This is a new log started on Sept 30 2016. For the older logs and procedures please see https://dcc.ligo.org/LIGO-T1600205
Goal: cheking repetability of the tempreture elevation
Setup: no gasket at the ring heater; no thermal pad on the thermocouple, thermocoupel at the center of the back plate
Current: 250 mA
Expected max temperature: 200 C
Pressure: 2 10-7 torr
Increasing resistance with temperature (decreasing current):
Goal: thermal conductivity test depending on pressure
Current: 200 mA
Expected max temperature: 130 C
Pressure: 2 10-6 torr - 8 10-8 torr
I measured the temperature during 3 days at constant current just to if there is any influence of the pressure on the result.
Result: The temperature measurement in future can be started at low 10-6 torr range (an overnight pump down for Thomas vacuum chamber)
Pumping down on Quad Nov 25th.
With Vac at 2.15e-5 Torr ran B&K system for 256s with 1 average. df=3.9 m Hz. Re-ran Graphical Setup in Trigger and changed hold off to 100 from 1000s.
I forgot to enter this on the 18th, so here is what I did the week ending on the 18th.
I completed FEA of the overall middle mass and found the "wing mode." It occurred at 217.03 Hz.
I have begun on a rendering of the HSTS with the new middle mass. In doing so, I have realized that the clamps on the middle mass do not quite line up with the wires. I have done some tweaking and we will see when Norna returns if the fix is acceptable.
We also began work on the mini-project Calum presented to us. I have some preliminary designs, but I'd like to get my hands on some of the mesh I want to use to get a feel for it.
This week I tackled items 1-3 on the to do list I got last week.
All of the parts I have drawn for the new HSTS middle mass have been added to a sandbox file on the vault. I have also summarized all of the work done so far on the new middle mass in a review document on the DCC (found here). Finally, I began running FEA on the new blade design to A) find its normal modes and B) make sure the deflection we calculated was accurate. The findings of that analysis are in a report on the DCC (found here). At first, the deflection was not looking correct, but after consulting with Calum and reviewing an FEA he ran on some other blades, I realized I had entered my loading conditions wrong. I corrected them and got the following deformation.
I'll begin next week with doing FEA on the entire mass and adding all the FEA results to the overall report. Hopefully we will also begin getting quotes for parts
I had a few things left over from last week to finish up early this week, like finishing a few engineering drawings and fleshing out the Bill of Materials (I have attached its state so far to this entry). I also made a drawing of the new blades for this mass using the parameters Norna found.
In addition, I added in a roll adjuster similar to the pitch adjuster and added tapped holes for set screws to hold the adjusters in place.
Norna, Calum, and I met on Thursday to discuss what I'd be doing for the next couple of weeks. The tasks we settled on are as follows:
1) Finish Bill of Materials (BOM). Finish getting DCC numbers. Put onto Vault(?)
2) Write up what you have done in the design and explain why. Could add to existing document.
3) Blade design/ drawing . Also FEA of blade. See Calum's reference.
4) Work with Eddie to get quotes for parts. Write statement of work. Could also get quotes for rapid prototype version.
5) Put together rendering of whole suspension including bottom wires going round mass - use a glass mass.
6) Adjust length of bottom wires to get the orignal overall lenght of HSTS. Note new length
7) Look into redesign of wire jig for producing clamp/wire clamp assembly to take your new clamp design. Draw up modification.
8) FEA of new mass - basic modes in free / free case cf top mass also look at adding loads to represent blades
9) Get set-up going to measure mode frequencies of triple suspension in lab Could use B&k or spectrum analyzer - need to think about non-contact probe or accelerometer ( this item in conjunction with Norna /Calum).
10) deep fallback - resurrect Kristen's middle mas for HLTS and apply design considerations used in HSTs to continue that design.
I forgot to make drawings of the T-section and I-section, I need to do that as soon as I return after the holiday weekend
The main goal for this week was to start getting engineering drawings in order for fabrication. With Eddie's help, I drew up all of the parts in the new middle mass. After a couple rounds of red lines, I got the drawings to a near-finished state. I also got DCC numbers for all of these parts.
While doing this, I realized that I had not figured a way to attach the two bottom pieces (pictured below).
We decided brackets were the way to go, so I drew some up in solidworks, got another DCC number for them, and added them to the assembly.
I also began a Bill of Materials for the new middle mass
This week was spent mainly finishing up designs for the new HSTS middle mass. The main tasks were:
The top plate was basically done at this point, all that remained was to make sure all of the holes were the correct tap size and such. What required the most attention was clamps holding the wires from above. I made an initial design and added holes to the top plate such that the clamp could be attached from below. However, once these clamps were in place, I realized the wire separation was too small. I made a change that created an asymmetrical piece with a handedness but, after a discussion with Calum, I modified the top plate so that we could go back to the symmetric design and maintain the correct wire seperation.
As for the clamps on the blades holding the bottom mass, I adapted a previous design to not only maintain the wire separation, but also to account for the new angle of the wires (previously the wires from the middle mass down to the bottom mass were vertical, the addition of the blades doesn't allow for this)
Harrison has put together a first look at what a revised HSTS with blades at middle mass might look like. This is a work in progress, some parts missing (magnet /flag assemblies etc.)
We wanted to compare the effect of the pitch adjuster on the top mass to the effect on the new middle mass. So, the center of mass and moments of inertia were found for both masses and recorded. The pitch adjuster was then moved 25mm in the Z-direction (solidworks coordinate frame) and the COM and MOI were found again. The results are in the attached document.
The pitch adjuster was then moved different distances, and the effect it had on the center of mass was recorded in the attached document
I have written a doc summarising current status of work on HSTS redesign of middle mass, including MATLAB transfer functions for a preliminary conceptual design.
See T1400290 at https://dcc.ligo.org/LIGO-T1400290
I'm currently working with Calum on change request for funding a prototype of the middle mass. Eddie is helping us to cost this based on Harrison's conceptual design.
Harrison is working on more details of the design.
This is image of the 4 sectioned green lantern on the mock up quad at cit.
1) BA to complete cabling for use in chamber
2) CT to clean & bake
3) KG to practice imaging. unit is in 318 Downs on quad mock-up.