Learning rigging

[AHPP]

11 minutes ago, kram said:

Or the adjustment could be built in and automatic, theres a few ways to do that

 

Go on? 

[kram]

1 hour ago, AHPP said:

 

Just to be clear, are you saying that EUR1300 for the DaWinchi (red thing with the turny bit) is expensive?

 

I dont know what bullshittery is required under EU rules for testing, rating and bringing a rigging product to market, but I see it as a fixed cost whether its a solid basic bollard or a fancy winch combo thing, and there are much, far cheaper bollards of higher capacity.

 

The lowering functionality is a plain bollard with a ratchet strap to the tree. The winching is a rotating bollard with a ratchet wheel and bearing. Its a very simple steel fabricated device. Steel is not great for your rope.

 

Could be improved by welding on a fairlead for the rope to exit when its in use as a winch, so that theres no need to tie it off and reset it every few feet.

If the rotating drum had a gear reduction, hidden in the base, you could have a massive mechanical advantage for a drill powered winch. Neither suggestion would add much to the price.

 

 

Edited 2 hours ago by kram

[openspaceman]

31 minutes ago, sime42 said:

Fire escape I reckon. 

 

Why the 8 wraps and 2kgs though OSM?

 

 

I reckon the 2kg would be enough to tension the wire on a capstan. With an 8mm diameter semicircular thread machined in the capstan and a fairlead to keep the wire in the groove. Drop the tail to the ground and then launch off on the active part of the rope. Once on the deck unclip and the next person clips on.

[AHPP]

20 minutes ago, kram said:

 

I dont know what bullshittery is required under EU rules for testing, rating and bringing a rigging product to market, but I see it as a fixed cost whether its a solid basic bollard or a fancy winch combo thing, and there are much, far cheaper bollards of higher capacity.

 

The lowering functionality is a plain bollard with a ratchet strap to the tree. The winching is a rotating bollard with a ratchet wheel and bearing. Its a very simple steel fabricated device. Steel is not great for your rope.

 

It perhaps could be improved by welding on a fairlead for the rope to exit when its in use as a winch, so that theres no need to tie it off and reset it every few feet.

If the rotating drum had a gear reduction, hidden in the base, you could have a massive mechanical advantage for a drill powered winch. Neither suggestion would add much to the price.

 

 

 

The DaWinchi is supposedly silent btw so they've probably used something cleverer than a ratchet. Maybe something tapered?

 

Now dearest kram,

You clearly have some imagination, mechanical experience, design intuition etc but once again I counsel and beseech you to consider what you might not know. I promise you, that to people who do know about tree rigging stuff, you come over as an absolute, weapons-grade walloper. I am genuinely interested to hear your perspective as effectively an outsider (not meant as an insult, you just don't know anything about tree rigging) but for the love of god stop writing as though you're the only one here with a brain cell, wondering how the rest of us got our feet down the correct trouser legs this morning.

 

Exit fairlead so you don't have to cleat and reset - that's a Hobbs.

Gears inside a drum - that's a GRCS.

The winch for a GRCS is £2600.

 

 

[AHPP]

And a lot of us have miraculously survived using ropes that touch things made of steel.

[kram]

2 hours ago, AHPP said:

There was a firm at the 2016 or 2018 APF who made automatic fall protection style lowering devices like you get at indoor rock climbing walls. They were pitching them for tree rigging. Don't recall technical details. I might have not asked. They might have not told me.

See here

 

Trublue is a magnetic brake, Perfect Decent a centrifugal brake. Performs quite well with a 450kg rock dropped on the slack webbing.

 

Edited 1 hour ago by kram