One of my customers wants me to build a swingset. She has some specific requirements (namely, it must look old-fashioned and be very simple) and she can’t find one commercially for purchase.
It sounds like an easy and fun one day job (at most).
For the legs, I’m going to use 4X4X10 angled at 30°. Does that sound right?
And for the top beam, I’m planning on a 4X6X12. There will be 3 swings. I want it strong enough for the worst case scenario which would be 3 adults at the same time. Does a 4X6 sound strong enough?
Replies
30 each or 30 total (15 ea) . . . last I did was 4x4 legs, 15 degrees out and back - compound cut. With braces across the legs and a short brace from the legs to the top, and that was 4x6x7', only held one 2 person swing, like a porch swing. At 12', dunno. Thats a decent span. It ought to hold, really an issue of how much sag over time. Can you get that in a lam?
I'd be fickle on the bracing. I plowed out rabbets for them all to join with kind of like you'd timberframe and anchored everything with structo GRKs. That swinging motion over time is going to be tough on those joints.
Real trucks dont have sparkplugs
I was planning on 30 degrees for each leg. That makes every angle 60 degrees which is an equilateral triangle. It's a wide footprint, but I'm not planning on anchoring it to the ground.
Everything will get lag-screwed together with a minimum of 3/8" lag screws. I will probably use HD lags rather than GRK because hardware alone is already about $150.00. Rabbets (or mortise) is a good idea, thanks.
I was just wondering that, if not anchored to ground, swinging could pull the legs up on one side (especially if three adults were all at the same point in the arc of their swing), but the wide stance (60 degrees) should prevent that, I guess. The swings will always remain within the foot print of the supports, right?
Edited 9/16/2007 8:24 am ET by Danno
The swings will always remain within the foot print of the supports, right?
Come on Danno, didnt you know anybody that could make the swing go parrallel with the ground? I sure did.
I dont know about the not anchoring the thing down though, would have to put it to some test.
Doug
screw in swing set supports can be bought for $4 or so. Work great.
This is slightly (slightly?) off the subject, but I remember watching "Secrets of the Dead" where modern scientists were reconstructing a trebuchet and the first thing they did was take off the wheels and anchor it firmly to the ground. Couldn't get it to work and it kept breaking. Finally someone decided to put wheels on it just to see what would happen and it worked just fine with wheels on it and it stopped breaking. They figured the wheels absorbed some of the stresses and were necessary to allow the arm to swing the way it should. Maybe a swing set (see, you knew I'd get back to the subject eventually!) would work better with wheels! At least it wouldn't tip--just might have to chase it around the yard!
PS--The people who impress me don't just go parallel to the ground, they make a complete circle!
Edited 9/16/2007 2:39 pm ET by Danno
I liked that Trebuchet show.
By the time you get parallel to the ground, there is very little pulling force on the top bar. In fact, if you're not careful, you can slip downwards off the seat since there's practically no centrifugal force.
With 3 adults swinging in unison for all they're worth, I'd be more concerned about something breaking than the swingset tipping over.
But 60° leg angles might look odd. I'm going to have to stop by the park and measure some typical swingets. Of course, those are all anchored in concrete so I may not be able to make mine with a stance quite as skinny.
By the time you get parallel to the ground....................
Have you ever been on a swing with several other people doing the same thing? I've seen swing sets lift off the back legs right at the point of your forward push - the heavier the person the more force there is. Take three adults and let them hit that spot at the same time and tell me that it cant lift.
You might be right about the weight issue making it impossible to lift, I dont know much about that, you'll be able to tell when your done with it.
Doug
Don't know if it would fit her desired "look", but I've made each end post from (4) 4x4s set in concrete ~ 20"apart, and wrapped in treated plywood to make an apparent 24" square x 8' tall "post".
On top of each of those was an octagonal "mushroom head" of mitered 2x12s about 30" across, and a double 2x12 across as the beam.
Neat look; very slim in profile with no angled bracing, and does not deflect at all.
Pix if you want.
Forrest
Found an old pic of that one I was working on. All recycled lumber from machinery pallets from France.
View Image
Forrest
Edited 10/26/2007 7:45 am by McDesign
You win :-). That's really nice.
Sorry! Not trying for one-upmanship. Just the only pic I had of the swingset end posts like I described earlier - (4) 4x4s skinned in ply.
Forrest
Sorry! Not trying for one-upmanship.
I knew that and I enjoyed seeing your picture. So please carry on and don't worry about me, but thanks.
Swing sets need to be safe don't use pressure treated materials and make sure all the edges are rounded over for no slivers. If it's heavy enough you can get away with not anchoring the set, but with three swings and the possiblity of three adults on you might need to.
Check out this place for ideas.
http://www.rainbowplay.com/SwingSets/Index.cfm?gclid=CNeR9sHkyo4CFRcIYgod4iz8wA
Rounding over the edges is a good idea, but I was planning on using PT lumber. Why isn't it safe? Because of the high chance of splinters or because of the embedded chemicals. If it's the chemicals, isn't that why we got away from CCA and went to ACQ?
splinters, chemicals and the fasteners corroding to the point the structure becomes unsafe...Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
ACQ exposed to the weather all the chemicals leach out anyways and with the prolonged wetness the fasteners are at a higher risk of dissolving..Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming<!----><!----><!---->
WOW!!! What a Ride!Forget the primal scream, just ROAR!!!
Here's an update:
I finished that swingset yesterday. Except for working in a light rain, it was a fun, simple project. Even being simple, it still took a little more than a full day to plan, gather materials, transport and assemble. It still surprises me how something that appears so straight-forward can take so much time.
My customer told me that she, and the kids, love it. The kids got home before their mother and immediately started using it. Everyone's happy. It makes me feel good.
I plan to get back there at some point to inspect it. The rope I used is rated to 1,000 lbs, but the knots are going to be the weak link. My helper and I tested it out. Together we're over 450 lbs. With a 60° leg angle, it can't be tipped, but it will slide along the ground if 2 big guys like us swing really hard.
View Image
Nice. Are those 4x4's for the A-frames and what for the ridge beam?
You got it. 4X4 legs. The ridge beam is a 4X6. If I were to do it again, I would use a 6X6, but this one is intended for kids only.