High-G Auto Cutaway Mechanism

[hufggfg 0]

With the idea of the water ski system, if the centre of spin was the board, i'm sure it would work perfectly, as your weight will pull you off, however if the centre of spin was your hips for instance, the only mass producing g-force is that of the board, which will be MUCH less. Another problem is that the drag this board will create will be quite high, so to stop it just coming off in the wind you will have to set the force on the bindings pretty high, so then if the board needed to release in some direction where the wind was not also creating drag (sideways for instance) the amount of spin to create the correct amount of g-force for detachment would surely be well above that which would kill you anyway. Did that make any sense?

I'm not saying that i don't think it will work at all, but you need to think really carefully about how the experience in the air is different from that on the ground.

[rsibbald 0]

I understand what you're saying.....

hmmmm

OK, how about a kill-lined drogue chute attached to the bottom of the board..... no bridle, so it can't wrap around to the front of the board.....
the kill line goes through the board and up the inside of the jumps suit in a hard housing to the left hand of the user. the user has to keep tension on the kill line, which should be fairly easy. In case they fall unconscious or lose control, the kill line will be released and the drogue will deploy, pulling pins on a dual 3-ring cutaway.

[rsibbald 0]

In fact, the drogue doesn't even have to be on the bottom of the board, it can be mounted anywhere it won't wrap around anything and it can pull cutaway cables at almost any angle.......

[hufggfg 0]

yeah i like that idea, how about making kind of like a pop-top underneath the board, then you don't have to have anything flapping, can use a bridle, and just run the line up through a hole in the board and then up some hard housing up your leg, the as soon as you drop the "cut away handle" the drogue will fall of the bottom of the board, catch the air and release the system. With a bit of technical jiggery pokery i'm sure it can be rigged so you only need 1 drogue which will by used to activate the system, and then bring it down saftly. Thoughts?

[mr2mk1g 10]

you thinking of a kind of ROL set up where the bridle first pulls a teflon cable from a three ring circus before actually suspending the board during it's solo decent.

Problems to think about - preventing a premi - velcro down the length of your leg to hold that bridle like on a ROL rig????

What are you going to do if you find the "board" (or whatever you're using) has not attached (edit) detached and you end up having to deploy past the fricking mess??

Keep it simple man. If you can't keep it simple be willing to walk away from the project until you can. Get video.

[rsibbald 0]

Sounds like it would look better, but may add extra complexity and Darwin factors to the system..........

I like the thought of using a pop-top spring though.

Dual redundant drogues, already exposed to the airflow like a collapsed PC on a HP canopy, hardly producing any drag.... but lightly spring loaded on the apex so that inflation will be instant when the kill line is released...

[rsibbald 0]

If the board has detached fully, that greatly reduces the risk.

If the board has detached partially, a separate set of procedures will need to be carried out prior to deployment. This will be hard to do in an out of control situation.

If the board is still fully attached and will not release, then separate procedures will need to be performed before deployment, but this should not be as dangerous as if the board is partially detached.

[rsibbald 0]

less of the ROL and less of the velcro....

Take one PC, mount it on the side of the board, spring load it so it will bounce off the board when needed. Tie a cord to the apex of the PC and feed this through the board and a hard housing all the way up to the arm of the user. When the user lets go of the cord, the spring fires the PC off the board, which will then initiate a pin based cutaway on both leg moutns.

[mr2mk1g 10]

I think you'd be better off with a simple sping loaded reserve pc that's held compressed by a pin just like a reserve. then all you have to do is pull the ripcord. Holding a bit of string tight so it doesn't let the spring fire is impractical and down right dangerous during climbout.

I'm thinking though that if you're pulling the ripcord you might as well pull the cutaway cable yourself too. Relying on a pc to cut me away isn't a nice idea - just do it yourself and eleminate the risk of not getting cutway cos the pc hangs up/malfunctions in some way.

Still... none of that really solves your auto cutaway problem.

[rsibbald 0]

climbout?

That implies the use of an aircraft

I think you're right, I might just decide to stick with a manual cutaway, along with a manual redundant backup and suck it up if it starts to spin.......

[PhreeZone 15]

I think if you define the problem better, more solutions can be tossed to you. Just about every object under the sun I think has been jumped at some time. Most have been skysurfed too. Troy Hartman surfed a tire on its rim, jetskis have been taken out, same with BMX bikes, kayaks and roller blades.

If you describe what you are wanting to do there is a good bet we could point you to someone who has tried something extremely similar in the past for their input.

Yesterday is history
And tomorrow is a mystery

Parachutemanuals.com

[cobaltdan 0]

i didnt read the entire thread so i appologize if any of this is redundant.

we have developed a "dead man" cutaway system for jumping sub-40 sq' canopies. steve curtis in elloy also has a promising design.

contact for more details.

sincerely,

dan<><>
www.atairaerospace.com
www.atairaerodynamics.com

Daniel Preston <><>
atairaerodynamics.com (sport)
atairaerospace.com (military)

[JohnGraham 0]

You seem to like the drogue idea, but as soon as you attatch that to something it'll behave differently, and you'll have to learn to use it. Unless you're not exposing it to air at high speed - and then is there much point?

Quote

That implies the use of an aircraft

Don't get a head of yourself, man...

If you just wanna snow-board off the edge of a cliff, I'm sure you can get plenty of video of it being done to help you out, and lots of advice on how to do it from those who have...

[Erroll 49]

Quote

Bill - I hate to be the one to point out a design flaw in one of your great ideas - but if you were using a Pucker Factor AAD and went to the curry house the night before, you might be at risk of a premature reserve deployment the next day

On the other hand, the PF AAD will put a very quick stop to farting in the aircraft!

[billbooth 10]

Good idea! I'm re-naming it the anti-fart, pucker factor AAD. A great design always has unseen fringe benefits.

[j3zz 0]

Ok I am no designer but this could work

If you are talking about a board.

Mount a reserve pc spring(only the spring) mount it so the narrow part would be furthest from the board when extended.

Make a 2 holes in the board one which is aligned to the center of the spring, attach teflon cutaway cables to the apex of the spring along with a closing loop.

Attach a long piece of hardhousing to the board probably with the eye located over the centred hole. now fashion a long reserve ripcord with a pin on one end. Run the housing up the leg, side and down the arm. Attach a pair of pliers(or something) which are spring loaded to open when released, link a hand grenade tricker. SO that when is is released it pulls the reserve ricord which then activates the spring which pulls this cutaway.

The need for the spring etc is to allow a long cutaway stoke.

Route the teflon cables through the offsett hole. Ensure the edges of this whole are curved inwards so as to allow easy estraction of the cutaway cables.

This is fairly poorly explained but I am sure you get the picture, configured correctly the spring in the hand unit should not have to exceed a push force of 20LBS to esure that the reserve pin is extracted.

one thing is to make sure the reserve pin is located in such away not to lock up. ie do not just have the closing loop coming though say soft wood as the pin would get longed in the wood which will make a bad day.

Where are you going to perform this stunt I have a camera and could come along and take some photo's if its anywhere near by

Jezz

"Now I know why the birds fly"
Hinton Skydivers

[rsibbald 0]

Cheers for the ideas guys, I'll probably end up doing it in Europe somewhere, although the design and construction will probably take several months and a sponsor would help. I'll let you know when it's happening

[DOA 0]

now being a newbie I have no idea how all the various bits attach to the canopy etc. But my 1st though was that if you're spinning at high g there is ample scope for using some sort of centrifugal force type device? If i can explain it well enough !

Imagine those types of scales u use to weigh fish with (fish on one end, u hold the other, big spring with an indicator slides down?)

Now I'm think of a crude type device attached to the body or leg. As u spin the the sping extends (as if a fish is in the load end)more and more as force increases to a point where it makes an electrical contact that fires the reserve?

well I did say I'd explain as best I could ;-)

Phil.

-------------------------------------
When I learn new stuff, it pushes the old stuff out of my brain!

[AndyMan 7]

Quote

Now I'm think of a crude type device attached to the body or leg. As u spin the the sping extends (as if a fish is in the load end)more and more as force increases to a point where it makes an electrical contact that fires the reserve?

well I did say I'd explain as best I could ;-)

Yup! Perfectly simple.

Now figure out how to stop that system from activating on a hard opening!

_Am

__

You put the fun in "funnel" - craichead.

[billbooth 10]

The best automatic high "G" cutaway system is the human brain. Try using it to avoid the situation in the first place.

[flighty 0]

Maybe the best would be a radio operated release that an observer could trigger in case you get knocked out on exit or whatever.that would use a human brain that wasn't in danger of not being able to do the job.

~Cindy~
Quantum materiae materietur marmota monax si marmota monax materiam possit materiari?
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