New SkyShed POD Zenith Table (PZT)
Posted: 12 July 2020
The morning of 11 June 2020, the local contractor (H2Iron LLC) that I selected to make the replacement for my original POD Zenith Table (PZT) came to do some initial fabrication. A few minutes before they arrived our local Federal Government electric company had a power outage that lasted for 2.5 hours. The observatory still had power from the Tesla Powerwall (installed a year ago), but the contractor decided to go back to his shop to get a gas-powered electrical generator for his arc welder. After all my issues with the wood table (detailed here), I had decided to go with a metal structure to support the dome. This should last way longer than the wood in the harsh environment here in southern Arizona.
Here are some photos of the initial work to design and weld the new metal frame. In the background of the photos is smoke from the Bighorn Fire (15 miles away), which was a very dangerous wildfire in the Catalina Mountains between Tucson and Oracle. (The fire got worse, even coming to about 3 miles from Oracle; see my updates on my Bighorn Fire reports 2020 page).
Once the basic structure of the frame was completed they took the frame back to their shop to complete it. Final installation was delayed while the contractor was waiting for some parts.
The frame was set up on Tuesday, 23 June, and initial checks were done. A lot more smoke from the still burning Bighorn Fire was in the sky and the temperature was 105°F, which made working outside rather exhausting. A couple of additional rails would be needed to support the pivot areas when the dome is first pushed off the wall and a ramp would be needed to help when pushing the dome back onto the wall. But I was very pleased with how the new PZT worked at this stage.
On Thursday, 9 July, the contractor came to do some more work on the replacement PZT. We made a slight design modification on the fly, but the initial tests of sliding the dome off and back on were highly successful.
On Saturday, 11 July, the work on the new PZT was completed.
A rain cover for the air conditioner exhaust vent was added.
The plastic rails (outdoor decking material) was cut to allow the dome to rotate when on the walls, yet slide on and off the walls easily.
The new PZT works beautifully! Sliding the dome off the walls onto the PZT and then back onto the walls is easy and is a very smooth operation. I also get a wider Zenith view as the dome can be pushed off a few more inches than was possible with my wood PZT and the rubber bumpers.
This new metal PZT frame and plastic sliders should last for many years. Cost for parts was $410. The total costs were a little higher as we did several design modifications during installation, resulting in additional parts and labor. Many thanks to H2Iron LLC for their outstanding work.
Go to my original SkyShed POD Zenith Table (PZT): Construction, Installation, & Use report.
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