Found Tribrid Engine

[MachDiamond]

I've been wanting to get more into hybrid rocket engines. If anyone has a tribird engine for sale please reach out to me. I especially would like a RATTworks K350, but I would consider any production tribrid or clone.

If you aren't familiar with these engines, you can learn more here:

https://www.rattworks.net/research_tribrid.html

They also come up from time to time in the hybrid thread.

These engines were a lot more common before 2009 back when APCP (Ammonium Perchlorate Composite Propellant) was considered an explosive by the ATF since these engines weren't subject to all the ATF regulations.

Thanks

 

[8thPaladin]

Interesting! Wonder why Rattworks quit making them? I see other hybrid motors, but not the tribrid

 

[MachDiamond]

RATTworks/Monterey Machine Products actually doesn't manufacture any hobbyist hybrid engines anymore. I called them up and they said their focus has shifted completely away from the hobbyist market and towards private aerospace and government work. The only company I know of here in the U.S. that actually still actively manufactures and sells hybrid engines that I am aware of is Sunward/HyperTek. A couple of others still have parts and you might be able to get them to do a small run if you place a large enough order.

Anyone have a Tribrid for sale?

 

[AlphaHybrids]

An IREC team I've worked with had one on loan and they cloned it for their testing. Very, very ingenious design.

Edward

 

[crossfire]

Contrail Hybrids is in the USA

 

[markkoelsch]

RATTworks/Monterey Machine Products actually doesn't manufacture any hobbyist hybrid engines anymore. I called them up and they said their focus has shifted completely away from the hobbyist market and towards private aerospace and government work. The only company I know of here in the U.S. that actually still actively manufactures and sells hybrid engines that I am aware of is Sunward/HyperTek. A couple of others still have parts and you might be able to get them to do a small run if you place a large enough order.

Anyone have a Tribrid for sale?

Last time I heard Cesaroni owns Hypertek. Sunward might well sell them.

 

[DRAGON64]

Andrew McMillan over on the yahoo hybrid motor group offered three Tribrids for sale last year. I was in line to get one, if he could not sell all three. He is still posting over there, so do not know current status. I will email him and see what he replies.

 

[DRAGON64]

@MachDiamond

Sending PM

 

[MachDiamond]

AlphaHybrids, thanks for stopping by. I always enjoy reading your posts, particularly on your Tribrid projects.

DRAGON64, your message is much appreciated. If nobody else has a tribrid for sale and Andrew is wanting to sell his three as a set, perhaps we can work something out.

 

[DRAGON64]

I received a very encouraging email from him today. More when I hear back from

DRAGON64, your message is much appreciated. If nobody else has a tribrid for sale and Andrew is wanting to sell his three as a set, perhaps we can work something out.

 

[AlphaHybrids]

For the tribrid design - it scales very well to a 4-inch chamber and tank. After that, the parts and dimensions get a bit unwieldy. Then it is probably best to switch a a valved system for something larger. An IREC team used this approach with a 6" tank and 4.5" combustion chamber. The downside to this is that you have two differing diameters and plumbing to line up.

I've been testing a new injector design this summer - it is a two-piece bulkhead that uses a pintle style injector. The nitrous flows around the pintle, the alcohol through the pintle. The main motivation is to remove the valve system and reduce weight and return to a monotube configuration.

Edward

 

[jjhdnd]

If there is any chance of getting a tribrid - I want in on the action!!!!!

 

[High Desert Rocketry]

Dave from Monterey Machine Products has been posting some new parts for the tribrid on the Amateur Experimental Rocketry Facebook group.
Www.rattworks.net

 

[cwbullet]

I would like to see more hybrids, but then again it is a niche of a niche market.

 

[OzHybrid]

I would like to see more hybrids, but then again it is a niche of a niche market.

As the Tribrid is liquid fuel, unfortunately it does not fall into any workable part of the NAR ot TRA code. This would mean it could only be launched at Friends of Amateur Rocketry of somewhere similar like Spaceport. Or perhaps as a demonstration with board approval at Balls. Thought of getting one years ago, but that put me off.
Norm

 

[CoyoteNumber2]

As the Tribrid is liquid fuel, unfortunately it does not fall into any workable part of the NAR ot TRA code. This would mean it could only be launched at Friends of Amateur Rocketry of somewhere similar like Spaceport. Or perhaps as a demonstration with board approval at Balls. Thought of getting one years ago, but that put me off.
Norm

http://www.nar.org/SandT/pdf/CombinedMotorsByImpulse.pdfSee K350TR-P and K600TR-P

 

[MClark]

I saw it launched at BALLS.

 

[Johnly]

I remember that flight. The pitch of the motor was almost a scream when the alcohol started dumping into the combustion zone.

 

[OzHybrid]

http://www.nar.org/SandT/pdf/CombinedMotorsByImpulse.pdfSee K350TR-P and K600TR-P

I see..... The only Tribrid certified?
However a certified motor is the whole thing. The case, propellant and following the manufacturers instructions for it.
I don't think you'll be able to get the certified reloads from RattWorks. To make the launch of a certified motor, certified. That launch was a while ago and Dave Griffith, mr RattWorks, stopped manufacturing some time ago after the BATF lawsuit got resolved. I bought out all the M900 and L600 reloads for my L/M 600/900 I could find at the time.

Which makes it experimental. Which comes back to.

No Tribrid definition in the Tripoli (or NAR) safety information I can see. Hybrid specific definition only mentions solid fuel.

Hybrid Motor: A special type of High Power Rocket Motor which combines liquid nitrous oxide with solid fuel to provide thrust. ( from Tripoli safety code definitions)

But if you've got one, and can work some pathway through the rules, I'm very jealous.

Good luck with the launches.

 

[Steve Shannon]

This is interesting from a historical perspective. In 2007, a proposal to the NFPA Pyrotechnics Technical Committee was adopted and the definition of hybrids was changed in NFPA 1125 such that the inclusion of a supplemental liquid fuel was permitted. That allowed Tribrids to be certified as hybrids.
However, the definition of hybrids was not changed in the Tripoli Research Safety Code, which means that although a manufacturer can submit them for certification and once certified they can be used by any organization that allows motors certified to NFPA 1125, a strict reading of the previous Research Safety Code or the current Tripoli Safety Code does not allow research tribrid motors.
It’s not unique in that regard. Certified black powder motors may be used but research black powder motors may not.

 

[OzHybrid]

This is interesting from a historical perspective. In 2007, a proposal to the NFPA Pyrotechnics Technical Committee was adopted and the definition of hybrids was changed in NFPA 1125 such that the inclusion of a supplemental liquid fuel was permitted. That allowed Tribrids to be certified as hybrids.
However, the definition of hybrids was not changed in the Tripoli Research Safety Code, which means that although a manufacturer can submit them for certification and once certified they can be used by any organization that allows motors certified to NFPA 1125, a strict reading of the previous Research Safety Code or the current Tripoli Safety Code does not allow research tribrid motors.
It’s not unique in that regard. Certified black powder motors may be used but research black powder motors may not.

Probably needs some advice from the Motor Certification Team and the board on what direction is possible.
I'd like to see tribrids approved experimentally, but recognise the difficulties. Having said that, what really is the difference from this and some unknown solid prop formula being tested. No need to answer that.
Norm

 

[Steve Shannon]

I will talk to the Research Committee and TMT and I’ll probably bring this up at the board meeting. Right now I don’t know enough to be sure how I feel about it.

Just because I think it’s interesting here’s the actual record at NFPA. This was a full ten years before I was on the NFPA Pyrotechnics Technical Committee, but I really sometimes enjoy looking back through the history. It looks like 2007 a major effort was made to align the definitions between NFPA 1122, 1125, and 1127 and this was something that was also adopted:

1125-6 Log #CP6 Final Action: Accept (3.3.26.3 Hybrid Rocket Motor)
SUBMITTER: Technical Committee on Pyrotechnics
RECOMMENDATION: Revise the definition as follows:
3.3.26.3 Hybrid Rocket Motor. A rocket motor in which one or more of the fuels exists in a different physical state (solid, liquid, or gaseous) different than the oxidizer and that derives its force or thrust from the combination thereof.
SUBSTANTIATION: The changes in wording permit the inclusion of a supplemental liquid fuel in a hybrid high power rocket motor.
COMMITTEE MEETING ACTION: Accept
NUMBER ELIGIBLE TO VOTE: 31
BALLOT RESULTS: Affirmative: 20
BALLOT NOT RETURNED: 11 ARNOLD, BOWES, BULIFANT, COLON, CONKLING, FADORSEN, GRUCCI, HANSON, HENDRICK, LAIB, PIER