Do I Need A Stuffer Tube?

I am building a tube finned rocket for a level one attempt. I have 5 feet of BT-60 tube, reinforced by BT-60 coupling material as the base airframe. Should I run a stuffer tube up the middle of this airframe to insure the ejection charge will deploy the laundry? I'm going to use a DMS Aerotech H motor for the attempt.

no you should be good. there are larger rockets such as the G-Force and Sumo by aerotech that are 4'' in diameter and about that height that eject fine with 29mm motors. that's a pretty small tube. what altitude are you looking at?

an Aerotech RMS 38mm reload comes with approximately 1.2g of bp, that is enough to pressurize about 19" of parachute bay...I would use a stuffer tube. note; that is measured from the base of the nose cone shoulder, not from the end of the tube.
Rex

other things that would be helpful to know is how long your motor mount is and how tight the laundry is in the tube.

I'd say go with a stuffer. Alternatively, have it break and deploy a parachute in the middle. Then you can even go zipper less (see some of QQUAKE'S Builds for ideas) especially if it's for a. Cert. Then it's better to put in a stuffer and not need it than need one and not have one :y:

I'm calculating about 21 PSI, using a pressurized length of 55" and the calculator at https://www.info-central.org/?article=303 ... of course this rocket also needs to work with MPR 29 mm motors at .7 g BP, which shows about 12 PSI, which results in about 24 pounds force on the cone, which sounds like enough to me although the author of these calculators appear to think you need at least 100 pounds. Frankly you may never see this one again on an H and maybe you should use some stuffer so you can also use 24 mm motors . As another data point, the Estes Partizon is 2.5" x 5' and uses no stuffer.
The Estes Tomahawk is 1.8" x 40" x 24 mm and does use a stuffer, though.

With an H, I kind of think a break in the middle wouldn't be great for strength, although dual deploy capability would be good.