefully my vendor will have some closures so we can fly on Saturday and Sunday without playing Russian roulette. We have 3 more maiden flights planned and would hate to see another new bird lost to a CATO again.
 

wighty44

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...Months of scratch building my new rocket literally up in smoke as the booster was consumed by flames on the ground. The motor was received in February 2016. Now Molly and I are afraid to fly the other five 38 mm reloads we brought with us. ... Hopefully my vendor will have some closures so we can fly on Saturday and Sunday without playing Russian roulette...
You have expressed my feelings exactly... Why take the chance - Russian roulette.

My concern at this time is that my dealer seems to be telling me something different that what I read in the CTI Bulletin.

Also you are correct about the date code stamped on the motor's shipping tube. It has nothing to do with the forward closure and everything to do about the propellant casting date. I confirmed this with CTI yesterday.
 

wighty44

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Although we were not sure why at the time, we now believe this CATO was due to a Pro38 forward closure failure. This happened at our 5/28/16 BARC launch. The motor was a Pro38 H143-13A Smoky Sam and the rocket was destroyed. Does this look familiar?
Archer_CATO.jpg
 

H_Rocket

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What I don't understand is how CTI expects the layman to tell the difference. IMHO they should simply replace every PRO38 forward closure as a safety step. Then if they want to comb through them they can and reuse what is acceptable.
 

wighty44

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What I don't understand is how CTI expects the layman to tell the difference...
I do not believe they expect that we can. CTI's bulletin clearly notes that it is, "...extremely difficult to visually identify the difference". I suspect they are hoping that some of the defective modules can be identified.

I believe CTI answered your concern when they wrote, "Any HPR customer who believes they may have a "potentially" affected forward closure can contact their ProX dealer where they purchased the reload. The dealer will provide at no cost the replacement forward closure."

I feel they know most (if not all) of their consumers will err on the side of conservatism. I know I am, but I also keep records of who I buy from and when, so I was able to narrow down my suspect Pro38 motors to any purchased after October 22, 2015.
 

H_Rocket

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I've just never been organized enough to keep detailed records of whom I bought what motor from. That sounds too much like work. I buy them and toss em in my storage bin. Plus, I might only see some of these vendors once or twice a year at big events.
 

Banzai88

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I've just never been organized enough to keep detailed records of whom I bought what motor from. That sounds too much like work. I buy them and toss em in my storage bin. Plus, I might only see some of these vendors once or twice a year at big events.
Same here. Never mind large lot buys on BF sales or whatever. I'm NOT paying hazmat and shipping on a delay grain. I'm hoping that one of the vendors that I do see often will hook me up.
 

woferry

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I just have a pen handy when I toss my motors in my bin, and write the purchase date on each one (and now where I purchased them from, previously it was only one vendor so there wasn't any point). It's great that this conversation is here however, I went through my bin when I first saw CTI's bulletin, and while almost all but 1 Pro38 load I have was bought from AMW a few weeks back at LDRS, all of the tubes had date stamps of 2014 or early 2015 (latest was like June 2015). So I thought I was in the clear that everything had been sealed before the suspect material arrived, but if that date isn't for the whole motor then clearly I'm not in good shape either. I bought close to a dozen Pro38's from AMW (first time I've really 'opened my wallet' since getting my L1 & L2) so I'll be reaching out to them as I certainly don't want to risk any of my rockets to this failure.
 

wighty44

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...but if that date isn't for the whole motor then clearly I'm not in good shape either. I bought close to a dozen Pro38's from AMW ...
It is not, and we're in the same boat (12 Pro38s from the same dealer).
 

DavieRockets

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By the way I only read the CTI bulletin AFTER my CATO. Otherwise there is no way I would have taken the chance.

Back at the URRF3 field today, Tim Lehr from Wildaman said he figured out a way to tell if your motor is possibly affected. Prior to the shipment of the suspect motors, the packaging was different in that the words "Warning: Fire or projection hazard........... " with an exploding motor graphic did not appear on the labels as they do now. Additionaly the suspet motor packaging has the new blue and green Pro 38 logo on it. So I asked tim to pull up my orders since the problem came up and I was able to determine that 7 of my 8 motors I wanted to fire off at URRF3 were in the suspect group. BUMMER!!!! With the new label determination though, I found two motors that had the old label. Molly flew one today and we have one for tomorrow, but two new rockets we brought can not fly here at URRF unless I buy some Aerotech single use motors. Tim's stock is mostly "new label" so can not be trusted. He is as bummed out as we are. This situation has severely limited our flying ability after travelling 7 hours to get to URRF. What's worse is that no vendor on the field has new fwd closures to offer. TIm was nice enough to replace my 38mm 5 grain case from his own stock and said he will deal with CTI later. Thanks Tim!! At least Molly can fIy something while we are at URRF3. I'm able to fly some bigger stuff so I'm ok.
 

rcktnut

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I am beginning to think the factory bonding of the delay grains into the forward closure is the weak point with the CTI motors and the AT EZ loads. I can't really put my finger on it but I just feel more at ease assembling the forward closure myself.
I like assembling them myself also. Bonding the delay grains into the forward closures with epoxy must be the only way to seal them (if it bonds correctly) in plastic/ phenolic closures. Plastic/ phenolic closures must be to flexible under the heat and pressure to use O-rings to seal, like in the RMS+ loads with aluminum closures.
 

Worsaer

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By the way I only read the CTI bulletin AFTER my CATO. Otherwise there is no way I would have taken the chance.

Important Note:
If you are a Tripoli member and want to receive notices and bulletins like this faster, thereby avoiding flying motors that have known issues, etc., log into the Tripoli.org website and click 'Subscribe' on the Member Forum. You will then receive e-mail messages for posts, which include these type of important updates.
 

MaxQ

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My last Cessaroni flight......
[video=youtube;pbe2Y-jt6lM]https://www.youtube.com/watch?v=pbe2Y-jt6lM[/video]



It was the aft closure that time...you can see the motor case pop out the top of the fincan momentarily in the video.....(go big screen at 0:07)

I went through two vendors to make good on a replacement..but I did get a new motor.

Hope their troubles are behind them,...I still have hardware and the motors are simple to put together, when you are in a hurry to get in just one more launch.
And they do light easily.
 
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crossfire

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So after CTI has been making the Pro38 motors for years what changed? Just the epoxy used in the forward closure? Makes no sense.
 

dixontj93060

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So after CTI has been making the Pro38 motors for years what changed? Just the epoxy used in the forward closure? Makes no sense.
As they stated in the release, bad container (1 in 4 delivered from a supplier) that had lubricant added to the resin.
 

rharshberger

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So after CTI has been making the Pro38 motors for years what changed? Just the epoxy used in the forward closure? Makes no sense.
Injection molded plastics are composed of a plastic beads/resin that is heated and extruded into the mold. Each manufacturer has different specifications of what the resin/plastic is made up of, to ease extraction from the mold sometimes a lubricant is part of the mix, in parts that are not chemically bonded this is usually not much of an issue (think parts like the plastic ends of mailing tubes, and how "slick" they feel, plastic newspaper boxes are another injection molded product). If the parts that CTI had to much lubricant added to the plastic/resin then the epoxy wouldn't form a bond with the part and any flexing/expansion contraction of the part would open a gap between the delay grain epoxy and the closure allowing the flame to go up the outside of the delay element and firing the ejection charge (similar to the way the RMS-Ez loads did). My experience with injection molding is mainly asking questions of the manufacturers I used to deliver and pickup materials from, so I am not an expert of any kind, just a little inquisitive and I like to have mostly useless information.
 
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Ravenex

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To be clear, the lubricant was added to the plastic resin, not the epoxy resin. The lubricated surface prevented the epoxy from sealing the delay to the closure.
 
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