more fun with knucklebooms

Mangoes, I dont believe Mike's truck has an LMI system, but it does have a "power beyond" feature he has mentioned somewhere. At 90% the crane slows down its functions (limits shock loads) and allows it to pick up 110% of its load chart safely.

I would think a tensometer would be handy. It can hang off the hook on the crane between the hook (or eye) and the load, with a remote display. Seems like it would be a handy thing to have.
 
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Trying to shave some weight maybe?

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Shave weight? I dunno. If I were having to pick it in two pieces for weight, I'd cut at least a 12'-16' log instead of leaving 5'. I hate picking those little hunks up later. What's the answer Mike?
 
exactly mangoes! you hit it onthe head. the log was resting on the stub at hte top of the log. (it probably would have lifted out fine but cutting it high saved 800-900 lbs.) the best part; the forest preserve crew did all the clean-up!!! you're right lumberjack a tensometer would be handy (i rented a 80 ton last week to make picks 130' away and me & oprtr. played weight calc. game with lmi and stayed within 200 lbs.) i tend to be pretty cautious because with tree removal you are really going against what safety systems are designed for. these systems are designed mostly for lifting bldg. matrl. and then extending out until the safety system stops you! with tree removal you're usually reaching way out picking an undetermined weight off it's resting "shelf" if you've picked too much no system in the world is going to help!!! and it's going to be ugly!!!
 
130' with an 80 ton, good for around 2200lbs capacity? I used an older boom 100 ton making pics between 30-135', it was good for around 2700 lbs I believe, with the 2 stage jib fully out.

To date with my limited crane experiance I havent been more than 10% off with my LMI guessing games. One pic I thought I majorly flubbed on the weight (nearly 40%) was due to the LMI wire being caught up in a limb making the computer think the radius was 15' more than it was. WHEW!
 
hey mark chisholm, (you got that last post in b4 i could finish mine) the answer was that the root plate had lifted enough that i didn't want to stand (tied into) the trunk fearing that it might fail. the top of the log was resting on a 4" stub and i couldn't tell how much weight it had on it. so cutting the log to within load chart from the top wasn't an option (not much room for a 2nd crane) so cutting the thing at shoulder hgt. was the simple sollution (if i had a penny for every time i looked for a simple sollution.....) hey todd k, i'm definately diggin' the s.i.p.s. 5.1's thanks for the feedback on those. lumberjack that's a good record on weight calculation! the co. i rented the 80 ton from hired out to a local tre serv. last yr. the climber told the oprtr. the pick was going to weigh 3000. well actually it weighed over 7000!!! the winch cut out and there went the house!!! needless to say the crane owner won't rent to that tree serv. any more.
 
hey norm, i know the climber from that job (where they hit the house) and he's normally good & 20 yrs exp. but the oprtr. told me the 4' dia. celtis/ hackberry log couldn't be figured with grn log chart (most log charts only go to 3') that's where they got into trouble! i have a rule of thumb: when the diameter doubles, the weight quadruples. so if you have a 6' dia. log to pick, you multiply the 3' weight per foot times 4 and that gets you close. their hackbeery log 4' dia was about 640 lbs. per ft. i figure. it never hurts to figure on the heavy side right?
 
Mike, somewhere on here I have posted 2 weight charts built in Excel that go up to 90" diameter and 26' long, one is pine, the other is for oak. If you would like I could find which computer its on and repost it, each chart fills a page, so front and back makes both charts on one page, its what I use from time to time:). Also it had a Doyle Scale on the 3rd page of the workbook.
 
hey lumberjack, that would be great, it's hard in the tree to try to figure weighton logs over 3' dia ( i've memorized most info on the grn. chart and lg. dia logs at one foot increments or use my "rules of thumb") but with those charts you know! in arboriculture you can't "think" you gotta know! (arborist in ca. i worked for said that alot) i like the 2 woods yuo choose: pine (the light end of the chart) and oak (the heavier end)
 
Had to rig them like this to get close enough to the ground without hitting the roof. I thought to myself, if I had Mike's knuckle with the jib it would reach the ground and I could still use the grapple!
 

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I bet he could lift the grinder over the roof easy enough.

Mark, with the fly jib I dont think you would have enough hydro circuits to have a grapple. That would require 4 circuits to the end of the main boom, 2 for the jib (extension/retraction and its elevation cylinder) and 2 for the grapple (rotation and squeezin!). I havent seen a fly jib with a grapple, but I bet it could be done.
 
Cozmo, Rob worked it in a little and then moved the wheels using the cutter wheel. He's tricky like that.


Carl, We could've rigged the grinder in probably, but I have only picked it up once to place it into the truck and use it on one job. We didn't have one more driver for the trailer. /forum/images/graemlins/smirk.gif

I think that if we wanted a grapple on a jib, you'd have to have a switch over valve for other controls. Like if we wanted a winch added to ours. We would have to have the same set up.
 
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