Tensahedron Stand

[raftingtigger]

For all you out there with slipping lashings. There is a really easy solution. Take any wood removal device and round/narrow the ends of the poles just enough to make a lip that the lashing can't slide past. 1/2 the width of the lashing rope should be more than enough. It should not change the strength much at all.

If your poles are square/rectangular then just round the corners a little.

That or skip the lashings all together. Drill a small, but adequate, sized hole near each end and run a rope through them and tie.

[Hangdang]

For all you out there with slipping lashings. There is a really easy solution. Take any wood removal device and round/narrow the ends of the poles just enough to make a lip that the lashing can't slide past. 1/2 the width of the lashing rope should be more than enough. It should not change the strength much at all.

If your poles are square/rectangular then just round the corners a little.

That or skip the lashings all together. Drill a small, but adequate, sized hole near each end and run a rope through them and tie.

That was totally my thought, drill hole and tie!

Sent from my SAMSUNG-SM-N910A using Tapatalk

[CaptainGravity]

If your poles are square/rectangular then just round the corners a little.

Thanks! Last week I was thinking this as I hoped to again try the 2x2s the troop has, so I'm glad to hear a bit of confirmation of my thinking. (Rainy weather prevented any attempt.)

To summarize: To help with slipping lashings, make square poles somewhat "less square". If poles are round, make them MORE square. (These are of course in addition to the usual pioneering solutions of lincoln-logging the poles or wetting cordage, both of which I may want to avoid.)

Hadn't thought of drilling a hole into the wood (duh). I think I had mentally crossed off that idea since I may not be near my garage when attempting this. But since my multi-tool has a file I think I'm in the corner-removing business on the next campout. If I use bankline, I may go 1/2" wide to accommodate all 4 wraps or so (for manilla/hemp ropes, I see your point about the "flattening" only needing to be 1/2 the width of the rope.)

PLUS... a lot of my motivation is "look, boys, no trees? No problem. YOU can do this. HERE is where you can use the skills you've learned in scouts to solve a problem using what you have on hand." They really like hammocking. (Too many trees in Virginia to really force any creativity though!)

[CaptainGravity]

Just want to toss out this musing for discussion:

Would a "Tensahedron Chair" ever work?

I'm looking for an alternative to the backpacker chair frequently sold by REI et al that won't tip backwards.

leiavoia, I've been thinking about a camp stool in the more traditional tensegrity style, rather than tensahedron-ish as in Latherdome's picture. Perhaps 3 legs, 4 might make more sense (and be easier to create a duct-tape seat for.)

Like this:
https://www.behance.net/gallery/1245...nsegrity-Stool
tensegrity stool 3 strut.JPG

Although I just found this picture which is pretty cool too
tensegrity_01.jpg

What would a tensahedron-style small chair look like? would it still be staked to something? Just a mini-version of Latherdome's video above?

[Baka Dasai]

Like this:
https://www.behance.net/gallery/1245...nsegrity-Stool
tensegrity stool 3 strut.JPG

Wow. I want one. Could you use spreader-bar poles for this? With a ripstop triangle "saddle" on top? A super-light, super-compact, foldable camp chair?

[CaptainGravity]

Baka Dasai, when the chords are at the top of the struts, the forces on the struts are theoretically entirely compressive (which may also be the case with the Tensahedron stand). This should allow light-weight materials. (I don't know what speader-bar poles are made of.) In reality, and especially if the "fabric" parts are on an extension of the struts, there are probably some bending forces. So I'm not sure which materials one can trust one's weight to.

I've seen camp stools lashed together from "sticks on hand". Bring your ripstop seat & some cordage, find an appropriate stick (easier in Virginia than parts of Australia I'd imagine), cut appropriate lengths, lash the sticks together in the middle with a tripod lash, put seat on, done. The tensegrity is cool (to me) because of what it is: struts bear only compressive, chords are only under tension, struts (probably) don't touch.

LATHERDOME & others: Anyone done the math/geometry on the tensahedron stand to ensure compressive force only? Obviously, the free-moving apex is guaranteed to not have a bending force in one of the directions... but it seems to me there should be a single ideal width of the base chord that ensures compression-only forces on the struts (again, in theory). Is it as wide as the strut length, for an equilateral triangle? Seems too wide. Or perhaps practically ANY LENGTH of base chord ensures compression-only forces on the struts?

[Latherdome]

LATHERDOME & others: Anyone done the math/geometry on the tensahedron stand to ensure compressive force only? [...] Or perhaps practically ANY LENGTH of base chord ensures compression-only forces on the struts?

I think your last supposition is correct. As long as the connectors don't impart bending moment, the poles are in pure compression, with only gravity acting as a (very modest) deflective force (imagine if the struts were weak and heavy like lead rod: you could see them buckling toward earth when compressed enough).

Back to tensahedron chairs, this is the arrangement I have yet to try, but think could be bees knees. Base image swiped from gear-report.com's review of the Terrapin Hatchling chair, hopefully fair use. Compressive members (poles) orange; tensile (cordage) yellow.

[DiceCaller]

So I was in the garden store yesterday and saw 3/4" x 8' garden stakes for $4 each. These seemed to be pretty strong and stiff and at a guess I would say they are about 1/3 the weight of EMT.

The tag said they were plastic coated steel. I think there is just a steel rod in the center to add stiffness.

Has anyone else looked at these or fiberglass tree stakes? I'm not a gram weanie, I'm not even a kilogram weanie but it would be nice to get one of these under 20 pounds.

[muledog19]

https://www.menards.com/main/buildin...2733022992.htm

If this is the type of garden stake you're talking about, I've used them for tomatoes. They are really weak and I have bent several just gardening.

Sent from my Moto Z (2) using Tapatalk

[muledog19]

I've wondered about the quality of a telescoping pool pole

https://www.menards.com/main/search....ol+pole&ipp=20

I've also wondered about taking the cheap steal poles out of this canopy kit

https://www.menards.com/main/outdoor...8506481&ipos=3

That whole kit weighs 13 pounds and, "features weather-resistant, powder-coated steel poles". They have got to be incredibly delicate steel poles. I haven't been bold enough to open the package in the store and check it out yet. I suppose I could buy them and return them if they are too flimsy.

Sent from my Moto Z (2) using Tapatalk