RC08Drive Module

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Revision as of 20:27, 14 April 2008 by Stefan (talk | contribs) (Action Log)
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As part of the Robocup 2008 Mechanical, the Drive Module packages the gears, wheel, and motor into an useful robot maneuvering tool.

2008 RoboJackets RoboCup Drive Module

Assembly Structure

Parts List

  1. 1 - Omni Wheel (RC-2008-02-00)
  2. 1 - Maxon Brushless Drive Motor (RC-2008-03-01)
  3. 1 - Drive Module Plate (inner) (RC-2008-03-02)
  4. 1 - Drive Module Plate (outer) (RC-2008-03-03)
  5. 1 - Base Attachment (RC-2008-03-07)
  6. 1 - Output Shaft (RC-2008-03-06)
  7. 3 - 1/2" Long Hex Standoffs (RC-2008-03-11)
  8. 1 - Input Gear (RC-2008-03-05)
  9. 1 - Output Gear (RC-2008-03-04)
  10. 2 - 1/4" Ball Bearings (RC-2008-03-08)
  11. 2 - 1/4" E-Clips (RC-2008-03-09)
  12. 4 - 8-32 Socket Cap Screws Counter Sunk (RC-2008-03-12)
  13. 3 - 8-32 3/8" Long (RC-2008-03-13)
  14. 1 - Washer (RC-2008-03-10)
  15. 3 - M3 Machine Screws (RC-2008-03-14)
  16. 1 - 5/16" E-Clips (RC-2008-03-15)

Instructions

  1. Press bearings in to plates so that flange is always on the the with out counter sinks.
  2. Using RC-2008-03-13 and RC-2008-03-11 attach the base attachment to the inner drive module plate (inner plate).
  3. Using RC-2008-03-12 fasten top stand off (RC-2008-03-11) to the inner plate.
  4. Mount motor with RC-2008-03-14. Position motor so that the wiring is coming out of the smaller removed corner.
  5. Place input gear on motor such that the hub is closer to the motor.
  6. Put output shaft in outer plate's bearing with hex side on the side with counter sinks.
  7. Place an e-clip on the groove outside the outer plate and immediately inside the outer plate.
  8. Put output gear on the output shaft (now in the inner plate) with the hub facing away from the outer plate.
  9. Add an e-clip to the last groove.
  10. Align the outer plate and then fasten it to the standoffs (already on inner plate) using RC-2008-03-12.
  11. Put omni wheel on output shaft with screws facing out.
  12. Using the washer (RC-2008-03-10) and 8-32 fasten the omni wheel in place.

Parts & Components

Bearings

1/4" Shaft Diameter
Vendor - Grainger
Part No. - 1ZEJ7
Cost - $5.59 Each
Description - Miniature Ball Bearing, Open, Flanged, Bore Dia 0.2500 In, Outside Dia 0.5000 In, Width 0.1250 In, Flange Dia 0.5470 In, Flange Thickness 0.0230 In, ABEC Level 3
Info - Web Link

Gears

Input
Vendor - SDP/SI
Part No. - S1063Z-072A020
Cost - $9.83 ($6.76 in bulk)
Description - 0.2778" Pitch Dia, 0.125" Face Width, 0.125" Bore (must bore out to 4mm)
Note - Al 2024
Input (Back Up Supplier)
Vendor - WM BERG
Part No. - P72S10-20
Cost - $13.25 Each (Same for bulk)
Description -
Note - Stainless 303
Output
Vendor - SDP/SI
Part No. - S1066Z-072S100
Cost - $17.72 ($13.02 in bulk)
Description - 1.3889" Pitch Dia, 0.125" Face Width, 0.25" Bore
Note - Stainless 303
Output (Back Up Supplier)
Vendor - WM BERG
Part No. - P72S28-100
Cost - Each
Description -
Note - Stainless 303 & thicker (7/16)"

Stock

5/16" Hex Bar Stock
Vendor - McMaster-Carr
Part No. - 6512K14
Cost - $5.85 Each
Description - 1018 Carbon Steel Hexagonal Bar 5/16" Hex Size, 6' Length
Al Plate 1/8"
Vendor - McMaster-Carr
Part No. - 89015K18
Cost - $26.06
Description - Alloy 6061 Aluminum Sheet .125" Thick, 12" X 12"
Al Angle (Base Attachment)
Vendor - McMaster-Carr
Part No. - 88805K54
Cost - $14.87
Description - Alloy 6063 Aluminum 90 Degree Angle 1/8" Thick, 1" X 1/2" Legs, 8' Length

Fasteners

8-32 Flat Socket Cap Screws
Vendor - McMaster-Carr
Part No. - 92210A190
Cost - $11.58 (Pack of 100)
Description - 18-8 SS Flat Head Socket Cap Screw 8-32 Thread, 1/4" Length
M3 Screws (Drive Motor Mount)
Vendor - McMaster-Carr
Part No. - 92005A116
Cost - $2.16 (Pack of 100)
Description - Metric Pan Head Phillips Machine Screw Zinc-Plated Steel, M3 Size, 6mm Length, .5mm Pitch
8-32 Low Head Socket Cap Screw
Vendor - McMaster-Carr
Part No. - 92220A152
Cost - $11.60 (Pack of 100)
Description - Alloy Steel Low Head Socket Cap Screw 8-32 Thread, 3/8" Length

Other

1/2" Long Hex Stand Off
Vendor - McMaster-Carr
Part No. - 91780A195
Cost - $0.34 Each ($0.27 in bulk)
Description - Aluminum Female Threaded Hex Standoff 1/4" Hex, 1/2" Length, 8-32 Screw Size
Shimming Washers (may not be needed)
5/16" Hex Broach
Vendor - McMaster-Carr
Part No. - 2875A17
Cost - $110.05
Description - Hexagon Broach 5/16" Hex, 7-3/4" Broach Length
1/4" E-Clips
Vendor - McMaster-Carr
Part No. - 97633A130
Cost - $6.54 (Pack of 100)
Description - Black-Phosphate Steel External Retaining Ring for 1/4" Shaft Diameter
Note - Inside of bearings
5/16" E-Clips
Vendor - McMaster-Carr
Part No. - 97633A150
Cost - $6.97 (Pack of 100)
Description - Black-Phosphate Steel External Retaining Ring for 5/16" Shaft Diameter
Note - Use behind omni due to hex size change.

Costs

Per Module (Estimated)

Note you cannot buy materials in small enough quantity. $85.00 + $9.83 + $17.72 + 2*$6.80 + $0.238 + 3*$0.0373 + $0.34*3 + $0.0654*3 + $0.304 + $0.34 = $128.36 --> $140.00

Action Log

  1. 12/26/2007 - Inner and Outter Drive Module Plates completed.
    Note - Motor mount holes should be rotated a few (3-5 deg) for better motor cable fitting.
  2. 01/27/2008 - Output shaft should be Steel 303, AL 2024, or AL 7075 (The AL is too weak to survive assembly)
    Note - The shafts we machined were out of spec and we should have paid to outsource them.
  3. 02/24/2008 - All holes were move down 0.1in to allow for better ground clearance.
    Note - Hole needs to be made in bottom plate to allow for gear to poke threw will cover opening with tape to keep out carpet fibers.
  4. 03/01/2008 - All gears will be stainless 303 and the output shaft will be a lower end steel.
    Note - This fixes shaft problems and some observed wear on the 2024 input gears.
  5. 03/19/2008 - Switched to ABEC 3 bearings form grainger.
    Note - Reduces cost per bearing from $6.80 to $5.59.
  6. 03/30/2008 - All holes moved down 0.1" and all standoffs repositioned.
    Note - Fixes low ground clearance concerns.
  7. 04/06/2008 - Drive modules reshaped (for machining time) and finalized.