HED solves the problem of doing DD on shorter rockets, where if you kept the rocket the same length, cut the airframe down to create a booster section and payload section, added a coupler to make a traditional e-bay between them, then you would be very linited on how long of a motor you could use or be very cramped trying to get proper sized recovery in. Traditional and HED both function in the same manner by separating or deploying a drogue at apogee and deploying a main at a set altitude
Why do you want any of that? More stuff to go wrong.
Head End Deployment. Using the nose cone to contain the secondary deployment/recovery chute and harness.
You would be incorrect. the 1000s of dual deployment flights where all that stuff is used wayyyyy more than any JLCR flights have been done. Weather its HED or conventional dual deployment. Properly done redundant dual deployment is the most reliable recovery method there is in the hobby. Ive personally been flying dual deployment for more than 20 years with great success including HED flights to over 35k ft agl. Ive seen more failures with motor deployment and Devices like JLCR than real electronic dual deployment.
The question was honest, the "too many TLA's (Three Letter Acronyms)" was for fun. Thanks!
Yep, people were doing this technique in Mini Maggs and such before it was coined and advertised as "HED."
It's like a VLA, but only 3. Ha ha. Three Letter Acronym.
Methinks he's yanking your chain! I started that mess upthread. Sorry! See post #9Damn, this has become like texting
I have had zero issues with any of that from 38mm, and 54mm minimum diameter HED stuff up to 5 inch diameter HED stuff. The type/manufacturer of chute used really makes a difference as does the size and length of the harness. I use primarily Spherachutes in their Ultralight line. They pack super tight/small. Also building as light as possible. My 54mm min diameter rocket burn out weight with a K250 was 40 oz. Even my 5 inch rocket that flew on an N1000 burn out weight was less than 20lbs.
Variable Length Acronym, could be anything from two to 8 or 10.
Hehehe (for the TLA)
I got my Punisher 3 to load with HED but used a chute release on the main. Unfortunately I packed the release into the chute so it could not determine the altitude. Doh. Lesson learned.
Ahhhh, That's more electronics involved to do the same thing. Deal with motor eject and JLCR one just has to sim a reasonable apogee deployment delay and drill a delay grain for the right time if a stock one doesn't work. A one second either way is no big deal. Or use a simple apogee only deployment device and have the JLCR unfurl the main.
An e-match is not wasted when you have 100% recovery success. People frequently screw up motor deploy timing and the JLCR.
Agreed
Beyond setting the timing right with the drill, and even beyond the imprecision of burning delay grains in general, with motor ejection you get to deal with chuffing motors shredding your rocket. The delay grain starts to burn when the motor first tries to light. By the time the motor finally comes up to pressure, the delay is almost done. Then the delay grain burns through while the rocket is under boost, and chaos ensues. Saw two rockets die this way at Airfest this year, and given the size of the launch, there were likely more I didn't see.
Chuffing motors is something I'm just learning about, so believe me I'm keeping my little Aerotech RMS 18/20 reloads sealed and sealed again until I might have a chance to use them! Your scenario makes 'way too much sense.
