Tree cut weight formula?

G

Gus_B

New member
Location
Toronto
Hey guys fairly new poster here and hoping you can help me out.
I'm a knuckleboom sales rep up here in Ontario Canada and I am looking for some info regarding weights when it comes to grapple saw cranes and the cuts they should be making.
The one thing that concerns me is that when you make the cut with a grapple saw boom package you literally "Own It" and if you exceed the cranes capacity once the cut is made you can get into some serious trouble.
Is there any sort of formula to determine the weight of a cut before you make it? I'm assuming different species of trees have different densities and weights but is there a way to "guesstimate" based on diameter and length prior to making the cut?
Any advise or direction you can provide would be greatly appreciated. Thank you.
 
A green log weight chart and some distance markings at the end of the boom to gauge the length of the piece and the diameter would probably help. I haven't used a grapple saw myself and wonder whether theres any indication at the operator station, of the diameter once the grapple jaws have closed.
 
cerviarborist said:
A green log weight chart and some distance markings at the end of the boom to gauge the length of the piece and the diameter would probably help. I haven't used a grapple saw myself and wonder whether theres any indication at the operator station, of the diameter once the grapple jaws have closed.
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Thank you sir just did a google search and got several links.

Reach said:
A green log weight chart will tell you, or we use an app called Log Weight Pro, which is a chart in app form. The ability to measure length and diameter from the ground while running the grapple saw would definitely seem to me to be a good idea too.
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Reach just looked up the APP you mentioned and will be recommending it to all my "Tree" customers. I thank you for the info and quick response.

Gentlemen I appreciate your help.
 
So I'll chime in on this thread. IMHO anybody who's not a Tree Industry Veteran really has no business running one of these rigs. Referencing the cut weights is a skill obtained with experience. Know tree species and habitat is essential. For instance, Pecan trees have an entirely different branch weight depending on if the have fruit on them or not. Branches with leaves weigh more than those dormant in the winter. Dead vs live, wet climate vs dry. I tend to watch the reaction of the saw. How hard the saw dips is an indication of weight to me. If its a vertical branch I'm making sure if it comes over it doesn't go past horizontal. If there is enough weight to allow the tilt cylinders to bleed off due to the weight, not just the saw center of gravity shifting, the piece is too big. It something only another operator can teach a new operator. I had a load pin made for my Mecanil 280 saw. That load cell reads in sheer and will show me actual weight and tare weight. I see a lot of stuff on the inter webs than make me question the actual understanding of the weak link in the system. That being the manual extension. I see guys with the same size crane as mine lifting thousands of pounds with a manual extension thats only good for 700kg. Its insane and sober or later we're gonna see a failure and then everybody is gonna scream that these units are unsafe. The fact being there isn't enough training on these units. You get one with a factory rep showing you the controls for a day or two then you go out there to the school of hard knocks. I would be so happy to talk to you more at length about this. Feel free to email me at steve.connally@gmail.com if you are interested in a discussion. If not, no worries, I hope you found what you were looking for.
 
Hi Steve thanks for your post and you make some very valid points especially concerning the capacity on the last manual extension which I make clear to all my customers. I'm the sole provider for my family and put food on our table of 5 by selling equipment for a living so it would be impractical to refuse a customer if they have the financial means to purchase. Of course we do our best to qualify, educate and train however it would be unwise for any company from a business perspective to question the end customers knowledge and risk insulting them. It's a free market and if someone wants to purchase a piece of equipment regardless of their experience level it is their money and their right and yes as someone who was once a new crane operator years ago I made some rookie and dangerous mistakes which thankfully never caused any harm. . I did send you an email along with my phone number and would be happy to have a conversation with you.
 
I can see where you're coming from but consider this. if you are successful enough selling other builds then why not screen new clients for their own good. The key is training. Provide a network of trainers for them to mentor under after the purchase. This is a russian roulette in the wrong hands. I respect you're business standpoint but i'm sure there is a means for vetting prior to a purchase without insulting the potential client. I know of one builder who actually does vet their customers and won't build one for inexperienced tree folks. It's like selling a parachute and showing them where the pull cord is and telling them, good to go. Have fun, don't die! I'm certain if anything ever happened with your customers, you and your family would have gladly made the financial sacrifice if you were able to turn back time and get a "do over" on that sales choice. As a young crane operator, you got lucky and i'm sure you recognize that. What if you hadn't? What if you had killed someone or yourself. Thats what were talking about here. The huge potential. Why shrug that off to inexperience? Why not prevent it? Prevent it via mentorship or if you feel like they are a cowboy, should you really sell to them? Those near misses will add up to a failure and possibly a dealth. I don't believe it's anything to be cavalier about.(not saying you are). These trucks are expert knowledge base only. You need to be a tree man first and learn to be a crane operator. Not learn both at the same time. It's a disaster in the making. This equipment does not in any way make anyone an instant tree service. Like I said, find X landscaper that says he can buy this and start taking down trees also, thats the type of perfect storm of lack of knowledge that will cause a disaster that will ripple effect through the entire industry. Every one of us who owns and runs one will feel the fallout. They're highly visible and people either love them or hate them. believe me, the first public failure that makes it across the internet is going to cause a witch hunt against the trucks. Prices will fall on resale, OSHA will be on high alert, insurance premiums will rise, and the eye will be on every one. I made plenty of mistakes learning to run mine, and still do. The difference is I know where the line is that could cause a disaster so all my screw ups are generally not high risk. I do respect your opinion on free marketplace but I will have to agree to disagree about the insults and turning away money for your livelihood based on choosing clients. I did get your email and would love to chat about the weights and such. No hard feelings, disagreements are healthy!! The cause deeper reflection.
 
The market perspective of Steve's point would be you may loose the tree market if inexperienced people start causing fatalities. They could be regulated out of the industry...

I don't have one: but they look so easy - so if I wanted to do removals, why not? Sit in the AC truck with a remote...heck yeah! (Note sarcasm....but I'm sure there are others who think/act accordingly)
 
ATH said:
The market perspective of Steve's point would be you may loose the tree market if inexperienced people start causing fatalities. They could be regulated out of the industry...

I don't have one: but they look so easy - so if I wanted to do removals, why not? Sit in the AC truck with a remote...heck yeah! (Note sarcasm....but I'm sure there are others who think/act accordingly)
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I've spent 8 hours in spikes in the tree never coming down and not be as fatigued as I was learning to run that thing. Brutal ,mentally. You are rite, it does look easy but it's not. Not even close. It's just not physical. No ac and no sitting. I spend my winter days freezing standing on a steel deck not moving all day and my summer roasting on the steel deck looking into the sun all day. I can't operate sitting. It puts my hands in a funny position and makes it more difficult. I'm operating 4 functions at the same time while trying not to break anything, tear anything down, or be jerky on the controls. I'm glad I have it but some days I wish somebody else was running it.
 
Hey Steve I want to thank you for your phone call.
It was a pleasure speaking with you and it was extremely informative on a wide range of topics.
You are a gentleman and clearly someone who takes the industry seriously. I appreciate the advise you gave and look forward to speaking with you again.
 
Gus_B said:
Hey Steve I want to thank you for your phone call.
It was a pleasure speaking with you and it was extremely informative on a wide range of topics.
You are a gentleman and clearly someone who takes the industry seriously. I appreciate the advise you gave and look forward to speaking with you again.
Click to expand...
Thanks so much!! I enjoyed the conversation. Learned some good stuff myself!!
 
Do you guys know, is there any research available on how the angular torque of a given leaning branch affects these trucks, the weight capacities, and the structural integrity?
Unlike a crane, these machines are dealing with more than the KiloNewton gravitational load straight down.
Given a particular branch, the weight distribution about the "x" axis of the grapple is always unbalanced, specifically because your saw's cut is made immediately next to the grapple. The limb's center of gravity is NEVER near the grapple, unless you're cutting a piece that's only with width of the grapple. This angular torque will vary greatly, with most of the variability coming from amount of foliage & the angle of the dangle.
Most of the vids I see, these trucks are hacking off 10-16" limbs full of foliage. The angular (twist) momentum has to be incredible. How can those forces be estimated, and eventually, regulated?

Cheers

And now that I've said weight distribution and x axis and angle, cue @*useless info* for discussion :)
 
So there are 2 knuckles. One on the rotator and one where the saw pins to the boom. Also those saws will rotate and change orientation based on the COG. This shifting movements reduce a lot of what you are asking about. IMHO the key is to take off only that which doesn't cause a violent change in orientation either to the branch or the saw. You can also chase the cut to reduce those loads even better. The cut isn't just the cut. Theres slewing, lifting or lowering and rotation to happen during or just immediately after the material changes or is changing orientation. Call it finesse. I'm not the expert but I do everything I possibly can to reduce any increased stress on the boom. Horizontal or near horizontal branches are the worst. You just have to take a reasonable cut and counter those forces by moving with what the branch wants to do. Hard to explain and even harder to figure out at first. I think we all are a little misunderstanding of what goes into operating these units. I went from being scared shitless operating it to having a huge amount of respect for its strength as well as how delicate it is. You can beat the shit out or your machine and bust out trees in minimal time or you can work the tree with the machine and do it at a reasonable time frame. Unfortunately reasonable doesn't excite instagram so what you see often on there is some tough use of machines. I personally can't afford to replace mine every 5 years so I have to be gentle. It takes a little more time but in the end, hopefully I won't add to the future statistics of failures of these units. Trust me I cringe at what I see sometimes. I did it when I first got the truck. I was trying desperately to prove the technology and my machine to a market that doesn't progress. I learned a lot of what not to do and made some mistakes. I backed off at the advice of other more experienced operators and have actually gotten way more efficient and faster. I just don't make good click bait because i'm not blowing out half a tree at once. Hope that helps!!!
 
I think we will see torsion sensors get added at every knuckle before too long, but they will only inform you of what you've already cut.
Only a proven experienced operator will be able to judge a cut before the cut.
Cheers
 
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