Ye Olde Rocket Forum - View Single Post - Scrounged-Up Designs 2006

Quote:

Originally Posted by snaquin

Since the Semroc BTH-70 wall thickness would be correct at .036" given the stated tubing dimensions, should the BNC-70HAC nose cone really be 2.497" OD or I wonder if that is a typo? I would think it should be 2.247" as well?.

Thanks! The web site has been corrected. The correct diameter is 2.247". The tube was designed for multiple uses:
1. Thicker wall BT-70 for TARC rockets.
2. 1/2 scale ARCAS body tube for SLS ARCAS.
3. Tube coupler for LT-225 tubes (reason for the .003" undersize.)

The planned SLS ARCAS is the reason for the 1/2 scale nose cone. The original BNC-55AC was designed for the Estes ARCAS and later "re-used" for the Cherokee-D. The BTC-70HZ is the balsa boat tail for the SLS ARCAS.

Hawk Hobbies has a great Cherokee-3D that uses the slightly bigger version of the BNC-55AC. I wish we had have thought of that one first. 3 D engines!