Tensahedron Stand

**MAD777** · 10-21-2017, 14:38

What the material & specs for Raftingfinger's poles?

Also, in his 2nd picture above, the angle of suspension lines is way different from the angle of the poles. Doesn't that put a bending force on the pole that we want to avoid?

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**CaptainGravity** · 10-21-2017, 14:47

Originally Posted by CaptainGravity

88" pole length (actually 8'=96" wood tree stakes, but since I plan to lash together, I need to subtract a few inches from each end. 2" diameter FYI)

Some success this morning! Tree stakes are plenty strong. My lashing skills are weak though. Also I will start subtracting ridge lines etc; I will say the main ridge line was helpful a I set it up without the hammock. More to come when I get out of this swim meet.
IMG_2869.jpg

**Latherdome** · 10-21-2017, 14:57

Originally Posted by CaptainGravity

Some success this morning! Tree stakes are plenty strong. My lashing skills are weak though. More to come when I get out of this swim meet. IMG_2869.jpg

Thing of beauty there, nerdgasms here. Must. Stop. Reloading. Thread.

MAD777: no bending moment as long as your attachment points are on the pole ends instead of anywhere else. Raftingtigger too busy hanging in chair in sunny park to report any problems

**GadgetUK437** · 10-21-2017, 15:11

Originally Posted by MAD777

if the poles are shortened also to give an 18" (half meter) sitting height.

Sit height can be adjusted by changing base width.
Also found a base width of 45" is too narrow for me, head and feet were touching poles.

--
Gadget

**jellyfish** · 10-21-2017, 15:40

I am curious what would happen if you made the leg lengths asym.

**Latherdome** · 10-21-2017, 15:44

Originally Posted by jellyfish

I am curious what would happen if you made the leg lengths asym.

Decreases stiffness requirement of short legs, more of long. Accommodates diagonal lay with marginally better material efficiency. Otherwise not much different in my test (of inadequately stout poles, summarily scrapped).

**Greenman** · 10-21-2017, 16:08

Great idea..... keep up the work Latherdome..... This is why I love this forum, so many bright ideas..

**raftingtigger** · 10-21-2017, 17:47

Originally Posted by MAD777

What the material & specs for Raftingfinger's poles?

Also, in his 2nd picture above, the angle of suspension lines is way different from the angle of the poles. Doesn't that put a bending force on the pole that we want to avoid?

Sent from my SM-G900V using Tapatalk

Just measured them at 1" OD, 1/16" CS Al 6061. I just took a break down turtle dog stand I made several years ago and used 4 of the 6 legs. The rest was by feel. The 7.5' poles made for a comfortable hammock seat in the park today. Anything longer than a hammock chair needs longer poles in my book.

Latherdome has a source of Al 7075 1" OD Easton tubing. If it isn't too expensive I'll make a stand like this with that material. FYI, He tried with AL 7075 0.742" OD poles (same as my NoGround Trekking uses) and they did not hold. Since 7075 is stronger and stiffer than 6061 it should work well.

Remember bending strength decreases exponentially with increasing length, while strength increases substantially with greater diameter and cross-section. It is a balancing act between these parameters for optimizing adequate strength (plus safety margin) and weight.

Great design Latherdome.

As for the suspension line angles: Latherdome initiated a conversation with me last night right before bed. I played with what I had first thing in the morning. Still trying to wrap my head around the physics of why this works. I hadn't even thought about the suspension angle.

**raftingtigger** · 10-21-2017, 18:22

Just went over my measurements. Poles used in my pictures are approx 6.5' long. I added a 22" segment to ONE pole (it was all I had that would fit) and that segment (now about 8.5') is wobbly. The remaining poles are solid. I only weigh 140#, so either the thickness of the poles or the diameter of the poles should be a little bigger IMHO.

Made 3 12.5 inch extensions. So 7.5 feet on three poles and 8.5' on the last. Nice sit height with my 11' hammock. Virtually no suspension cord used. I then took out the 22" and a 12" extensions on opposite ends (made it assymetrical) and with a fulcrum spread of 48" that works for sit height and head /foot clearance from the poles. Feels solid enough that I would sleep in the system without qualms - but then I only weigh 140# and am 66" tall.

**Latherdome** · 10-21-2017, 20:08

Originally Posted by raftingtigger

Made 3 12.5 inch extensions. So 7.5 feet on three poles and 8.5' on the last. Nice sit height with my 11' hammock. Virtually no suspension cord used. I then took out the 22" and a 12" extensions on opposite ends (made it assymetrical) and with a fulcrum spread of 48" that works for sit height and head /foot clearance from the poles. Feels solid enough that I would sleep in the system without qualms - but then I only weigh 140# and am 66" tall.

Awesome! You say 3x 7.5' and 1x 8.5' (asymmetric), "then" took out 22" and 12" extensions to make (further?) asym. To confirm, I think you now have 2 6.5' and 2 7.5' poles, irregular parallelogram when flat? I think taking an average (7') should work same for a symmetric stand, but asym has interesting optimization opportunities.

Re splay, I suppose taller users can always just lower seat heat/increase splay if shoulder/foot clearance of poles inadequate, as long as a certain acceptable minimum is available to the tallest users. To the extent that taller may imply heavier also, thus greater fail risk, it's sort of insurance that any fall distance be minimal.