CNC Blog
Here, we post about what we do with our Roland MDX-40A rapid prototyping machine.
In addition to using the CNC machine to mill the wheels for our minibot, we decided to use it to make a new control board. In past years, our control board was just a piece of white, plasticky material called regolith with all the necessary equipment velcroed on, but this year we made an aluminum frame with blue acrylic on the top and bottom and chemical wood inserts to hold everything in place.
Our control board sitting at our practice field.
We modeled the chemical wood inserts to be exact negatives of the joysticks, then painted them silver. The joysticks fit perfectly, and velcro lets us carry the control board by the handle on the side.
We milled these four right angle inserts out of hard, white plastic to fit snugly at each corner. The inserts let us use 1 by 1 aluminum tube for the frame without having to use gussets.
Since the acrylic top can be easily removed, we can use this control board every year, even if the game requires a new kind of control system. We can make a new acrylic plate with holes in different positions to accommodate any arrangement of joysticks, switch boxes, and other elements.
Part of the 2011 game, Logomotion, involved building a small "minibot" to race to the top of one of four 10-foot steel poles at the end of each match. Teams were limited in the types of material and electronics they could use, and though the supplied motors were slow and powerful, the allowed wheels were small. Since we wanted our minibot to be as fast as possible, we calculated the optimum wheel size and used our Roland MDX-40A 3D Milling Machine to mill the prototype and final wheels out of polystyrene, acrylic, and polycarbonate.
Our first recognizable prototype, above, did not use a milled wheel.
Our minibot design was simple: One large drive wheel on an aluminum bar was connected by a joint to another arm, which remained parallel to the pole and contacted it with two low friction rollers. Surgical tubing between the arms held them to the pole just enough to keep the robot from slipping.
The milling machine allowed us to create our ideal wheel: concave to line up perfectly with the diameter of the pole, wide enough to keep it from falling off, and as large as we wanted it to be. We modeled and milled each wheel in seven sections and bolted them together. Our first wheel was a quick prototype polystyrene wheel with surgical tubing for traction, and our next wheel was slightly larger and made of acrylic. Once we had a final design and size, we made two wheels out of polycarbonate and covered them with thick, sticky rubber for traction.
Our second CNC machine milled wheel was originally intended to have the surgical tubing woven back and forth through the grooves, but it didn't work out.
Our final polycarbonate wheel on the minibot that competed at the Chesapeake Regional.
Our minibot could climb the 10-foot steel pole in under 3 seconds. Here is a video of the minibot climbing a 6-foot section of the pole
We hope to use the CNC machine to mill more and more parts of our robot in the future.
When school came back in session, the team decided that we wanted to build a cabinet to house the CNC machine. The machine is kept in the school's shop, and we needed a way to make sure that this valuable piece of equipment stayed secure. We wanted it to have a sturdy counter height surface, for easy access. Since some of the things we would be milling might take longer than we were at the school, we wanted to be able to lock it and leave it running undisturbed. We decided that the cabinet would need to have an open area below the machine to catch and vacuum up the shavings from the milling. Also, we wanted the cabinet to have a window so that we could watch the milling process.
Initial plans for the cabinet were drawn up and CAD drawings were made. Several students and two of our mentors got to work procuring the material needed to build the cabinet. Attached: plans, photos
Having just received the CNC machine, we weren't entirely sure how to use it. We were also nearing the End of the Year party, so a few of us decided to create a small souvenir to distribute at the party. This would be a perfect opportunity to learn to use the machine. After thinking of different ideas for souvenirs, one team member suggested handing out chocolate pieces in the shape of our logo at the party. Everyone loved it! A couple people familiar with 3D design software quickly put together a design for the chocolate. After 12 tedious hours, the CNC machine finally finished that logo, which we used to create molds in which we could pour the chocolate. It was a wonderful learning experience, and the chocolate came out great as well!
Finished Mold
Finished Chocolate Piece
This is a video of the CNC machine fresh out of the box. We were anxious to see it in action and here is our 1st test using the tutorial which was achieved by using their software introduction manual and guidance.
Welcome to the CNC blog, where we talk about anything and everything related to our CNC machine. In April of 2010, we acquired a Roland MDX-40A 3D Milling Machine. We can input 3D objects that we create in design software like Autodesk Inventor, and this machine will create a lifesize 3D model of it. This will be extremely helpful to us during build season, when we are prototyping new ideas. We can create a new design or parts of a new design with the machine, and we wouldn't have to waste special parts or material doing so. Its wide variety of "mill-able" materials makes it a very powerful tool to also make souvenirs, trophies, and other fun things. We are definitely going to use this machine whenever we can.
The CNC machine working on the infamous "Hook" from CAD class at school.
