MARD for the Infinity

[sundevil777 93]

The VSE Facebook page has some teasers with Kelly confirming it can’t be retrofitted to older rigs. 

[sundevil777 93]

It is officially available:

http://www.velocityrigs.com/about/news/mard-now-available/

I like how Kelly thinks in terms of what is important - how it works. I like that the design is significantly different than the skyhook in ways that are important.

I have never been comforted by statements from other MARD designers that mentioned how carefully the relative lengths of this vs that had to be fine-tuned, etc. I do not want such a mechanism to have needed to be fine-tuned!  That makes me think that the design is not tolerant of unknown conditions/variables, and too dependent on being assembled/rigged "just right". I am much happier with a design where the geometry isn't critical.

 

Edited March 16, 2020 by sundevil777

[voilsb 1]

It's been a few weeks now; has anyone gotten their hands on a mock up or a rig yet? Kelly mentioned in a facebook post that it's different from the RAX from 10 years ago. Has anyone played with both and can comment on the designs?

[JerryBaumchen 1,047]

34 minutes ago, voilsb said:

It's been a few weeks now; has anyone gotten their hands on a mock up or a rig yet? Kelly mentioned in a facebook post that it's different from the RAX from 10 years ago. Has anyone played with both and can comment on the designs?

Hi voilsb,

IMO the basic design/function remain the same.  Only the details of how it is configured differ.

Let's say you have a raw design of something.  You want your design detailed, functional & operational.  You give the raw design to two engineers, put each in a separate room.  You will get two different devices that both work just fine, yet slightly different.

Prior to all of this 'shelter in place,' Kelly and I were going to get together to take the necessary installation/packing photos for his new manual.  Now, time will tell.

Jerry Baumchen

[Binary93 65]

Aside from this one, the only "mechanical MARD" (as they call it) that doesn't allow for release once it begins extraction with the main, that I know of, is Mirage's Trap.

Are there any others on the market?

[mark 102]

2 hours ago, Binary93 said:

Aside from this one, the only "mechanical MARD" (as they call it) that doesn't allow for release once it begins extraction with the main, that I know of, is Mirage's Trap.

The Trap can release under circumstances similar to all the other non-Infinity MARDs.

[Binary93 65]

3 minutes ago, mark said:

The Trap can release under circumstances similar to all the other non-Infinity MARDs.

I was under impression that once the "trap" catches the bridle and pulls on it, because it's not slippery, it wouldn't release as easily even when it lost some of the tension (never seen it in person, maybe if you or anyone else who's seen/installed it could confirm this)? And if the main and the PC diverge in terms of position/angle, it will keep squeezing the bridle. Other MARDs as I understand them are much more sensitive to relative angle rather than force.

[mark 102]

2 hours ago, Binary93 said:

I was under impression that once the "trap" catches the bridle and pulls on it, because it's not slippery, it wouldn't release as easily even when it lost some of the tension (never seen it in person, maybe if you or anyone else who's seen/installed it could confirm this)? And if the main and the PC diverge in terms of position/angle, it will keep squeezing the bridle. Other MARDs as I understand them are much more sensitive to relative angle rather than force.

I can confirm that the Trap releases under circumstances similar to all the other non-Infinity MARDs, especially folding-bridle MARDS like Boost and Ace.

[KellyF 16]

On 6/23/2020 at 4:18 PM, mark said:

I can confirm that the Trap releases under circumstances similar to all the other non-Infinity MARDs, especially folding-bridle MARDS like Boost and Ace.

Mark, I was looking over your shoulder at the Symposium at one point, and saw a still shot from, I assume a test jump, where the MARD (not sure who's) released prematurely. It looked pretty nasty. Almost like the reserve bag got ejected out of the container at the same time as the reserve PC.

I wanted to produce a device that I had as much confidence in as the snap shackle that's the first link in the chain. When you think about it, our main deployments rely on the pilot chute being able to pull the pin to initiate the deployment, and then finish it- there's no need for second PC inside the container to take over the deployment once the PC has pulled the pin.

In testing, we found the same to be true with the Infinity MARD- if there's a horseshoe malfunction (for example) where the main is still in the bag, it doesn't create enough drag to open the riser covers, or separate the risers from the harness rings (even if the riser covers are open), let alone pull the reserve pin. So if the jumper cuts away the main, and pulls the reserve (standard EP's), the reserve bridle will disconnect from the Infinity MARD before the risers and RSL can lock the MARD to the bridle. So, from our testing, it appears as though the concept that the MARD needs to be able to "change it's mind" mid deployment isn't accurate.

Maybe there's some fringe entaglement/malfunction scenario where an aerodynamic MARD would be beneficial, but since you're starting with an entanglement already, nothing can really be predicted.