What is your project for Thunda Down Under 2019?

OverTheTop · Postby **OverTheTop** » Mon Jan 22, 2018 10:52 am

What is the official statement regarding the allowability of HEI (head end ignition) at the Thunda event? Is it a proscribed technique? Is it allowable with certain caveats? Some info on this would be great as there are a few multi-stage rockets to be flown there by the looks of it.

drew · Postby **drew** » Mon Jan 22, 2018 4:17 pm

OverTheTop wrote:What is the official statement regarding the allowability of HEI (head end ignition) at the Thunda event? Is it a proscribed technique? Is it allowable with certain caveats? Some info on this would be great as there are a few multi-stage rockets to be flown there by the looks of it.

From the conversations I've had OTT this HEI hardware is kosher for all AMRS launches. I suspect one of the benefits of creating your own rocketry governing body is the ability to make rules that are a little more sane than other orgs, especially when it comes to this sort of modification that can easily be described as providing safer staging options. From a technical perspective I believe you have a much higher chance of success staging with HEI when compared with bottom lighting from the booster or leveraging conduit or tape wire for lighting a motor via sustainer electronics; especially with MD attempts.

All that said I'm 100% certain that I'm the only Australian customer that has this set of hardware so the answer might be different with other hardware, especially if it's home brewed and relatively untested. Charlie Ogino and Jim Hendricksen have put a lot of effort in these HEI forward closures to ensure both a safe experience and repeatable capability. They've been static tested and flown on numerous occasions from my understanding.

Finally, from my perspective HEI isn't the primary safety concern when it comes to staging, well configured staging electronics are the primary concern. I definitely don't want to light a L sustainer motor if my rocket is more than 12 deg off vertical when the ignition is meant to occur. IMHO the "logic" in flight computer programming that controls staging is much more important from a safe staging perspective when compared to commercial HEI hardware.

TLDR; Ask. I've asked Blake and Scoop regarding this hardware and their responses have been positive. YMMV dependent on HEI hardware leveraged and the testing regime it's been subjected to.

OverTheTop · Postby **OverTheTop** » Mon Jan 22, 2018 5:28 pm

Thanks for the comments Drew. So that is the official AMRS stance on HEI? If so, is it documented somewhere, and what are the requirements for using other HEI setups other than the CJ system?

Agreed. HEI is definitely not the main safety issue for staging. Not so bad if things go awry up at altitude when it lights, but an unintentional ignition during setup on the ground is more than just frightening.

drew · Postby **drew** » Mon Jan 22, 2018 5:39 pm

OverTheTop wrote:So that is the official AMRS stance on HEI?

I didn't say that at all...

I only said my conversations with Blake and Scoop regarding this HEI hardware have been positive.

OverTheTop wrote:HEI is definitely not the main safety issue for staging. Not so bad if things go awry up at altitude when it lights, but an unintentional ignition during setup on the ground is more than just frightening.

And this is where staging goes from "a good idea" to "did I just crap my pants?" :wink:

drew · Postby **drew** » Mon Jan 22, 2018 5:48 pm

To be more pedantic, my conversations specifically regarding Carolina Composite Rocketry HEI hardware with Blake and Scoop have been positive. At an absolute minimum any HEI hardware will require appropriate due diligence from the flyer hoping to leverage it at an AMRS launch. To my knowledge the AMRS has no formal framework for HEI staging but I do plan to bring up this point in the near future in my "official" capacity as a Records Committee member.

I also expect more due diligence will be required to gain approval for staging shots that attempt to leverage HEI (and staging shots in general). Also remember that any flight that sims to 18k' or above requires it to be reviewed by the High Altitude Flight Review Committee (I'm not 100% sure that's what it's called) and so there is already a rough framework in place for managing many of these attempts at THUNDA, especially the more aggressive ones.

OverTheTop · Postby **OverTheTop** » Mon Jan 22, 2018 5:55 pm

Thanks Drew. I am looking at making my own HEI adaption and have been considering it for a number of years. It will, of course, be based around materials and methods that are up to the task.

I have a few other ideas around the safety theme too, but I don't want to hijack the thread too much

.

jase · Postby **jase** » Tue Feb 27, 2018 3:48 pm

SO just on rules etc...

I'm still a member of Tripoli - are Tripoli members allowed to fly? Y'all going to have temporary memberships available for just the event for us infrequent frequent flyers?

I'd love to fly a minimum diameter O or just a big P in something (if they are available)...

Speaking of projects, I'd probably just chuck the 6" Darkstar up on an N or the like, it's only had 1 x O, 1 x N and maybe 6 or so M's through it - poor old thing is just collecting dust now :cry:

yep, and a minimum diameter O something... and a bunch of 54mm L's just for fun (because, they are fun!)...

Any word on another M Sparky drag race? I'd go in that again too... good fun!

We'd probably fly up then motorhome it across.

Cheers hope y'all having fun

OverTheTop · Postby **OverTheTop** » Tue Feb 27, 2018 6:04 pm

Sounds like you are hanging out to burn some APCP Jase

Look forward to catching up when you come over to the Big Island :wink:

jase · Postby **jase** » Wed Feb 28, 2018 7:17 pm

Isn't everyone?

Likewise my friend, it's been too long

I'd also like to tame the N5800 - Binder fincan 'look mum no hands' type flight, that'd be a great name for a rocket :lol:

Might be good for 50k near Mach 3 and some change :wink:

jase · Postby **jase** » Tue Apr 10, 2018 9:19 am

Just saw the dates :cry:

Easter is one of the busiest times of year for our business - I can't make it...

Best of luck to everyone going and if you haven't been before, GO - it is an awesome event.

CATO · Postby **CATO** » Wed Apr 11, 2018 1:38 pm

jase wrote:Just saw the dates Easter is one of the busiest times of year for our business - I can't make it....

What a load of bollox.... My guess is that you are scared of the retribution that "Crazy Jim" is going to pay out on you for the 2015 igniter incident... :mrgreen:

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"I don't blame you mate"

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Digit · Postby **Digit** » Wed Apr 11, 2018 2:48 pm

snake eyed rascals

jase · Postby **jase** » Wed Apr 11, 2018 4:00 pm

Well played David

...a couple of things - I wasn't the guy who showed up to an M drag race with an 'augmented' K motor!

The alligator clip thing - I thought I was helping!!! :lol:

It was one of the best thing ever, no really, it was!

We ended up drinking the additional nose cone weight - cheers Simon

AND, last but not least - a fact that not many have cottoned onto but I'll freely admit now, CJ wasn't the only one that cheated that day :wink:

Footnote - Blake and Nic couldn't even get theirs up that day :lol:

late scratching due to 'electrical' issues, but it sure was fun testing if their motor grains worked afterwards :wink:

03flyer · Postby **03flyer** » Wed Apr 11, 2018 8:54 pm

Hey Jase, are you from Bruny Island?

matthew · Postby **matthew** » Wed Jul 04, 2018 2:31 am

jase wrote:Just saw the dates Easter is one of the busiest times of year for our business - I can't make it...

Wait, what? Say it ain't so! :cry:

I'm going to be skipping class to be there. Not just to fly a rocket or two, but for the shots of bourbon from all the new L3s! :lol:

Not sure what I'll fly yet. I'm restricted by what I can fit in my rocket transport box. I have a 4" SAAB RB-05A I might build. I'm counting on there being some kind of sparky race, so I might throw an L820 skid into the mix. Or, as mentioned above, I could just drink beer. Either way, Kathy and I, and our friends that came with us last time - Andrew and Catherine - will be there.