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#1
Posted to alt.home.repair,sci.electronics.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Just to update this thread, we completed the 250 feet of steel cabling
today by lashing the two ends together using these cable clamps: https://c3.staticflickr.com/3/2942/1...845164f7_c.jpg To keep the cables from cutting into the trees, and to allow the trees to grow outward, we put up a series of these wooden standoff blocks: https://c3.staticflickr.com/3/2945/1...94070f9b_b.jpg You'll notice that we doubled the cables as they wrapped around the trees so that the strength is always two time 14,000 pounds, at all times: https://c3.staticflickr.com/3/2944/1...3de04150_c.jpg Here, you can see the two cables, hanging as two catenaries, from which we will hand the suspension bridge: https://c3.staticflickr.com/3/2943/1...edf3ba0c_c.jpg We're starting to get used to working in the heights, as you can see by this photo of my neighbor coming down from disentangling the lines: https://c4.staticflickr.com/4/3901/1...7461b64d_c.jpg As you can imagine, we wear harnesses and we have static lines hanging from all the trees, as you'd be amazed how many times you need them: https://c3.staticflickr.com/3/2945/1...61137c64_b.jpg In fact, my unenviable job today was to stand at the TOP of this ladder and position the cables, which I did with two hands on the cables so I had to be wearing a harness or I would have fallen off in no time: https://c4.staticflickr.com/4/3870/1...f45d19e2_b.jpg I'll let you know when we drill the redwoods to put in the tree bolts, which will anchor the house; but first, we're working on the suspension bridge (you can see our cargo netting in some of the pictures above). Tomorrow we're putting up WiFi on a neighbor's roof, so we wont' be working on the treehouse until next week. |
#2
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
OFWW wrote, on Sat, 27 Sep 2014 23:55:45 -0700:
If you installed these without lock washers I would recommend you go back up and at least put nylock nuts as safety nuts. Heating and cooling will cause those nuts to walk off the u-bolts. Thank you for that safety suggestion! That is a good point. Safety is paramount. This treehouse 50 feet in the air in the redwoods has to outlast us and it has be safe at all times. Since we didn't use lock washers on the steel clamps, I will advise my neighbor and I will snap a picture of the results for you. You will notice that we doubled up the two ends of the steel cable as they wrapped around the tree, so that we'd always have two cables supporting the bridge. On the big tree, 125 feet away, we will add a wraparound additional steel cable, so that the middle also has two cables. Any other safety ideas are welcome, as we're just at the point now where we can start hanging the suspension bridge from the two steel catenaries. For example, you will notice that we followed the rule as shown he http://www.pirate4x4.com/tech/billav...dead%20end.jpg Following that diagram, we put the "saddle" of the clamps on the "live end" (the mnemonic we used was "don't saddle a dead horse"). http://www.pirate4x4.com/tech/billav...pe%20clips.jpg Any other tips are welcome, as we're just now at the stage where we have the ability to build the 125 foot long bridge starting about 15 feet up in a pine, and then going straight across a steep slope through the set of two redwoods, and then on to the really big redwood 125 feet down the slope. The treehouse will be in the middle of the bridge. |
#3
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
On 09/28/2014 11:50 AM, Danny D. wrote:
OFWW wrote, on Sat, 27 Sep 2014 23:55:45 -0700: If you installed these without lock washers I would recommend you go back up and at least put nylock nuts as safety nuts. Heating and cooling will cause those nuts to walk off the u-bolts. Thank you for that safety suggestion! That is a good point. Safety is paramount. This treehouse 50 feet in the air in the redwoods has to outlast us and it has be safe at all times. Since we didn't use lock washers on the steel clamps, I will advise my neighbor and I will snap a picture of the results for you. .... I don't believe there's any reason to think the environmental thermal cycling has any chance of loosening those sufficiently to worry over from that standpoint. We've got several miles of cable in feedlot fences with the same style cable clamps with tension on them sufficient for retaining cattle while working them. They've been installed w/o lock washers for some 60 yr in SW KS which is quite extreme in both temperatures and particularly in changing in extremes over very short time frames relative to CA redwood country. Not a single one has come loose on its own in that time. What I'd suggest and use would be a) at least two/ location, preferably three, and b) for looped connections (very few in this application; the cables are terminated at the clamps which are welded to rod)(+), we also used compression connector at the end to hold the cut end to the running cable. (+) The rod is then connected via a turnbuckle for takeup tensioning to a second rod which penetrates the end post/tie. -- |
#4
Posted to alt.home.repair,sci.electronics.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
OFWW wrote, on Sat, 27 Sep 2014 23:55:45 -0700:
I hate ladders like these, seen the two by's pull off after a short while especially if your shouldering a load going up or down. The rungs should be in notches. This is a good point. We have so many ladders, most of which are roped end-to-end to the trees for height, that we just made them as simply as we could. You can see that we have cargo netting, to allow us to cross from tree to tree once we climb up the ladders: https://c4.staticflickr.com/4/3865/1...e8c93589_c.jpg But, we also usually wear safety harnesses and ascenders whenever we work more than 15 or 20 feet up (which is almost always since it's a steep slope so what is 15 feet up at the uphill end of the cables is something like 50 or 70 feet up at the downhill end. |
#5
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
dpb wrote, on Sun, 28 Sep 2014 12:04:29 -0500:
I don't believe there's any reason to think the environmental thermal cycling has any chance of loosening those sufficiently to worry over from that standpoint. I don't know. But, safety is cheap, if you know what to do, so I'm not against the advice at all. This has to handle kids and adults, and has to outlast us. They've been installed w/o lock washers for some 60 yr in SW KS which is quite extreme in both temperatures and particularly in changing in extremes over very short time frames relative to CA redwood country. Not a single one has come loose on its own in that time. This is great information, as your environment is the same as ours! We're on steep hills in California, in the redwoods. What I'd suggest and use would be a) at least two/ location, preferably three, and You can see that we used *eight* on the connection he https://c3.staticflickr.com/3/2944/1...3de04150_c.jpg |
#6
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Sun, 28 Sep 2014 16:50:02 +0000 (UTC), "Danny D."
wrote: Following that diagram, we put the "saddle" of the clamps on the "live end" (the mnemonic we used was "don't saddle a dead horse"). http://www.pirate4x4.com/tech/billav...pe%20clips.jpg Just curious. Is there a torque spec for those clamps? Or ... |
#7
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
dpb wrote:
On 09/28/2014 11:50 AM, Danny D. wrote: OFWW wrote, on Sat, 27 Sep 2014 23:55:45 -0700: If you installed these without lock washers I would recommend you go back up and at least put nylock nuts as safety nuts. Heating and cooling will cause those nuts to walk off the u-bolts. Thank you for that safety suggestion! That is a good point. Safety is paramount. This treehouse 50 feet in the air in the redwoods has to outlast us and it has be safe at all times. Since we didn't use lock washers on the steel clamps, I will advise my neighbor and I will snap a picture of the results for you. ... I don't believe there's any reason to think the environmental thermal cycling has any chance of loosening those sufficiently to worry over from that standpoint. We've got several miles of cable in feedlot fences with the same style cable clamps with tension on them sufficient for retaining cattle while working them. They've been installed w/o lock washers for some 60 yr in SW KS which is quite extreme in both temperatures and particularly in changing in extremes over very short time frames relative to CA redwood country. Not a single one has come loose on its own in that time. What I'd suggest and use would be a) at least two/ location, preferably three, and b) for looped connections (very few in this application; the cables are terminated at the clamps which are welded to rod)(+), we also used compression connector at the end to hold the cut end to the running cable. (+) The rod is then connected via a turnbuckle for takeup tensioning to a second rod which penetrates the end post/tie. -- I agree with the turnbuckle, or some way to adjust the tension in case the bridge wants to tilt to one side. -- GW Ross 1st Law of Thermodynamics: Go to class!! |
#8
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
On 09/28/2014 12:11 PM, Danny D. wrote:
dpb wrote, on Sun, 28 Sep 2014 12:04:29 -0500: I don't believe there's any reason to think the environmental thermal cycling has any chance of loosening those sufficiently to worry over from that standpoint. I don't know. But, safety is cheap, if you know what to do, so I'm not against the advice at all. This has to handle kids and adults, and has to outlast us. .... If you feel the need to do something, I'd use a) threadlock b) nylon insert nut c) star washer over split-ring locknuts. There's a camp that have a theory that they serve no useful purpose at all (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900009424_1990009424.pdf for the NASA Fastener Design Manual). BTW, for overhead use, malleable wire rope clips are not recommended; drop forged are ok. For rigging overhead lifts, cable clips aren't allowed at all, but with the above caveat on type they are allowed for static overhead loads. See http://blog.uscargocontrol.com/how-to-use-wire-rope-clips/ for some other specifics. -- |
#9
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
On 09/28/2014 12:31 PM, Oren wrote:
On Sun, 28 Sep 2014 16:50:02 +0000 (UTC), "Danny D." wrote: Following that diagram, we put the "saddle" of the clamps on the "live end" (the mnemonic we used was "don't saddle a dead horse"). http://www.pirate4x4.com/tech/billav...pe%20clips.jpg Just curious. Is there a torque spec for those clamps? Or ... Yeah...just noticed Danny has referenced the Crosby data so he undoubtedly has seen the table there...for the 3/8", they recommend 45 ft-lb. http://www.fdlake.com/wrclips.html I still think the clips should be used as delivered by the manufacturer (w/o any additional locknut, that is), with, at most, some threadlock or perhaps substituting a nylok nut. If were really, really, paranoid, guess could test the fully-torqued position and then drill and go to castle nut and pin on a couple. But, thermal expansion is not an issue that's going to cause any loosening of the fasteners if torqued. -- |
#10
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Sun, 28 Sep 2014 13:54:02 -0500, dpb wrote:
On 09/28/2014 12:31 PM, Oren wrote: On Sun, 28 Sep 2014 16:50:02 +0000 (UTC), "Danny D." wrote: Following that diagram, we put the "saddle" of the clamps on the "live end" (the mnemonic we used was "don't saddle a dead horse"). http://www.pirate4x4.com/tech/billav...pe%20clips.jpg Just curious. Is there a torque spec for those clamps? Or ... Yeah...just noticed Danny has referenced the Crosby data so he undoubtedly has seen the table there...for the 3/8", they recommend 45 ft-lb. http://www.fdlake.com/wrclips.html I still think the clips should be used as delivered by the manufacturer (w/o any additional locknut, that is), with, at most, some threadlock or perhaps substituting a nylok nut. If were really, really, paranoid, guess could test the fully-torqued position and then drill and go to castle nut and pin on a couple. But, thermal expansion is not an issue that's going to cause any loosening of the fasteners if torqued. Good link. Danny should go back an torque the nuts on the clamps. I would, for sure, now that is important to do so. I'd agree on some threadlock too. -- Definition of a camel: A horse designed by a committee |
#11
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
On 9/28/2014 9:50 AM, Danny D. wrote:
.... snip On the big tree, 125 feet away, we will add a wraparound additional steel cable, so that the middle also has two cables. .... snip Any other tips are welcome, as we're just now at the stage where we have the ability to build the 125 foot long bridge starting about 15 feet up in a pine, and then going straight across a steep slope through the set of two redwoods, and then on to the really big redwood 125 feet down the slope. The treehouse will be in the middle of the bridge. Are you saying that the tree house will be in the middle of a 125 foot suspension bridge. How much will the tree house weigh when fully loaded and do you have any idea of the forces that may be in the cables? Dan |
#12
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
dpb wrote, on Sun, 28 Sep 2014 13:54:02 -0500:
I still think the clips should be used as delivered by the manufacturer They *are* designed for this purpose, are they not? They didn't come with lock washers. I'm sure we have nothing against putting them on; but, if they really needed lock washers, wouldn't they have come with them? |
#13
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Oren wrote, on Sun, 28 Sep 2014 12:30:52 -0700:
I'd agree on some threadlock too. Threadlock isn't a bad idea. In fact, it's a great idea. Wish I had thought of that sooner; but we still have the backside of the big redwood downhill to add the extra wire to, so there's still time yet. |
#14
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
G. Ross wrote, on Sun, 28 Sep 2014 13:39:26 -0400:
I agree with the turnbuckle, or some way to adjust the tension in case the bridge wants to tilt to one side. We plan on balancing the load. Maybe that won't work - maybe it will. If we need to, the turnbuckle can be added (somehow) as a rube goldberg; but at the moment, the load is supposed to be balanced when we build the bridge hanging from the cables. |
#15
Posted to alt.home.repair,sci.electronics.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Dan Coby wrote, on Sun, 28 Sep 2014 12:34:27 -0700:
Are you saying that the tree house will be in the middle of a 125 foot suspension bridge. How much will the tree house weigh when fully loaded and do you have any idea of the forces that may be in the cables? The tree house will be where our cargo net currently is. That's roughly half way from the uphill pine to the downhill big redwood (with two little redwoods, side by side, in between). The steel cables can handle 14,000 pounds each. That's 28,000 pounds (because we maintain a double cable throughout). We don't know how much the bridge & treehouse will weigh, but if it's close to or greater than 28,000 pounds, then we have a problem. How much do you think a treehouse will weigh? |
#16
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Sun, 28 Sep 2014 21:11:55 +0000 (UTC), "Danny D."
wrote: dpb wrote, on Sun, 28 Sep 2014 13:54:02 -0500: I still think the clips should be used as delivered by the manufacturer They *are* designed for this purpose, are they not? They didn't come with lock washers. I'm sure we have nothing against putting them on; but, if they really needed lock washers, wouldn't they have come with them? Mentioned twice here. Torque the nuts on the cable clamps to specs. I would. |
#17
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Oren wrote, on Sun, 28 Sep 2014 14:21:31 -0700:
Mentioned twice here. Torque the nuts on the cable clamps to specs. Yup. 45 foot pounds. Thanks. I'm relaying all this information to the neighbor as I'm just a helping hand. I jokingly refer to myself as the "union worker" because I make jokes about OSHA getting on their case every time I have to climb one of those ladders! I do apologize that updates are slow, as I can't snap a picture unless I'm there, and the treehouse is only worked on during the weekends, and I'm not always there to help, but I will try to snap pictures as we progress. Dunno if I should append all to the same thread, as the way "I" read this newsgroup is that I only look at the threads from the last day or three. Dunno how others look at older threads, 'cuz this could take a few months elapsed time. |
#18
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Sun, 28 Sep 2014 21:13:12 +0000 (UTC), "Danny D."
wrote: Oren wrote, on Sun, 28 Sep 2014 12:30:52 -0700: I'd agree on some threadlock too. Threadlock isn't a bad idea. In fact, it's a great idea. Wish I had thought of that sooner; but we still have the backside of the big redwood downhill to add the extra wire to, so there's still time yet. I'm not an expert but at a minimum I would use threadlock AND torque nuts on those clamps. Some torque wrenches are small and short, will give what you need and are easy to carry up to the project. Double check your work... |
#19
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Building a treehouse in the redwood grove of a neighbor (pics included)
Danny D. wrote:
dpb wrote, on Sun, 28 Sep 2014 13:54:02 -0500: I still think the clips should be used as delivered by the manufacturer They *are* designed for this purpose, are they not? They didn't come with lock washers. I'm sure we have nothing against putting them on; but, if they really needed lock washers, wouldn't they have come with them? Yes. -- -Mike- |
#20
Posted to alt.home.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
On 09/28/2014 4:14 PM, Danny D. wrote:
G. Ross wrote, on Sun, 28 Sep 2014 13:39:26 -0400: I agree with the turnbuckle, or some way to adjust the tension in case the bridge wants to tilt to one side. We plan on balancing the load. Maybe that won't work - maybe it will. If we need to, the turnbuckle can be added (somehow) as a rube goldberg; but at the moment, the load is supposed to be balanced when we build the bridge hanging from the cables. I'd suggest it (balance control) will become mandatory and mayest as well design it in from the git-go. W/ as much effort as you're investing, this is a pretty minimal addition. -- |
#21
Posted to alt.home.repair,sci.electronics.repair,rec.woodworking
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
On 9/28/2014 2:18 PM, Danny D. wrote:
Dan Coby wrote, on Sun, 28 Sep 2014 12:34:27 -0700: Are you saying that the tree house will be in the middle of a 125 foot suspension bridge. How much will the tree house weigh when fully loaded and do you have any idea of the forces that may be in the cables? The tree house will be where our cargo net currently is. That's roughly half way from the uphill pine to the downhill big redwood (with two little redwoods, side by side, in between). The steel cables can handle 14,000 pounds each. That's 28,000 pounds (because we maintain a double cable throughout). You also have to consider the geometry of what you are creating. If you are tensioning the cables for very little sag then the forces in the cable can be many time the weight of the tree house. Without knowing exactly what you are creating then I cannot guess. That is why I asked if you had any ideas of the forces in the cable. We don't know how much the bridge & treehouse will weigh, but if it's close to or greater than 28,000 pounds, then we have a problem. How much do you think a treehouse will weigh? I do not know what you are planning upon building. That was why I asked you. If you are talking about the tree houses that we built as kids with a plywood floor and a few boards and a tar paper roof then only a couple of hundred pounds. If you are talking about some of the multi story creations that I have seen on TV then many tons. Dan |
#22
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Dan Coby wrote, on Sun, 28 Sep 2014 20:32:48 -0700:
If you are tensioning the cables for very little sag then the forces in the cable can be many time the weight of the tree house. We "tensioned" the cables, by hand. What we literally did was put a broomstick through the 60 pound wooden spool of 250 feet of 3/8" steel cable and we mounted that on two chairs about 15 feet downhill of a big pine tree. Then we went uphill to that pine tree at a point about 15 feet off the ground and then back to the chairs with the spool of wire. At that point, we tied a rope to the end of the wire, and we walked the wire downhill a little less than about 100 feet to a big redwood. At that redwood, we climbed up to the same height as the pine (which, since it's downhill, is about 40 or so feet up in the air) and we pulled the rope with the wire cable attached. Then we pulled the rope which pulled the cable back up the hill back to the point on the path 15 feet below the pine, where we pulled it tight by hand, and then clamped the 8 clamps on. Then, we simply slid the cable around the big redwood and slid it around the pine, until the cable clamps were symmetric around the pine, as shown in the last set of pictures. I won't mention the fact that we accidentally crossed the cables because we went around the big redwood the wrong way, as that's embarrassing to mention. Nor will I mention how many times we got hung up in the branches between trees, necessitating mid-air precarious surgery on the trees. Given all that, I wouldn't call the tension all that tight. You can see the sag in the photos. Maybe it sags, oh, I don't know, about 5 to 10 feet maybe? I do not know what you are planning upon building. That was why I asked you. If you are talking about the tree houses that we built as kids with a plywood floor and a few boards and a tar paper roof then only a couple of hundred pounds. If you are talking about some of the multi story creations that I have seen on TV then many tons. I think we're talking just a plywood box, with a deck. I should mention that there will be anchors on the two little redwoods, so, the treehouse won't actually be floating on all sides. The bridge *will* be floating though. It should be fun once it's done and wired for Internet. It has a great view once you're up in the redwoods. |
#23
Posted to rec.woodworking
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Building a tree house in the redwood grove of a neighbor (pics included)
"Dan Coby" wrote You also have to consider the geometry of what you are creating. If you are tensioning the cables for very little sag then the forces in the cable can be many time the weight of the tree house. Without knowing exactly what you are creating then I cannot guess. That is why I asked if you had any ideas of the forces in the cable. We don't know how much the bridge & treehouse will weigh, but if it's close to or greater than 28,000 pounds, then we have a problem. How much do you think a treehouse will weigh? I do not know what you are planning upon building. That was why I asked you. If you are talking about the tree houses that we built as kids with a plywood floor and a few boards and a tar paper roof then only a couple of hundred pounds. If you are talking about some of the multi story creations that I have seen on TV then many tons. I agree with Dan's concern. Someone with good trig math skills needs to figure this for them. I would "eyeball" calculate that the load on the cables would be at least 3 to 5 times the weight of the structure and the added weight of the occupants and furnishings. It could be much higher than that. It would appear to me that you are beginning to cross into the zone of pushing the design strength of the cable. Another engineering principle here would also be involved. That of safety design limits. A totally dependant system such as this, where failure of one system could and would probably cause loss of life would be designed with a 150% safety factor. That means that a structure weighing 4200 pounds would be the maximum, if you used the figure of the tension increased by the geometry from the load by five times. You seriously, seriously need to get a structural engineer involved before you proceed. I believe you are playing with fire, that could get someone baldy hurt, or worse. -- Jim in NC --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com |
#24
Posted to rec.woodworking
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Building a tree house in the redwood grove of a neighbor (pics included)
"Morgans" wrote in
: "Dan Coby" wrote You also have to consider the geometry of what you are creating. If you are tensioning the cables for very little sag then the forces in the cable can be many time the weight of the tree house. Without knowing exactly what you are creating then I cannot guess. That is why I asked if you had any ideas of the forces in the cable. We don't know how much the bridge & treehouse will weigh, but if it's close to or greater than 28,000 pounds, then we have a problem. How much do you think a treehouse will weigh? I do not know what you are planning upon building. That was why I asked you. If you are talking about the tree houses that we built as kids with a plywood floor and a few boards and a tar paper roof then only a couple of hundred pounds. If you are talking about some of the multi story creations that I have seen on TV then many tons. I agree with Dan's concern. Someone with good trig math skills needs to figure this for them. I would "eyeball" calculate that the load on the cables would be at least 3 to 5 times the weight of the structure and the added weight of the occupants and furnishings. It could be much higher than that. It would appear to me that you are beginning to cross into the zone of pushing the design strength of the cable. Another engineering principle here would also be involved. That of safety design limits. A totally dependant system such as this, where failure of one system could and would probably cause loss of life would be designed with a 150% safety factor. That means that a structure weighing 4200 pounds would be the maximum, if you used the figure of the tension increased by the geometry from the load by five times. You seriously, seriously need to get a structural engineer involved before you proceed. I believe you are playing with fire, that could get someone baldy hurt, or worse. If his eyball sag estimate is accurate, the geometry could be multiplying the forces by a factor of ten. Four average 180 lb adults + weight of cables and structure and it already looks marginal. Also, real suspension bridges dont anchor the cables to the end towers. They take the cables over saddles to properly engineered ground anchors (grouted into bedrock if possible) to mimimise or eliminate the bending stress on the end towers. A static side load of 10000 lb or more 50' to 70' above ground level on a tree growing from a steep slope that may well have an assymetric root ball or have major roots compromised by having grown round boulders is *NOT* a good idea. Dynamic loading is going to make the situation even worse. I wouldn't be surprised if the whole lot comes down in the first big storm taking several of the trees with it. I wouldn't want to be within 50 yards of any of the cables or anywhere downslope if anything fails. Also the lifespan is going to be pretty short. I wouldn't trust it more than 5 years later unless the cables and their fixings are professionally inspected and maintained and cable replacement every 10 years will probably be required. -- Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED) ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk [at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL |
#25
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
On 09/28/2014, 2:18 PM, Danny D. wrote:
Dan Coby wrote, on Sun, 28 Sep 2014 12:34:27 -0700: Are you saying that the tree house will be in the middle of a 125 foot suspension bridge. How much will the tree house weigh when fully loaded and do you have any idea of the forces that may be in the cables? The tree house will be where our cargo net currently is. That's roughly half way from the uphill pine to the downhill big redwood (with two little redwoods, side by side, in between). The steel cables can handle 14,000 pounds each. That's 28,000 pounds (because we maintain a double cable throughout). We don't know how much the bridge & treehouse will weigh, but if it's close to or greater than 28,000 pounds, then we have a problem. How much do you think a treehouse will weigh? Have you allowed for a windstorm where the trees may be moving in opposite directions to each other? Temperature affects the length of the wire rope, have you allowed for maximum and minimum temperatures? You want some sort of shock absorption built in too. Old antennas used porcelain blocks for joining cables, the porcelain would shatter under unexpected loads giving the cables a chunk of extra slack to avoid their collapse by stretching beyond limits. May I suggest you find an engineer to look over your design? I'm not one, but can think of a few ways for this to go wrong already including the clamps failing etc. Suspension bridges are close to what you are building - read up on the design criteria for these. Seat of the pants design may give you another Tacoma bridge... John :-#)# PS, it looks like a lot of fun though! |
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
John Robertson wrote, on Mon, 29 Sep 2014 09:54:57 -0700:
Have you allowed for a windstorm where the trees may be moving in opposite directions to each other? Have you allowed for maximum and minimum temperatures? Only that each cable supports 14,000 pounds! You want some sort of shock absorption built in too. Hmmmmmm.... The cables don't "give" a little when you walk on the bridge that would be hanging below it? May I suggest you find an engineer to look over your design? The neighbors are all owners of companies and people with graduate degrees, so, they *are* engineers (of all types). The one having the most fun with the design is the retired carrier fighter pilot. Suspension bridges are close to what you are building Yes. I'm told the catenary will turn into a parabola once we hang the bridge off of it. Since the bridge starts uphill about 15 feet above the trail, it will be fun to just step onto the bridge, at the level of the trail, and then walk "downhill" level but going higher and higher above the steeply sloping ground, to get to the two smaller redwoods in the middle of the span. At that point, we will be in the "treehouse" which will have a deck and WiFi and a great open view of the mountains. Then, if we want, we can walk further to the *big* redwood, which will have sleeping quarters (hammocks and cargo nets) for the nights we'll spend there. It should be fun, once done, and I'll try to keep you guys informed; but I personally am not designing or building it; I'm just the free help (we all have Spanish nicknames when we do free labor. I'm "Rodruigo", and my wife's nom-de-labor is "Marisol", for example). I keep threatening that I'm gonna call OSHA on them if I fall or if they don't provide cold soda (the free soda has been warm, to date). |
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Oren wrote, on Sun, 28 Sep 2014 14:32:36 -0700:
Double check your work... Speaking of doublechecking my work ... notice this pictu https://c3.staticflickr.com/3/2946/1...0d135ae2_b.jpg It's how I *finally* learned how to hook up the ascender so that when I climb the precarious ladders, the ascender just slides *up* the rope, with effortless ease, but, it *locks* into place instantly if/when I fall. You won't notice, but, there are *two* mistakes that I didn't make in *that* picture, but which I had made when I *first* hooked up: The amber carabiner placement is critical: 1. It goes AROUND the rope (not outside the rope). 2. It goes on the TOP (not the bottom of the ascender). I learned both those tidbits the hard but gentle way. At first, I had hooked the carabiner on the bottom of the ascender, thinking that the top hole was already *busy* with the rope, but, what happened when I tried climbing up the ladder was that the ascender, which is clipped to my waist by a locking carabiner, flipped upside down as I went up the ladder. Then, I tried hooking the amber carabiner to the top hole, which prevented the flip, but which actually hindered the rope movement if it was outside the rope. So then I hooked the amber carabiner *around* the rope, and then everything worked smoothly, as it should. As I climb the ladder, the ascender just slips on the rope, causing no problems whatsoever; but the moment I descend, it locks instantly in place. Trial and error ... but it works nicely now that I know how to set it up. |
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Oren wrote, on Sun, 28 Sep 2014 10:31:43 -0700:
Just curious. Is there a torque spec for those clamps? Or ... I had forwarded this thread to the owner of the treehouse in the redwoods, who replied with the following ... ----------- People worry too much. I simply design for 10 times the expected load, and pay the premium. Trying to finely engineer the solution where torque and special fasteners are important is a way to save money, and I'd rather spend the money and not waste my time. I've never seen a malleable cable clamp. Drop forged ones are cheap, and I use more than normal anyway, not because I think they are needed, but because they help keep the cable from slipping out of place on the wood block spacers. The reason for keeping the U-bolt on the dead end of the cable is because the saddle has a lot more surface area, and thus does not reduce the strength of the cable as much as the U-bolt does. But they make dual-saddle cable clamps, for those who don't use the over-engineering approach I do. Each cable can support 7 tons, so the total weight of treehouse and occupants can be 14 tons. (Although there will be other supports besides the cable -- one end will rest on the ground, and another end will be anchored to the tree, and there may be other support cables used just to make installation and leveling easier.) If half of the weight is treehouse and the other half is people, we have 7 tons of treehouse possible (although the actual treehouse will probably weigh less than 1.4 tons fully furnished), and 7 tons of people (70 people, if they are all 200 pounds). I doubt we will ever have 70 people in the treehouse -- they'd be shoulder-to-shoulder. |
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Mon, 29 Sep 2014 19:37:20 +0000 (UTC), "Danny D."
wrote: Oren wrote, on Sun, 28 Sep 2014 14:32:36 -0700: Double check your work... Speaking of doublechecking my work ... notice this pictu https://c3.staticflickr.com/3/2946/1...0d135ae2_b.jpg It's how I *finally* learned how to hook up the ascender so that when I climb the precarious ladders, the ascender just slides *up* the rope, with effortless ease, but, it *locks* into place instantly if/when I fall. You won't notice, but, there are *two* mistakes that I didn't make in *that* picture, but which I had made when I *first* hooked up: The amber carabiner placement is critical: 1. It goes AROUND the rope (not outside the rope). 2. It goes on the TOP (not the bottom of the ascender). I learned both those tidbits the hard but gentle way. At first, I had hooked the carabiner on the bottom of the ascender, thinking that the top hole was already *busy* with the rope, but, what happened when I tried climbing up the ladder was that the ascender, which is clipped to my waist by a locking carabiner, flipped upside down as I went up the ladder. Then, I tried hooking the amber carabiner to the top hole, which prevented the flip, but which actually hindered the rope movement if it was outside the rope. So then I hooked the amber carabiner *around* the rope, and then everything worked smoothly, as it should. As I climb the ladder, the ascender just slips on the rope, causing no problems whatsoever; but the moment I descend, it locks instantly in place. Trial and error ... but it works nicely now that I know how to set it up. Looks like you're having fun. You couldn't pay me to do that project. My knees start knocking together on a secure scaffold. |
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Mon, 29 Sep 2014 21:41:56 +0000 (UTC), "Danny D."
wrote: Oren wrote, on Sun, 28 Sep 2014 10:31:43 -0700: Just curious. Is there a torque spec for those clamps? Or ... I had forwarded this thread to the owner of the treehouse in the redwoods, who replied with the following ... ----------- People worry too much. I simply design for 10 times the expected load, and pay the premium. Trying to finely engineer the solution where torque and special fasteners are important is a way to save money, and I'd rather spend the money and not waste my time. I've never seen a malleable cable clamp. Drop forged ones are cheap, and I use more than normal anyway, not because I think they are needed, but because they help keep the cable from slipping out of place on the wood block spacers. The reason for keeping the U-bolt on the dead end of the cable is because the saddle has a lot more surface area, and thus does not reduce the strength of the cable as much as the U-bolt does. But they make dual-saddle cable clamps, for those who don't use the over-engineering approach I do. Each cable can support 7 tons, so the total weight of treehouse and occupants can be 14 tons. (Although there will be other supports besides the cable -- one end will rest on the ground, and another end will be anchored to the tree, and there may be other support cables used just to make installation and leveling easier.) If half of the weight is treehouse and the other half is people, we have 7 tons of treehouse possible (although the actual treehouse will probably weigh less than 1.4 tons fully furnished), and 7 tons of people (70 people, if they are all 200 pounds). I doubt we will ever have 70 people in the treehouse -- they'd be shoulder-to-shoulder. My point was, if the clamps call for a torque spec, and we now understand they do - why not follow the details made by the manufacturers? I'd just feel comfortable doing so. Your friend can do as he pleases. I get the point of over building something. I've done hear for a patio cover on my house. Pick your poison |
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Mon, 29 Sep 2014 19:25:42 +0000 (UTC), "Danny D."
wrote: I'm just the free help (we all have Spanish nicknames when we do free labor. I'm "Rodruigo", and my wife's nom-de-labor is "Marisol", for example). I keep threatening that I'm gonna call OSHA on them if I fall or if they don't provide cold soda (the free soda has been warm, to date). It's an insult to call a Mexican a Spaniard! -- "..,what is good is the front end if you don't have the back end"-- Kimberly Guilfoyle |
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Oren wrote, on Mon, 29 Sep 2014 16:02:48 -0700:
It's an insult to call a Mexican a Spaniard! I guess it's like calling an Asian an Oriental? Who is insulted when I equate Mexico with Spain anyway? The Mexicans? Or the Spaniards? (I don't know these things.) |
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Oren wrote, on Mon, 29 Sep 2014 15:20:20 -0700:
Your friend can do as he pleases. I get the point of over building something. The good news is that, if the whole thing collapses, *he* gets sued, not me! |
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Mon, 29 Sep 2014 23:15:51 +0000 (UTC), "Danny D."
wrote: Oren wrote, on Mon, 29 Sep 2014 16:02:48 -0700: It's an insult to call a Mexican a Spaniard! I guess it's like calling an Asian an Oriental? Crazy Uncle Joe Biden? Who is insulted when I equate Mexico with Spain anyway? The Mexicans? Or the Spaniards? (I don't know these things.) The Mexicans are offended. Ask one that knows some history or lack of. |
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Mon, 29 Sep 2014 23:20:40 +0000 (UTC), "Danny D."
wrote: Oren wrote, on Mon, 29 Sep 2014 15:20:20 -0700: Your friend can do as he pleases. I get the point of over building something. The good news is that, if the whole thing collapses, *he* gets sued, not me! But you are one of the conspirators in negligence, unwittingly. Neither can sue the clamp maker. (G) |
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
On 2014-09-29, Danny D. wrote:
Oren wrote, on Mon, 29 Sep 2014 16:02:48 -0700: It's an insult to call a Mexican a Spaniard! I guess it's like calling an Asian an Oriental? No, that's pretty much correct (if rather dated). "Oriental" literally means somebody from "the East". Asia is usually defined as "East of the Urals". Both are somewhat vague terms with meanings that have changed over the centuries, but Wikipedia says the're pretty much the equivalent: The Orient means the East. It is a traditional designation for anything that belongs to the Eastern world or the Middle East (aka Near East) or the Far East, in relation to Europe. In English, it is largely a metonym for, and coterminous with, the Continent of Asia. Calling a Mexican a Spaniard is like calling somebody from the US "English" or "British". Rather than being insulted, I think people are just going to be puzzled over where you've been for the last 250 years. Who is insulted when I equate Mexico with Spain anyway? The Mexicans? Or the Spaniards? Either, both, maybe neither (it probably depends on the crowd). Regardless of whether it's insulting, it's incorrect. -- Grant |
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Mon, 29 Sep 2014 21:41:56 +0000 (UTC), "Danny D."
wrote: Oren wrote, on Sun, 28 Sep 2014 10:31:43 -0700: Just curious. Is there a torque spec for those clamps? Or ... I had forwarded this thread to the owner of the treehouse in the redwoods, who replied with the following ... ----------- People worry too much. I simply design for 10 times the expected load, and pay the premium. Trying to finely engineer the solution where torque and special fasteners are important is a way to save money, and I'd rather spend the money and not waste my time. I've never seen a malleable cable clamp. Drop forged ones are cheap, and I use more than normal anyway, not because I think they are needed, but because they help keep the cable from slipping out of place on the wood block spacers. The reason for keeping the U-bolt on the dead end of the cable is because the saddle has a lot more surface area, and thus does not reduce the strength of the cable as much as the U-bolt does. But they make dual-saddle cable clamps, for those who don't use the over-engineering approach I do. Each cable can support 7 tons, so the total weight of treehouse and occupants can be 14 tons. (Although there will be other supports besides the cable -- one end will rest on the ground, and another end will be anchored to the tree, and there may be other support cables used just to make installation and leveling easier.) If half of the weight is treehouse and the other half is people, we have 7 tons of treehouse possible (although the actual treehouse will probably weigh less than 1.4 tons fully furnished), and 7 tons of people (70 people, if they are all 200 pounds). I doubt we will ever have 70 people in the treehouse -- they'd be shoulder-to-shoulder. I hear that about over engineering stuff. When I was getting ready to pour the floor for my shop I calculated the concrete thickness for the various machines and then though about what happens if I move a machine and then what happens if I buy a heavier machine or one with a smaller footprint and so on. Then I realized how pointless this was in my situation, So I had the concrete poured to 7 inch minimum thickness, had fiber put in the concrete, and I put rebar and wire mesh in place before the pour. It's a good thing too because I later bought a lathe that covers 10 square feet with the base and sits on 4 9 square inch pads and weighs 8000 lbs. Eric |
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
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Building a treehouse in the redwood grove of a neighbor (pics included)
On Mon, 29 Sep 2014 23:38:14 +0000 (UTC), Grant Edwards
wrote: Calling a Mexican a Spaniard is like calling somebody from the US "English" or "British". Rather than being insulted, I think people are just going to be puzzled over where you've been for the last 250 years. Anything wrong with calling a 1980 Mariel Cuban prisoner a "Beaner"? They love black beans and rice. They didn't seem to be offended. -- Somtimes you just have a bad day at the dungeon |
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Building a treehouse in the redwood grove of a neighbor (picsincluded)
Danny D. wrote:
8 Snip At that point, we will be in the "treehouse" which will have a deck and WiFi and a great open view of the mountains. 8 Snip You keep talking about WiFi. More important is a refrig for the beer. Why would anyone want WiFi in a treehouse. I would think this would be a place to escape all that stuff. -- GW Ross 1st Law of Thermodynamics: Go to class!! |
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