New project - BT70 upscale Advanced Target Drone

The Rocketry Forum

Help Support The Rocketry Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Gee! I came into this thread kinda late. I'm inspired you built with a BT 70. It's such an overlooked tube size, but it happens to be one of my favorites. That BNC 70-G is a nubie to me. There aren't many cones to choose from for that tube. I have similar nose cones I turn on a lathe. What's the length and where did you get it? Sorry I missed this build thread. But anybody building with BT 70's gets my attention.
 
Thanks Riley.

Gary, I built it with a BNC-70K from BMS, described as "long ogive with blunt tip". It's not quite the right length/shape for upscaling the PNC-50Y, but it was the closest I've found. It's 7" long, but the rounded tip truncates what would be a longer ogive shape otherwise. I've done several designs with BT70 that I haven't gotten to yet. FWIW, Apogee has a 5:1 (IIRC) ogive cone that fits BT70, and is made to also be trimmed into a boat tail. I think its about 10.5" long. The cone was too long and raked to look right on the model, so I wound up with the 7" shorter ogive shape and extended the BT to make up the difference.
 
Last edited:
Launched in a cluster configuration over the weekend:
19874706949_627b1961a2_z.jpg

20035106976_a7089376da_z.jpg

20053514172_58aa744721_z.jpg

20053514862_f27f613654_z.jpg

19440411373_1be9e20a53_z.jpg
 
That sucker looks like it was posing for the pics on the way up.
Might be a contender for next year's calendar!
 
Back
Top