Yet anouther BIPOD plan w/ Questions

[CaptDoug]

OK guys -
I have seen some of the formulas some members are using....scary math.
I intend to build the below - I will make it out of 1.5"x1.5"x30" sections of mahogany. To connect the sections I will be using 1.5"x1.5"x12" sections of aluminum square tubing. 6 inches of each section will be in the Tubing- Iwill mill the Mahogany to fit snug in the tubes.

This will give me two 7' 6" legs - when I tie them together with a 6 inch welded "A" section (see picture) - Once put together I should have an equilateral Triangle that will stand 6' 6" tall - When I lean it to 75 deg (top away from hammock) the top will be at 6' 3" off the ground. ( did all using equilateral triangle math).

So according to the Hang calculator - I should be able to put 16 ft between hang points....(because my ridge line is 96 inches and I weigh 260 and like 18 inches under my but...

So 3 questions:
1. Is my math close
2. Do you think the system will work with proper anchoring.
3. Tough to find tubing here - I have found the above with 1/8" walls - Do you think it will be strong enough?

[CaptDoug]

I just received a quote to build a similar project out of carbon fiber poles of 517 USD.

It would only weigh 3 lbs.......but this was for one side only....so an independent set up with no trees would weigh 6 pounds and cost over a grand....nice folks great customer service but to rich for my blood....if you interested pm me and I'll send details :-)

[OneEye]

Based on your described layout, and assuming an anchor line at 60 degrees from horizontal, I did some back-of-the envelope math. My calculations put the axial load in a pole at ~170 for a static 200 lbs in the hammock. You will want to allow for some dynamic forces (sitting, rocking, etc), so maybe 250lbs or so. Before fabricating everything, make sure your poles can withstand that force. Ensuring your anchor line is perpendicular to the poles cuts that force by more than 40%.

Construction codes suggest your pole length to thickness ratio is too high. Expect deflections and load amplification effects. If one of the poles fails I imagine it will be quick and dramatic.

I've seen setups that defy the construction width guidelines and still work, but they do tend to deflect a bit.

Good luck. The engineer in me always keeps me from doing anything interesting. The handyhammock folks have done their engineering work and found a good monopole solution, although it might not be as high as you were hoping for.

[CaptDoug]

Thanks One eye,
I appreciate your engineering opinion. I just borrowed my friends table saw and will have the wood tomorrow....so I think I will give it a shot...but based on your view I will test it with a mattress under my butt....or better yet...I will convince my Boy Scout that it is a good deed to test this out for dad....

Thanks again- I will take picks and post when I am done...

[CaptDoug]

My planned project is on hold...I needed to be able to hang my sone as well...so I built a 3-person hammock stand described elsewhere on this site....great stuff work for my 255 lbs....