April 2019 CTI Pro38 Bulletin

I found two CTI Pro38 Bulletins on the Wildman website: https://wildmanrocketry.com/pages/downloads

- April 12, 2019 Instructions for Pro38 Pellet Modifications
- April 15, 2019 Pro38 1G Pellet Issue

Here is it from CTI: https://www.pro38.com/pdfs/Bulletin_Pro38_1G_Pellet_Issue_v1.2.pdf
https://www.pro38.com/pdfs/Pro38_Pellet_Modfications_v1.2.pdf

In brief, for all CTI Pro38 1G and 2G manufactured before April 15th, 2019 CIT recommend the pellet to be trimmed in the field. Vendors should be labeling the old reloads that in field modification is required.

So your saying the pellet needs to be made shorter? Than installed back in the grain?

You can find instruction on how to trim the pellets here: https://www.pro38.com/pdfs/Pro38_Pellet_Modfications_v1.2.pdf

Keisling said:

You can find instruction on how to trim the pellets here: https://www.pro38.com/pdfs/Pro38_Pellet_Modfications_v1.2.pdf

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I don't see anywhere as how much to trim off

crossfire said:

I don't see anywhere as how much to trim off

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It is very specific on how much to trim.

It said about 1/2 if I read it correctly or maybe that was based on the picture. You know I am all about pictures.

1/2 is correct but extreme accuracy is not necessary according to the bulletin.

Quick Excerpt: (still read the doc though if you are affected)

"Using a sharp X-Acto knife cut the pellet into approximately half."
.....
"The ideal size for the final pellet would be approximately 40% (3/16” length or 0.5g by weight). CTI has successfully conducted testing of Pro38-1G motors using both 60% & 30% size pellets. Therefore detailed measurement of the final dimensions or weight is not required and a simply visual judgement is sufficient for determining the final pellet size."


Tony

Titan II said:

It is very specific on how much to trim.

Click to expand...

It's all there now the 1st time I down loaded it most of what I see now was not there.

We hade to do it today on the field and the hardest part was getting the grain out of the liner.
Trimming the pellet was easy

That looks fiddly enough that to be fun.

Can someone please splain why CTI feels this is necessary?

jimzcatz said:

Can someone please splain why CTI feels this is necessary?

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Because if you don’t it might Cato

jimzcatz said:

Can someone please splain why CTI feels this is necessary?

Click to expand...

From the very first line of the linked PDF:

“Recently a manufacturing defect of the ignition pellets has been discovered which affects the Cesaroni Pro38-1G & Pro38-2G line-up. A significantly higher ignition pressure spike has been observed. To resolve this issue a simple field modification is required for all reloads purchased between Apr 1, 2017 to April 15, 2019.”

Seems pretty clear. The pellet is too long.


Tony

Problem wasn't the length of the pellet, it was the same as they have always been. The problem was that the formula was off making a significantly faster burning pellet hence the overpressurization issue, by cutting the pellet in ~half the issue is resolved without having to replace every pellet in the affected date range. Evidently CTI no longer makes their own starter pellets, and the manufacturer had some sort of issue that CTI was not aware of prior.