Elements of Mechanical Design – Spring 2016

This page contains information for SYEN 3379. Elements of Mechanical Design.

MAIN DESIGN INFO

The front and rear steering wheels need to be actively powered and measured.  This design will be the main design for the class (a gearbox and sensor interface).

The steering needs to incorporate a Bourns 3852A potentiometer (bourns potentiometer, mouser info, cad model)

Stock Drive Worm and Gear models and spec. A1B6Z24018, A1Q5Z24

 

Design Project:  Two years ago, we started the “Dancing Robot” project to work with a Theater production.  Although we got close to a finished robot, many factors have changed, and it’s time to revisit the design and get it complete.

In scrub school, we’re going to measure the wheel parameters and get a solid model of the wheel.  The lack of a model made it tough to design the spacers, which led to a compromised drive system design.

In scrub school, we’re going to remake many of the suspension parts.  The first class didn’t seem to think that holding tolerances was all that important until they tried to put the thing together.

The controller has changed from a Vex controller to a Beaglebone.  The base plate in the controller box needs to be redesigned and refabricated to accommodate.  This will be the first class design project.

The front and rear steering wheels need to be actively powered and measured.  This design will be the main design for the class (a gearbox and sensor interface).

Finally, a skirt with sensors in it to stop the robot, a mounting for light sensors to measure lines on the stage, and a support to allow the dancers to vault the robot need to be designed.  These designs will be split among the class.

Since the “easy” design wasn’t built into the syllabus, I’m going to give you “bonus” credit for this.  Deliver on time and to specifications, design = up to +1 bonus point, build = up to +2 bonus points.

Design groups: Preliminary Design (solid models only) due 3/11.  Build due after Spring Break.

controller plate: Zac, Clay, Josh, James

Skirt: group one (Jeffrey, Colum, Jesus), group two (pamfil, Jack, Michael)

Launching Pad: group one (Tanner, Jarrett, Max), group two (Lottie, Grady, Sam)

Scrub School Assignment Due date
Measure the wheel provided and create a solid model.  Integrate the wheel into the existing wheel design. Redesign the spacers to keep the wheel in the center.  Build the spacers. 3 points (1 = model, 1 = spacer design, 1 = fab) 2/2/16
Assemble the robot as is.  Measure the force needed to turn the front wheel with extra weight.  Use 200, 400, 600 pounds. 2 points 2/9/16
Fabricate the following parts to print. 3 points

  • BearingPlate qty: 1 per student (Costello, Dandurand, Dial, Harris, Jones, Love, Metcalf, Pamphile) (material is .25″ thick, aluminum – left off drawing)
  • BearingBack qty: 1 per student, (Padilla, Richardson, Shelton, Tolleson, Tyhurst, Wemette, Wheeler, Williamson) (material is aluminum – left off drawing; do NOT put in the .124 diameter holes)
2/23/16
Measure the thickness of the leaf spring on the assembled robot.  How does this compare to the model from the FEM videos? Load the robot with 200, 400, 600 pounds and measure the deflection.  How does this compare with theory? 2 points 3/1/16
Shouldn’t be more Due date
Letters to Label Part
Name Letter Name Letter Name Letter Name Letter
Costello  C Jones  J Padilla  P Tyhurst U
Dandurand  D Love  L Richardson  R Wemette W
Dial  E Metcalf  M Shelton  S Wheeler X
Harris  H Pamphile  N Tolleson  T Williamson Y

Office Hours: By arrangement (569-8071)
Shop Open Hours [PDF] 

Mid-term grades available circa TBD

Drop Date: Mar. xx

Spring Break, March xx, No classes, University Closed March xx

Last Day of Classes: May xx

Consultation Day: May xx

Final Exam Period, Friday May xx, x-xx, EIT xxx

Last Semester’s content below this line.

Cool Videos Illustrating Mechanical Concepts

Reading
date source chapter
 1/12/16  functional requirements
 1/19/16  Shigley  Loads and Stress (3-1 through 3-11)
 1/26/16  Shigley  Loads and Stress (3-1 through 3-11)
 2/2/16  Shigley, Video Lecture 1Video Lecture 2Lecture Notes  Bending and Deflection (4-1 through 4-6)
 2/9/16  Shigley, Simply supported beam, intermediate load – worked problem Bending and Deflection, Frame Design
 2/16/16  Shigley, Failure  Failure (5-1 through 5-7)
 2/23/16  Shigley Failure (5-1 through 5-7)
 3/1/16(last week of 3 hours lecture)   GearsGears (sdp-si), Shigley ch. 13, 14 Gears
 3/8/16 Gears
 3/15/16 Gears
 3/22/16  Spring Break  Whew!
 3/29/16  Shigley, notes Bearings, chapter 11, notes
 4/5/16 Bolted Joint  (8-1 through 8-12)
 4/12/16  Shigley Bolted Joint  (8-1 through 8-12)
 4/19/16  Shigley   Bolted Joint  (8-1 through 8-12)
 4/26/16 Some thoughts on Clutches, Latches, and Ratchets [PDF]   Bolted Joint

 

Homework
date assigned topic assignment
1/22/2016(pushed back due to snow) energy approximation HWK1. assignment, globe motor spec, robot
1/22/2016 Identify the Functional Requirements of log the splitter below  HWK 3. Log Splitter
1/29/2016 review of Chapter 2 HWK 2

2/9/2016 Shear and Moment Diagrams HWK 4

  • 3-9, 3-10, 3-11, 3-12
  • For a uniform 20 foot long aluminum I-beam (e. g. McMaster Carr p/n 8003K11), what is the maximum deflection, due only to the beam’s weight?

Videos to get back into FEM

2/16/2016 Mohr’s Circle HWK 5. Mohr’s Circle

  • 3-15, 3-16 (you can use matlab for calculations if you wish)
2/23/2016 Failure Calcs  HWK 6: 5-1, 5-3
3/8/2016 Gears
3/22/2016 Bolted Joint HWK 7: 8-11, 8-12, 8-13
4/5/2016  Bolted Joint HWK 8: 8-24, 8-29, 8-32, 8-67 (no bending failure), 8-71
4/12/2016 Member Stiffness  http://calliope.ualr.edu/wp-uploads/calliope.ualr.edu//2016/04/3379_homework_x_S16.pdf
5/3/2016  Gear Box Design Problem - PDFHWK 6. Gear box calculations [PDF] Assigned: 11/25/13 Due: 12/2/13
Design Teams

 

Design Concept (individual) Design Exercise 1
Detailed Energy and Force Calculations (team) For your specific design, pick your energy storage element. Write a 1-page report detailing a very specific energy calculation.  If you’re going to use springs, pick an actual spring.  If you’re going to use weights, pick an actual weight.  If you’re going to use a pressure vessel, pick an actual pressure vessel.What forces might you have to impose on your frame?  If you’re going to use a ratchet, how much force will it have to exert to cock your mechanism?  Using a guess of 30J per cycle for a human to add energy to your device, how many cycles will a human have to add to get the device fully charged?
Frame Concept Design and Calculations (team) Design Exercise 2 
Frame Design  (team) Design Exercise 3
 Frame Design Final (team) Design Exercise 4
 Energy Storage and Coupling Design Rough (team) Design Exercise 5
 Latch Design Rough (team) Design Exercise 6
Final Design Report (team) Final Report Format … Potato chunking must be done by the date of the final exam. The report will be due the day after by 12:00 to give time to incorporate any data collected from potato chunking.
Final Design Grading .2*Design Exercise 1 + .1*Design Exercise 2 + .2*Design Exercise 4+.1*Design Exercise 5 + .1*Design Exercise 6 + .3*Final Report

 

Design Problems

  • Conceptual Design
  • Frame (set space claim, basic energy storage calculation, functional requirements, pivots and attachment points)
  • Energy storage and coupling
  • Latch
  • Ratchet/Winch/Pump
Links

Free CAD Models of Manufacturer Parts
CAD Models

McMaster-Carr
MSC
Grainger

Stock Drive Products

Links to Parts Available for Design

Actuators
FIRST CIM MOTOR (QTY: 1 per design)
Servo Motor for Latch and Clutch (QTY: 2 per design)
Sensors
Limit Switch
Potentiometer (Link TBD)
HEDS Encoder SolidWorks IGES
Yaw Rate Sensor

608 series bearing

3200 series angular contact bearing

——————- older stuff below here ———————-

From Shigley: 11-1, 11-2, 11-3, 11-4

HWK 5. 7-1, 7-3, 7-6, Assigned 11/11/13, Due: 11/25/13

 

 

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