- Location
- Longmont, CO
You gotta love included bark!
Job security for us.
Another thinker
- Thread starter Norm_Hall
- Start date
- Location
- Ontario, Canada
I would have considered wedging the back cut and boring from the back.
If the tree comes ahead, your saw is on the wrong side not to mention yourself.
If you weaken the hinge by boring, the tree comes ahead and pinches the bar then you release tension on the tree to free the bar the now weaker hinge could break leaving you without any control.
If nothing else it would at least reduce the risk to you and the saw.
If the tree comes ahead, your saw is on the wrong side not to mention yourself.
If you weaken the hinge by boring, the tree comes ahead and pinches the bar then you release tension on the tree to free the bar the now weaker hinge could break leaving you without any control.
If nothing else it would at least reduce the risk to you and the saw.
Norm_Hall
New member
- Location
- Wauconda, (Chicago),IL,USA
[ QUOTE ]
Could you set up a "double" DWT connected to the GRCS to increase the MA? [ QUOTE ]
I don't see why not. You would need 2 double sheave pulleys and lotsa rope.
Could you set up a "double" DWT connected to the GRCS to increase the MA? [ QUOTE ]
I don't see why not. You would need 2 double sheave pulleys and lotsa rope.
Norm_Hall
New member
- Location
- Wauconda, (Chicago),IL,USA
[ QUOTE ]
Ah, that makes sense of the photo now. Did you release some of the tension on the pulling line to prevent the stem moving forward and pinching the bar when boring the hinge?
[/ QUOTE ]
Yes, the tension was released. There was absolutely no way the spar was going to fell without MA. I don't even think single wedges woulda brought it over. Maybe double (stacking).
It had to be a pretty accurate fell (between the drive end and the utility wires). We wanted to leave as much 'live' hingewood as possible. Plowing out the center is a better option than 'thinning' the hinge.
Ah, that makes sense of the photo now. Did you release some of the tension on the pulling line to prevent the stem moving forward and pinching the bar when boring the hinge?
[/ QUOTE ]
Yes, the tension was released. There was absolutely no way the spar was going to fell without MA. I don't even think single wedges woulda brought it over. Maybe double (stacking).
It had to be a pretty accurate fell (between the drive end and the utility wires). We wanted to leave as much 'live' hingewood as possible. Plowing out the center is a better option than 'thinning' the hinge.
- Location
- Ontario
The reason I asked was that you said the grcs had a hard time picking it up. What I invisioned was using 4 regular blocks, essentially having a "double" DWT. Do you see any possible problems with that?
WP
WP
Norm_Hall
New member
- Location
- Wauconda, (Chicago),IL,USA
Can you draw a picture of how you would set it up?
Two double sheave pulleys wood be alot easier to set up.
Two double sheave pulleys wood be alot easier to set up.
- Location
- Ontario
Sure can.....on a piece of paper. Not sure about the computer, I'll try.
WP
WP
- Location
- Ontario
Ok here goes!
Wow it worked..... don't be too critical of the art work.
WP
Wow it worked..... don't be too critical of the art work.
WP
- Location
- Bloomington, Indiana
The picture looks fine. I agree with Norm that two double-sheave pulleys would be easier and more efficient.
- Location
- Madison, WI.
- Location
- Ontario
I don't disagree that double sheave pullies would make it easier and faster to set-up. I was thinking since Norm decided on using 3/4" rope, I'm guessing most of us wouldn't have suitable sized double sheave pullies for this application.
Just a thought.
WP
Just a thought.
WP
- Location
- Bloomington, Indiana
I think he said that the sling was 3/4" DB
[ QUOTE ]
The block is anchored with a cow hitch using a 3/4" BD.
[/ QUOTE ]
and the rope was 9/16" DB
[ QUOTE ]
...we set up a DWT using a 9/16's poly/dyneema DB.
[/ QUOTE ]
But you're right, most people would not have double-sheave pullys of that size.
[ QUOTE ]
The block is anchored with a cow hitch using a 3/4" BD.
[/ QUOTE ]
and the rope was 9/16" DB
[ QUOTE ]
...we set up a DWT using a 9/16's poly/dyneema DB.
[/ QUOTE ]
But you're right, most people would not have double-sheave pullys of that size.
Roger_Barnett
Participating member
- Location
- Seattle, in the PNWet
I have a couple that will handle 1 inch line, but they're uber heavy!
Nice work, as usual, Norm!!
Nice work, as usual, Norm!!
Roger_Barnett
Participating member
- Location
- Seattle, in the PNWet
[ QUOTE ]
[ QUOTE ]
We wanted to leave as much 'live' hingewood as possible. Plowing out the center is a better option than 'thinning' the hinge.
[/ QUOTE ]
True, Norm. And when felling a normal stick there's less need to have full width holding wood, so boring the center is always a good idea. In both cases, it allows for thicker hinge width which is easier to work with.
Yesterday, I was dropping 10 foot doug fir sections. Last cut before felling a 25-30 foot spar was a 30 inch cut...I had my 7900 with 32 inch bar on, and it was a mighty delicate maneuver to center bore the hinge with all that bulk....no desire to have a kickback!!!
This video is of felling the butt, which was simple..though it was a 44 inch cut....
http://www.youtube.com/watch?v=ZsE50_i03n0
[ QUOTE ]
We wanted to leave as much 'live' hingewood as possible. Plowing out the center is a better option than 'thinning' the hinge.
[/ QUOTE ]
True, Norm. And when felling a normal stick there's less need to have full width holding wood, so boring the center is always a good idea. In both cases, it allows for thicker hinge width which is easier to work with.
Yesterday, I was dropping 10 foot doug fir sections. Last cut before felling a 25-30 foot spar was a 30 inch cut...I had my 7900 with 32 inch bar on, and it was a mighty delicate maneuver to center bore the hinge with all that bulk....no desire to have a kickback!!!
This video is of felling the butt, which was simple..though it was a 44 inch cut....
http://www.youtube.com/watch?v=ZsE50_i03n0
Norm_Hall
New member
- Location
- Wauconda, (Chicago),IL,USA
You're illustration would create a 4 to 1 MA. There is, however, a more efficient system. It only requires 3 single pulleys. You will need 2 different ropes. It's called the 'piggyback' system. We have used it in combination with a port-a-wrap for lifting when we didn't have the GRCS with us.
See attachment
See attachment
- Location
- Ontario
Is there some limitations to the amount of pull (distance) and lowering distance in that system?
That is also a 4:1 isn't it?
WP
That is also a 4:1 isn't it?
WP
Norm_Hall
New member
- Location
- Wauconda, (Chicago),IL,USA
Yes, it is a 4 to 1 MA.
You're absolutely right. Depending on how far up the pulley is, you can run out of rope. Excellent observation.
You're absolutely right. Depending on how far up the pulley is, you can run out of rope. Excellent observation.
knudeNoggin
New member
[ QUOTE ]
You're illustration would create a 4 to 1 MA. There is, however, a more efficient system. It only requires 3 single pulleys. You will need 2 different ropes. It's called the 'piggyback' system. We have used it in combination with a port-a-wrap for lifting when we didn't have the GRCS with us.
[/ QUOTE ]
But note two concerns with this piggyback system:
1) you're limited in range of movement (if H is the reach to the redirection pulley,
you move the object H/2; and
2) the green rope must now bear 1/2 the load (since it is doubled), as must
its block.
In the original, the 4 strands of rope all led to the object, and its resistance was
thus distributed over them.
But I think that THAT system would be more efficient were the haul line led to
the higher point, hauling on the farther end of the object, opposite to the drawing.
*kN*
You're illustration would create a 4 to 1 MA. There is, however, a more efficient system. It only requires 3 single pulleys. You will need 2 different ropes. It's called the 'piggyback' system. We have used it in combination with a port-a-wrap for lifting when we didn't have the GRCS with us.
[/ QUOTE ]
But note two concerns with this piggyback system:
1) you're limited in range of movement (if H is the reach to the redirection pulley,
you move the object H/2; and
2) the green rope must now bear 1/2 the load (since it is doubled), as must
its block.
In the original, the 4 strands of rope all led to the object, and its resistance was
thus distributed over them.
But I think that THAT system would be more efficient were the haul line led to
the higher point, hauling on the farther end of the object, opposite to the drawing.
*kN*
New threads New posts
-
test
-
-
-
-
-
Light 14 or 16" narrow kerf bar for 200t or 201t- Started by southsoundtree
- Replies: 9
-
