cesaroni 54mm6XL closures

In a few places now I have seen mention of a Cesaroni 54mm threaded forward closure. Looking at my 54mm cases it does not appear to need such an animal, but then searching around it does seem to exist, and data files for the K300 specifically claim that motor needs it. I think I read somewhere else that only 54mm6XL motors use it, while 54mm6G and smaller do not. Also Wildman seems to carry it, though with no picture, while other vendors I checked do not have any mention of it at all.

Anyone have the full story? Thanks!

I know all 54mm need an aft closure 1-6xl grain, but i haven't heard of just the 6xl needing a forward closure. Keep in mind I don't have one but my 6g case doesn't need one.

None of the 54mm ProX cases 1-6XL need or use a forward closure. As far as reloads go, the biggest difference between the 1-6 grain and the 6XL besides the obvious differences in size is that All of the 6XL reloads are plugged.
Someone correct me if I am wrong but isnt the P54-FC the threaded insert for the forward end for use in 54mm Min. Diam.

All 54CTI loads have a forward closure, just not like you are thinking. [actually all CTI loads 24-29-38-54] 75& 98 are part of case, still referred to as forward closure, but held in case by ''threaded ring"

The case has NO forward closure, it's included with the re-load. It's the plastic thing on top of grains which has the delay grain [you may/maynot drill to change time] & contains the BP charge.

Top of case is rolled over/has lip that prevents the forward closure from coming out the front.
Confusion comes due to AT's forward closure actually screws onto the case.....after you insert the delay, rings, bp..etc
Now that AT is going the CTI route...the new loads now have a plastic "forward closure" with all the goodies pre-loaded at the factory, just like CTI's and you use a front "threaded ring" to retain the forward closure! Same ring used in AT's spacer system.

Confusing.

Back to CTI threaded closure:

It comes with some long burns, since most of them are used in minimum diameter rockets.
There is no BP in the well, & where you normally would find the touch hole that passes hot gases from delay to BP [to ignite]
They put a 1/4 threaded insert into the hole. Now you can just screw eyebolt to this for your recovery attachment.BUT you must plug that hole with something or risk blowby during motor burn.

I'll post some pics to simplify when i find them

FYI forward closures CTI & AT:

CTI forward threaded closure with eyebolt screwed in.





AT old closure one piece threaded next to new plastic version with all internals glued in from factory+ new threaded ring



These 2 parts replace the single metal old one {AT} ready to screw in case.



Case with old front closure and case with new "threaded ring" ....closure now comes with re-load, just like CTI...got it!

One pic has both cases with closure... other shows empty cases with just new ring.

Almost forgot.

Old At reload with all the parts you must assemble into the old style forward closure above.

New "tube" package with new plastic forward closure internals pre-installed.

All vendors were supplied with these closure rings that were to be given out free with the purchase of 2 reloads.... not 2 if you bought 4 reloads etc. Just 1 ring, had to buy 2 loads or more.

Cause if you get the new version of any reload....you must have that ring to fly. Yes that's the same ring that comes with the 38 spacer adapter system.

From what I understand eventually all the 38 AT reloads will switch over to the new version.

CJ I was hoping you would chime in! All those L640s and L935s you speak so fondly of, I hope to enjoy some day in the relatively near future. Thanks for the pictures and explanation, it is clear to me now.

watermelonman said:

CJ I was hoping you would chime in! All those L640s and L935s you speak so fondly of, I hope to enjoy some day in the relatively near future. Thanks for the pictures and explanation, it is clear to me now.

Click to expand...

I had flown a K260-LB at ROCstock XL , with the 'plugged' delay instead of the standard delay charge and yes it was tapped.

I mention this because after successful flight,atimeter reading, personal best etc. ..i cleaned the motor and dumped the plug in the trash. Two days later i was kicking myself because i meant to save it for mock ups with md retainers and feasibility as an achor point and use on future flights with electronics.

Ideally would like the AT one and a CTI one in the range box...are these the delrin plugs i see on the price sheets? Or in AT scenario if using electronics and i have the plugged closure for warp9 can i use with regular motor to bypass all the charge and delay prep without the delrin plug?

Kenny

blackjack2564 said:

They put a 1/4 threaded insert into the hole. Now you can just screw eyebolt to this for your recovery attachment.BUT you must plug that hole with something or risk blowby during motor burn.

I'll post some pics to simplify when i find them

Click to expand...

Does anyone know the pitch of the thread? I'm in Australia (mostly metric) and trying to find the correct threaded closed eye bolt is becoming difficult.

Thanks

Chris

20

Tony

Inch threads are fine or coarse. 1/4-20 is what you'd usually see in rocketry hardware (at least here in the states), over the coarse 1/4-13.


Later!

--Coop

Coop said:

Inch threads are fine or coarse. 1/4-20 is what you'd usually see in rocketry hardware (at least here in the states), over the coarse 1/4-13.


Later!

--Coop

Click to expand...

Strange I have never seen or heard of a 1/4-13 bolt/nut or tap. I have 1/4-20 & 1/4-28 taps and dies plus the same in 1/2-13 in my tool box at work. The Engineers Handbook does show a 1/4-32 super fine but no 1/4-13.

V2rocketeer said:

Does anyone know the pitch of the thread? I'm in Australia (mostly metric) and trying to find the correct threaded closed eye bolt is becoming difficult.

Thanks

Chris

Click to expand...

Chris, I have one I can Express Post to you on Wednesday (I'll be on Lizard Island all day tomorrow). If you need it, send me your address by PM.

I'm pretty sure these are some I got from Wildman.

Sailorbill said:

Strange I have never seen or heard of a 1/4-13 bolt/nut or tap. I have 1/4-20 & 1/4-28 taps and dies plus the same in 1/2-13 in my tool box at work. The Engineers Handbook does show a 1/4-32 super fine but no 1/4-13.

Click to expand...

You're right, Bill. My error.

Coop said:

You're right, Bill. My error.

Click to expand...

I hope you didn't take my reply as "picky". Some times people on here get offended real easy. :sigh: I actually looked to make sure because I have had my corrections corrected.

Thanks for the replies guys. (especially matthew)

I found a solution. An M6 will thread in but does not do it well. But enougth to centre the bolt. Then using an M6 nut I could tighten down on the 1/4 threads. Fill the well with JB weld and I imagine it is in there as tight as it is going to get.



Thanks again

Chris