156B Week 8

Overview of Status of Analysis, Design, Fabrication, Tests, etc.

• • Analysis:

    • Finished analysis needed to purchase load cells

  • Design

    • Finalized design of all components except the take-up spool key-lock design.

    • Began design of control system in previous week with Ed Pogue

  • Fabrication

    • Fabricated small PP rollers for idler, but need to remachine without bearing holes

    • Waiting on other PP stock to fabricate take-up spool

    • Need to begin fabrication of vertical mounts

  • Tests:

    • Completed test to determine load cell sizing as discussed in accomplishments from previous week

    • Will do length tracking test with new higher-torque motor.

Accomplishments from Previous Week

• • Developed full system CAD as seen in the figure below.

Figure 1: CAD of Entire System except supply spool mount

• • Setup full system prototype with feeder mechanism, idler pulleys, tension monitoring, servo guide, and horizontally mounted take-up spool.

Figure 2: Full system prototype.

• • Purchased raw materials, hardware, etc for system prototype and final system.

  • Contacted CMC about their load cell transducers for tension sensing and received the following quote:

    • Tension Sensor: 829.99

    • Amplifier: 629.99

    • Cable: 89.99

    • Total: 1549.97

    • Determined this was out of our budget, and decided to make our own tension system using two 1kg load cells with amplifiers which were determined by the following test.

  • Setup preliminary tension monitoring system and measured tension in rewind section of the spooling system over 60 seconds

    • Max tension: 1.2 N

    • Average tension: 0.42 N

    • Resolution: 10 mN

    • Outcome: Using two 1 kg load cells we would have a range of 20 N with a resolution of 5 mN which is sufficient for our requirements.

Figure 3: Tension in rewind section in full system prototype.

• • Sent purchase order to Roxanne to order load cells and amplifiers.

  • Jhon and Anthony visited IMS for aluminum stock on the recommendation from the machine shop and purchased aluminum sheets to begin machining vertical mounts.

Goals for Next Week (list names after each item). Use specific and measurable objectives.

• • Finish full assembly with real parts and raw materials

    • Idler pulley system (Jhon)

    • Tension monitoring system (Anthony/Pat)

    • Feeder mechanism with aluminum side mounts (Iman)

    • Take-up spool and mount (Anthony/Pat)

    • Supply spool mount ( Iman)

    • Servo guide ( Jhon)

    • Enclosures ( Pat)

  • Implement control system when higher torque motor arrives for second spool. (Anthony/Patrick by 5/25/19)

  • Purchase all remaining parts and materials that are required for final fabrication and assembly. (Anthony/Patrick by 5/22/19)

    • Aluminum stock from IMS

    • Dry bushings (4x)

    • PP sheet

    • PP 5" diameter stock

  • Begin fabrication of final parts starting on Thursday (5/23/19)

Sponsor Comments from Last Meeting and Actions Taken to Address these Comments (indicate date of comments and if via email or in person)

• • Non-contact material:

    • Aluminum and other metals should be fine

    • No rusting

    • If it is not touching the lumen it should be fine

    • Aluminum is probably ideal (look into anodize it)

    Cleanroom standards

• • • Use dry bearings

    • Should be fine if enclosed.

• • Sponsor indicated that our plans to ensure no damage of the tubing was sufficient

    • Compression test

    • Compressed air test

    • Tension test

  • Sponsor is fine if load cell calibration has to be done every so often as long as we include a protocol

  • Ordering PP from McMaster is fine

  • Use PP or anodized steel or aluminum for the base

Instructor Comments from Last Meeting and Actions Taken to Address these Comments  (indicate date of comments and if via email or in person)

• • Load cells will introduce unknowns into the system and need to account for this (i.e. mounting..)

  • Need to consolidate slides better and focus on outcome of analysis not the analysis itself.

  • Discuss cleanroom standards with sponsor including dust and IPX standards

  • Look back into screw drive system if servo does not work for guide

  • Get finalized quote from CMC on transducers

Comments from Other Students in the Class (indicate date of comments and if via email or in person)

• • Need to work on better representing our analysis in more consolidated slides

  • Work on oral delivery better

  • Better explain the need for this project with our sponsor

Risks and Areas of Concern

• • Key mechanism for take-up spool cap and shaft mounting

    • Will discuss with advisor and machine shop staff

Resources or Information Required but not Available

• • N/A

Schedule

• • Second report draft and website by this upcoming Friday

  • PDR scheduled for next Tuesday

  • Hardware demo to sponsor in two weeks

  • Final poster presentation in three weeks.

  • Updated Gannt Chart.

Budget (list amount spent and amount remaining)

• • Update purchase list

Progress on Report and Webpage

• • No updates on this yet, will begin working on it tomorrow and the rest of the week.