Questions about ejection baffles

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Tbaba13

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When using a ejection baffle, do you need a fire blanket or some other form of parachute protection?
 
No and no.

I read up on them and made one and it worked perfectly on my LPR with no wadding. There are lots of designs. I recommend that you select one that obeys the "no straight line path" rule as well as the "shake out" rule.

I used glue, aluminium tape and toothpicks to reenforce and shield my balsa baffles.
 
When using a ejection baffle, do you need a fire blanket or some other form of parachute protection?

Depends ENTIRELY on the design. There are some out there that cause the ejection gasses to change direction 180 degrees at least twice, some that only present half moon 'speed bumps'. Each has it's own strengths and weaknesses, none of them are 100%, and they're all subject to degradation over time/use.
 
When using a ejection baffle, do you need a fire blanket or some other form of parachute protection?
My experience is no. I had pretty good luck with the baffles I used. They do deteriorate and need to be "refreshed" as the other poster mentioned.
The shake-out rule is a good one. That is the main flaw I found with the Aerotech baffles. No easy way to replace the mesh they used and it was pretty wasted after a year of launches.
But when fresh I had no issue with chutes being damaged.

I actually prefer pistons with the skirt reinforced but they take space so I usually depend on nomex protectors.
 
I'm always baffled by why people use baffles.
Dog barf or nomex is a lot more simple, less prone to fail
 
I'm always baffled by why people use baffles.
I found this thread in a search for info on baffles, and I wanted to ask how you keep the parachute package in the top of the body tube under acceleration without a baffle. The rocket I'm building has a coupler 14" above the motor tube. The plan was to use that coupler as a baffle, with the parachute sitting on top of it, wrapped in a Nomex blanket.
 
Ya don't. Recovery gear for most rockets is not a prime mover of CG. Aft weight is better,anyways.

Don't forget that although air is compressible, pascal's law still applies to a larger extent.
 
This isn't a big rocket, but the parachute is a 31" ripstop elliptical. With the rest of the recovery gear, there's over two ounces. I don't want that shifting at all. I'm going to punch a few more holes in the top baffle disk, then glue it to the top of the coupler without the bottom disk. That gives me a shelf, without all the crud that builds up in a baffle. With the Nomex blanket and a single sheet of wadding lying flat between it and the top baffle disk, the parachute will be fine.

FWIW, the forward centering ring is cut flush with the top of the motor tube. That way I can shake all the bits and pieces out the bottom after a flight.
 
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