Trying to design a fall arrest system

dtuuri

dtuuri

Final Approach
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dtuuri
To practice some footwork on roller skates in my garage. Anybody know how much sand bags would have to weigh to balance my 150# (nominal) body:
Fall arrest system.jpg​

:confused:

dtuuri
 
That is not a fall arrest system. That is a force balance system. Practicing with it will do no good.
 
Clark1961 said:
That is not a fall arrest system. That is a force balance system. Practicing with it will do no good.
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What's a "force balance system"? I'm a roller skater, don't understand engineering. :redface:

dtuuri
 
GlennAB1 said:
You want to research pulley mechanical advantage? Google.

https://www.google.com/search?q=pul...X&ved=0ahUKEwjdlPeqsJTKAhVU4GMKHTwBCv0Q7AkIMA
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The problem is being able to practice 3-turns, pigeon-toes, spins and mohawks without breaking my 68 year-old bones. That means having an arrest system that's real light-weight, follows me fore and aft and left and right too. It needs to fit in a two-car garage and work either with the door up or down without hitting the rails or motor mechanism. It can't pull the walls in or ceiling down on top of me when I fall either. Got any ideas? :dunno:

Oh yeah, it can't have to attach to either of the two windows on one side or the man-door entry on the other.

dtuuri
 
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You need an overhead support, cable system, fall arrest lanyard, and harness.

Fore and aft or left and right are no big deal, doing both is.
 
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Inflatable Sumo Wrestler suit - forty bucks. Wear a helmet too.
 
GlennAB1 said:
If you are only going a couple feet left or right a single fore and aft overhead cable should work with a fall arrester like this attached to your harness: http://www.globestock.co.uk/products/fall-arrest-blocks/g-stop-fall-arrester-7-metre-cable/

It should keep you from smacking the concrete.
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Good idea, but those usually take some distance to get stopped. They state the stopping distance is 2m+the height of the user. IMO you just need something that will abruptly stop you since your a few feet off the ground.
 

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Wouldn't it be easier to not do this and go back to your porch rocking chair? :D

Nah, go for it! Have fun! Can't help though.

David
 
GlennAB1 said:
If you are only going a couple feet left or right a single fore and aft overhead cable should work with a fall arrester like this attached to your harness: http://www.globestock.co.uk/products/fall-arrest-blocks/g-stop-fall-arrester-7-metre-cable/

It should keep you from smacking the concrete.
Click to expand...

Nope, not gonna work. Too expensive and not enough radius of action. I was thinking of stretching aircraft cables across, span-wise, say on three or four feet centers and placing a light pipe, like PVC, perpendicular across the cables and on top them. Hanging below from the pipe, a length of UniStrut with a trolly. That way I could glide fore and aft with little resistance to my harness and laterally too, assuming the pipe/UniStrut assembly is light-weight enough to slide on the cables without much drag/inertia. That would give me a gantry-like apparatus, but the tension on the wall studs anchoring the cables has me concerned. That's what got me thinking about pulleys to share the load with another anchor, say, on the truss members. Then I ran across the "fools tackle" in the first post, something that's impossible to build, but can be drawn. So I got the idea to ask the forum. :) The trouble is, there's always an obstacle: Drywall hides the studs, the roof trusses go the wrong way, windows and doors are where I want to anchor the cables, etc.

dtuuri
 
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Silvaire said:
Inflatable Sumo Wrestler suit - forty bucks. Wear a helmet too.
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Ha, ha! LOL! I can see myself now: lying on my back like a great American Dog Tick, kicking my arms and legs and hollerin' for the widow up the street to come flip me over. She prolly calls 911 and the beat reporter follows the rescue squad to my garage. Why, there'd be color photos in the second edition before everybody stopped laughing long enough to flip me over so I could go to the bathroom. Not gonna do it.

I might use this as a, um, fallback solution though.

dtuuri
 
When I learned to roller skate I had armored gloves for my wrist and palm and padding on my knees. Broke nothing more than my ego. Big parking lots are ideal, and quit bitching about the weather. I walked 3 miles into work this morning.
 
Capt. Geoffrey Thorpe said:
You can build it. But the one block will just end up jammed against the top.
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I don't think so. The whole thing will fall down when you let go of the parts.

steingar said:
When I learned to roller skate I had armored gloves for my wrist and palm and padding on my knees. Broke nothing more than my ego. Big parking lots are ideal, and quit bitching about the weather. I walked 3 miles into work this morning.
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Heh, you didn't skate to work?

bflynn said:
Airbags?

http://www.gizmag.com/wearable-airbag-hip-protection/35594/
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That's for the elderly. Besides, after it goes off--you still hit the ground: "When the wearer hits the ground, the bag reduces impact force to the hip bones by a claimed 90 percent." I want to stay vertical even after I trip.

dtuuri
 
Check out the footwork in this video, speakers on of course. Those are the kind of steps I want to perfect before trying them in public.

dtuuri
 
dtuuri said:
Heh, you didn't skate to work?
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Did a couple times. I wasn't thrilled with my own abilities, and thought mixing it up with cars a bit too dangerous.

That, and I did manage to gink my elbow hard enough that it didn't work right for 6 months. Big parking lots on Sunday morning, when everyone is in supplication to the invisible man in the sky. Broken sidewalks downhill aren't anywhere near so good.
 
steingar said:
Did a couple times. I wasn't thrilled with my own abilities, and thought mixing it up with cars a bit too dangerous.

That, and I did manage to gink my elbow hard enough that it didn't work right for 6 months. Big parking lots on Sunday morning, when everyone is in supplication to the invisible man in the sky. Broken sidewalks downhill aren't anywhere near so good.
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Take it to a rink. One with good organ music and no rug rats. A place with some ladies who can do the circle waltz. Trust me on this.

dtuuri
 
just get Life Alert....you know you're gonna need it.
tumblr_lpoqltvVwF1qf6o78.gif
 
dtuuri said:
Take it to a rink. One with good organ music and no rug rats. A place with some ladies who can do the circle waltz. Trust me on this.

dtuuri
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Probably a good idea, but I just did the local sidewalks, which are free for their use and considerably more convenient. I put the rollerblades down when I started walking in. Wouldn't mind picking them up again, I always thought that was a fun activity.
 
steingar said:
Probably a good idea, but I just did the local sidewalks, which are free for their use and considerably more convenient. I put the rollerblades down when I started walking in. Wouldn't mind picking them up again, I always thought that was a fun activity.
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No! Quads are what you want. We have one lady on blades and I have to give her a wide berth for fear she'll knock me down with those things. Here's another vid--of me just learning how to do the flea hop. Don't mind the date, it's wrong. I started skating (the first time) in 1975 and this was a month or so afterwards. I'm at 2:50 1:50 into the reel being towed around by a girl I hadn't seen before nor since: https://www.youtube.com/watch?v=OocRAAaUifQ

When I stumbled onto this a couple years ago I got back at it after 35 years. :)

dtuuri
 
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Dave, would fabbing something around an automotive seat belt work? Especially one with an inertial lock?

Put a swivel on the carabiner that attaches to your harness (so you can do your spins). Then the belt reel on some sort of overhead track system that permits you to move about the garage.

You can get a sat belt from a local pick-n-pull for less than $40


(PS. This sort of thread really shows off that Henning is absent. He'd have 8 different opinions and 3 different designs in less than 5 posts.)
 
steingar said:
When I learned to roller skate I had armored gloves for my wrist and palm and padding on my knees. Broke nothing more than my ego. Big parking lots are ideal, and quit bitching about the weather. I walked 3 miles into work this morning.
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Record your lectures, teach from home. LOL My OSU accounting course was pretty much like that. Felt ripped off.

David
 
AggieMike88 said:
Dave, would fabbing something around an automotive seat belt work? Especially one with an inertial lock?
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No, I don't like that idea. It was one of the first ones that came to mind, but I really want something that already takes up nearly all the slack or even takes some weight off the feet until the turns are mastered. Any miscue would immediately be caught. Keep those thoughts coming though, you might want one yourself.

steingar said:
Blades are faster.
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You want to go slow enough to talk to the ladies and dance with them without knocking 'em down. Quads are plenty fast enough when you fall down trying to turn around in time with the music. I know. :redface:

steingar said:
Weren't you the handsome devil.
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Well dressed too. I wore a tie! I remember that night well. Nobody did that even though there was a dress code back then: girls wore skating skirts (smart owners) and guys couldn't wear blue jeans. I wanted to make a good impression on those people, since I just paid some fireman $35 for his old skates, which made skating a weekly commitment on my salary as a copilot. And the girl--I remember her. And the camera guy--only time I ever saw a camera at the rink. The girl grabbed my wrist and said, "Let's do this!" Before I could tell her I'm not checked out yet, we're flying past the guy holding the camera and I was silently praying to "the invisible guy in the sky" to not let me fall in front of it.

dtuuri
 
Consider visiting the local theatre groups. Especially the ones that have experience "flying" a performer. Connecting with the right rigging person might help you refine your idea and provide sources for products to fab it together.

And if they ever do a production of Starlight Express, you might get an audition.
 
AggieMike88 said:
Consider visiting the local theatre groups. Especially the ones that have experience "flying" a performer. Connecting with the right rigging person might help you refine your idea and provide sources for products to fab it together.

And if they ever do a production of Starlight Express, you might get an audition.
Click to expand...

Hmm, good idea about a theater person.

"Starlight Express"? Years ago they did a film called Xanadu which was about roller skating. The critics called it Xanadon't. :rofl:

dtuuri
 
what if it's "couples skate, couples only"...then you'd need a double arrest system.
 
So if you build this, get arrested, do you need to report the incident at your next medical?
 
Hire two college kids to stand next to you and make sure you don't fall.

As for the fall arrest, it's a good idea only if you're homeless and need a place to stay for the winter. A brick though the window of a police station will usually get you room and board until the spring thaw.

Rich
 
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