Autobelay Rope Treadmill

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Re: Autobelay Rope Treadmill

Postby lefalaf » May 14, 2012 10:30 pm

lefalaf wrote:
cavedoc wrote:Since this is "No hands" then it could work for any climbing system?

I am hoping so, but I haven't tried anything but the ropewalker with it yet. I'm planning to give some others a shot and it will be fun to test. :grin: I'll shoot some video to share and take some photos as I go about it. Stay tuned...

I tried the frog tonight with mixed results.

Had a few problems, which may have skewed my results:
- I don't have a frogging harness, so my technique is less than optimal.
- I'm not that good at frog in general.
- I'm never that far from the ground with this setup, so constantly self-starting is a pain.

I did have a few ok cycles through the motion, to see that this might be plausible for the frog. Due to the sit stand nature, the autobelaying gives the climber more of a start/stop feel rather than a steady belay like with the ropewalker. As you stand, you are belayed down. While raising the upper ascender, you do not move. I am not sure if this is prohibitive or not - really depends on the climber, but I couldn't get past the frustration of needing to self start with every cycle, so I gave up.

I tried tying the tethers both to the upper ascender as an alternative, but that seemed worse.
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Re: Autobelay Rope Treadmill

Postby chh » May 15, 2012 6:38 pm

So my question is, in your diagram, do you run the "blue" rope up to the ceiling, then to the floor, and then to your knot just to keep things more smooth or to limit the amount of weight you need on the floor?
It seems to me that you could do away completely with this whole section of rope and just have a fixed distance tether to the knot on the belay line from the weight on the floor. Your "puke green" line still runs from your harness to the floor and then up to the to the PMP above the knot. If your rack is dialed right why do you need the "blue" line to run all that way?
Your words of caution are no match for my disaster style!
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Re: Autobelay Rope Treadmill

Postby snoboy » May 15, 2012 6:57 pm

My understanding is that the blue rope causes the system to stop feeding rope when you climb. You would weight it a little, and that would pull on the friction knot, stopping the rope from feeding into the rack. Acts like a backup prusik on rappel.
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Re: Autobelay Rope Treadmill

Postby chh » May 15, 2012 8:17 pm

snoboy wrote:My understanding is that the blue rope causes the system to stop feeding rope when you climb. You would weight it a little, and that would pull on the friction knot, stopping the rope from feeding into the rack. Acts like a backup prusik on rappel.


I get that, but I think that with a hitch that has been set properly, it would lock on it's own by virtue of the rope travelling through it. That's my point, it functions exactly like a rappell backup or a self belay. All you really need is something to release the hitch by pushing it down and then stop pushing when you want to stop.
As you travel up, the PMP above the hitch pulls down on the hitch. The hitch releases. You descend, until there is no more pressure on the hitch from the PMP. The hitch would have to push the additional weight of the PMP and dangling cord up the rope as well, which is perhaps why the blue rope must be set up the way it is, I just wondered if it would work without the blue rope travelling in a "z" fashion. It's my editorial urge. I'm always trying to prune unneccessary stuff away;) But it may very well be necessary to do this, I don't know. I might try it this week if I get a chance. Perhaps lefalaf went through this permutation on the way to his current setup and can tell us why this doesn't work?
Your words of caution are no match for my disaster style!
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Re: Autobelay Rope Treadmill

Postby lefalaf » May 15, 2012 9:31 pm

chh wrote:
snoboy wrote:My understanding is that the blue rope causes the system to stop feeding rope when you climb. You would weight it a little, and that would pull on the friction knot, stopping the rope from feeding into the rack. Acts like a backup prusik on rappel.


I get that, but I think that with a hitch that has been set properly, it would lock on it's own by virtue of the rope travelling through it. That's my point, it functions exactly like a rappell backup or a self belay. All you really need is something to release the hitch by pushing it down and then stop pushing when you want to stop.
As you travel up, the PMP above the hitch pulls down on the hitch. The hitch releases. You descend, until there is no more pressure on the hitch from the PMP. The hitch would have to push the additional weight of the PMP and dangling cord up the rope as well, which is perhaps why the blue rope must be set up the way it is, I just wondered if it would work without the blue rope travelling in a "z" fashion. It's my editorial urge. I'm always trying to prune unneccessary stuff away;) But it may very well be necessary to do this, I don't know. I might try it this week if I get a chance. Perhaps lefalaf went through this permutation on the way to his current setup and can tell us why this doesn't work?

Yep - the blue cord is simply for the autostop. It really serves no other function. The rack *should* be able to take care of all other friction the system needs.

The Z arrangement is simply to translate the down pull of my body into a down pull on the knot which is at the same level as the climber.

I like your idea to try it simply tethered to a floor anchor. :kewl: That seems plausible to me and I love the simplicity, so I will definitely try that out. I don't think I'll have time for a week or two, so go to it and let us know!
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Re: Autobelay Rope Treadmill

Postby Carl Amundson » May 16, 2012 10:30 am

Great stuff, thanks for posting the pics and diagram
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Re: Autobelay Rope Treadmill

Postby Radiolocation » May 16, 2012 9:15 pm

I am new to Cavechat, but started caving when manila rope and prusik knots were all the rage.
This spring I created my own version of an auto-belaying rope treadmill. It was easy to build, and works so well, that I thought I would share. I will try to add images.
My goals were:
1) Completely automatic belaying. The caver starts climbing as usual but stays halfway between floor and ceiling.
2) Completely non-critical. It has the ability to handle any weight from child to overweight adult, any climbing speed or technique, etc with no adjustments required.
3) Works either with a normal single long rope (which I use) or with a loop.
4) The climber lowers himself to the ground at any time by pulling on a bungee attached to his belt.
5) There is no rack at the ceiling, so the rope can be reset in just a minute (I store it on a garden hose reel with a hand crank).
6) Easy to build, and easy to re-configure during setup.
7) There is no tension on the bottom, on purpose, to force me to use proper climbing technique. My Frog self-feeds anyway when I am 3-4 ft off the floor, if I am climbing correctly.
8) The secret to smooth operation is the very stretchy 1/8" bungee, which is high quality from a caver supplier and has more than a 2:1 stretch ratio. It stretches several feet before the rope starts to slip.

I have 14 feet to the rafters of a big garage. After experimenting, for the smoothest operation, I ended up with the climber supported by a rescue pulley. The rope is then led several feet horizontally along the ceiling to a steel biner, then down near floor level to a micro rack with only a single pivoting bar engaged. The rope only touches 2 bars. This leaves considerable braking force for the Auto Belayer, which is what makes the system so non-critical. There are three pieces of aluminum tubing that act as brake bars screwed into notches in the wood. The hinge attachment is the only critical thing. The gap is set to squeeze the rope tightly just before the long pivoting board becomes horizontal. The leverage multiplication factor is huge. A long piece of extremely stretchy bungee cord attaches to the climber's belt and gradually pulls on the board until the rope starts slipping. The climber stays within a 1-2 ft height. In a test, the Auto Belayer can hold my body weight (and operate) without using the rack at all, so it is plenty strong enough. I expected to have to add weight to the board, but none was needed.
So far I have done a number of 200 ft frog climbs with no problems, using my retired 300 ft bluewater rope.
[http://Radiolocation.tripod.com/AutoBelayerAnnotated.jpg][/img]
[http://Radiolocation.tripod.com/BelayerOpenedAnnotated.jpg][/img]
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Re: Autobelay Rope Treadmill

Postby lefalaf » May 16, 2012 10:31 pm

Radiolocation wrote:I am new to Cavechat, but started caving when manila rope and prusik knots were all the rage.
This spring I created my own version of an auto-belaying rope treadmill. It was easy to build, and works so well, that I thought I would share. I will try to add images.
My goals were:
1) Completely automatic belaying. The caver starts climbing as usual but stays halfway between floor and ceiling.
2) Completely non-critical. It has the ability to handle any weight from child to overweight adult, any climbing speed or technique, etc with no adjustments required.
3) Works either with a normal single long rope (which I use) or with a loop.
4) The climber lowers himself to the ground at any time by pulling on a bungee attached to his belt.
5) There is no rack at the ceiling, so the rope can be reset in just a minute (I store it on a garden hose reel with a hand crank).
6) Easy to build, and easy to re-configure during setup.
7) There is no tension on the bottom, on purpose, to force me to use proper climbing technique. My Frog self-feeds anyway when I am 3-4 ft off the floor, if I am climbing correctly.
8) The secret to smooth operation is the very stretchy 1/8" bungee, which is high quality from a caver supplier and has more than a 2:1 stretch ratio. It stretches several feet before the rope starts to slip.

I have 14 feet to the rafters of a big garage. After experimenting, for the smoothest operation, I ended up with the climber supported by a rescue pulley. The rope is then led several feet horizontally along the ceiling to a steel biner, then down near floor level to a micro rack with only a single pivoting bar engaged. The rope only touches 2 bars. This leaves considerable braking force for the Auto Belayer, which is what makes the system so non-critical. There are three pieces of aluminum tubing that act as brake bars screwed into notches in the wood. The hinge attachment is the only critical thing. The gap is set to squeeze the rope tightly just before the long pivoting board becomes horizontal. The leverage multiplication factor is huge. A long piece of extremely stretchy bungee cord attaches to the climber's belt and gradually pulls on the board until the rope starts slipping. The climber stays within a 1-2 ft height. In a test, the Auto Belayer can hold my body weight (and operate) without using the rack at all, so it is plenty strong enough. I expected to have to add weight to the board, but none was needed.
So far I have done a number of 200 ft frog climbs with no problems, using my retired 300 ft bluewater rope.
[http://Radiolocation.tripod.com/AutoBelayerAnnotated.jpg][/img]
[http://Radiolocation.tripod.com/BelayerOpenedAnnotated.jpg][/img]

Very interesting. I would be curious to see a video of it in action if you are able to do that. Or maybe photos of the rest of the setup.

Do you stay in a single fixed place (more or less), or does it pay it out rope in chunks?
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Re: Autobelay Rope Treadmill

Postby Radiolocation » May 17, 2012 9:46 am

I stay in place within about a foot, more or less, unless I start swinging sideways, which results in jerky drops of a couple of feet. I think this is pretty good for sit-stand. The bungee cord also prevents rotation, which lets me keep an eye on the reel and see the distance marks on the rope.
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Re: Autobelay Rope Treadmill

Postby lefalaf » May 25, 2012 12:37 am

lefalaf wrote:
chh wrote:
snoboy wrote:My understanding is that the blue rope causes the system to stop feeding rope when you climb. You would weight it a little, and that would pull on the friction knot, stopping the rope from feeding into the rack. Acts like a backup prusik on rappel.


I get that, but I think that with a hitch that has been set properly, it would lock on it's own by virtue of the rope travelling through it. That's my point, it functions exactly like a rappell backup or a self belay. All you really need is something to release the hitch by pushing it down and then stop pushing when you want to stop.
As you travel up, the PMP above the hitch pulls down on the hitch. The hitch releases. You descend, until there is no more pressure on the hitch from the PMP. The hitch would have to push the additional weight of the PMP and dangling cord up the rope as well, which is perhaps why the blue rope must be set up the way it is, I just wondered if it would work without the blue rope travelling in a "z" fashion. It's my editorial urge. I'm always trying to prune unneccessary stuff away;) But it may very well be necessary to do this, I don't know. I might try it this week if I get a chance. Perhaps lefalaf went through this permutation on the way to his current setup and can tell us why this doesn't work?

Yep - the blue cord is simply for the autostop. It really serves no other function. The rack *should* be able to take care of all other friction the system needs.

The Z arrangement is simply to translate the down pull of my body into a down pull on the knot which is at the same level as the climber.

I like your idea to try it simply tethered to a floor anchor. :kewl: That seems plausible to me and I love the simplicity, so I will definitely try that out. I don't think I'll have time for a week or two, so go to it and let us know!

Well, I tried it w/o the Z (upper tether) and instead had that tether anchored to the floor. In my limited testing, it was, well :down:.

What happened, as far as I could tell, was that with this variation, the friction knot was constantly pulled tightly and resulted in jerky belaying due to the other tether having more trouble releasing the friction knot. Whereas with the Z tether, the tension on the friction knot varies, allowing the other tether to release it more easily. It seems that they need to work in conjunction for it to work smoothly.

I tried different numbers of wraps on both the klem and FW to no avail, I also tried differing (tighter) lengths of the other tether to give it more force, but still no dice. That's not to say that there isn't an adjustment that might work for that variation on the system, but I couldn't find it. I like the simplicity it would add, and wanted it to work, but it just wasn't happening. Should anyone try that variation - especially if better results - do share your experience. For now I'm going back to the Z.

With the original system (w/the Z tether), the system self adjusts (in my testing at least) and I find it keeps you in a smooth equilibrium. With the variation, it was sending me up and down a foot or two at times which killed my efficiency.

The only things to know with the original system:
1) the Z/upper tether should be about the length to make a continuous loop from ceiling to floor if it were tied;
2) and the bottom tether can be any length - at 1x the distance from ceiling to floor, the system will belay you in the middle of the height; at less than 1x, then you will be belayed at less than half the height; and at greater than 1x, you will be belayed at a point above half the height of the system.

Always open to more ideas.

Happy Climbing,
Jon
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Re: Autobelay Rope Treadmill

Postby Arlen » Jan 9, 2013 5:27 am

Hi lefalaf,
Never heard about autobelay rope treadmill and new information for me so thanks for sharing with others also. Great physical activity to increase stamina, boost strength, burn body fat and to get in shape again. Bookmarked the link to share with others also so keep keep sharing.
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