Finally got to a point to where I've started making progress. Currently have all the pieces in order for it to be completed just a few misc kinks to work out.
Cut the fins from 1/8" fiberglass with a dremel.
Body is BT60 from mach 1 with couplers for nose and motor mount
Nosecone will be a custom fiberglass.
Kinks
Still have to work out the electronice due to the motor I have selected (H-999) being a plugged. Might step it down to a H-550. Similar numbers just a little less speed and max alt.
To stick with the streamer idea or switch to chute with JLCR
Shock cord attachment.
Your G10 fins are good at 1/8" - if you properly prep the fins and body tube and do good fillets, no need for any extra fiberglass. I've gone past Mach 2 with a variety of MD rockets and I've never done anything other than just surface mount. In addition to good surface mounting, the other biggest factor to success is fin alignment - from a longitudinal standpoint. A lot of folks worry about getting the fins right vertically, but if you have fins that are not perfectly aligned 'front to back' that can create very significant additional stress on the fins. I now use a 3D printed fin jig to
try and create perfect alignment, but whatever you use, make sure to try and get them as close as possible.
I know I'll get flak for this, but I would just friction fit the case. I've done it with 6XL 54mm cases with no issues. It's not hard - you just have to practice until you get it right. Basically you wrap strips of tape that are cut to a point at the fore end and wide at the aft end in a spiral fashion around the last 1 -1/2" of the motor case or so. (They will basically look like screw threads.) When you push it in, you have to slightly twist the case the last inch or so. Once in, no matter how hard you pull on the rear closure the case should not move at all. You should need to push the case out from the front using a large dowel (like 1") or a piece of PVC pipe.
Otherwise buy a threaded closure and use a solid bulkhead with the proper sized hole for motor retention. But for that you will need electronic ejection.
The problem with any kind of electronics is it starts upping the cost and complexity. You could use the single deploy altimeter from Eggtimer (the Apogee) that costs $15 plus your time to build it. But now you need a payload bay - either in the body tube or nose cone. If you use a JLCR, you've basically stuck $125 in your rocket, so now you need to make sure you get it back and you need a tracker. And of course you have the cost of the case if you use a reload. If you stick with the DMS H550, you cut your losses if you don't get the rocket back. So it's a cascading decision once you start using electronics.
For recovery, in my experience, large streamers really do not work as well as they should when it comes to tracking rockets. I've used nearly every kind of streamer available, including several homemade versions. In nearly all cases they underperformed my expectations. In the end I tried making bright silver mylar streamers from emergency blankets. The biggest issue is that beyond a certain width they seem to fold inwards which greatly reduces the visible surface. And as they fall they twist up on themselves. I even resorted to using pieces of music wire to try and hold them straight. The other issue is unless you have good eyes on the rocket at apogee, it's nearly impossible to pick up the streamer on its way down. So if you really want to get it back, I think you'll need a tracker of some sort, or at least a very loud sonic locator.
For chute attachment one method I use on small diameter fiberglass tubes is to drill a hole straight thru both sides of the body tube and then insert a piece of music wire - 1/4" would be more than sufficient for that size tube. Cut the music wire as close to the right length as possible. Contour it to the body tube with a variety of methods, a grinding or sanding wheel on a Dremel, a small file, even sandpaper on a block all work. Use either epoxy or heavy CA to glue it in place. You can then use your choice of knot or other method to attach your shockcord to the horizontal piece of music wire. I've never had that method fail.
Minimum diameter rockets, especially in small body tubes, offer some unique building challenges. And then you have to get it back.
Good luck and keep us posted,
Tony
