100_0224
Oli doing his patented cone assembly yoga
100_0225
Inserting the foam channel pieces to lock the final sector
100_0229
Leveling the top to epoxy on the aluminum brackets
100_0205B
We roped off the receiving area of MAPO for the assembly
100_0222
The aluminum brackets and apex ring...
100_0223
...and the foam bits they are glued to.
100_0240
To get the epoxy for the tabs on the rim to cure, we elevated the ring on a stand off of the cold floor.
100_0241
100_0245
This arrangement allows easy access to the inside of the cone.
100_0248
The foam panels were cut by the manufacturer to the wrong angle; the seams are tight on the outside, but a 1/4 inch gap on the inside edge.
100_0250
The foam/glue/aluminum bracket arrangement holding the apex ring, from the inside
100_0257
Some of the rim tabs, after epoxying in place
100_0258
We supported part of the weight from the apex to carry the cone out to the primary. The original plan had been to lift entirely from this ring with the crane.
100_0261
Carrying the cone out...
100_0264
...supporting the rim when we got out of the wind-shadow of the building. The wind was 7 knots, well below average. The increase in force over the ~15 lbs. weight of the cone was barely perceptible.
100_0265
As we brought it to the platform, the cone cracked around the apex ring brackets and in some cases along joints and around the bottom rim tabs that joined sectors.
100_0266
100_0267
We set it down immediately and covered it in place, to avoid further damage.
100_0293
One of the sector-joining rim tabs that cracked off--it is apparent that there was very little contact area between the epoxy and the foam, which failed along granule boundaries.
100_0299
The top of the cone showing the cracked foam bits. In consultation with John C and Clem, we determined to reinforce this cone to make it robust enough so that it has at least a chance of holding together through the winter to allow tests of the thermal stability of the primary/cone system.
100_0302
A modified hot wire set will allow us to cut the top of the cone off, flat.
100_0303
Gluing all of the cone seams with RTV silicone on the outside...
100_0304
...and on the inside, where the gaps were very large.
100_0306
Cutting the top of the cone flat to provide maximum solid foam surface area for bonding.
100_0307
It is cut flush with a reinforcing copper tube ring...
100_0311
...and capped with a very strong blue-board styrofoam apex cap, glued on with RTV.
100_0310
A reinforcing ring was also added lower down.
100_0313
This ring will provide tie-down points to hold the cone on in tension. Note the 8 rim tabs so far that have snapped off.
100_0314
The foam apex cap from the inside
100_0316
All the joints are now reinforced with ample RTV.
100_0320
To get RTV to cure requires humidity. We have three space heaters and bins of snow/water under and around the cone, and are misting it regularly with water to attempt to get it to cure in the short time available. Rumor has it that RTV will cure in the cold as well, but very slowly.