1. Leach Backplate and Connector Mount Critical Design Review Iain Marcuson 12/03/2013

2. 2 Instructions: Goals 1.The goal of the CDR is to ensure that the design is ready for fabrication, assembly, and validation.

3. 3 Instructions: Required Elements 1.Goal of Review 2.Goal of system 3.Requirements 4.Constraints 5.Functional block diagram 6.System block diagram 7.Analysis showing that system satisfies requirements 8.Parts list, with costs and availability 9.Sequence of tasks 10.Schedule of tasks with identified resources 11.Budget 12.Risks and mitigations 13.Monitoring plan

4. 4 Instructions: Review Success Criteria 1.There is an explicit demonstration that each requirement is satisfied by the design. 2.>80% of drawings are ready to be submitted for fabrication. 3.All quotes have been obtained, including costs and lead times. 4.The proposed budget is less than the available budget. 5.The final need date has been identified from an existing project schedule. 6.The system will be delivered by the need date. 7.Lead times are compatible with the schedule.

5. 5 Goal of Review 1.The goal of this review is to validate the drawings for the back plate and new mounting scheme of the new Leach assembly.

6. 6 Goal of System 1.Connect internal clock and video boards to external connectors. 2.Maintain compatibility with current external connectors.

7. 7 Requirements 1.The new back panel must be compatible with the current external Leach connectors. 2.It must be possible to connect the internal connectors to the back panel from the outside, with little internal manipulation.

8. 8 Constraints 1.The backplate must be of a thickness that only requires cutouts and counter-boring. 2.The backplate must accommodate available solder-cup connectors. 3.The design must not put stress on the board connectors.

9. 9 Functional Block Diagram Card Connector x9 Backplate External Cable to Dewar Card x5 There are five cards. Four cards have two connectors and one card has a single connector. The connectors are rear-mounted to the backplate, with an aperture for each connector.

10. System Diagram Dewar Leach Power Supply Computer Leach Backplate

11. 11 Detailed Designs

12. 12 Drawings

13. 13 Drawings

14. 14 Drawings

15. 15 Drawings Female 50 PinMale DB-15Male DB-25Function 114Input -A 2 33Input -B 417Input -C 5 66Input -D 720Input -E 8 99Input -F 1023Input -G 11 12 Input -H 13 147Bias out 7 155Bias out 5 163Bias out 3 171Bias out 1 181Input +A 1915Input +B 20 214Input +C 2218Input +D 23 247Input +E 2521Input +F 26 2710Input +G 2824Input +H 29 30 316Bias out 6 324Bias out 4 332Bias out 2 342Ground 355Ground 368Ground 3711Ground 3813Ground 3916Ground 4019Ground 4122Ground 4225Ground 4311Ground 4410Ground 459Ground 468Ground 4712+16.5 V 4813-16.5 V 4914+6.5 V 5015-6.5 V

16. 16 Analysis/Results We must be able to drive the jackscrew externally, ideally without needing a large counterbored hole to provide room for the driver. The below diagram shows that we have enough length of jackscrew to drive.

17. 17 Analysis/Results Rear Panel Mounting Scheme and Fit Check

18. 18 Parts List, Costs, and Lead Times Part Number Part Descriptio n VendorCost Each Quantity Needed Quantity Available Total Cost 5115MEA- ND Male DB- 15 Digi- Key 3.37451113.48 5125MEA- ND Male DB- 25 Digi- Key 3.79430515.16 1237ME- ND Male DB- 37 Digi- Key 2.8514582.85 289-016-DLow Profile Jackposts Glenair34.579>=25311.13 MD50F200 00 Female DB-50 Arc4

19. 19 Risks 1.Panel connectors could be inline with board connectors, leading to undesired stresses and broken connections. 2.Jackscrews may not hold in place due to lack of lockwasher. 3.Bob Leach may discover the price of the jackscrews to be excessively high.

20. 20 Mitigation 1.Connectors in line a.We can collaborate with Leach to ensure that cutouts are such that connectors are not in line. b.It may be the in line connectors are not a problem. c.Extra wire could be added to the internal cables to prevent stress transfer. 2.Jackscrews loosening a.Threading tape may be used to increase adhesion and provide expedient removal. b.Thread-locking compound may be used to ensure adhesion at the cost of ease of removal.

21. 21 Mitigation (continued) 3.High Cost of Jackscrew a.We can provide additional funds for the jackscrews. b.We have successfully machined such jackscrews ourselves in the past, and could supply the jackscrews separately.

22. 22 Schedule 1.Design will be submitted to Bob Leach. It is presumed that the back panel will be ready by the end of the Leach system fabrication time.

23. 23 Sequence of Tasks 1.Fabrications will be performed by Mr. Leach. He will conduct fabrication along with the Leach system.

24. 24 Budget 1.This project is included in the budget for Leach.

25. 25 Monitoring/Verification Plan 1.A one-to-one drawing has been made to test fit components. 2.If all nine connectors can fit into the back plate and be attached, the mechanical design will be verified. 3.If successful Leach gain experiments can be conducted, we have evidence of preliminary correct cable construction and operation. 4.Dark current data, compared with similar experiments from the previous Leach system, will provide confirmation of cable correctness.