Tender Descenders

Overview

The Tender descenders are used by the team for achieving a single separation dual deploy architecture. For most of our large rockets (including Hermes), we use the "L2" model of Tender Descender. The sales page can be found here: http://www.tinderrocketry.com/l2-tender-descender-tether

Width of opening/maximum diameter of line = .16 in.

Student Modifications

The Tender Descender currently used by Rocket Team has a hole drilled and tapped for a 1/4-20 bolt to screw in where the E-match is normally located. Our 1/4-20 bolts have holes drilled in them with E-match glued in–we call these "FireBolts." This allows us to screw our E-matches and secure them with Teflon tape.

Setup and Operation Checklist

Materials Needed:

• Tender Descender
• Two Quicklinks (make sure they fit in the Tender Descender)
• Black Powder
• Safety Supplies
• Scale, weighing tray, popsicle stick
• Teflon Tape
• Scissors
• FireBolt (1 for each firing!)
• Isopropanol
• Wiping Rag

Procedure:

• If needed, clean the Tender Descender with isopropanol and the rag. This needs to be done after each firing to remove the spent black powder residue.
• Put the Tender Descender string through one of the Quicklinks so it stays attached to our stuff after firing
• Ensure Quicklinks are tightened - it will be hard to turn the nut after they're integrated.
• Put the two Quicklinks (one of which now has the string through it) into the Tender Descender
• Put the bridge piece into the Tender Descender, unifying all of the components that have been used so far.
• Using a funnel, pour the pre-measured black powder charge into the small hole in the base of the Tender Descender. Pour slowly to avoid the funnel clogging.
• Wrap ~5 turns of Teflon Tape around the FireBolt. Generally go a little light rather than a little heavy. If too much tape is on, the FireBolt may not be able to drive far enough into the body.
• Screw the FireBolt into the Tender Descender, finger-tight. You definitely don't want more than ~4 threads of screw to be exposed.
• Attach Tender Descender to rest of system. Unscrew the system's Quicklinks, not the Tender Descender's, because again, it's hard to undo the TD's Quicklinks.
• When connecting the E-match to the firing system, ensure that the wires are well-gapped to avoid shorts.

Testing Campaign

Team Members are in the process of conducting tests to ensure that we understand proper Tender Descender operation and to verify our student modifications.