Single Deploy Airframe question

Hello all,

I am building 3 kits right now and they all have the same configuration: Main Body Tube, Couple, Upper Body Tube, Nose Cone. I have seen both the upper tube attached to the nose cone and to the main tube, sometimes attached with sheer pins, but sometimes attached with epoxy. Is there any issue in attaching the upper body to the main body permanently, or should I keep them separate and use sheer pins? These rockets will be mid to high power and single deploy only. I just want to doublecheck before applying glue. Thanks.

The problem is that if in the future you decide that you would like to convert it to dual deploy, you are out of luck if you have glued the payload tube to the coupler. I had that problem with my Porsche DX3 which was my level 1 cert rocket.

https://www.rocketryforum.com/showthread.php?59761-The-Porsche-DX3

Also, the payload tube (upper tube) would not normally be attached to the coupler with shear pins. Shear pins are only used for sections that are to be blown apart by an ejection charge. So for dual deploy the payload tube would normally be attached to the coupler with removable bolts or rivets, and the booster tube (lower tube) would be attached to the coupler with shear pins.

On single deploy, I wouldn't use sheer pins. No need at all and just adds wear points on a paper rocket. Personally I'd glue the coupler to the upper section. This allows you to use it as a payload bay. You can add weight for larger and heavier motors, ride along altimeters, cameras or trackers. My current work horse is in this configuration. There is no benefit to gluing both body tube together via the coupler. That adds internal volume that must be overcome by the ejection charge.