RobotGeek Snapper Assembly Guide

This guide is for the old version of the snapper, which uses a 9G Mini Servo Gripper. If you have the old version of the snapper arm which uses a RG-13 parallel gripper, go to the new RobotGeek Snapper Assembly Guide for proper instruction.

Tools Needed

2.5mm Hex driver (included)
1.5mm Hex driver (included)

Kit Parts

Base Plate

Middle Deck Plate

Top Deck Plate

Top Deck Plate Ring

Upper Arm Side Plate

Lower Arm Side Plate

Lower Arm Centering Plate

Bottom Control Panel Plate

Top Control Panel Plate

Sensor Shield

Geekduino or Seeeduino board

~duino Mounting Plate

RobotGeek 180° Servo

C Bracket

RobotGeek Pushbutton

Thumb Joystick

RobotGeek Rotation Knob

7v 5A Power Supply

Sensor Cable

90 Degree Power Cable

9G Spacer Plastic Plate(1/8" thick)

9G Spacer Plastic Plate(3/16" thick)

Gripper Top Plastic Plate

Gripper Bottom Plastic Plate

Back Plastic Plate

Back Spacer Plastic Plate

Left Finger Plastic Plate

Right Finger Plastic Plate

Fingertip Front Plastic Plate

Fingertip Side Plastic Plate

Gear Plastic Plate

9G Servo

Foam

The following hardware is required to build the kit. You may have received extra parts with your kit. The parts for the Gripper are listed separately in the gripper assembly guide.

54x

Hex Nut
M2

Hex Nut
M3

28x

Hex Socket Head Bolt
M2 x 5

40x

Hex Socket Head Bolt
M2 x 6

12x

Hex Socket Head Bolt
M2 x 8

Hex Socket Head Bolt
M2 x 10

Hex Socket Head Bolt
M2 x 16

108x

Hex Socket Head Bolt
M3 x 6

12x

Hex Socket Head Bolt
M3 x 8

Hex Socket Head Bolt
M3 x 10

16x

Hex Socket Head Bolt
M3 x 16

38x

Hex Standoff F/F
M3 x 10

Hex Standoff F/F
M3 x 15

11x

Hex Standoff F/F
M3 x 20

Hex Standoff F/F
M3 x 25

Hex Standoff F/F
M3 x 30

25x

M3 Washer

3 Pin Connector

12x

Small Bumper Foot

1/4 x 1/8 Spacer

Pre Step: Peel Your Plastic

Some of your plastic pieces will have paper masking on one or both sides. Peel the masking paper off before getting started.

There also may be some dust on your parts. This is from the laser cutting manufacturing process. It is harmless and can be cleaned up by wiping with a rag or being washed with water.

Each plastic piece will have 2 sides - a matte side and a glossy side. When you're assembling your kit, the matte side should point up while the glossy side should point down.

Step 1: Prep your servos

If you have not already, MAKE SURE you have centered your servos before getting started with this guide by following the servo centering guide here.
Put both horns on 3 of the servos and only the drive horn on one.

Step 2: Mount the Base Servo

Hex Socket Head Bolt
M2 x 6

Hex Nut
M2

Mount the base servo using 8 x M2*6 bolts and 8 x M2 Nuts
NOTE: The base servo does not need the second passive horn.

Step 3: Add the Lower Standoffs

Hex Socket Head Bolt
M3 x 6

Hex Standoff F/F
M3 x 20

Mount the 8 x M3*20 lower standoffs using 8 x M3*6 bolts.
Make sure you are using the holes in the corners.

Step 3: Add the Upper Standoffs

16x

M3 Washer

Hex Socket Head Bolt
M3 x 8

Hex Standoff F/F
M3 x 25

Mount the 8 x M3*25 upper standoffs using 8 x M3*8 bolts and 16 x M3 washers (2 per standoff).

Step 4: Mount the Assembly to the Base

Small Bumper Foot

Hex Socket Head Bolt
M3 x 6

Mount the assembly to the arm base using 8 x M3*6 bolts.
Now is also a good time to mount the feet to the base bottom so that you don't scratch up any surfaces. Place 8 x Small Rubber Bumpers where you want to have them on the underside.

Step 5: Prep the Bearing

Hex Socket Head Bolt
M3 x 16

Hex Nut
M3

Prep the bearing by bolting the center plate to the inside ring using 8 x M3*16 bolts and 8 x M3 nuts.

Step 6: Mount the Bearing

Hex Socket Head Bolt
M3 x 16

Mount the bearing and outer top cover ring to the assembly using 8 x M3*16 bolts.

Step 7: Bolt the C Bracket to the Servo Horn

Hex Socket Head Bolt
M2 x 8

Bolt the C Bracket down through the inner bearing plate in to the servo horn using 8 x M2*8 bolts.

Step 8: Build the Lower Arm Section

M3 Washer

Hex Standoff F/F
M3 x 20

Hex Socket Head Bolt
M3 x 10

16x

Hex Nut
M2

16x

Hex Socket Head Bolt
M2 x 6

Hex Socket Head Bolt
M3 x 6

First bolt the M3*20 standoff to the left plate as shown using 1 x M3*10 bolt and 3 x M3 washer.
Then bolt the full assembly together as shown using 16 x M2 x 6 bolts, 16 x M2 nuts, and 1 x M3*6 bolt.
Make sure the matted surface on the side plates are facing out so your robot looks good!

Step 9: Build the Upper Arm Section

M3 Washer

Hex Standoff F/F
M3 x 20

Hex Socket Head Bolt
M3 x 10

Hex Socket Head Bolt
M3 x 6

16x

Hex Nut
M2

12x

Hex Socket Head Bolt
M2 x 6

Hex Socket Head Bolt
M2 x 8

First bolt the centering plate to the C bracket using 4 x M2*6 and 4 x M2 nuts. Make sure that the plate is parallel to the bracket edges before tightening down the bolts.
Next bolt the two side plates together as shown using 2 x M3*20 standoffs, 6 x M3 washers, 2 x M3*6 bolts, and 2 x M3*10 bolts on the washer side. DO NOT over tighten the bolts. Tighten them until they are firmly in place, but do not over tighten them.
Use tape to temporarily hold the M2 nuts in place and bolt the assembly to the C bracket using 4 x M2*8 bolts.
Lastly, attach the servo using 8 x M2*6 bolts and 8 x M2 nuts.
If you have already built your gripper, skip to Step 20, otherwise, continue to step 10.

Step 10: Start Building the Gripper - Build the Back Bracket

Hex Socket Head Bolt
M2 x 10

Hex Socket Head Bolt
M2

Attach the Back Plate and the Back Spacer Plate to the C-Bracket using 4 M2*10 Bolts and 4 M2 Nuts.

Step 11: Mount the 9g Servo

Hex Socket Head Bolt
M2 x 16

Hex Nut
M2

Stack the 9G Spacer Plastic Plate(1/8" thick) , the 9G Spacer Plastic Plate(3/16" thick) and the Gripper Top Plastic Plate together.
Attach the 9g servo to the 3 plastic plates using 2 M2*16 Bolts and 2 M2 Nuts

Step 12: Mount Finger Plates

Hex Socket Head Bolt
M3 x 10

Hex Standoff F/F
M3 x 15

1/4 x 1/8 Spacer

Fit the 1/4 x 1/8 Spacers into the center pivot holed on the Left Finger Plate and Right Finger Plate
Attach the finger plates with spacers to the Top Plate using 2 M3*10 Bolts and 2 M3 * 15 Standoffs
The shiny side of the plastic should face away from the servo, as shown in the photo
Make sure that the finger edges create a flat edge as shown in the photo

Step 13: Attach the Gear Plate

If you haven't already set the servo position on the 9G servo, return to the Getting Started Guide and set the position to 150°.
Carefully push the Gear Plastic Plate onto the shaft of the 9G Servo. You will need to attach the gear in such a way that is meshes with the gear on the right finger plate. Make sure that the gripper fingers stay in position creating a flat edge at the top.

Step 14: Add the Back Standoffs

Hex Socket Head Bolt
M3 x 10

1/4 x 1/8 Spacer

Hex Standoff F/F
M3 x 15

Connect the 1/4 x 1/8 Spacer to the Gripper Top Plastic Plate using 2 M3*10 Bolts and 2 M3 x 15 Standoffs

Step 15: Attach finger standoffs and fingertip sides

Hex Socket Head Bolt
M3 x 6

Hex Socket Head Bolt
M3 x 8

Hex Standoff F/F
M3 x 15

Attach 2 M3*15 Standoffs to the middle holes of the Left and Right Finger Plates using 2 M3*6 Bolts.
Attach a Fingertip Side Plate to the top holes in each of the Left and Right Finger Plates using 2 M2*15 Standoffs and 2 M2*8 Bolts

Step 16: Attach Bottom Fingers

Hex Socket Head Bolt
M3 x 6

Lay the Bottom Left and Right Finger Plates on the 6 standoffs. Line the plates up directly over the Top Left and Right Finger Plates.
Use 2 M3*6 Bolts to connect the middle holes of each plate to the standoff underneath.

Step 17: Install Fingertip Fronts

Hex Socket Head Bolt
M3 x 8

Insert the Fingertip FrontPlastic Plate into the grooves on the Fingertip Side Plastic Plate.
Fit the Fingertip Side Plastic Plate into the other tabs on the Fingertip Front Plastic Plate.
Use an M3*8 bolt to connect each Fingertip Front Plastic Plate to the Finger Plates and standoffs.

Step 18: Close Case and Mount Back Bracket

1/4 x 1/8 Spacer

Hex Socket Head Bolt
M3 x 10

Fit 2 1/4 x 1/8 Spacers into the bottom holes in the Bottom Left and Right Finger Plastic Plates. Place the other 2 1/4 x 1/8 Spacers over the bottom 2 standoffs.
Insert the bracket assembly from step 1 to the Gripper Top Plastic Plate slots.
Lay the Gripper Bottom Plastic Plate over the gripper.
Use 4 M3*10 bolts to attach the Gripper Bottom Plastic Plate to the gripper.

Step 19: Trim the Foam Padding

Trim the Foam Padding to the correct size to fit on a Fingertip Front Plastic Plate and attach it to each plate.

Step 20: Assemble the Arm Sections

18x

Hex Socket Head Bolt
M2 x 5

Bolt the two arm sections together as shown using 6 x M2*5 bolts. (You can use 10 if you wish.)
Bolt the arm to the base C bracket as shown using 6 x M2*5 bolts. (You can use 10 if you wish.)
Bolt the gripper to the wrist servo as shown using 6 x M2*5 bolts. (You can use 10 if you wish.)

You have completed the Snapper Arm Core Kit. At this point, you can check out the Wiring Guide to help you integrate your arm into a project!

Step 21: Mount the Geekduino & Sensor Shield

11x

Hex Socket Head Bolt
M3 x 6

Hex Standoff F/F
M3 x 10

Using 8 x M3*10 standoffs and 8 x M3*6 bolts prepare the Geekduino mounting plate as shown.
Mount the plate onto the arm in the position you desire using 4 x M3*6 bolts.
Mount the Geekduino onto the mounting plate using 3 x M3*6 bolts.
Mount the shield onto the Geekduino.

Step 22: Add Standoffs and Feet to the Control Panel

20/24x

Hex Socket Head Bolt
M3 x 6

12/16x

Hex Standoff F/F
M3 x 10

Hex Standoff F/F
M3 x 20

Hex Standoff F/F
M3 x 30

Small Bumper Foot

Mount the 12 x M3*10 standoffs as shown using 12 x M3*6 bolts. These standoffs are for the joysticks
Mount the 4 x M3*20 standoffs as shown using 4 x M3*6 bolts. These standoffs are for the knob
Mount the 4 x M3*30 standoffs as shown using 4 x M3*6 bolts. These standoffs are for the top plate.
Put 4 x rubber bumpers on the bottom of the bottom control plate.
If you plan to mount the control panel to the arm base or another workstation mount 4 x M3*10 standoffs on the underside using 4 x M3*6 bolts.

Step 23: Mount the Sensors and Top Plate

20x

Hex Socket Head Bolt
M3 x 6

Remove the knobs/sticks from your sensors
Mount the sensors as shown using 16 x M3*6 bolts.
Connect the 3-pin sensors cables to your sensors as shown. Connect sensor cables on the top (vertical) pins for each joystick, and on the bottom (horizontal) pins for the left-most joystick.
Mount the top control panel plate to the bottom control plate using 4 x M3*6 bolts
Attach the control sticks to the joystick
Attach the rubber knob to the rotational knob. Line up the arrows as shown.

Step 24: Attaching Buttons and the Control Panel

16x

Hex Socket Head Bolt
M3 x 6

Hex Standoff F/F
M3 x 10

Attach the 2 pushbuttons to the snapper arm using 8 X M3*10 standoffs and 16 X M3*6 bolts.
Optional - use 4 X M3*6 bolts to connect the control panel to the snapper arm.
If you want to attach the control panel to the arm as well, move the buttons closer to the geekduino.

Step 25: Wiring

2/3x

3 Pin Connector

Add two sensor cables extensions to the Gripper and Wrist servo.
You might also wish to add a cable extension to the Elbow Servo depending on where you mount your Geekduino.
Run your cables and ziptie them as needed for clean wiring.
Wire your cables to the Sensor Shield as follows:
- Analog Input:
  - 0 - Joystick 1 (Horizontal)
  - 0 - Joystick 1 (Vertical)
  - 2 - Joystick 2 (Vertical)
  - 3 - Joystick 3 (Vertical)
  - 4 - Rotation Knob
- PWM IO:
  - 3 - Base Rotation Servo
  - 5 - Shoulder Servo
  - 6 - Elbow Servo
  - 9 - Wrist Servo
  - 10 - Gripper Servo
- Digital IO:
  - 2 - Pushbutton 1 (Capture)
  - 4 - Pushbutton 2 (Play)
If you choose to use the 90 degree to straight DC adaptor you can connect it and zip tie it down to your position of choosing.