Beginners guide to rigging.......

[Grass hopper]

Has anyone got a HTC phone , have a small video clip to post , but can't down load it.

Thanks.

[Pete Bannister]

Thats not actually true, its the distance the centre of gravity ( COG) of the piece you are cutting is away from the block that that defines the amount of travel.

 

As long as you tie on between the gob and the COG then its irrelavant where you tie, as long as its not beyond the COG.

 

In fact, if you tie on as high as possible (still below the COG) then the groundie can pull in more slack as the piece goes over and that will reduce the amount of travel. GRCS works well for this.

 

Very good point well made. Also valid because it adds rope to the system, thereby reducing stress on your weakest link and increasing its life

[jpbeaver]

Peter, how many clicks per rotation on a Hobbs?

 

I'll check mine tomorrow and post back if you like.

[toprotter]

Thats not actually true, its the distance the centre of gravity ( COG) of the piece you are cutting is away from the block that that defines the amount of travel.

 

As long as you tie on between the gob and the COG then its irrelavant where you tie, as long as its not beyond the COG.

 

In fact, if you tie on as high as possible (still below the COG) then the groundie can pull in more slack as the piece goes over and that will reduce the amount of travel. GRCS works well for this.

 

Ta Rupe eloquently put x 2 you knew what I was sort of getting at

[toprotter]

Right I do agree to a point but I'm having trouble getting my head around this after sitting

in bed.....

I'm on a stem on spikes with my pulley on far side under where I will gob, I attach rope to stem above gob with hitch then higher timber hitch, for arguements sake I'm chogging 8ft lumps.

Now when a free falling object starts of it builds up velocity the further it travels the more it builds up I think it's called kenetic.... But I'm not a physics master.. The more speed that object gains through gravity the more pressure it will shock load?

So as the lump is travelling the shortest distance the less load it will put on the pulleys rope etc?

If for cog 's sake I move my hitch to just below COG and the stem hasn't a major taper that's an extra 3.5 ft of rope/travel and velocity = more shock load on kit.

For the same reason you wouldn't hitch on the top and let it free fall 8ft of velocity surely it

makes sense to have it as low as poss without the risk of it slipping off......

Can someone explain for me in laymans as I'm not getting it.

But it is late!

If you where anchored had hold of a rope tied to a car and it started to roll down a slight gradient it would be easier to pull against it to stop it in the first few seconds than if it ran away and built up momentum wouldn't it ?

Now I am in need of my bed!!

[Paul Smith]

If you look where your gob cut is, now imagine the whole piece at 90 degrees. This is roughly where it is when it goes over( not taking into account of hinge and gob size etc). In this position it has fallen very little no matter how long it is.

Does this make sense?

[toprotter]

If you look where your gob cut is, now imagine the whole piece at 90 degrees. This is roughly where it is when it goes over( not taking into account of hinge and gob size etc). In this position it has fallen very little no matter how long it is.

Does this make sense?

 

got it simple lol especially as Rupe says the line is

taught...just having one of those moments !!

[Rupe]

Yep, if the line remains taught the whole time, then it doesnt matter where its tied off.

 

But the maths of it is quite simple, you use the distance to the COG to calculate how far the thing is falling, not the distance to where its tied.

 

Of course the top end of your log falls a long way, and the bottom end falls not so far, but the COG takes all that into account, and its still irrelavant where its tied on.

 

The reason you dont tie beyond the COG is cos you dont want the piece to flip over, and tieing lower (nearer to the gob) will help the piece to lie vertically when its being lowered, so still could be a good idea, but has nothing to do with the distance of the fall.

[WorcsWuss]

http://www.mcftoa.org/wp-content/uploads/2011/05/Rope_PP.ppt

 

 

I stand corrected, a lesson indeed!

 

BOOOM! There it is! I'll take that thank you very much

 

Can't see that happening again in my lifetime....

[Stephen Blair]

Where Adam tonight?

How about rigging stuff up the way, has that been covered yet? Not with cranes,tip tieing etc:biggrin: