On May 28, 1:35*am, theedudenator wrote:
On May 28, 12:19*am, "Lew Hodgett" wrote:

"theedudenator" wrote:
The center beam will be 18 foot long. *It will be 3 2x6's bolted
together *(to make a 6x6 beam)
This beam will be close to 10 foot off the ground

You're comments above indicate a lack of understanding of the design
fundamentals of beam design.

I don't want to burst you're bubble, but you have some serious
engineering study ahead of you before attempting to design a structure
that could possibly inflict serious bodily harm to the users if it
fails.

Lew

What am I missing on beam design? *sandwiching 2x6's to make a beam is
not correct???

Lew's point is that a beam gets _much_ stiffer with increasing depth/
height of the beam as compared to increasing the width/thickness.

You definitely want a stiff beam.
You definitely want a shorter continuous span, so either have an
intermediate A-frame support, or build two swing sets and put them
together. I'd think that having two separate swing sets would be a
little more work, but not much, and would be more interesting for the
kids to play on. They could more easily see each other and have
competitions and such.

R