Last week the team controlled the upper X screw for the first moves. The electrical team put the new Az wrap in place. Over the weekend we had a one-woman-team come in and paint the remaining weldments.
This week the mechanical team should finish getting the lower X components in place: encoder, lead screw, and energy chain. After those lifts occur the structure will be locked out and the temporary test cables will be removed and the final cables for the tracker will be installed. This is likely to take the rest of the week and perhaps the first few days of next week.
This will allow us a few days to test the upper and lower X motion both independently and working together in preparation for the New Tracker lift mid-Feb.
Last week we got the upper X rail ready for testing. This involved putting in the motor, encoder, rail and trolley. The test cables for the communication and control of upper X have been hung in place but not connected.
This week Ron Leck is on site to begin testing of the communications to the motors on upper X and if we can get all of the components in place to lower X as well. This will require us to connect the test cables (which do not go through the Az wrap) and thus will largely lock out any structure rotation of the duration of the test. The first motions of the slew motors will be open loop and will allow the mechanical team to see if the X-axis is well aligned. If all goes very smoothly near the end of the week we may get the laser tracker up and running to see the relative distances of the lower and upper trolleys over their range of motion.
While the structure motion is locked out, this will give the electrical team time to rearrange the Az cable wrap and once that is done to install the new cable wrap. This is likely to carry over into the next week as well.
Last week the team worked on getting the upper X rail ready for the lift of the encoder. We should be able to get the encoder in place and wired up by the end of the week. Over the last weekend we had Praxair truck on site to make sure that we can start our liquid nitrogen deliveries once the tank and VIRUS are in place. This went smoothly and TxDot was on site and will make a recommendation to widen a small portion of the Y at SPUR 77 and SPUR 78 to give the truck good purchase when making its wide turn.
Last week I also reported “The original scheduled date for the tracker to arrive was the week of Jan 27, as see in the gantt chart blogged on August 12, 2013. We should be able to make this milestone without any delays.” Given the high price of the crane services and the delicate nature of the operation we wanted to make sure we had everything in place and well tested before the tracker goes on. Thus, we have rescheduled the tracker lift for the week of February 17th.
Next week we will have Ron Leck out from Austin to test the upper X rail motion while the mechanical team assembles the lower X rail.
Just before the winter break we had the Physical Plant team and some of the HET staff work on taking down the walls and roof of the MRS enclosure. The MRS is being stored away and that space will be used in the next 8 months for storage of the VIRUS units as they begin to arrive. We still have to remove the huge optics benches and the floor of the enclosure but once those are out we will be ready for the first VIRUS unit to arrive in West Texas by the end of January.
Work continues on putting components of the lower and upper tracker drive assembly in place. All of that work needs to be done before the new tracker can arrive. The original scheduled date for the tracker to arrive was the week of Jan 27, as see in the gantt chart blogged on August 12, 2013. We should be able to make this milestone without any delays.
The electrical and mechanical contractors worked over the Christmas break to try to make up for delays earlier in the planning part of the project. We now have 480 V power in the lower electrical room and the trenches cut in the concrete dome floor are in place ready for the liquid and vapor nitrogen lines.
Happy New Year all; it looks to be an exciting one!