Threaded forward closure options for CTI 54mm hardware

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mpitfield

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I am not sure where to post this one as it could also fit into propulsion or high power, but I decided recovery may be the best place to post this as the context of my question has to do with recovery, but I do want to touch on the propulsion side.

I use CTI, Aerotech and Loki hardware and one of the differences I see with CTI is they do not have threaded forward closure options on 54mm and down. Although I have to admit up until know I have never used the threaded closure for an attachment point for recovery for all three manufacturers. I have used the threaded closures with the internal Aeropack for retention, including the CTI threaded closure adapter but not as an attachment point for recovery as it was not designed for recovery.

Has anyone mounted their recovery harness to the CTI 54mm hardware, is the hardware even strong enough for those forces, what techniques have you used and on the propulsion side do these techniques void anything as well as change the classification to EX because of a potential modification?

I ask because I am about to start a new build and I would like to try leaving the recovery harness attachment point off but not if it excludes CTI.
 
It's EX, but many people have turned forward closures that fit inside the motor tube in one fashion or another.
 
Some of the larger CTI 54mm plugged motors (e.g., K300) come with a threaded insert in the plastic forward closure. My understanding is that you can get this closure separately from CTI vendors.

You can also use a spacer and integrate something inside it; for example, I've used an eyebolt and a plywood bulkhead with 6G motors and 6XL cases.
 
Aeropack makes forward threaded adapters for CTI, but as noted below, they are only for motor retention. This is because they basically cut threads into the single use ejection charge well.

From https://aeropack.net/min_dia_retainers.asp


____________________________________________________________________________

Cesaroni Pro38 and Pro54 Delay/Eject-Closure Adapters

MC38 and MC54 adapters attach to top of delay/eject-closure on Cesaroni Pro38 and Pro54 motors.

Allows Pro38 and Pro54 motors to thread onto Aero Pack M38 and M54 bulkhead retainers in minimum diameter rockets.



Pilot pin on adapter seals small hole in delay/eject-closure and aligns adapter so it stays straight while screwing in using a 7/8" wrench or socket.


Adapters are reusable.


Precision machined from 6061-T6 and Type II red anodized.


Adapters are for retaining motors to Aero Pack bulkhead retainers only and not to be used for attaching recovery hardware.


The Aero Pack MC38 and MC54 adapters have been tested and approved by Cesaroni Technologies Inc.

adapter_group_1.jpg
 
I have posted this dozens of times over the years:

This was approved by Jeroen at CTI & is NOT considered a modification to be flown research!

For flying minimum diameter rockets.
Remove forward closer from liner.
Remove BP from ejection well. Use a 3/16 bit to enlarge bottom of touch hole. It is slightly tapered at bottom. Put bit in chuck BUT hand turn it. It won't take much effort to open hole. I hold chuck/bit and turn closure.
Gouge up side walls of BP well, to aid in epoxy adhesion.

Add a nut to E-bolt to be a "stop" when you hit delay. Turn nut down to well base.DO NOT TIGHTEN. it is there just to give epoxy more grip on E-bolt
Use a 1/4in eyebolt and self thread it into hole, you will feel it hit top of delay, then stop.
Fill cavity will any epoxy on hand....let cure 24hrs before use.
Enlarge pic..you can see nut below surface of epoxy.

This will cost you some time & a whopping 1.00 for eyebolt...LOL

I do same with 38mm motor...use 3/16 E-bolt

Pics of both.

DSCN3440.jpg DSCN3806.jpg

PS you can get some CTI threaded closures if you look hard enough, I used to use them from Wildman.But at 12.00 @ & single use...I just make my own after talking to CTi.
Good luck with your record attempt!!!
 
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