Learning rigging

[Dan Maynard]

3 hours ago, kram said:

Do any lowering devices use a mechanical brake to move the heat disipation away from the rope?

Can't think of any. Rope moving along carries heat away, anything mechanical is a complication and potential failure point, need for maintenance etc. How would you control a mechanical brake? 

 

I think rope friction just wins on simple and effective. Only real problem is potential for riding turns but that can be managed.

[AHPP]

3 hours ago, kram said:

How much?!?

 

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

Edited 1 hour ago by AHPP

[AHPP]

51 minutes ago, Dan Maynard said:

How would you control a mechanical brake? 

 

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.

 

Parafans are paddles spinning in open air. These things were encased. Perhaps oil and Tesla pump plates.

 

Air resistance (and presumably that of other fluids) acts on the square of velocity. Presumably these devices deal with variable loads on that principle.

Edited 1 hour ago by AHPP

[sime42]

Bit like a Holtzman shield in Dune.

 

 

[Pete Mctree]

There are sheaved pillows that can act as line breaks I.e. rock exotica’s downroper 

Irrespective you need to apply predictable friction to work a rigging system with any degree of finesse 

[AHPP]

14 minutes ago, sime42 said:

Bit like a Holtzman shield in Dune.

 

 

 

Had to google but broadly yes.

[openspaceman]

17 minutes 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.

 

Parafans are paddles spinning in open air. These things were encased. Perhaps oil and Tesla pump plates.

 

Air resistance (and presumably that of other fluids) acts on the square of velocity. Presumably these devices deal with variable loads on that principle.

I wonder if it was an eddy current device, a large copper disc spinning between two static discs embedded with permanent magnets. I would expect it would need gearing up.

 

The whirly bird type speed regulator ( basically a centrifugal fan in free air) absorbs power with the cube of RPM.

 

If I ever had to live in a high rise flat I would have an eddy current device above the window with an 8mm wire rope wrapped round the capstan 8 times and a 2kg weight on both tail and active end

[AHPP]

Cubed is it? My mistake.

 

You've lost me with your high rise living. Are you needing to bring hay up?

[kram]

25 minutes ago, Pete Mctree said:

There are sheaved pillows that can act as line breaks I.e. rock exotica’s downroper 

Irrespective you need to apply predictable friction to work a rigging system with any degree of finesse 

The downrigger appears to be a moving cam that is applied by the load, but its still rope based friction to slow the load.

 

Predictable friction yes, it needs to be adjustable for heavier and lighter loads. Or the adjustment could be built in and automatic, theres a few ways to do that but I'd suggest its a step too far. Adjustable, like adding a  extra wrap on the bollard, is what arbs are used to.

 

 

[sime42]

Fire escape I reckon. 

 

Why the 8 wraps and 2kgs though OSM?