Rocketry Planet

COVINA, California USA — David Griffith, owner of RATTworks, has been nose to the grindstone again, this time finally bringing a long-awaited pyrotechnically activated recovery system tether-and-release device to market, the Advanced Retention and Release Device. 

RATTWorks to release Advanced Retention Release Device

The device is designed to retain a portion of the recovery system inside of the airframe until an electronic event triggered by an altimeter, accelerometer or timer fires, releasing the remainder of the recovery system.  This system is typically used in recovery systems where dual deployment is accomplished all out of the same end of the airframe, rather than using separate drogue and main recovery compartments.

The market for similar products was controlled early on by Blacksky, with their ARRD device, and later one by Defy Gravity with their Tether devices, although both companies are currently out of business or production of their devices.  Griffith's device builds on the Blacksky concept, using a tapered stainless steel pintle pin retained by ball bearings which is released by a tapered cup-shaped piston fired pyrotechnically.

Although retail price is not known at press time, as Griffith just finished his production run of the Advanced Retention Release Device today, you should be able to find the information soon on his website.

Website: http://www.rattworks.net/

Reader comments:

#1 Re: Article: RATTWorks to release Advanced Retention Release Device

Way to go Dave!!!
I want one, (or a few).

Your products are always spectacular in quality and design. What a great asset to rocketry.
Tom

Tom Rouse on 08-13-2009 08:56 PM

#2 Re: Article: RATTWorks to release Advanced Retention Release Device

That is very compact. I wonder what the mass and jerk force ratings are? I flew Zinc-Sulfur rockets with Dave in about 1970-71 at MTA. HIS MACHINE SHOP IS AMAZING.

Jerry

Just Jerry on 08-13-2009 11:38 PM

#3 Re: Article: RATTWorks to release Advanced Retention Release Device

I have used both Blacksky and Defy Gravity tethers. Defy Gravity turned out to be much more reliable. The Blacksky tether was really tempermental and not very reliable. I hope RATTWorks has solved the design flaws that caused the problems.

Arnold Roquerre on 08-14-2009 12:54 AM

#4 Re: Article: RATTWorks to release Advanced Retention Release Device

The only problem with the Black-Sky ARD was some folks who used the device, did not take the time to completely clean the unit after each and every use. Any ball type release latch must be free of residue/foreign matter, or reliability will be inconsistent. The RattWorks unit will be no different. I can't wait to get my hands on one, (or two), as RattWorks hardware is "ALL" first class...

Fred

frederocket on 08-14-2009 08:22 AM

#5 Re: Article: RATTWorks to release Advanced Retention Release Device

What is the mass and what are the dimensions? How much load is it designed to withstand? Are there smaller ones planned?

Adrian A on 08-14-2009 08:46 AM

#6 Re: Article: RATTWorks to release Advanced Retention Release Device

Quote:

The only problem with the Black-Sky ARD was some folks who used the device, did not take the time to completely clean the unit after each and every use. Any ball type release latch must be free of residue/foreign matter, or reliability will be inconsistent. The RattWorks unit will be no different. I can't wait to get my hands on one, (or two), as RattWorks hardware is "ALL" first class...

Fred

The device also needed to be assembled in the proper sequence, which I don't think I ever saw written. Scott Bartel showed us how to properly assemble an ARRD, and when done correctly, could withstand a 400lb rocket having a high speed deployment with a 20' Rocketman Ballistic Drouge.

Great device, and we plan to pick up a handfull.

The old ARRD was appr. 1 1/4" in dia. and 1 3/4" in length. I assume the new one is real close in size.

Erik

MOD NOTE: I have attached a copy of Erik's assembly instructions for assembling an ARRD.

Porthos II on 08-14-2009 09:28 PM

#7 Re: Article: RATTWorks to release Advanced Retention Release Device

Quote:

The device also needed to be assembled in the proper sequence, which I don't think I ever saw written. Scott Bartel showed us how to properly assemble an ARRD, and when done correctly, could withstand a 400lb rocket having a high speed deployment with a 20' Rocketman Ballistic Drouge.

Great device, and we plan to pick up a handfull.

The old ARRD was appr. 1 1/4" in dia. and 1 3/4" in length. I assume the new one is real close in size.

Erik

Roger that on the assembly sequence. Are the RATTWork units, the special run you and I talked about @ LDRS or were you talking about a run of Scott's ARRD units?

Fred

frederocket on 08-15-2009 03:56 PM

#8 Re: Article: RATTWorks to release Advanced Retention Release Device

Actually, the device failed the first time it was used. I had purchased two. I loaned the other one out. It failed too. Two for two failures is a sign of a problem in design. A lot of people reported problems with the BlackSky unit. One weekend I had a friend over who was into serious body building and had been in special forces. He could break 1/8" kevlar braid with little effort. Everytime we assembled the ARD and had him jerk the line the ARD was attached to, it came apart. He had no such luck with the Defy Gravity unit, though he did manage to bend the clip. We never did fiqure out how he managed to do that! In short, the Defy Gravity ARD never failed. BlackSky made a killer deployment altimeter, but the ARD was not nearly as robust. I hope Defy Gravity has not shut down permanently, I was planning on buying some additional units.

Arnold Roquerre on 08-15-2009 08:27 PM

#9 Re: Article: RATTWorks to release Advanced Retention Release Device

I have attached a document Erik created on how to load an ARRD. Look up three posts.

ddmobley on 08-15-2009 08:35 PM

#10 Re: Article: RATTWorks to release Advanced Retention Release Device

Quote:

Actually, the device failed the first time it was used. I had purchased two. I loaned the other one out. It failed too. Two for two failures is a sign of a problem in design. A lot of people reported problems with the BlackSky unit. One weekend I had a friend over who was into serious body building and had been in special forces. He could break 1/8" kevlar braid with little effort. Everytime we assembled the ARD and had him jerk the line the ARD was attached to, it came apart. He had no such luck with the Defy Gravity unit, though he did manage to bend the clip. We never did fiqure out how he managed to do that! In short, the Defy Gravity ARD never failed. BlackSky made a killer deployment altimeter, but the ARD was not nearly as robust. I hope Defy Gravity has not shut down permanently, I was planning on buying some additional units.

We had three flights at LDRS this year with an ARRD. My sons L3, Porthos and the Sumo.

2 out of 3 were successful. My son assembled his ARRD, I put the ARRD together for Porthos, and a third party assembled the ARRD for the Sumo. The two we assembled worked flawlessly, and the one that I cannot attest to its assembly failed. Like I said, if not assembled correctly, they WILL NOT function correctly.

I am putting together assembly instructions for the ARRD and getting them to Darrell to post or publish. Let me know if you assembled the ARRD in the manner I recommend, and if you assemble it in this fashion, if you can get it to fail.

Erik

Porthos II on 08-15-2009 10:23 PM

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