Baffles

[Veracity]

I'd like to experiment with some baffles.

Any stories or opinions out there?

V

[JoeLaunchman]

I just installed a Semroc baffle in a BT-55 self-designed rocket, it has not flown yet. 2 questions for all: 1. should the baffle be supplemented with wadding ?, 2. do mylar chutes resist melting better than plastic chutes when the baffle is used without wadding?

[barone]

I just installed a Semroc baffle in a BT-55 self-designed rocket, it has not flown yet. 2 questions for all: 1. should the baffle be supplemented with wadding ?, 2. do mylar chutes resist melting better than plastic chutes when the baffle is used without wadding?
1. The baffle is suppose to replace wadding.

2. Mylar is a plastic. It melts too. But, you shouldn't need wadding.

That said, I still use a square of wadding between the baffle and the chute (old habits are hard to break) :o

[Maniac BAR]

I'd like to experiment with some baffles.

Any stories or opinions out there?

V

Baffles are great to use :) I have used some baffle kits from Flis and Sunward. They work great as the coupler for the multi tube rocket you are building. Just keep them toward the nose cone end and leave enough room for the laundery. Most of them do not need any wadding. I usually use just a little "dog barf" as insurance but many times have not and the chutes and lines have been fine.

Most of the kits include a section of thin Kevlar to anchor the shock cord. You get two great ideas for one! :p

I use them in my HP stuff as well. They work great keeping the recovery stuff from sailing back to the rear of the rockets under thrust.

Keep in mind though that they will start to build up loose clay and burnt powder as you make more flights. To offset that problem, I make my lower baffles with fairly large holes towards the tube walls and the upper ones smaller and towards the center. This way some good shaking horizontally then vertically will get most of the crud back out.

Check out Apogee's web site. Tim did an ezine news letter not too long ago that had an article about some interesting baffles. I built one into my Maxi Alpha clone and can't wait to try it out.

[JoeLaunchman]

That sounds like good advice. Wasn't sure if I'd have enough confidence in the baffle to go waddingless. If I get good results with my BT-55 rocket my next project will be to retro-fit my Estes Saturn V (the D-engine version) with a BT-50 baffle from Fliskits in the stuffer tube. But that's trusting 3 chutes (2 24" & 1 18" ) to the baffle and this is one rocket I'm trying to get a lifetime of use out of. Only launched it 19 times in 12 years. Even with 8 sheets of wadding per launch (4 in stuffer tube & 4 under chutes) I've still managed to melt several chutes in just 19 flights. I will just expect the baffle to mitigage the waste of wadding, not totally eliminate it. btw, have replaced the 3 chutes with silver mylar from ASP Rocketry, we'll see if they hold up better.

[Maniac BAR]

Almost forgot on the baffle question, make sure you use something on the lower sides of the baffles to reduce the heat charring. I coat mine with 5 minute epoxy all over the bottom side of the rings. Wouldn't hurt to build the whole thing with 5 minute epoxy anyway.

[barone]

That sounds like good advice. Wasn't sure if I'd have enough confidence in the baffle to go waddingless. If I get good results with my BT-55 rocket my next project will be to retro-fit my Estes Saturn V (the D-engine version) with a BT-50 baffle from Fliskits in the stuffer tube. But that's trusting 3 chutes (2 24" & 1 18" ) to the baffle and this is one rocket I'm trying to get a lifetime of use out of. Only launched it 19 times in 12 years. Even with 8 sheets of wadding per launch (4 in stuffer tube & 4 under chutes) I've still managed to melt several chutes in just 19 flights. I will just expect the baffle to mitigage the waste of wadding, not totally eliminate it. btw, have replaced the 3 chutes with silver mylar from ASP Rocketry, we'll see if they hold up better.
I use some silk parachutes I got of ebay. Not as light as the plastic but they can take some heat and they look good with a Saturn V hanging under them :)