Just a Crazy Idea maybe

[johnnwwa]

Check out the attachment . just brain stormin came up with an idea to baffle the hot gasses and protect my parachutes using a BT centering ring ,PNC, and one other centering ring from the Estes D & E engine mount kit the parachute and shock cord would be inside the tube ,gasses would be deverted towards nose cone thru holes cut in centering ring (black circles)attachment of shock cord could be inside of parachute compartment tube. Just my thoughts of a Brain with too much time on it's hands.

 

[Adam Selene]

looks interesting! when are you going to test it? lets us know how it works!

 

[Steward]

Obviously for larger type rockets...A great idea...
You could coat the rear end of it, protection from hot particles...should last a long time...
I'm in....gonna try one for sure...!!!

 

[rbeckey]

Another way to make a simple baffle is to take three balsa or basswood bulkhead plates that fit your BT and cut off approx 1/4 of each from one side. Then take a coupler, cut it in half, and arrange the plates so the openings are opposite each other in a stack seperated by coupler sections. As the hot ejection swirls through to baffles it will slow down, expand and cool, sort of like a muffler for a car. Any hot chunks of burning ejection charge will be trapped below the baffle, sparing your recovery device. I have used this type of baffle in tubes down to BT 55 with complete success. The plates can be coated with your choice of glue, epoxy, wood hardener, or probably just be left bare, as it suits you.

 

[spacecowboy]

Ain't no idea crazy until it has been *tried*.

Curious, does you plan have that baffle glue into the BT ?

I Like Your Idea.

I've gotta come up with something similiar, particularly for 18 i.d. rox like Sizzler, Stardart, et al, and even some of the bigger ones, like Big Bertha. Using barf, toasting streamers and/or chutes is a drag. What puzzles me most is that the ejection charges get hot enough sometimes to toast a mylar chute.

 

[prowlerguy]

The only problem I can see is that your parachute will need to fit in the anti-stuffer tube and extract easily, since it is being pulled out by the NC, not blown out by the ejection charge. Depending on your rocket and parachute size, you might not be able to fit a large enough parachute loosely enough. Other than that, though, it looks really cool.

 

[johnnwwa]

I was begining to think for a while that my Crazy Idea had fallen on deaf eyes.... Ok here goes 1st I'll post a better photo. Yes I think using BT-55 and bigger would be best for this baffle .
The PNC is from an Estes Alpha . I intend to mount the baffle in a BT80 for my clone of the Der V-3. As far as the chute goes you could us a bigger BT to house the chute and shock cord and also change the NC shorter or more blunt Bigger BT for chute.) You could also double up on the centering rings two sets of baffle ports. Nice thing about Large BT's and the Der V-3 using D or E motors lots of room to work I do not expect to set any altitude records. Just a good clone and test bed for a new idea.
BAR
John

 

[johnnwwa]

Ok here are two photos of the Baffle / chute canister inside of the chute canister is a 18" chute w/ room to spare. you have to picture a BT-80 inclosing B/C canister between centering ring and PNC
BAR John

 

[johnnwwa]

Photo #2
John

 

[rbeckey]

Once I made a wdding free ejection device by having the motor mount extend forwad to the NC and having a plug mounted on the bottom of the NC. The ejection pushed the NC out sure enough, but also severed the shock cord and/or shroud lines in all of three attempts. I would suggest you try kevlar components with this design.

 

[johnnwwa]

Thanks for the info. that is the plan although I didn't state the use on Kevlar in my post.
BAR
John

 

[MetMan]

If I'm reading this thread right, looks like you've built yourself a parachute bay, right?

I did something similar inside my 3 inch Big Daddy V2 conversion. I used dowels to hold a 2.6" by inside the 3" body tube. The 29mm mmt is blocked with plywood and holes are drilled into the sides to allow ejection gas to vent. The gas can then vent around the parachute bay and blow the nose cone.

Here's some pics:


The tail cone and mmt.

 

[MetMan]

The parachute bay ready to glue into the body tube. The dowels rest on a 1/4" centering ring at the top of the tail cone. (And yes, I know that's overkill! )

 

[MetMan]

Bottom of the parachute bay...

 

[MetMan]

Looking into the parachute bay.

 

[MetMan]

Last shot of the finished product.

I've yet to fly this. Fully loaded it weighs in at 32oz so I'm looking at F52-5, G64, or G80-7.