Meet Arlan, a fun robot with a lot of personality. He lives in my sister's classroom (she is a 5th grade science teacher). I rebuilt him to be the mascot for her class's robotics team, he's also the classroom helper. The kids like to see technology in action and my sister likes to be lazy and have Arlan walk around and pick up the kids' papers (just kidding sis!). He was so much fun to build that I'm currently working on another robot. My dog misses the company too, Arlan is a great playmate because he keeps going and going. This Instructable is Arlan's story.
Step 1: Find an old robot
I was antiquing with my mom when I came across an old Omnibot 2000 sitting in a pile of junk. Omnibots were made in 1985 by Tomy. They were ahead of their time but time had caught up to this one. It was filthy, missing parts, the plastic on top and back had yellowed and the remote was missing. However, the style of this robot was irresistible and the function was fairly solid. It was a prime candidate for a renovation project. I bought the robot and took him home. (If you don't like antiquing you can almost always find an omnibot on ebay.)
Step 2: Disassemble the robot
You'll need to disassemble the robot for a couple of reasons. You'll need to clean it, and you'll need to inspect the parts to see what you've got to work with, and you'll need to have it in pieces to paint it. Take copious pictures as you disassemble the bot so you'll be able to put it back together correctly. Here is the sequence for taking apart the Omnibot:
1. Lay the Omnibot on it's back and remove the 6 screws from the bottom of the robot. Remove the lower wheelbase section of the robot, unplug the wires coming from the main body of the robot to completely detach the lower wheelbase.
2. With the lower wheelbase removed and looking up through the bottom of the robot you'll need to remove 8 screws to detach the upper half of the wheelbase.
3. Sit the robot upright. Looking at it from the back, there will be six screws that will release the back panel from the front. When you do this, the arms will slip out of place and the head will be released as well. Separate these parts gently and unplug the wires coming from the motorized arm and the head.
Step 3: The arms and the head
The arms and the head of the bot contain gears that must be timed correctly. If your bot is in fairly good shape you may want to leave these parts as is and simply clean the exterior of the arm and head without opening them up. If your bot is as gritty and dirty as mine was, or if it has been previously disassembled you will need to break down these pieces.
The arms have one screw at the elbow that attaches the upper and lower arm. Separate these two parts. Now remove the screws that attach the front and back plates of the upper and lower arms. You'll see the gears inside. Look at the gears; are they dirty? are they greased? are they aligned? If the gears are in good shape close the arms back up, if not, take a picture of the gears and then remove the gears and motors and carefully set them aside.
The head section contains gears in it's neck. If needed, remove the four screws from underneath the neck to detach the head from the neck piece. Remove the screws that hold the top and bottom of the head together, also remove the face plate screws. Detach these pieces and lay them aside.
Step 4: Clean, Clean, Clean
We're almost ready to clean the bot. There are a few small circuit boards and electronics screwed to the interior of the bot. You will need to remove as many of these as possible (carefully) to clean the bot. My robot had nearly 30 years of grime in every nook and cranny. It needed to be thoroughly scrubbed. Use a sink full of hot sudsy water and wash and dry every part (except for the electronics of course).
Cleaning the omnibot isn't just for cleanliness, years of grime, dust and bugs will damage gears and electronics. Old robots tend to be very squeaky due to plastic gears, this gets exasperated when those gears are dirty. It is tempting to skip the cleaning, but you shouldn't.
Step 5: Loosely reassemble and add a base for height
Now that the robot is clean, reassemble the body parts loosely and find a base to add between the upper wheelbase and the lower wheelbase. For my purposes the robot needed to be taller to patrol the classroom and pick up/drop off items at the kids' desks. I found a plastic file box at IKEA and bought two. The box didn't exactly fit the robot body so I cut a piece of 3/4" pine for the top and bottom of the box and routered the top edge to create a curved edge that blended into the robot. I also replaced the yellow eyes with blue by unscrewing the grey face plate and replacing the yellow plastic with blue plastic (I cut the blue lids from some inexpensive tupperware for the blue lens).
Step 6: Paint the body parts
Because the bot is plastic I used a plastic primer before I painted. I used a spray can for smooth finish and applied two light coats of primer 5 to 10 minutes apart. After letting the primer dry for an hour I sprayed on two light coats of maroon paint, waiting 5 to 10 minutes between layers. This method creates a nice strong paint job that will stand up to heavy classroom use.
The color choice was based on the elementary school's colors. The cap shown in the picture does not show the maroon color. I accidentally stepped on the cap and used this gray cap as a replacement to keep the paint for future touch ups.
When the paint has dried overnight, replace the small electronics that were removed earlier. If you broke down the arm and head gears put them back together now. Use your pictures to reassemble and realign the gears. Grease the gears generously and then reassemble the arms and head.
Step 7: Turn the base into a storage locker
I used the file box for extra height but it occurred to me that this was great potential storage. I had the extra file box to experiment with, so I used a panel from the extra box and cut a large square for a door. I used a Dremel with a plastic cutting blade. I then cut a square opening (just smaller than the door) into the base. I wanted the storage box to be secure, so I bought a keyed lock. I used a strip of hide-a-cord and cut pieces to slip over the edges of the door panel to give the door a finished look. I cut the edges at a 45 degree angle to make nice tight corners.
To attach the door to the box I used a rivet gun to attach a simple hinge to the door and to the box. the rivets created a nice flat finish on the inside of the hinge, allowing it to close fully. The tall side of the rivet was hidden under the cord keeper trim.
Once the door was attached I drilled a hole in the edge of the door to install the lock. The keyed lock basically just slips through the hole and screws on a nut to secure it in place, very simple.
Now that the box is going to be used for storage it needs a floor. Build a simple frame to support a raised floor which will keep everything clear of the turning wheels. I used 1"x 1" stick trim and stacked it. I used this method instead of a 1"x 3" turned on it's side because I had the 1"x 1" in my garage. With the frame built, I cut a piece of pegboard to create a floor. It fits nice and snug on the bottom of the box. The pegboard is not fastened to the frame, this allows my sister's students to lift up the floor and watch the gears in action.
I did have to cut the wires between the wheelbase and the circuit board in the robot's chest. I spliced in wire extensions to allow for the extra length needed for the robot's taller body. I ran into a bit of trouble with it but I found help online from the smart community at EZ Robot. If you need help with this step those guys are great.
Step 8: Drill an access hole for the wires
The wires from the drive train will need to run through the top of the storage locker base to reach the circuit board in the robot's chest. Drive a wide hole through the top of the wooden transition piece and through the top of the plastic file box. Sand the holes thoroughly to avoid damaging the wires that will run through it.
Now pre-drill holes in the wooden piece to attach the screws from the underside of the wood to the plastic screw columns inside the upper wheelbase. You can mark the location of the holes by measuring the distance of the plastic screw column from the edge of the wheelbase case. Then transfer the measurement onto the wood, mark it and drill.
Step 9: Assemble the robot
To assemble the robot start with the upper body. Rest the head on the front of the chest and plug in the wires running from the head to the circuit board in the chest. Slide the arms into the square sockets on either side of the body. Plug in the two sets of wires coming from the motorized arm to the circuit board in the chest. Slide the head into place on top of the chest. Slide the back into place taking care to not catch the gray arm trim in the arm socket. Fasten the front and back pieces together with the 6 screws you removed during the disassembly process. Your upper body is now assembled. Now place the upper body into the top of the upper wheelbase case and fasten the 8 screws you previously removed from the bottom of the case.
Now the assembly process becomes different from the disassembly procedure because we are adding the new base. First, take the wooden base transition piece and attach it to the bottom of the upper wheel base case using 2" screws.
Now place the assembled top piece on the top of the file box. Attach it with screws from the inside of the box up into the wood. Pass the drive train wires from the circuit board through the hole in the top of the box. Run the wires down the inner corner of the box and lift the pegboard floor to plug them into the drive train.
Step 10: Add personality to the robot
The robot needed a name. Having a name gives a robot personality and I wanted the kids to really like him. I named him Arlan. The kids' school was named after a retired science teacher that is still a very active volunteer at the school. The teacher goes by Ray but his real first name is Arlan. I figured it would be a great way to honor a really neat teacher and it would also fit with the teaching purpose of this robot. Plus, Arlan is a really cool robot name. I used raised metal letters to add the name on the front of the bot.
When Arlan was fully assembled I realized his original amber eyes looked better with his maroon and gray color scheme so I switched his eye lens back to the original.
I had to remove Arlan's original Omnibot 2000 decals on his upper arms to disassemble him. Those decals covered the screw head that attaches the arms to the arm socket. I recreated the school's compass logo in a graphics program and printed it onto new decals to cover the holes. It really added to his personality.
I wanted my sister's students, specifically her 5th grade robotics team, to have some input into Arlan's design and function. Their input is still to come, in his electronics. We've ordered some components to replace his electronics and the kids will have a a chance to bring Arlan to the cutting edge of robotics. More to come in our follow-up Instructable on Arlan's electronics renovation.