Grapple Saw on Kboom

Here is my question...

If you owned a kboom why would you not have one of these!?

I already wanted a mini before i saw a bmg.
I bought a mini because of the bmg.

I already wanted a kboom before I saw a grapple saw...
Think I'm gonna try and sell the bucket truck this summer.
 
I'll text Mike and ask him to weigh in

The Mecanil's individually controlled functions (via radio remote) are likely better suited for the bigger knuckle booms that move slower than a log loader, excavator, skid steer, etc. The GMT produces much faster (I'm thinking, haven't ran the Mecanil) than the Mecanil units when you can move the boom faster and activate the functions faster.


The GMTs are attempted to keep in stock in the US. The Mecanil is to order, takes ~6 weeks to get one in unless you want to pay extra for air freight. Neither come with a rotator, which was much to my surprise.

I do have access to a quick connect that fits between the grapple and the rotator. With it, you can go from the grapple saw to a bigger/different grapple so the rotator stays on the machine and there are only 2 hydraulic quick connects to deal with when swapping grapples.


If it would EVER stop raining, I will be able to get the excavator out on a residential job. I sold three jobs last week with multiple removals. The grapple saw will likely cut half a day off one of the jobs. With a knuckle boom I could do them now!
 
Here's the brochure on the rotator to grapple quick connect. List price is $1300 for the kit. The kit is one rotator side and two grapple side quick connect plates, 2 male/4 female hydro quick connects, tool to connect/disconnect the hydraulic quick connects, and 18 bolts/nuts.

Here's a quick video of the quick connect:

Here's a video from 2011 of Mr Gierkink (builds the GMT 035) swapping grapples:
 

Attachments

climbhightree said:
I've been waiting to hear xman and Mike poor's thoughts on this topic.

A kboom is already on my short list...after a chipper upgrade.
Click to expand...

a friend texted me to alert me of this thread.

I actually have one of "these" I bought used in 2008 for my kboom. Still in a crate, but this winter I delivered to the crane company so they can think about setting it up on my kboom. Hope to have it going this spring or summer. I'd like to read this thread sometime and comment.
 
We have a "new" almost 30 year old Denis felling head that works the same as the GMT and about the same size as the Mecanil sg280. I've thought avoid adapting it many times but I want something that functions like the Mecanil so there would be much more control.
 
Like this?

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Yep, no torsional load. Unless the knuckle runs out of travel or the grapple contacts the boom, there will never be a torsional load from the grapple on the boom. There can be a side load from the piece the grapple is holding, but that is up to the operator to be mindful of. Don't take a 16" top at a 100' radius!

One thing about the Mecanil's separate functions is the tilt cylinders don't let the piece down automatically like the GMT. The speed and overriding pressure (cylinders extend on their own) on the GMT is adjustable. The cylinders extending (tilt down) can increase the clearance from the boom to the grapple.


I never thought I'd be able to justify a knuckle boom here in poor Mississippi, but I'm beginning to think that's not correct. I'm not in the position to plunk $400k down for the knuckle boom, but am beginning to see it on the horizon.
 
That would all depend on the size of the kboom and what the capacity was at the reach. Of course you would have to deduct the weight of the whole grapple set up from the capacity.
 
Yep. The GMT035 has a 4klb rated capacity, the grapple starts to open in the 7-8klb range.

I don't know what Mecanil rates their grapple saw for, gives me something to research!
 
i understand that, but I'm still confused. Just for argument sake, we'll say you are good for 4000lbs. Would you be willing to take a 30'-35' log that's 18" in diameter? I'm assuming there is a SWL for these especially when "picking" opposed to flopping trees from the base. Just trying to understand:)
 
You could take a 35', 4klb piece ONCE with a knuckle boom crane!

The dynamic loading nature of a grapple saw and their use on cranes will require the operator to use requisite skill and judgement. I've taken a ~20"x40-50' piece before with my excavator (cut the tree off about 5-6' up), but I didn't "catch" it.
 
I used that example as an exaggeration. So what weight would be considered safe if the kboom had the capacity. Or a rough % of the capacity of the grapple/kboom would be considered ok. I'm very interested in these and I am just wondering what some rough numbers on capacity are needed to effectively use one of these with a kboom.
 
It entirely depends on the situation. Taking a long skinny log that has nothing to break its rotation would be far different than taking 36" chunks of solid white oak which would also be far different than taking a horizontal limb or top that could break the rotation up on the lower limbs (less impact to the knuckle boom).

Start off taking small pieces, same as any new rigging technique. As you get a better understanding of the dynamics, you can better judge what your capabilities are.
 
A lot of info is being thrown out here that I don't agree with. A Kboom is designed different than an excavator and I'm not sure why they are being compared even remotely relevant in their use, design, and ability to safely handle rotational mass once a piece gets cut. This is a crane forum, right?


I am leaning towards purchasing the Mecanil sg280, however there are a lot of unanswered questions that I can not even obtain from kboom manufacturers. Yet people on these forums just want to push product irresponsibly. I can tell you that if you are rated at 4k lbs, and the grapple saw weighs 800, you should NOT be picking near 3200lbs. Effer, Palfinger, Fassi etc combined with Mecanil and GMT need their engineers to weigh in on this and re adjust our load charts and or boom configurations when using the attachment. This opens up liability between one company and the other. What I am finding is no one wants to be responsible for a kboom failure.

Gerasemik seems to stay way under his capacities, but is he being overly cautious or not? Or is he following a chart, say a 30% reduction of his normal load chart capacities. This all newly charted territory and should be taken seriously.
 
I wouldn't say anyone is pushing irresponsibly, but I definitely agree with your other statements. If there will be movement, then there will be some added force. That added force needs to be calculated into your load chart. If not, your boom will be damaged or your crane will tip. Great point. I also like the call out of the manufactures to weigh in here. That is a great idea.
 
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