Ever since LDRS ended, I’ve been working on a specific project XPRS this upcoming weekend. The project in question is a 54mm ‘flying case’ rocket designed around the CTI Pro54 6g XL case with the ultimate goal of setting a new Tripoli K altitude record, and possibly setting a new L altitude record a month or two from now.
First thing I got started with was the fin can. I didn’t like the way commercial tubing fit loosely on the motor case, so I decided to make my own tube using an old motor case as a mandrel. I don’t have any good pictures of the process, so here’s the end result instead:
Fins were cut from 1/16” carbon from dragon plate and beveled with a Crazy Jim style beveling jig with 150grit sandpaper
Fin can is a perfect fit on the case.
Next up is the attachment method for the upper airframe section. The CTI K300s come with a plugged forward closure that has a1/4-20 threaded insert. My plan is to utilize that to attach the rest of the airframe to the motor using an aluminum adapter piece. I borrowed a friend's mini lathe for a week and spent around 11 hours of machining time making this small piece. One important thing was I put a radius on the underside to as close as possible match the radius of the forward end of the case. It’s not perfectly clean, but it the lathe really didn’t like the large piece (relative to the lathe) that I was working with and struggled every bit of the way.
Conforming to a Pro54 case.
First thing I got started with was the fin can. I didn’t like the way commercial tubing fit loosely on the motor case, so I decided to make my own tube using an old motor case as a mandrel. I don’t have any good pictures of the process, so here’s the end result instead:
Fins were cut from 1/16” carbon from dragon plate and beveled with a Crazy Jim style beveling jig with 150grit sandpaper
Fin can is a perfect fit on the case.
Next up is the attachment method for the upper airframe section. The CTI K300s come with a plugged forward closure that has a1/4-20 threaded insert. My plan is to utilize that to attach the rest of the airframe to the motor using an aluminum adapter piece. I borrowed a friend's mini lathe for a week and spent around 11 hours of machining time making this small piece. One important thing was I put a radius on the underside to as close as possible match the radius of the forward end of the case. It’s not perfectly clean, but it the lathe really didn’t like the large piece (relative to the lathe) that I was working with and struggled every bit of the way.
Conforming to a Pro54 case.