Big Augie, Gas Assist Stability Rocket

This design is inspired by the Estes Augie II, plans available from JimZ rocket plans, as well as general discussions regarding gas induction in model rockets.

The induction body tube is a rare one. It is from the Estes D-Region Tomahawk that I had left over from a cato. It has been built and flown twice with good results, more posts will follow as I find time.

I use a lot of ducted gas, but it doesn't help my stability. Oops, I see you're talking about rockets.

This design really looks cool and upscale is intriguing. I don't believe that ducted rockets can augment thrust appreciably. There have been several posts on augmentation,

I use a lot of ducted gas, but it doesn't help my stability. Oops, I see you're talking about rockets.

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:wink:

There is reason to believe that ducted rockets under some conditions can contribute to stability.

Is that motor is recessed way over three calibers back?:y: I thought the RULE was no more than two! With a big old Estes E motor flame, long burn and a hot delay.:eyepop: Can we say big time burn on the end of the tube? Can we say hello Mr. Krushnik? This sort of thing takes years of experimentation, numerous prototypes, and vast rocket science experience to get right. No way it can work the first time. This is a first time test rocket, it should not be finished with a museum quality paint job as it is sure to crash and burn when the button is pushed. All this GDS - air induction stuff is way over rated. Yep, mindsim says it is time to sit back, watch and hear all the motor power sucked by Krushnik effect as it lifts off, then starts to burn on the end as it crashes into a flaming pile of goo. Such confidence from the peanut gallery!

Skp said:

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This design is inspired by the Estes Augie II, plans available from JimZ rocket plans, as well as general discussions regarding gas induction in model rockets.

The induction body tube is a rare one. It is from the Estes D-Region Tomahawk that I had left over from a cato. It has been built and flown twice with good results, more posts will follow as I find time.

Click to expand...

Intriguing design. Two successful flight already ? Congratulations! I agree with Daddy; Mindsim says the Krushnic Effect should have operated to keep the altitude to 50 feet tops. Any video you can share with us ?

Cool rocket! I don't agree with daddyisabar that GDS is over rated. I like rockets that waste good motors and that require rework after each launch. The air gap is s'posed to keep Mr. Krushnik at bay. My now meager experience with such things is that they can be stable without fins but I have yet to provide a large enough air gap that Mr. Krushnik is totally defeated. However, the main lack of performance is due the abrupt instability after boost and this one has nice big fins to make sure it keeps going in the UP direction. As for charring, my last try on the BT-60 based Not-A-MIRV only resulted in the deposition of exhaust splatter and no actual burning. Please take a tail end picture to prove this to the deniers.

Big Augie is a pain to prep for launch. The starter for the motor has to be inserted into the motor and attached to a pigtail before the motor is loaded from the midsection of the rocked. Then a stuffer tube slides in after it to hold it in place. The upper tube is locked onto the lower section. I have a piston in place to protect the altimeter from ejection gases and everything deploys out the nose in a regular fashion. The 1st launch was on a D12-5 and had very little soot, the second flight was an E9-6. Most of the soot came on that flight. I don't believe that it charred the tube at all. The tube did get a Borax solution bath prior to construction, because I am a cautious person.

No denying Gas Dynamic Stabilization or fancy, hi bypass airflow induction is the bee's knees, just the best dern thing when it works right. Heap on the praise and highly rated for this one. That motor is wayyyy up there and just a little soot to wipe off the heavy ex-Tomahawk tube after a mighty E9 6 long burn. Not even a tiny blemish, burn mark of blister on the perfect yellow paint. The sound is muffled right at ignition but then straight up with little or no power loss observed. I think the induction airflow is established about half way up the rod and then it is smooth flyin' from there on in. Kind of a gurgle-gurgle-whoosh-pop effect. Good bye Mr. Krushnik, good bye black powder burning. Hello deeply recessed motor and good performance. Now fer some really tiny fins or no fins at all!

Daddyisabar said:

No denying Gas Dynamic Stabilization or fancy, hi bypass airflow induction is the bee's knees, just the best dern thing when it works right. Heap on the praise and highly rated for this one. That motor is wayyyy up there and just a little soot to wipe off the heavy ex-Tomahawk tube after a mighty E9 6 long burn. Not even a tiny blemish, burn mark of blister on the perfect yellow paint. The sound is muffled right at ignition but then straight up with little or no power loss observed. I think the induction airflow is established about half way up the rod and then it is smooth flyin' from there on in. Kind of a gurgle-gurgle-whoosh-pop effect. Good bye Mr. Krushnik, good bye black powder burning. Hello deeply recessed motor and good performance. Now fer some really tiny fins or no fins at all!

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[DOH! ] Did you see Big Augie fly Daddy ?

Skp said:

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Big Augie is a pain to prep for launch. The starter for the motor has to be inserted into the motor and attached to a pigtail before the motor is loaded from the midsection of the rocked. Then a stuffer tube slides in after it to hold it in place. The upper tube is locked onto the lower section. I have a piston in place to protect the altimeter from ejection gases and everything deploys out the nose in a regular fashion. The 1st launch was on a D12-5 and had very little soot, the second flight was an E9-6. Most of the soot came on that flight. I don't believe that it charred the tube at all. The tube did get a Borax solution bath prior to construction, because I am a cautious person.

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Yeah, all 4 of my 'gassers' are slightly a pain to prep. Nice to see it wasn't all burned up inside. I would do the Borax thing if I had 20 Mules

[video]https://youtu.be/3_LB7X9N8yg[/video] [video]https://youtu.be/Tw9Rap_WV7U[/video]
The Maiden flight video is pretty grainy, and the second on the E9 tipped slightly off the rod, and I am not sure why. It was a calm day.

Nice flight, despite the tip I didn't notice.

If someone knows how to embed the videos on this site let me know or go ahead and post them.

Just copy the video addy, click the video button in the menu bar. Copy the addy. The entry pop up shows the format you need.

[video=youtube;3_LB7X9N8yg]https://www.youtube.com/watch?v=3_LB7X9N8yg[/video]

[video=youtube_share;Tw9Rap_WV7U]https://youtu.be/Tw9Rap_WV7U[/video]

samb said:

[DOH! ] Did you see Big Augie fly Daddy ?

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Yes, and my faith in GDS was renewed!

Great videos. You can hear the "throatiness" or muffled sound of the recessed motor at ignition. The hard hitting D12 got the induction working right away where as the wimpy and heavy E 9 might have taken more time, not kicking in to an instant after leaving the rod. Only awesome, kick booty D12s for a fin less design! Blast the DENIERS! GDS RULES!

Deep throatiness...reminds me of the late 70s

rstaff3 said:

Deep throatiness...reminds me of the late 70s

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That sounds like another rocket destined only to be revealed in the Dungeon.

[video]https://youtu.be/Y4F8IVDyCgA[/video]

3rd flight of Big Augie. 806ft on a D12-5. Chuff of smoke on liftoff that had not occurred before and darker burn marks on the tube.

Skp said:

[video]https://youtu.be/Y4F8IVDyCgA[/video]
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3rd flight of Big Augie. 806ft on a D12-5. Chuff of smoke on liftoff that had not occurred before and darker burn marks on the tube.

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The guys in the background are real rocket scientists and know what they are taking about!

Nice flight! gassers rule!

The chuff was probably just caused by escaping gas leaking out the vent then being pushed back by the acceleration and resultant airflow around the rocket. Mr. Bernoulli and Krushnik had nothing to do with it. The initial gurgling sound was probably just the amplified sound of the igniter starting the motor in the hollow tube.