If you are going to use multiple points of attachment, you may as well build them a structural carport as it looks like all this will be interfering with the drive. You could have each Bent supporting a different part of the limb. Now that is overkill.
Propping a Pine
- Thread starter NickfromWI
- Start date
- Replies 40
- Views 6K
sawinredneck
Treehouser
I googled "ball and socket" and dug. I've also built a few of them back in the day.
Porkbrick
TreeHouser
i just did a support for a large oak limb. 4" pole 1/2" wall with a piece of 2" round stock welded on the top. i drilled a 2" hole in the bottom of the limb, then jacked it up and slipped the support underneath. it is anchored at the bottom through a 1/2" plate to a footing. an idea i saw when researching designs for the ball/socket allowance for movement was simple, when pouring your footing embed a short piece of pipe of a larger diameter than the post, this makes a socket in the footing. the post simply rests in the socket. i dont imagine this would work in your situation though, that is a lot of tree to hold up. i agree about the fulcrum issue, and the need for soil analysis.
Ha, there is a tree just like that propped up on an old estate about 20 mins from here...the props are wood with steel bands and they are just about rotted away and need to be replaced, I was JUST looking at that tree today. it's a pine of some sort, really long needles, not as much canopy as yours but hefty all the same.
Next time I'm up there I'll get some pictures...
Next time I'm up there I'll get some pictures...
NickfromWI
King of Splices
- Thread Starter Thread Starter
- #30
So my welder gave me an estimate and it was literally 10X the cost of the last one he made. I think he thinks I'm making a ton of money off of this and he's trying to get in on the action or something, but anyway- I digress.
I brought another welder into the mix. He's supposed to give me prices tomorrow. I'm keeping my fingers crossed!
So a question for you guys. I asked the new welder how he recommends connecting the bolt to the prop. He said he'd have a 1/4" plate at the top with a hole drilled into it, then just put a nut on the top and bottom of the bolt.
Do you think that's enough to hold the weight? I know little in the way of steel and just wonder how much force the threads can handle.
Also, I feel like I should do a 3" threaded rod at the top, welder wanted to do 1". Any thoughts?
love
nick
I brought another welder into the mix. He's supposed to give me prices tomorrow. I'm keeping my fingers crossed!
So a question for you guys. I asked the new welder how he recommends connecting the bolt to the prop. He said he'd have a 1/4" plate at the top with a hole drilled into it, then just put a nut on the top and bottom of the bolt.
Do you think that's enough to hold the weight? I know little in the way of steel and just wonder how much force the threads can handle.
Also, I feel like I should do a 3" threaded rod at the top, welder wanted to do 1". Any thoughts?
love
nick
sotc
Dormant hero!!
We still don't know where your placing the prop.
NickfromWI
King of Splices
- Thread Starter Thread Starter
- #32
Whoops- making diagram now...
Paul B
I dig hammocks.
NickfromWI
King of Splices
- Thread Starter Thread Starter
- #34
Okay, here's a pic showing where it'll be.
This is about 25' away from where the trunk meets the ground (it's hard to measure exact). The prop will be placed right under the spot where the trunk stops leaning and starts going straight up. I know it's hard to see by the pic. This diagram shows it most clearly.
I don't think the fulcrum thing could happen here. I don't see the whole root system pulling out. It could....I guess...I just don't see it happening.
This is about 25' away from where the trunk meets the ground (it's hard to measure exact). The prop will be placed right under the spot where the trunk stops leaning and starts going straight up. I know it's hard to see by the pic. This diagram shows it most clearly.
I don't think the fulcrum thing could happen here. I don't see the whole root system pulling out. It could....I guess...I just don't see it happening.
NickfromWI
King of Splices
- Thread Starter Thread Starter
- #35
Boy that sketch turned out a lot smaller than I expected...
NickfromWI
King of Splices
- Thread Starter Thread Starter
- #36
Paul, did it work? Looks way to short to be effective, but the shape of the tree might not of given you much choice
bonner1040
Nick from Ohio
Nick I think you are spot on about the fulcrum. The placement makes it much more of a pillar than the center of of a lever. If you were to go half way back towards the trunk you would have problems in my estimation. From the diagram you look good. Although I probly have a better grasp on fulcrums and levers than the actual holding power of roots.
Burnham said something about 10+tons tipping over medium to to large sized trees I think? Could be wrong.
Burnham said something about 10+tons tipping over medium to to large sized trees I think? Could be wrong.
sotc
Dormant hero!!
Depending on the support under the plate it could work though I think i'd go 3/8 and have my support within 2" of the hole
Burnham
Woods walker
That estimate I made of the pull load we used to take over large conifers is at best a SWAG...
.
.
Paul B
I dig hammocks.
Nick, I dunno, it looked like it had been there a couple years, it was in Kelowna BC where the pnw isa chapter deal was a couple years ago. If one of the members here ends up in that town, let me know and I can tell them exactly where the tree was/is.
Marc-Antoine
TreeHouser
To get an idea of the strength you can hope, the WLL of the standard stock iron is 8kg/mm², or around 11.000 pounds per square inch. You can obtain two or tree time this with the hight strength steels in some hight load bolds. But I don't think you need that; 2" stock rod can handle over 36K pound.
Now, look at the wood's strength :it's a lot less. For example, oak's WLL is around 1kg/mm², or only 4600 pounds on the 2" rod without showing any damage in the wood. There's a good security's margin, but after that, the steel begins to sink in the wood, crushing his structure.
Why not just thinking at your bold as only a center pin, instead of an adjustable rod doing a jack's job?
The trunk stands on the top of the prop, and the pin is only here to avoid side way movements. Much less stress on the pin (and on the wood).
Now, look at the wood's strength :it's a lot less. For example, oak's WLL is around 1kg/mm², or only 4600 pounds on the 2" rod without showing any damage in the wood. There's a good security's margin, but after that, the steel begins to sink in the wood, crushing his structure.
Why not just thinking at your bold as only a center pin, instead of an adjustable rod doing a jack's job?
The trunk stands on the top of the prop, and the pin is only here to avoid side way movements. Much less stress on the pin (and on the wood).
