RP1 GEN2: MOTOR MODULE

ASSEMBLY GUIDE

Table of ContentsLower Housing Assembly.............................................................................................................................5

Needed parts:..........................................................................................................................................5

Needed Tools:..........................................................................................................................................5

Assembly:................................................................................................................................................5

Wheel Assembly..........................................................................................................................................6

Needed parts:..........................................................................................................................................6

Needed Tools:..........................................................................................................................................6

Assembly:................................................................................................................................................6

Inserting Retaining Ring...............................................................................................................................8

Needed parts:..........................................................................................................................................8

Needed Tools:..........................................................................................................................................8

Assembly:................................................................................................................................................8

Inserting Centering Bearing.......................................................................................................................10

Needed parts:........................................................................................................................................10

Assembly:..............................................................................................................................................10

Motor Instilation........................................................................................................................................11

Needed parts:........................................................................................................................................11

Needed Tools:........................................................................................................................................11

Assembly:..............................................................................................................................................12

Drive Axle Instilation..................................................................................................................................18

Needed parts:........................................................................................................................................18

Needed Tools:........................................................................................................................................18

Assembly:..................................................................................................................................................19

Connecting the Upper and Lower Housings..............................................................................................25

Needed parts:........................................................................................................................................25

Needed Tools:........................................................................................................................................25

Assembly:..............................................................................................................................................26

Final Assembly...........................................................................................................................................27

Needed parts:........................................................................................................................................27

Needed Tools:........................................................................................................................................27

Assembly:..............................................................................................................................................28

Idler Drive Axle..........................................................................................................................................32

Needed parts:........................................................................................................................................32

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Needed Tools:........................................................................................................................................32

Assembly:..............................................................................................................................................33

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SafetyTake all proper safety procedures while assembling the Motor or Idler Modules and always wear safety glasses.

Pre-AssemblyPlease review all associated documents before attempting to assembly a MM. Make sure all components are in place and oriented correctly before tightening any set screw. Failure to correctly line up a set screw with the corresponding flat surface on the axle can lead to damage of the axle.

Important documents:Bill of Materials: https://edge.rit.edu/content/P09203/public/Bill%20of%20Materials.xlsmTechnical drawings: https://edge.rit.edu/content/P09203/public/Solidworks%20PrintsEncoder Assembly: http://usdigital.com/assets/general/85_e4p_datasheet_1.pdf

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Sub Assemblies

Lower Housing Assembly

Needed parts:Lower HousingSteering Axle

Needed Tools:Arbor press

Assembly:Using an arbor press, press the steering axle into the lower housing long side down

Figure 1: Before pres Figure 2: After press

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Wheel Assembly

Note: This should be done shortly before the wheel needs to be installed into the Motor Module or Idler Module so that the Loctite® doesn’t set up.

Needed parts:Wheel HubWheel TireWheel Set Screw

Needed Tools:3/32” Hex KeyLoctite® 242

Assembly:

1. Place Loctite® on set-screw2. Screw the set screw into the wheel hub, make sure the end of the set screw does not

protrude into the drive shaft hub

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3. Pry the wheel tire onto the wheel hub

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Idler Retaining Ring Groove

Motor Retaining Ring Groove

Inserting Retaining Ring

Note: The drive bearings in the lower housing are held in place by a bearing seat and a retaining ring. There are two grooves that a retaining ring can be pressed into each groove corresponds to the placement of the drive bearings for either the Motor or Idler Module.

Needed parts:Lower HousingRetaining Ring

Needed Tools:Pliers

Assembly:

1. Turn the retaining ring perpendicular to the hole and begin pressing it into the desired hole.

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2. Using pliers slowly turn the retaining ring so that it sits in the retaining ring groove in the lower housing

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Inserting Centering Bearing

Note: The drive bearings in the lower housing are held in place by a bearing seat and a retaining ring. There are two grooves that a retaining ring can be pressed into each groove corresponds to the placement of the drive bearings for either the Motor or Idler Module.

Needed parts:Upper HousingCentering Bearing

Assembly:1. Align the Centering bearing with the bearing seat on the upper housing

2. Gently press the centering bearing into the upper housing until the bearing is flush with the top surface

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Assembly Motor Module

Motor Instilation

Needed parts:Lower housing DC MotorMotor CouplingGearDrive BearingGear Set Screw (Should be in the gear)2x Nylon Tipped Motor Set Screw2x Motor Coupling Set Screw

Needed Tools:.050” Hex Key1/16” Hex KeyPliersLoctite® 242

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Assembly:

1. Line up the motor with the motor mounting hole in the lower housing

2. Gently press the motor into the mounting hole until the motor shaft is even with the opposite side of the lower housing

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3. Place Loctite® on Nylon tipped set-screw, the screw into set screw hole in lower housing with 1/16” hex key

4. Repeat step 3 for the other side

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5. If motor shaft is not parallel with side of the lower housing, using a pair of pliers gently turn the motor shaft until it is parallel

6. Place Loctite® on the motor coupling set-screw, and screw into set screw hole in motor coupling with a .050” hex key until the end of the set screw is flush with the motor coupling

7. Repeat step 6 for the other motor coupling set screw

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8. Slide the motor coupling onto the motor shaft

9. Tighten the motor coupling set screws

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10. Place the drive bearing on the motor coupling

11. Slide the bearing down the motor coupling until it is flush with the side of the lower housing

12. Remove the set screw from the gear using a 1/16” hex key, apply Loctite® to the set screw and screw loosely into the gear. Note: set screw comes with gear

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13. Place the gear on the motor coupling, push until flush with the end of the motor coupling

14. Tighten the gear set screw.

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Drive Axle Instilation

Note: This assembly process can be difficult to accomplish alone, you may want some help if the rubber wheel is too stiff.

Needed parts: Lower housing (with retaining ring installed, see Inserting Retaining Ring)Drive Axle2x Drive Bearings2x Drive SpacersGearGear Set screwWheel sub assembly (follow instructions in Wheel assembly)Encoder baseEncoder circuit boardEncoder code diskEncoder Case2x Encoder Screws

Needed Tools:1/16” Hex KeyPliersLoctite® 242Phillips head screw driverEncoder spacing tool

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Assembly:

1. Insert the drive bearings into the bearing seats

2. Insert the drive axle into the drive bearing and place a drive spacer on the axle

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3. Align the wheel with the drive axle and push the axle into the wheel

4. Push the remaining spacer into place and push the drive axle through so that the center flat on the drive axle is approximately centered in the lower housing

5. Remove the set screw from the gear using a 1/16” hex key, apply Loctite® to the set screw and screw loosely into the gear

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6. Place the gear on the drive axle, matching the flat surface to the set screw

7. Make sure the gear is flush with the end of the drive axle and tighten the set screw (this is done to help keep the drive axle in the correct location for the next step)

8. Pry the rubber wheel so that the set screw in the wheel hub is visible (you may want to have someone help hold the wheel in place when you complete this step)

9. Align the set screw in the wheel hub to the set screw on the gear and tighten

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10. Place the encoder base onto the lower housing so that when completed the encoder wire will connect towards the DC motor

11. Place the encoder circuit board on top of the encoder base

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12. Center the encoder base and circuit board and screw to lower housing

13. Place the encoder code disk on the drive shaft (Note: you should see markings on one side of the disk, this side should face the encoder circuit board)

14. Place the encoder spacer tool on the encoder code disk

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15. Press the spacer tool down until it contacts the encoder base

16. Press the encoder case onto the encoder base

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Connecting the Upper and Lower Housings

Needed parts: Lower housing (completed)Upper housingThrust bearingC-clipWire Tie downServoServo CouplingServo Coupling Screw (the course thread screw)4x Servo ScrewsUpper housing screw

Needed Tools:3/32” Hex KeyPhilips head screw driverPliers

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Assembly:1. Place a thrust bearing on the steering axle

2. Insert the steering axle into the centering bearing

3. Push the c-clip onto the steering axle (note: this can be done with your fingers or with the help of pliers)

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Final Assembly

Needed parts: Lower housing connected to Upper housingWire Tie downEncoder wireServoServo CouplingServo Coupling Screw (the course thread screw)4x Servo ScrewsUpper housing screw

Needed Tools:3/32” Hex Key7/64” Hex KeyPhilips head screw driverLoctite® 242

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Assembly:

1. Set the servo to the counter-clockwise stop

2. Push the servo coupling onto the servo, so that the screw head is in the direction of the below picture

3. Screw the servo coupling to the servo using the course thread screw that came with the servo coupling (do not apply Loctite® 242 to this screw)

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4. Press the servo with coupling into place

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5. Screw the servo into place

6. Align the lower housing in the counter-clockwise position

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7. Place Loctite® on the screw that came inserted in the servo coupling and tighten

8. Attach the encoder wire

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Assembly Idler Module

Idler Drive Axle

Needed parts:Lower housing (with retaining ring installed, see Inserting Retaining Ring)Upper housing (with centering bearing installed)2x Drive bearings2x Drive spacersIdler drive axleThrust bearing

Needed Tools:1/16” Hex KeyPliers

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Assembly:

1. Insert both drive bearings into the lower housing into the idler bearing position

2. Insert the idler axle and place one drive spacer on the axle

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3. Thread the wheel onto the idler axle

4. Push in the remaining drive spacer and push the idler axle into position

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5. Pry the wheel to the side so that the set screw can be tightened6. Attempt to align the flat on the idler axle with the set screw on the wheel hub (this can

be very difficult and may not be possible)

7. Place the thrust bearing on the steering axle

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8. Insert the steering axle into the centering bearing

9. Press the c-clip onto the steering axle

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