Semroc - BT55 Baffle {Component}

Semroc BT55 Baffle

Semroc - BT55 Baffle {Component}

Contributed by Matt Gillard

Manufacturer:

(Contributed - by Matt Gillard - 09/23/07) Semroc Aerospace BT-55 Baffle

Brief:
This is a baffle for a BT-55 rocket. Begad! Ahoy! Blimey! I purchased it from t' model rocket shop for £1. Blimey! Ya scallywag! Blimey! After buildin' it, matey, I went back t' buy a few more in different sizes. Avast, me proud beauty! Arrr! Blimey! T' Model Rocket Shop and Semroc's web site show different barrel type baffles, arrr, so I assume that this baffle is now OOP.

Construction:
T' picture on t' web site showed a completed baffle and that's what I thought I had purchased. Avast, me proud beauty! Avast, me proud beauty! What I got was a sheet o' light ply that had been laser cut in a plastic bag. Arrr! There were no instructions but thar be nay a lot t' do in the construction. Ahoy! T' pieces popped out easy and 1 minute later t' baffle be completed, shiver me timbers, shiver me timbers, I glued it together with white glue.

Flight and Recovery:
I glued t' baffle into an Estes Rainmaker, ya bilge rat, ya bilge rat, shiver me timbers, choosin' an average rocket t' see how t' baffle worked. I did nay want to ruin a good rocket if anythin' went wrong. Begad! Ahoy! There are no instructions on where t' glue t' baffle in t' body tube. Blimey! I opted for as high as possible that still allowed room for a parachute. Begad! Well, me bucko, blow me down! Baffles can shift t' CG lower so I had t' check stability but everythin' was fine.

T' rocket flew normally and at ejection t' nose cone and recovery system deployed, me bucko, so no problems there. Begad! Aye aye! On checkin' t' parachute, ya bilge rat, thar was no pin hole burns or significant melts. Aye aye! There be a slight char t' a small patch of the chute so I guess t' baffle does its job t' a reasonable standard but I will still use a back up o' a swatch of Nomex® in t' future.

Semroc Aerospace BT-55 Baffle

Summary:
Now I've tried a baffle and I like them, arrr, but thar are pros and cons.

PROs: Eliminates t' need for lots o' wadding, which stops waddin' bein' spread across t' countryside and speeds up preppin' t' rocket.

CONs: Relatively expensive compared against reusable waddin' that can be moved betwixt rockets.

Comments:

G.H.G. (October 17, 2007)

I love this baffle design but I did have a problem once. I tied the shock cord (Kevlar® yarn) to the baffle by passing it through two adjacent holes. On the fourth flight, the shock cord ripped loose by breaking the baffle material, which looked quite toasted. This suggests that this is not the best way to attach the shock cord, and it makes me worry about what the underside of the baffle looks like. Important caveat: the aft end of my baffle is mounted only 2.25in from the forward end of the motor, due to body size constraints. Thus, it probably gets more heat than intended during ejection.

M.G. (December 9, 2008)

I have used this baffle 4 times on my cloned Cherokee D. So far it has worked perfectly. I used one square of wadding each time.

Post a Comment