2. Overview Background Fabrication and Parts Testing Lessons Learned Future Improvements BudgetConclusion

3. Design Team #10 Michael Noel Brian Brown William Matheson Gavin Mills Supervisor Dr Alex Kalamkarov Dr Alex Kalamkarov

4. Purpose Design and fabricate a device capable of scaling steel oil storage tanks Device will have a payload of various sensors – eddy current, visual, ultrasonic Will be used to inspect oil tank walls for defects – common corrosion, pitting, welds Source:http://www.fotosearch.com/EYW1 92/e008752/

5. Design Requirements Move at a speed of 10 m/min vertically up tank. Carry a payload of 30 lbs. Must be completely wireless. Able to scale vertical, steel tanks with diameters greater than 15 m. Mechanical structure expected to withstand 5 years of daily use. Project should not exceed a budget of $2500.

6. Frame and Track System

7. Main Frame Basic box design 1/8” thick sheet aluminum Size was determined by track length and internal mechanics and electronics Cut top to proper size and welded sides in place Holes were cut for shafts and mountings Slots cut for front shaft/tensioning system

8. Frame Angle aluminum support added to top Angle aluminum support added to rear shaft bearing mounts Tensioning system installed Handle added for safety line when testing Finishing touches/painting

9. Tracks and Sprockets Primo 2” wide motorcycle drive belts Strong, rigid, and reinforced (allowed holes to be drilled) 4 aluminum sprockets mated to belt

10. Tracks and Sprockets Sprockets were manufactured by in-house technician Keyways were cut in drive sprockets to match keyed shaft Press fit bearings in front sprockets, free rotating on shaft

11. Magnets Rare earth magnets called Neodymium (Nd2Fe14) magnets were used Approximately 30 lb force Dimensions: {2 in (length) x ½ in (width) x 1/4 in (thickness)} 24 magnets/ track Scrape easily, covered with nylon tape Brittle, require strong backing

12. Magnet Holders Steel bar stock Slots for magnets were milled Channels-(2 x ½ x 3/16) in Cut to 2” lengths Bolt holes drilled and threaded Magnets extend past holders’ top edge to ensure contact with tank

13. Holder Attachment and Track Guides Holders were attached by two 3/16” X 1” bolts. Bolts are fitted with two rubber 9/16” dia – ¼ R washers Screwed through track and into holder Ends were ground off Rubber washers act as track guides

14. Track Alignment Tracks shifting more than anticipated Rubber washers were wearing from contact with sprocket Guides were added 3/4 “ birch plywood Had to run smoothly between washers Kept track in line

15. Drive Train Independent drive trains Independent drive trains

16. Planetary Motors Astro Flight 940P Astro Flight 940P 24 volt, 750 watts 24 volt, 750 watts 15:1 all steel planetary gear reduction 15:1 all steel planetary gear reduction 45 rpm/volt * 24 volts = 1080 rpm unloaded 45 rpm/volt * 24 volts = 1080 rpm unloaded Wall climber draws ~25 amps without payload Wall climber draws ~25 amps without payload Max continuous current 35 amps, 100 amps stall Max continuous current 35 amps, 100 amps stall

17. Planetary Motors

18. Worm and Worm Gear Martin hardened steel worm and worm gear Martin hardened steel worm and worm gear Worm gear has 1.67” pitch diameter, 20 teeth Worm gear has 1.67” pitch diameter, 20 teeth Worm has 1” pitch diameter, 1 thread Worm has 1” pitch diameter, 1 thread 20:1 gear ratio 20:1 gear ratio Acts as a brake when the motor is not powered, preventing the robot from rolling down under gravity Acts as a brake when the motor is not powered, preventing the robot from rolling down under gravity Source: http://www.martinsprocket.com

19. Bearings Worm shaft supported at each end by radial roller bearings Worm shaft supported at each end by radial roller bearings Thrust bearing assembly (right) has 2 thrust bearings to absorb worm axial forces Thrust bearing assembly (right) has 2 thrust bearings to absorb worm axial forces Drive shaft rotates between a pillow block bearing and a flange bearing Drive shaft rotates between a pillow block bearing and a flange bearing

20. Speed Controllers IFI Victor 883 IFI Victor 883 60 amps continuous 60 amps continuous Vary output voltage from 10 – 100% Vary output voltage from 10 – 100% Forward and reverse motion Forward and reverse motion Active cooling with 24V fan Active cooling with 24V fan Low voltage drop Low voltage drop

21. Radio Controller Airtronics Avenger 2X 2 channels Wireless receiver plugs into speed controllers Joystick A controls right motor, joystick B controls left motor Source: http://www.airtronics.net

22. Battery Packs 24 volt nickel metal hydride battery backs 24 volt nickel metal hydride battery backs 20 cells * 1.2 volts per cell 20 cells * 1.2 volts per cell 3.5 amp*hour capacity 3.5 amp*hour capacity One pack per motor One pack per motor Rated capacity falls as discharge rate increases Rated capacity falls as discharge rate increases Source: http://www.uniross.com

23. Testing Testing was done on two structures.

24. Testing Problems and Solutions Problem Solution (s) 1. Body flex under load Angle-bar installed across top Angle-bar installed across top 2. Flange bearing shift due to track tension Angle-bar support installed against flange housing Angle-bar support installed against flange housing 3. Friction wearing on worm gear Pillow block mount shortened and drive train realigned Pillow block mount shortened and drive train realigned Lithium grease added to worm/worm gear assembly Lithium grease added to worm/worm gear assembly 4. Track misalignment while turning Runner added between front and rear cog Runner added between front and rear cog 5. Short battery life Multiple charges and discharges Multiple charges and discharges Drive train lubrication and realignment Drive train lubrication and realignment

25. Testing Results CriteriaDesiredAchieved Speed 10 m/min upward 21 m/min upward Payload 30 lbs 50 lbs Wireless operation yesyes Onboard inspection camera yesyes Battery life 15 min 10 min Turning on vertical surface yesyes Smallest oil tank diameter 15 m 10 m Robot weight 30 lbs 52 lbs

27. Lessons Learned Fabrication Fabrication Measure Twice ~ Cut Once Measure Twice ~ Cut Once Liaise with technicians regularly Liaise with technicians regularly Expect a busy machine shop Expect a busy machine shop Small changes in design can decrease fabrication time & costs Small changes in design can decrease fabrication time & costs Research suppliers ie. size of stocked parts during the design phase Research suppliers ie. size of stocked parts during the design phase Source: http://www.acclaimimages.com/_gallery/

28. Lessons Learned Components/Parts Components/Parts Order ASAP Order ASAP Expect delays Expect delays Inform seller how to ship Inform seller how to ship Plan for: Plan for: Defective parts Defective parts Wrong parts Wrong parts In stock today ~ Out of stock In stock today ~ Out of stocktomorrow Ask what comes in the box Ask what comes in the box

29. Future Improvements Smaller overall size Reduce weight Reduce weight Additional support for drive shaft Limit flexing of shaft Limit flexing of shaft Sub-frame assembly More rigid than current aluminum body More rigid than current aluminum body Redesign magnet holders Reduce weight / prevent movement of magnets Reduce weight / prevent movement of magnets Investigate battery options Increase operational time Increase operational time

30. Future Improvements Redesign track alignment system

31. Future Improvements Find guide material with higher abrasion resistance

32. Budget Major Expenses $ 2677.40 Bearings$145.00 Stock Metal$245.00 Gears$160.00 Belts$316.40 Paint$47.00 Batteries$240.00 Motors$882.00 Magnets$179.00 Customs$175.00 Mock Up$200.00 Note: Speed controllers were not included ($385) $2500.00

33. Special Thanks Supervisor Dr Alex Kalamkarov DP Coordinator DP Coordinator Dr Ted Hubbard

34. Special Thanks Dept Technicians Albert Murphy (Lead) Angus Macpherson Stewart Carr Mechanical Dept Peter, Greg, Luke, and Lisa

35. Special Thanks Our Client Dr Jason Gu Dalhousie Electrical Department