Grapplesaw Heads

[oceans]

Years Ago I was doing a lot of work on the forestry side of things, and I remember the nicer grapple skidders had “snubbers” on the 2 link pins above the rotator. When properly tightened, the grapple swinging movement was much more dampened when empty and riding over rough terrain. I could only see a benefit to them. If the Mecanil can’t go as far as the GMT clutch brake pins (TTC system which looks pretty awesome), maybe snubber pins can be used?

I’m wondering if a grapplesaw head would benefit from this in a number of ways, but mostly to slow down the dynamic movement as picks come off. This might help with:
- Long laterals with decent leverage. Perhaps they would stay a bit steadier and potentially remedy the issue of downward tilt prior to the cut being finished.
- Tallish trunk picks that really reorient during initial lift off.
- Grab & Cut scenarios where the grapple is one side or the other of the branch’s overall balance point, limiting movement exposing a climber at risk.

What do you all think?

 

[Lumberjack]

I think you need the snubbers to be selective, free swinging at times, tight other times... like the TTC. Isn't the way the snubber pins and TTC works basically the same, a friction stack that has either springs or hydraulics to apply pressure to the stack to reduce the swing?

The Mecanil has the advantage of already having the tilt down cylinder as a separate function compared to the non + or TTC versions of the GMT grapples.

 

[oceans]

To my understanding, yes, the TTC has hydraulic clutches that lock both dangle pins in place, but don’t know if they allow dampened movement.

There are things I like about both GMT and Mecanil but it seems like over 90% of saw trucks are running the Mec.

 

[Lumberjack]

They dampen above the limit of their torque holding ability.

A snubber on a skidded uses the same kinda pack with adjustable preload on the pack. For a grapple saw you'd have to pick the amount of torque you want, what works on a large long log would be way too much for a smaller limb and being able to get the grapple to self align.

You can also use TTC to hold the grapple considerably out of plumb to be able to get the grapple in positions that would be otherwise cumbersome.

The hydraulic brakes could be controlled on the machine side of the system instead of the grapple, you'd just need another line or perhaps circuit.


What do you like better about the Mecanil over a TTC equipped GMT?

 

[oceans]

They dampen above the limit of their torque holding ability.

A snubber on a skidded uses the same kinda pack with adjustable preload on the pack. For a grapple saw you'd have to pick the amount of torque you want, what works on a large long log would be way too much for a smaller limb and being able to get the grapple to self align.

You can also use TTC to hold the grapple considerably out of plumb to be able to get the grapple in positions that would be otherwise cumbersome.

The hydraulic brakes could be controlled on the machine side of the system instead of the grapple, you'd just need another line or perhaps circuit.


What do you like better about the Mecanil over a TTC equipped GMT?

It makes sense that a snubber setting wouldn’t be a one-size-fits-all kinda thing. I was more thinking an overall dampening and not really full lockout like the GMT.

I can’t say what I like better about a Mecanil, I was just saying I like things about both of them. This is only based on research and anecdotal experience from others.

When DC talked to me about the TTC at Expo a few years back I was pretty blown away. I also hear from a lot about how much they like an SG160 and how nimble it is. I don’t know anyone with decent experience with both.

 

[Lumberjack]

I had a SG280 G2 on my 2017 PK40, I bought a 035 back in 2014-2015, and I bought a 050 in January of this year.

I want to make a hanger for my 050 to mount on my rotating telehandler. If the situation presented itself I’d be game for a TTC 035 or 050 for it.

I don’t really want another Mecanil.

 

[oceans]

I had a SG280 G2 on my 2017 PK40, I bought a 035 back in 2014-2015, and I bought a 050 in January of this year.

I want to make a hanger for my 050 to mount on my rotating telehandler. If the situation presented itself I’d be game for a TTC 035 or 050 for it.

I don’t really want another Mecanil.

That’s really good to know. I’m working on a build of my own and have always had a place in my mind for the GMT TTC. Donyou know specifically what it takes to engage those clutches? Independant circuit or solenoid diverter?

 

[Lumberjack]

A valve in the grapple gets pressurized oil from an accumulator in the grapple and back feeds it through a single port in the rotator.

 

[oceans]

A valve in the grapple gets pressurized oil from an accumulator in the grapple and back feeds it through a single port in the rotator.

So it sounds like the rotator has a dedicated case drain port?

 

[Lumberjack]

I don't know what the port was originally intended for from the rotator mfg.

 

[oceans]

Copy. Well, for what it’s worth, a little birdy just told me Mec is releasing their own version of clutch brake pins in a few months. Might wait to pull the trigger until I see what they come up with.

As my first crane isn’t huge, I will likely go with the lighter offering of the 2 brands.

 

[Treetopflyer]

I’m getting interested in the gmt heads
I’ve only seen them minimally on YouTube so know virtually nothing about them.
Thanks for the learning opportunity I’ll be following this thread.

 

[oceans]

Folks will likely never stop innovating so we will likely never stop learning.

If you search over the GMT, try to add “TTC” or “Total Tree Control” in your search. The system is dang impressive!

 

[Steve Connally]

I prefer not to have a hold fast option. Part of the dissipation of leverage is to have the piece find the orientation that is best. Sometimes the pivot in the connecting interface just isn't enough. Trying to keep something Locked in a position could put some additional forces the boom isn't designed to handle. I personally try very hard not to take stuff that ends up with tips to the ground or thats so heavy the piece comes over with a vengeance. I think having something locked into position would increase the amount of torque the boom sections see. The other trick is to learn how to chase the cut with the crane and eat the torque through movement. You can't always do that but I try especially on those long laterals. That locking head for the mecanil was put on a crane that had all but 1 fly jib sections removed. I believe, if they hadn't, they'd twist the saw and jib right off. I do see the benefits of increased dampening like you guys are saying but I guess I've just gotten used to what I have. My newer saws are different than the older Mecanils. They don't dump over as quick and there is no passive dumping like the old saws. You actively have to hit tilt. That makes it very difficult setting down long poles somebody else cut as I was holding them. The active tilt function is so dramatic it torques something terrible. I don't know if I missed the mark on what you guys are discussing. If so apologies. You clearly have way more understanding of the mechanics of this stuff than I do.

 

[oceans]

I prefer not to have a hold fast option. Part of the dissipation of leverage is to have the piece find the orientation that is best. Sometimes the pivot in the connecting interface just isn't enough. Trying to keep something Locked in a position could put some additional forces the boom isn't designed to handle. I personally try very hard not to take stuff that ends up with tips to the ground or thats so heavy the piece comes over with a vengeance. I think having something locked into position would increase the amount of torque the boom sections see. The other trick is to learn how to chase the cut with the crane and eat the torque through movement. You can't always do that but I try especially on those long laterals. That locking head for the mecanil was put on a crane that had all but 1 fly jib sections removed. I believe, if they hadn't, they'd twist the saw and jib right off. I do see the benefits of increased dampening like you guys are saying but I guess I've just gotten used to what I have. My newer saws are different than the older Mecanils. They don't dump over as quick and there is no passive dumping like the old saws. You actively have to hit tilt. That makes it very difficult setting down long poles somebody else cut as I was holding them. The active tilt function is so dramatic it torques something terrible. I don't know if I missed the mark on what you guys are discussing. If so apologies. You clearly have way more understanding of the mechanics of this stuff than I do.

Everything you’ve said makes sense to me, I just don’t understand what you’re referring to with passive and active “dumping”. I understand the function just not the difference of passive and active.

In regard to the Mecanil tearing a boom apart, I would add that we don’t necessarily have to go so big. A lack of movement can be useful even with a smaller pick near some kind of obstruction.

I still can’t see how some added dampening would be undesirable.

 

[climbhightree]

So passive is when you are not pumping fluid through the valve to do the desired action. You are just opening the valve and letting the fluid (tilt etc) do what it wants. So if the butt of a long branch (that I mid grabbed) is against the ground, the grapple tilt function could be adding tension to me laying the branch down. If I open the valve, by pressing a button, the tilt basically becomes free floating.

An active dump is forcefully making the grapple tilt up or down, by pumping the fluid through the valve.

Force, leverage, rotation etc has to go somewhere when you are holding a large long limb by one end. With a kboom vs a stick crane, wallboard crane, merlo etc - the main issue in my non engineer scientific mind is the number of sliding sections. This increases the flexibility and movement of the boom...therefore amplifying the effects of the above forces. With a greater chance of damage occurring. If the saw head is completely static (with no pivot point, no tilt drop if overloading), all that force goes right into your boom sections.

I personally think a lock for the pivot would be nice for over wires or a house. But I guarantee I would be taking small limbs. To be honest they would probably be small enough that the mecanil/pivot wouldn't move much anyways. So yes the lockout would be helpful (for peace of mind), but needed....questionable.

Steve, did the passive go away with the new saws or the new truck? I was told by my shop this is a plumbing issue. I had asked about it because my client that bought f390 wallboard, can't passively dump (I I described above).

 

[oceans]

So passive is when you are not pumping fluid through the valve to do the desired action. You are just opening the valve and letting the fluid (tilt etc) do what it wants. So if the butt of a long branch (that I mid grabbed) is against the ground, the grapple tilt function could be adding tension to me laying the branch down. If I open the valve, by pressing a button, the tilt basically becomes free floating.

An active dump is forcefully making the grapple tilt up or down, by pumping the fluid through the valve.

Force, leverage, rotation etc has to go somewhere when you are holding a large long limb by one end. With a kboom vs a stick crane, wallboard crane, merlo etc - the main issue in my non engineer scientific mind is the number of sliding sections. This increases the flexibility and movement of the boom...therefore amplifying the effects of the above forces. With a greater chance of damage occurring. If the saw head is completely static (with no pivot point, no tilt drop if overloading), all that force goes right into your boom sections.

I personally think a lock for the pivot would be nice for over wires or a house. But I guarantee I would be taking small limbs. To be honest they would probably be small enough that the mecanil/pivot wouldn't move much anyways. So yes the lockout would be helpful (for peace of mind), but needed....questionable.

Steve, did the passive go away with the new saws or the new truck? I was told by my shop this is a plumbing issue. I had asked about it because my client that bought f390 wallboard, can't passively dump (I I described above).

Thanks for the info, Brian. Very helpful. Is your shop Crane Specialists? I’ve been talking with them and they seem quite knowledgeable.

 

[climbhightree]

Thanks for the info, Brian. Very helpful. Is your shop Crane Specialists? I’ve been talking with them and they seem quite knowledgeable.

Yep, they are about 20 minutes from me. They build my truck from the ground up, 7 years ago now. They have come a long way with grapplesaw crane knowledge...mine was their first build (not sure if they did a mecanil retrofit before my truck or not). Super knowledgeable on Fassi booms and now with grapplesaws.

 

[Treetopflyer]

I have a Mecanil gen 1 220 That will dump the head down just activating the tilt down function.
I also have the Mecanil g2 160 head that requires active flow from touching the close function as well activating the tilt down button. This allows you to slowly tilt down with the amount of flow you a lot to the paddle to activate the movement
Maybe this is what Steve is referring to?

 

[climbhightree]

I have a Mecanil gen 1 220 That will dump the head down just activating the tilt down function.
I also have the Mecanil g2 160 head that requires active flow from touching the close function as well activating the tilt down button. This allows you to slowly tilt down with the amount of flow you a lot to the paddle to activate the movement
Maybe this is what Steve is referring to?

Interesting.