Is lateral sway in swing set a big deal?

[Builder]

This weekend we built most of a swing set project for our two kids. Before we get too much further into things we want to make sure everything is structurally sound as There seems to be some lateral sway when the swing is in use -- an inch or two. Beam is 2 2x6x12 sistered together with bolts resting on 3 4x4 post A frames with 2x6 bracing at the top (middle frame is 4' from end for slide platform). Frames on either side of swings are kicked out a couple inches to try to reduce lateral sway. If it is a big deal, can I remedy it by sinking an extra 4x4 post under the peak of the outside frame by swings? It feels solid but I want to be confident it won't collapse on my kids.

[Coop]

Neat looking build. If it were me, I would tie the three vertical uprights with two 2x8 or at least 2x6 horizontal pieces across the peak, one on each side, on the outside, mitered at the top, tying the three pieces together. Right now, you only have one. However, the lower the horizontal placement of the pieces, the more rack support you have. I take it that the uprights are not anchored into the ground in cement? 

[Builder]

Correct; nothing anchored, yet. Considering a steel-coil type anchor system into the soil...This is my first swingset build and I may have gotten the horse before the cart on a few steps. That's a great suggestion on tying the three together and is something I will try to incorporate. Thanks!

[wtnhighlander]

The slide platform should incorporate more horizontal bracing, like a climbing wall or full width ladder. That's how many commercial wooden play set designs add rigidity.

[Brendon_t]

It looks like there is more to assemble being the slide from nowhere, I would have it totally put together and check it out. Chances are it was designed right, just gotta finish. It's very easy to strengthen later like coop said above.

[Tom King]

I would expect any lateral sway to only get worse over time, so I would get rid of as much of it as possible.

[Chestnut]

I feel like there should be more than 1 bolt thingy in the red circles. It takes 2 to resist twisting and you want them as far apart as possible.

Also agree if you brace the slide area thing it'll increase the rigidity.

[Byrdie]

Agree with Nut - one bolt is a pivot point, two add rigidity.  Also, the diagonal bracing should add stiffness to the design but the piece you have both might not be big enough or at enough of an angle.  I feel like they should be more of a 45.

[Brendon_t]

Did your set not come with a few flat metal triangles with holes in them? 

I've owned 3 sets. All had them to triangulate the corner. 

But seriously, finish putting it together.. we don't dovetail a drawer then test for racking before the bottom has been fit. Of course it's not solid yet, the stiffening aspect hasn't been installed yet!  Take the design to completion and make sure there's an issue before trying to fix an issue the designers very likely took care of, as it's a kids toy...

[riqmar]

8 hours ago, Byrdie said:

Agree with Nut - one bolt is a pivot point, two add rigidity.  Also, the diagonal bracing should add stiffness to the design but the piece you have both might not be big enough or at enough of an angle.  I feel like they should be more of a 45.

Agreed, especially the last sentence.  The diagonal braces should be remade so as to form larger triangles.  If there is then some lateral sway from the posts themselves flexing a bit I would hazard a guess that that would not be a problem........Additionally, some triangulation of the slide platform might be considered...........

[Chestnut]

Man this reminds me of my childhood swing set. Most parents would think "better make it low to the ground so when they climb on top they wont' get hurt". My dad's method was to build ours 12-13 feet tall so we were to afraid to climb on top.

I wanted to put 20 feet because that's how I remember it. He made it from cedar 6x6s for legs and laminated 3 2x8s for the beam across the top. It never moved because each post was 5 feet in the ground and then had concrete poured around each leg..... I think it had room for 4 plus the slide.

[Builder]

3 hours ago, Brendon_t said:

Did your set not come with a few flat metal triangles with holes in them? 

I've owned 3 sets. All had them to triangulate the corner. 

But seriously, finish putting it together.. we don't dovetail a drawer then test for racking before the bottom has been fit. Of course it's not solid yet, the stiffening aspect hasn't been installed yet!  Take the design to completion and make sure there's an issue before trying to fix an issue the designers very likely took care of, as it's a kids toy...

It's not a pre-made kit, but I have been looking at those metal brackets you're talking about. The original plan wasn't to have any knee bracing with how the beam is set in the a frame fulcrum -- I'm not sure there are long enough metal plates available to stretch from beam to leg how I have it. That said, you make an excellent point about putting it all together before worrying about issues that might not exist after a few steps are completed

[Coop]

Growing up, we had two swing sets. One was a rope with an old tire at the end suspended from a Chinaberry limb and the other a rope loop with a board as a seat, hanging from a clothes line pole. A slide was something the rich kids had, so we were told. 

[Builder]

2 minutes ago, K Cooper said:

Growing up, we had two swing sets. One was a rope with an old tire at the end suspended from a Chinaberry limb and the other a rope loop with a board as a seat, hanging from a clothes line pole. A slide was something the rich kids had, so we were told. 

Our 3.5 yo is especially excited about the slide! 

[Chet]

Also, you want to remember that no matter how tight you get all of your fasteners, over time you will have to go back and tighten them again.  The wood will dry and shrink and the fasteners will become loose.

[Ronn W]

Try putting an x-brace betweeen the 2 A-frames under the slide.  As a test just nail them in place ( 2x4's) and see if it reduces the sway. 

[Brendon_t]

9 hours ago, Builder said:

It's not a pre-made kit, but I have been looking at those metal brackets you're talking about. The original plan wasn't to have any knee bracing with how the beam is set in the a frame fulcrum -- I'm not sure there are long enough metal plates available to stretch from beam to leg how I have it. That said, you make an excellent point about putting it all together before worrying about issues that might not exist after a few steps are completed

Now that makes much much more sense to me.

[Dave H]

19 hours ago, K Cooper said:

 A slide was something the rich kids had, so we were told. 

When I was 16 a family moved in across the road from us, the rich kid had a dirt bike and, rode it around all the time I hated that guy (he thought he was so cool because he had a dirt bike). A couple weeks later he came over and said hi I'm Steve hey do you drink beer, finally we had found common ground we've been best friends for 50 yrs.

[Brendon_t]

10 hours ago, higtron said:

hi I'm Steve hey do you drink beer, finally we had found common ground we've been best friends for 50 yrs.

I could hang out with Steve, but no Chad's.

 

[Coop]

I’ve HAD friends like that, they drink but don’t buy! 

[AJ_Engineer]

Yep you need some x-bracing or diaphragm somewhere. X-bracing under the slide would be a good spot, or adding a plywood climbing wall to get up to the slide deck would work. Alternatively you could add some plywood to form a small roof down from the peak of the slide area between the two A frames. Nail it in often to the A-frames.