Introduction: SERVOCITY NOMAD Robotic Arm Attachment
The NOMAD is a great product but I wanted it to build a arm for it and with the understanding that it would need to be light weight but strong, compact and relative to the NOMAD's size. This can be done in a few different combinations using servocity parts and this is just the way that I have chosen to do it. Balance would need to be close to the batteries and center mass and fold into position for the arm to hold any weight. This project requires five channels on a RC receiver and a 5volt connection. By my estimate this arm can pick up a total of 10lbs safely and possibly more with this configuration. I also want to add that I am using 4 lipo 5200mah batteries and have moved them to counter balance the system inside the the rovers bay.
Step 1: Attaching the Servo GearBox
Place the SPG7950A-CM Channel Mount Servo on its side on the non-moving top of the channel on the side of the NOMAD. line up two screw holes and use the Dual Screw plates for the others placing them at a angle until they line up.
When placing the servo mount make sure that the large gear of the servo is approximately one inchish from the front tire. This should make it close to the center of NOMAD. Go ahead and fasten it securely once the position looks centered by placing two screws up the center under the channel into the side of the servo gearbox and four in each Dual Screw plate.
What it looks like
Step 2: Adding the First 10 Inch Section
Next take the 10' 5/8 tubbing and slide the 90º clamp so that 90 is facing the back tire and Clamping Tube Hub on the front of the gear of the servo. Then slide both Clamping Tube Hubs on the tube but do not fasten them down all the way as we will be adding wire and verifying alignment and this will make it easier.
Step 3: Put the Servo Block Together
Build your ServoBlocks using the Even Stronger Servo (HS-7950TH) and the other using the HS-645MG this process is strait forward. Open one package at a time so that you don't get confused and measure your screws they go on the top.
Step 4: Attaching HS-7950TH Servo Gear Box and 90º Tube Clamp on the Top of the 10' Tube.
Make sure that the servo's are zeroed because if they aren't it will slam into the other components when you power up! Verify the sweep by slowly moving the servo back and forth to check full range of motion. Put the 90º clamp on the 5/8 pipe. Then put the channel on the 90 on the third hole from the bottom facing on the back of the channel with the large gear facing up.
Also remember the servo wire is going down in the tube so no need to fasten completely until you measure your servo wire.
Step 5: Put the 6 Inch 5/8 Tube on the Servoblock
The smaller part of the arm should be above the nomad channel and should do a 180º rotation. Also the six inch isn't load-bearing so both HS-645MG should be under the 6inch tube.
What it looks like
Step 6: Putting the Servo Block on the Standard Parallel Griper Kit
Step 7: Put the 2 Inch Tube on the Bottom to Protect the Servo Wires.
To keep the servo wires out of the gears I used a tube and put heat shrink tube in that to make it rigged.
Remember adjust your wires so that they have enough movement so that when the arm goes all the way down they can reach.
What it should look like
Step 8: Running the Servo Wires
Running the wires should be the second to the last step I used a zip tie to run the wires smoothly down the pipes.
After the wire is run screw down the components of each section of the arm. I used blue loctite but only after I made sure everything was working as I wanted.
Step 9: Last Step Power Up
When you are powered up be sure to be able to cut the power fast just to be safe and to prevent any damage as you may need to make an adjustment.