On domes up to 30 feet all you need is a strong center pole about 3 feet longer than the dome is high. We use two 4x4s end to end with a square metal sleeve over the joint for strength. The top end has a pully and a large eyebolt to which three 50 foot lengths of rope are tied. The bitter end of these ropes go to big angle-iron stakes arranged 120 degrees apart in a circle. The bottom of the pole has a metal spike to keep the pole from moving laterally. On the side of the pole is a boat winch loaded with steel cable. Cable goes up to the top of he pole, around a pully, and down the pole.
Assembling the dome becomes a simple, 2-person operation. No climbing needed and everything gets done with feet on the ground. Assemble the top pentagon, connect the cable to the spider (just a pre-made load spreader that attaches to the first set of vertexes) and crank it up to chest height. Add the next level of struts and crank again. Repeat until you have a dome hanging just off the playa in front of you, then lower it to ground.
Takes about an hour and a half to do each dome this way, and its the safest way I have found yet without resorting to on-playa hydraulics. No need for aerial antics on a ladder either, which for old duffers like me is a GOOD thing.
Even for the big dome, we only bring a 8 foot ladder. And this is only needed when we install the 2nd floor (a hanging half-moon loft) due to some poor design choices I made years ago.
If I can find pictures of the lift rig I will post them.
"Resistance is futile. You will be commodified"..."
c.f Larry Harvey, The BMOrg