Відео

You can use the equations and approach from my other video on this topic (ua-cam.com/video/a1KPl-M-dpM/v-deo.html) to guide your design. You will certainly need to go beefier than what I did, my "deck floor" on the start end was only about 3.5 feet high.

Man, that is an expensive cable but it seems like a reasonable diameter for that length. Your anchor points are going to need to exert 3 or 4 tons of force, those are going to be expensive anchors also. Good luck, and I look forward to seeing the video!

@@BILLYSHED it’s on my channel already! But video in Russian language) I just wanna make sure the diameter is safe.

@@misty_mountain Awesome zip line! That was a lot of work. Do you plan to sell rides on your zip line someday?

@@BILLYSHED no, just for fun.

Thanks and good luck!

You flatter me!

Home Depot or Lowe’s, I forget

@@BILLYSHED i dont really know anything about foam. Is there a specific rating on the hardest foam available at these stores?

@@danikd9802 use the pink stuff. Dont overthink it.

Thanks for sharing, and well done!

There is a reasonable amount of tolerance.

Thanks man! Yep - I'm using the same foam boards now for the FOURTH season

The fundamental solution of using stacked foam is not particular to round pools. Rectangle is probably easier, tbh. I'm sure you can figure it out.

Personally, I'd fix it up front - but I concede that it's a judgment call. Let me know how it works out!

Not sure what you mean by "appreciable deflection around [my] circumference due to [the wedges]" ? But I am about to edit and publish another video so maybe that will answer your question...

I assumed four feet in order to roughly estimate the tension in the line. And, 4 feet is a decent estimate just considering how my zip line worked. If I assumed 3 or 5 feet, the rest of the math wouldn't change much. The slope of my yard over 90 feet was about 6 feet.

You really only need some basic tools, like a sharp knife, a tape measure and a straight edge. Might take you a little longer to make the bevels but it’s not too bad. I’m sure you can figure it out

The short answer (specific to a 90-foot zipline with 3/16" diameter cable) is "Nah, not so much". The preload force needed to pull the sag to a reasonably small amount is significantly less than the load once a rider jumps on. If you have the preload pulled so tight that it significantly loads the endpoints, your rider is probably going to plow hard into the end of the ride. Consider that ziplines are designed around stiffness / deflection. Anyway, longer runs with heavier cables... yeah you will probably start to need worrying about the cable weight (or the preload force).

Thanks 😘

Cool. For what it's worth, I am going on year four of re-using the foam and it has held up very well.

Regarding alternative materials: Nope. 2 x 12's were readily available and cheap. But if you can find a source of metal poles, then you can still use my cantilevered-beam calculations, you would just need to change your modulus of elasticity (E) to either 70 GPa (aluminum) or 210 GPa (steel), and you would need to re-figure your cross-sectional moment of inertia (I) based on an annular cross section rather than a solid rectangle. Regarding guy wires: That's a great option if you are willing to deal with more anchor points and a larger footprint, including wires that are a trip hazard. Wifey nixed guy wires so I went cantilever.

@@BILLYSHED Not set in stone yet, looking at 6" square alum column, if not then wood. Got it, thanks

Sorry friend - no ideas. I am sure you will figure it out. "Necessity is the mother of invention" - someone famous

Not enough info

4” galvanized steel pipe to prevent rust , cemented in ground , won’t deteriorate like pressure treated wood over time .

Drill a hole , run a eye bolt through the top of the pipe and attach the cable

Check out my other video where I perform the calculations. You can use that same approach to calculate for your proposal, just need to change the cross-section from a rectangular solid to a hollow pipe and obviously you’ll need to change the material stiffness from wood to steel. Steel has a stiffness of 210 GPA, by the way. But go for it, you should be able to calculate it using the exact same approach I showed you in my other video.

Thank you so much !

Yes, it was the same sized post on each end of the line. Each end had two laminated 2x12s. My yard naturally sloped about 6 feet from the start to the end of the line, so I did not need to construct a taller support post on the starting end.

Aaron - I think you'll be fine with laminating three 2 x 12s. Manufacturer's instructions conservatively spec using minimum 12" diameter trees as anchors. Triple laminated 2x12's are ~64% of the stiffness of a 12" diameter cylinder, so that initially seems concerning... but remember that live wood is ~50% less stiff than the dried lumber you are using. So Bob's your uncle and you're back to parity with the conservative manufacturer's guidance. Have fun and shoot / post a video - I'd love to see.

@@BILLYSHED Thank you! I will definitely post a video

"Makes no sense" to you... sorry dude but it's not magic. I can only imagine what else blows your mind. I'll make another video soon to demystify the pressures and forces. You're not the first person to be skeptical.

​​​​@@BILLYSHEDStill waiting for that video.

Ok, it will be pool season soon and I’ll make the video then.

​​@@BILLYSHEDAwesome! I look forward to it. I'll be checking back throughout pool season to find your video.

What did you end up doing?

Same issue yesterday, it's almost like I wrote this!

I understand your intent. I think a 10” dish on an 18’ pool is reasonable. Go for it and shoot a video and let the rest of us see!

Did you try it? How did it work out?

I’m 6 weeks into the third season and the foam is fine. I should post a video to document my current setup and answer some other questions

@@BILLYSHED you are very helpful thank you soo much!

Sounds great, I think you will be fine with this method. Use a few layers of packing tape at the seams between pieces of foam. And, do your best to ensure the bottom of the pool is properly positioned before you start filling it. Post a video and notify me after you get it up!

@@BILLYSHED Thank you sooo much. Makes perfect sense. Will post you the outcome. I am a little nervous about it but will be diligent.

Don’t be too nervous- you will know soon enough if it needs better alignment and you can drain and refill. Go for it. Have fun and I’m looking forward to your video!

This is exactly what I'm trying to do; I want to put the pool on the far end of my driveway. Same size pool 15'x48"; inflatable rim. I watched this video last year and did measurements and my slope is NINE inches. I didn't get the pool set up last year (it was late in the season anyway), but hoping to do so this year. Over the winter, I have accumulated a bunch of interlocking foam mats (for gym floors) and may use them. I used them to (mostly) level my soft-sided spa.... but that was before I found this video! Now I have a method to measure accurately and hopefully I'll get it done! Good luck @deborahsimmons, and Thank you @billyshed for the video! I'm going to study it and make a plan!

At 5:11 in the video

@@MommiiNLea The angled sides were cut at a 15-degree angle, for a total wedge angle of 30 degrees. That’s because my circular pool has 12 poles and 12x30=360. If you have a different pool, you will have to figure out your own situation.

@BenvanBroekhuijsen Once again, proof that snarky /worthless comments always come from folks who have never contributed any videos of their own.

@@BILLYSHED Hmm I guess my comment was a bit snarkier then I wanted. I apologize for that. The video in general was very useful, I should have commented about that as well :D It was nothing personal, it was about the system that the US keeps using despite the fact that virtually every other country advanced.

You have redeemed yourself. All good. For what it’s worth, I have been using metric units in my professional calculations for 30+ years. Just hard to buy tools here in USA that aren’t setup for imperial!!

Robert, I am confident that this solution would also be fine for deeper pools. It's the water *depth* (not the diameter) that imparts stress to the foam and downward force on the legs. A 52" water depth wouldn't even double the stress on the foam. You might benefit from padding-out the leg supports to distribute the extra downward force over a little more foam, but the extra pressure on the interior portion of the foam that just has liner pressing on it... would absolutely be fine with a 52" head of water pressure.

​@@BILLYSHEDWhat about a much larger pool though, say 24x12x52?

@@Superman-xr1oh I literally answered your question above. It's only the DEPTH of the water that puts any stress on the foam, not the diameter. The foam doesn't care if your pool is ten miles wide, just how deep it is.

Never mind I see what you did

Yes, I believe the bevel is pretty reasonable insurance against stressing the liner at the otherwise sharp(ish) edges of the steps. Also, by beveling the edges, the bottom of the liner doesn't have to stretch as far as steps would require. Think: "Shortest distance is a straight line". You will figure how to cut the foam. Its not difficult.

Q1: So you don't suggest placing any foam in the middle of pool or completely covering foam underneath the pool? A1: That’s not necessary for reasonably minor slopes like mine. There’s enough slack in the liner to conform to the gentle steps resulting from my approach. The benefit is a little bit of a deep-spot near your low-point. Yay. Q2: So as long as the legs & outer perimeter is leveled that will level the water in the pool? A2: The outer perimeter is the important part to get level, yes.

​@@BILLYSHED Thank you. Your video is Awesome & especially Thank you for taking your time to answer additional questions. Much appreciated

Yes, I strongly believe the bevel is important. And…oval. Interesting. Good luck. Post a video after you complete your install.

Slayer, food coloring - good idea. And thanks.

Thanks!

You will have to calculate that depending on your pool diameter and how much slope you need to compensate for.

Personally, I would do a CAD drawing, but you could sketch it out on paper.

Thanks, man! In another week or two I will be putting it all back in place for a third year of service after storing the foam outdoors under my deck stairs since last Sept. Everything is still in good shape.