Line Grabber updated video on YouTube

Hey,

If you saw my previous post from 2008 on the \"device\" that grabs/retrieves the throw-bag from a distance, you might want to see an updated and superior version of the design.



It works on the same principle as before. Super easy to make and much more practical. One of the main features is that it can be designed and constructed to accommodate about any diameter limb.

Cheers,

EB

Hi Elliott!

I've just made a simplified version, which seems to work very well. It uses nothing but a single coat hanger - see attached photo: I would call it the BLG-MJS



The line attachment works by threading a clove hitch onto each side of the 'u' shape at the climber end of the grabber. These hold the grabber in place and the distance between them (approx. 5\") combined with the tension in the line due to the weight of the throwbag is enough to raise the hook end of the grabber to the corect position. I have also increased the size of the hook and put a red marker flag on it to make it more visible from a distance.

Let me know what you think!

Michael[/color]

Wow, I like the simplicity of that. I might have to try it.

Here is an improved version on the BLG-MJS:



I have turned the rear line attachment point (the bight in the coathanger wire!) upside down from an 'n' to a 'u'. Only one clove hitch is required on the front attachment point - the line then simply runs through the rear 'u', stopping the device from tipping forward.

I have also put a hook on both sides of the grabber, making a large arrow shape so that it can grab a line from either side.

I recommend 14 oz throwbags or heavier.

Works a treat in the willows by my house!

Michael

Here's a photo of it:



Michael[/color]

This is the technique I've been using for a while now.

Advantages are:
1. You can jump the retrieval device over branches so a clear path is not required to set a traverse.
2. You can reliably grab the line on the blind side of the trunk
3. Minimal amount of gear required

I use a New Tribe grapnel and an 8 oz throwbag with 2.2 mm throwline.

Four illustrations showing the technique here

-moss

So the shot bag needs to be heavy enough to pull the grapple over to the branch while bouncing it over obstacles, yet light enough to not drop any further when you let the grapple swing down to the dangling position to grab the line. Does this ever fail to work if the target branch is either very smooth or very rough?

Michael

michaeljspraggon wrote:

So the shot bag needs to be heavy enough to pull the grapple over to the branch while bouncing it over obstacles, yet light enough to not drop any further when you let the grapple swing down to the dangling position to grab the line. Does this ever fail to work if the target branch is either very smooth or very rough?

Michael

There's a lot of leeway there, I haven't had any failure with variation in bark texture of limb friction. With a very high friction situation you can go to a 10oz bag. To move the bag down (whether there is an obstacle or not), just bounce the grapnel up slightly, its weight is now off the line, the bag moves down. So... the bag is always heavier than the grapnel and you bounce the grapnel up more or less depending on bark texture or limb diameter which can create more friction even on smooth bark. Better to have a lighter bag (8 oz) than a heavier bag because you don't want the bag to pull so hard that you can't set the grapnel position where you want it before you swing it to make the grab.
-moss

That makes perfect sense to me! Thanks.

Michael

Pretty cool to see all the different ways to grab a distantly thrown line. I like them all! One pro about the BLG that I had posted on YouTube: It works even when the toss is nearly straight up! The fact that the device \"clamps\" onto the line means that it can be directed anywhere that the line went. You don't have to make a second toss with a grapnel, etc. No worries of an upwardly thrown grapnel coming back down on top of you!

The improvement that I want to initiate in version 3.0 is some way to \"fold it up\" in a compact sort of way so that it can squeeze through the tightest \"holes\" in the canopy. Right now, the bottom half kind of dangles about 12-15\" below the line and can potentially get snagged on branches, etc. while in route to its ultimate destination. Any best guesses on how to \"unfold\" it? Maybe I need to talk to the NASA techs that dropped those bouncing robots onto Mars!

The problem is that every time to release the tension on the line to let the bag drop, pulling the device towards the branch, the weight of the hook makes it tip downward.

Perhaps the hook could be shaped so that it actually sits on top of the line until a tug on a second line attached to it pulls it off the line, allowing it to dangle so that it can catch the line. The same tugging action on ther second line could also allow the hook to be pulled to the side so that it can catch the dangling line, allowing for a much smaller hook (on one side only) to be used, which would reduce the chances of the hook getting snagged on the way back to you. I'll draw something up when I get the chance...

Michael

Alternatively you could make it remote control like the ill-fated Beagle II probe. If only Prof. Colin Pillinger climbed trees...

Here is a sketch of the sort of thing I was suggesting.



See how the device is bent into a yoke just before the hook. This sits on the line but can be pulled to the side so that it comes off the line by pulling on a second line attached to and arm coming out of the side of the unit which points sideways and backwards but NOT downwards. (This arm won't get snagged on the way back to the climber because it has the second line attached to it.)[/color]