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/3/2942/15372056651_7a845164f7_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/3/2945/15188529430_6294070f9b_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/3/2944/15188634078_2b3de04150_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/3/2943/15188529300_bbedf3ba0c_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/4/3901/15188714847_e77461b64d_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/3/2945/15375216105_9961137c64_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/4/3870/15188634228_37f45d19e2_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.
On Mon, 29 Sep 2014 21:35:11 -0400, Stormin Mormon
<[email protected]> wrote:
>>> beer. Why would anyone want WiFi in a treehouse. I would think this
>>> would be a place to escape all that stuff.
>>
>> The WIFI is how one orders more beer delivery. Can I help you further?
>>
>With your antenna that high, can't you pirate a
>signal from a neighbor?
Who manages the network?
On Mon, 29 Sep 2014 19:25:42 +0000 (UTC), "Danny D."
<[email protected]> 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
On Mon, 29 Sep 2014 23:15:51 +0000 (UTC), "Danny D."
<[email protected]> 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.
On Sun, 28 Sep 2014 13:54:02 -0500, dpb <[email protected]> wrote:
>On 09/28/2014 12:31 PM, Oren wrote:
>> On Sun, 28 Sep 2014 16:50:02 +0000 (UTC), "Danny D."
>> <[email protected]> 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/billavista/Recovery/use%20of%20wire%20rope%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
"Danny D." wrote:
> Only that each cable supports 14,000 pounds!
----------------------------------------------
In days of yore I worked as a design engineer for heavy duty
steel mill and foundry equipment, but that was then and this is now.
For designs involving steel cable and human safety, the basic
safety factor applied was 5.
IOW, 14,000/5 = 2,800 pounds as the basic design limit.
Dynamic loading would apply another 50% derate.
IOW, 2,800*50% = 1,400 pounds for dynamic loads.
Based on the posts I have seen, your group needs some
serious help before people get hurt or worse.
Lew Hodgett, PE Retired
"Danny D." wrote:
>> Only that each cable supports 14,000 pounds!
----------------------------------------------
"Lew Hodgett" wrote:
> In days of yore I worked as a design engineer for heavy duty
> steel mill and foundry equipment, but that was then and this is now.
>
> For designs involving steel cable and human safety, the basic
> safety factor applied was 5.
>
> IOW, 14,000/5 = 2,800 pounds as the basic design limit.
>
> Dynamic loading would apply another 50% derate.
>
> IOW, 2,800*50% = 1,400 pounds for dynamic loads.
>
> Based on the posts I have seen, your group needs some
> serious help before people get hurt or worse.
>
> Lew Hodgett, PE Retired
-----------------------------------------------------
What I forgot to include was that the above design loads are for
tensile loads.
Bending loads require a further derate.
The reader is left to determine the value from any decent
structural engineering text.
And now you know one of the reasons why I'm retired.
Lew Hodgett, PE Retired
On 9/30/2014 8:37 PM, Lew Hodgett wrote:
>> IOW, 14,000/5 = 2,800 pounds as the basic design limit.
>>
>> Dynamic loading would apply another 50% derate.
> Bending loads require a further derate.
>
> The reader is left to determine the value from any decent
> structural engineering text.
>
> And now you know one of the reasons why I'm retired.
>
> Lew Hodgett, PE Retired
>
Sounds like not much fort, at derate we're going.
--
.
Christopher A. Young
Learn about Jesus
www.lds.org
.
On Mon, 29 Sep 2014 20:38:51 -0400, "G. Ross" <[email protected]>
wrote:
>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.
The WIFI is how one orders more beer delivery. Can I help you further?
On Mon, 29 Sep 2014 21:41:56 +0000 (UTC), "Danny D."
<[email protected]> 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 :)
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!!
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!
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
On 09/29/2014, 8:37 PM, Danny D. wrote:
> Lew Hodgett wrote, on Mon, 29 Sep 2014 18:29:57 -0700:
>
>> IOW, 14,000/5 = 2,800 pounds as the basic design limit.
>
> Times two cables, which is 5,600 pounds, at least. :)
>
My last comments - this is not looking so good..
Bending a cable around a support weakens the cable - there is a formula
for that:
http://unirope.com/products/slings/wire-rope-slings/rigging-guidelines/dd-ratio-and-the-effect-on-sling-capacity/
So that derates the cable strength from 10% to 60% depending on the
curve. Note too that they are using wooden standoff/chocks to hold the
wire, I hope they chamfered a notch - but in any case the load is not
consistent on the tree, rather it is concentrated on only a few of those
wooden chocks. This is a derating aspect too.
Looking at picture:
https://c3.staticflickr.com/3/2944/15188634078_2b3de04150_c.jpg
It looks like the cable does a bit of a sharp bend where it leaves the
standoff...this is potentially a real problem - kinks are possible. The
pinching of the cable at the clamps also derates the cable strength...
Wire Rope is certainly varied in structure. However I do keep seeing the
1:5 load factor (1/5 of rating) in various Wire Rope 101 pamphlets...
It does appear that the folks selling wire rope are only too happy to
advise in its use - your friends would be advised to show them the
proposal for comment before they put too much weight on these wire ropes.
John
--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
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!!
On Mon, 29 Sep 2014 21:41:56 +0000 (UTC), "Danny D."
<[email protected]> 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
On 9/29/2014 8:49 PM, Oren wrote:
> On Mon, 29 Sep 2014 20:38:51 -0400, "G. Ross" <[email protected]>
> wrote:
>
>> 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.
>
> The WIFI is how one orders more beer delivery. Can I help you further?
>
With your antenna that high, can't you pirate a
signal from a neighbor?
.
Christopher A. Young
Learn about Jesus
www.lds.org
.
On Sun, 28 Sep 2014 21:11:55 +0000 (UTC), "Danny D."
<[email protected]> 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.
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
On Mon, 29 Sep 2014 23:38:14 +0000 (UTC), Grant Edwards
<[email protected]> 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
On Tue, 30 Sep 2014 14:05:29 -0500, Leon <lcb11211@swbelldotnet>
wrote:
>On 9/29/2014 6:02 PM, Oren wrote:
>> On Mon, 29 Sep 2014 19:25:42 +0000 (UTC), "Danny D."
>> <[email protected]> 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!
>>
>
>Why did you say that? Having a Spanish nick name does not assess any
>nationality at all.
I was suggesting to Danny, based on my experience, that Mexicans do
like to be called Spaniards. They take is personally. I can't speak
for every Mexican, just what I have observed. Call a Mexican a
"wetback" - they don't seem so bothered by it.
On Sun, 28 Sep 2014 16:50:02 +0000 (UTC), "Danny D."
<[email protected]> 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/billavista/Recovery/use%20of%20wire%20rope%20clips.jpg
Just curious. Is there a torque spec for those clamps? Or ...
On Mon, 29 Sep 2014 23:20:40 +0000 (UTC), "Danny D."
<[email protected]> 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)
On 9/29/2014 7:42 PM, [email protected] wrote:
> 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
>
Sounds like my elementary school lunch room
monitor woman. We used to call her Bubbles.
.
Christopher A. Young
Learn about Jesus
www.lds.org
.
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 here:
http://www.pirate4x4.com/tech/billavista/Recovery/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/billavista/Recovery/use%20of%20wire%20rope%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.
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.
--
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/4/3865/15195194790_8fe8c93589_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.
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 here:
https://c3.staticflickr.com/3/2944/15188634078_2b3de04150_c.jpg
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.
--
On 09/28/2014 12:31 PM, Oren wrote:
> On Sun, 28 Sep 2014 16:50:02 +0000 (UTC), "Danny D."
> <[email protected]> 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/billavista/Recovery/use%20of%20wire%20rope%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.
--
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?
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.
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?
"Morgans" <[email protected]> wrote in
news:[email protected]:
>
>
> "Dan Coby" <[email protected]> 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
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-
[email protected]
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.
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.
--
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.
"Dan Coby" <[email protected]> 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.
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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).
Oren wrote, on Sun, 28 Sep 2014 14:32:36 -0700:
> Double check your work...
Speaking of doublechecking my work ... notice this picture:
https://c3.staticflickr.com/3/2946/15206962868_bf0d135ae2_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.
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.
On 2014-09-29, Danny D. <[email protected]> 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
On 09/29/2014 6:42 PM, [email protected] wrote:
...
> ... 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.
8k/4/(9^2) --> 56 psi
Not much load, really.
--
On 2014-09-30, Oren <[email protected]> wrote:
> On Mon, 29 Sep 2014 23:38:14 +0000 (UTC), Grant Edwards
><[email protected]> 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"?
That's generally considered offensive, racist, and ignorant.
> They love black beans and rice. They didn't seem to be offended.
Perhaps they have better manners.
--
Grant Edwards grant.b.edwards Yow! This PORCUPINE knows
at his ZIPCODE ... And he has
gmail.com "VISA"!!
Grant Edwards wrote:
> On 2014-09-30, Oren <[email protected]> wrote:
>> On Mon, 29 Sep 2014 23:38:14 +0000 (UTC), Grant Edwards
>> <[email protected]> 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"?
>
> That's generally considered offensive, racist, and ignorant.
No - that's considered a Politcally Correct way of thinking. It's neither
ignorant, nor is it offensive, unless someone like yourself decides to
declare it so. But - your declaration does not make it reality. I would
argue that regardless of the PC community, things like this are not at all
"generally considered" to be the way you view them.
--
-Mike-
[email protected]
"Danny D." wrote in message news:[email protected]...
Lew Hodgett wrote, on Mon, 29 Sep 2014 18:29:57 -0700:
> IOW, 14,000/5 = 2,800 pounds as the basic design limit.
Times two cables, which is 5,600 pounds, at least. :)
************************************
If you have a long cable and pull on the middle of it 90 degrees to the
cable, and pull it 12 inches out, you would move the end of the cables about
an inch. That means you have 21 to 1 mechanical advantage.
Now you take your de-rated cable at 5,6000 pounds, and divide that by 12.
5,600/12 = 467 pounds before safety limits are exceeded and the possibility
of catastrophic failure. That is how much can be supported if it does not
pull the trees over, which it probably will.
I agree with many others here. If this project continues, we will read
about a tragedy in the papers. NO joke.
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On Tue, 30 Sep 2014 12:32:29 -0700, Oren <[email protected]> wrote:
>>> It's an insult to call a Mexican a Spaniard!
>>>
>>
>>Why did you say that? Having a Spanish nick name does not assess any
>>nationality at all.
>
>I was suggesting to Danny, based on my experience, that Mexicans do
>like to be called Spaniards. They take is personally. I can't speak
>for every Mexican, just what I have observed. Call a Mexican a
>"wetback" - they don't seem so bothered by it.
Leon,
Read that as "do not like to be called Spaniards"...
On Sun, 28 Sep 2014 21:13:12 +0000 (UTC), "Danny D."
<[email protected]> 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...
On Sun, 28 Sep 2014 02:41:13 +0000 (UTC), "Danny D."
<[email protected]> wrote:
>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/3/2942/15372056651_7a845164f7_c.jpg
>
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.
>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/3/2945/15188529430_6294070f9b_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/3/2944/15188634078_2b3de04150_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/3/2943/15188529300_bbedf3ba0c_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/4/3901/15188714847_e77461b64d_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/3/2945/15375216105_9961137c64_b.jpg
>
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.
Hope no one or nothing falls.
>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/4/3870/15188634228_37f45d19e2_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.
On Mon, 29 Sep 2014 19:37:20 +0000 (UTC), "Danny D."
<[email protected]> wrote:
>Oren wrote, on Sun, 28 Sep 2014 14:32:36 -0700:
>
>> Double check your work...
>
>Speaking of doublechecking my work ... notice this picture:
> https://c3.staticflickr.com/3/2946/15206962868_bf0d135ae2_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.
On Sun, 28 Sep 2014 12:34:27 -0700, Dan Coby <[email protected]> =
wrote:
>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
You better check it. Wind loads can exceed the dead loads by many times.
Wind loads may be the real issue.
?-)
=20
On 09/29/2014, 5:38 PM, G. Ross wrote:
> 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.
>
Hmm, well with two separate cables your power requirements are fine,
just run them on 24VAC @ 50A (120VAC @ 10A equivalent) and then use step
up transformer or AC to DC regulators to power everything in the tree
house. No unsightly wires!
John :-#)#
--
(Please post followups or tech inquiries to the newsgroup)
John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9
(604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)
www.flippers.com
"Old pinballers never die, they just flip out."
On 9/29/2014 6:02 PM, Oren wrote:
> On Mon, 29 Sep 2014 19:25:42 +0000 (UTC), "Danny D."
> <[email protected]> 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!
>
Why did you say that? Having a Spanish nick name does not assess any
nationality at all.