Accomplishments/Updates/News: (details below)
- Second meeting with Dr. Anderson
- Second visit to DeDe
- Serious questions answered from Ernest
- Preliminary part analyses
- Pin stress and fatigue (SolidWorks)
- Thermal analysis of solid vs. proto plates
From meeting with Dr. Anderson:
- Risk Reduction presentation logistics
- 20 minutes per group after all
- Look into Dry Ice as alternative to liquid nitrogen. Viable?
(Dry ice sublimates at: -78.5C / Heat of Sublimation: 572.2 J/kg)
Delta Design visit v.2:
- Received the prototype!
- New pictures too...?
Questions for Ernest from last week:
Administrative:
q1: Have you signed off the budget sheet yet?
a: Attached
q2: Do we have permission to borrow the prototype shuttle? If so, when's the soonest we could borrow it?
a: Things changed and it looks like you might be able to borrow it maybe for next quarter (I’ll let you know if sooner). We will need it back though. You can come in this week if you want, let me know when.
Failure-Related
q3: The pins that fell out--were they originally press-fitted? And was there any visible damage to the pins?
a: Press fit, no significant damage on pins. Wear seen on its hardstop. Steel pin, Aluminum hardstop……
q4: We noticed in the thermal testing data that, when ramping up to the high temperature, there's an overshoot of about twenty degrees. Is this normal or significant?
a: Usually there is an overshoot as part of the control process, it can be optimized though. The issue is not really not having enough power, the duty cycle on the heaters is like 20%-30% to get to a standard shuttle to 175 deg C. The issue is more improving the thermal path to the device pockets, to not have to run such high offsets (see attached most recent ppt).
q5: How are the solid shuttles usually brought to the required temperatures? How was the prototype shuttle tested heat-wise--in similar conditions to the solid shuttles? We're assuming that this isn't just a matter of heating the shuttles for longer to reach the setpoint temperature.
a: Good ? There was a test done recently where the shuttles (proto) was done like a standard shuttle would (ideal conditions covered) and the issue with gradients across the 8 different sites went away. So this is no longer an issue. (see ppt) And no it was not simply a matter of time, as the data I gave you guys shows, the shuttle did reach steady state.
q6: Did the rubber O-rings used in the prototype suffer any temperature damage after the heat-testing, or do they still function well?
a: The ones in the pneumatic actuator are silicone, good for the temp, everyone asks that ? I thought the same, they look cheap don’t they? lol
Design/Manufacture-Related
q7: We noticed Guhring gun drills and extended drill bits listed in the COTS supply list. Were these used in manufacturing the prototype, and will we need to buy our own to make similar prototypes?
a: That was for the lines for the pneumatic sensing provisions, so yes.
q8: Are we allowed to use lubricants in the design, or does the mechanism have to function well without?
a: Yes and no, you can add grease to things like the radial bearings because it will be in the bearings. We don’t want to add lube all over the place where it will make a mess. Remember those rotators will have pockets for customer property, we don’t want to contaminate their devices.
q9: Are there any materials that you'd prefer we stick with? Pretty broad?
a: Can’t think any off the top of my head to not use (assuming it meet the temp requirements, and conducts electricity and doesn’t cost a ridiculous amount, so don’t make it out of gold or platinum….).
Assorted
q10: In 'rotating shuttle temps.xlsx', what are the kit/sys offsets?
a: (see new ppt)
Pin analysis: (ongoing)
Ideas so far:
- Greater pin diameter (less force per area on stops/puck)
-
Results:
-
Thermal analysis: (ongoing)
Ideas so far:
- Ribbon of copper to lie across top of plate between two rows of pucks
- Copper blocks to increase total thermal conductive area w/ better conduction coefficient
Results:
-
Looking forward:
- Risk Reduction group presentation - Tuesday, Dec. 10th 2012 Finals Week Fall
https://sites.google.com/a/eng.ucsd.edu/mae156a/sponsored-projects/files/risk-reduction-presentations
- Start to set up the team webpage (google docs) by the Tuesday Final
https://sites.google.com/a/eng.ucsd.edu/156b-2013-winter-team9/
- Individual Component Analysis reports will be due second meeting of Winter Quarter (approx Jan. 10th?)
- Max two pages, etc:
https://sites.google.com/a/eng.ucsd.edu/mae156a/sponsored-projects/files/individual-component-analysis
- Workshops cancelled: instead 3D printing and software packs covered in 156B lectures
- Project update due second meeting of Winter Quarter
https://sites.google.com/a/eng.ucsd.edu/156b-team-template/internal-proj-manag/project-management/156b-week-1
- When do we start ordering/buying parts? Talk to J.J. Agneau (spl)