pics

[Old Mill Tree Care]

And of course I always put a back up on, honest.

[avatar tree climber]

I agree with Scots Pine on the issue of strap position in relation to bollard position.

 

However, I have a Stein Dual and notice that all the Stein bollards have the strap in line with the bollard and they work fine.

 

thank you

[Pete Mctree]

How did you calculate the SWL for the bollard?

[Old Mill Tree Care]

thank you

 

You're welcome.

I think the argument here is based around one factor that no one has noticed. It's always been obvious to me, because I'm obsessed with design, but it all rotates around the length of the bollard.

I used the word 'rotates' deliberately. If the bollard is short like the Stein, there won't be a problem. Some of the home made bollards I've seen on Arbtalk are very long compared to the area and height of the mounting plate.

THIS is the crucial factor.

 

It's simple. If you make a bollard 2ft long, you better make sure the plate is 10ft x 3ft. If you don't, the vertical pull from the rope could make the device rotate around a fulcrum in the mounting plate. Know what I mean.

 

If the relationship between bollard length and mount plate height is good, the strap position is not important.

 

I'm not saying that the GRCS and Hobbs is wrong, if I made my own I would probably do what they've done anyway.

[avatar tree climber]

How did you calculate the SWL for the bollard?

 

i didnt i just rung lewmar who make the winches they said 1.3 tonne for the winch .the bolts that hold the winch to the back plate the braking straine is huge so dont worry about that its just the straps and there marked up

[avatar tree climber]

You're welcome.

I think the argument here is based around one factor that no one has noticed. It's always been obvious to me, because I'm obsessed with design, but it all rotates around the length of the bollard.

I used the word 'rotates' deliberately. If the bollard is short like the Stein, there won't be a problem. Some of the home made bollards I've seen on Arbtalk are very long compared to the area and height of the mounting plate.

THIS is the crucial factor.

 

It's simple. If you make a bollard 2ft long, you better make sure the plate is 10ft x 3ft. If you don't, the vertical pull from the rope could make the device rotate around a fulcrum in the mounting plate. Know what I mean.

 

If the relationship between bollard length and mount plate height is good, the strap position is not important.

I'm not saying that the GRCS and Hobbs is wrong, if I made my own I would probably do what they've done anyway.

i agree i put 2 straps on my homemade one and it grips the trunk better than the grcs

[High Scale]

Inverted base plate?

 

Pic from Giorgio.

 

New GRCS better get the welder out.

Edited January 6, 2013 by High Scale

[MOG]

Very very nice:)

[BabyBuzz]

Tim said your vectors aren't right,

[PaulPryTim]

Dear mr climbing aviator, it is patently obvious to my good self that ' bling ' shinies and anodised crap are the most important features in your pony climbing and rigging kit. One needs to sit down and have a complete reality check, before this obsession gets totally out of hand and begins to take over, sadly I suspect it could be to late.