Here I've broken down how to build a simple ROV frame.
Here's what you'll need:
- PVC Pipe
- PVC Elbows/Joints
- Pipe Cutters/saw
(These items can be substituted if desired)
Step 1: Find a Design
The first step to building your frame would be to do some research on what type of frame you would like to build. You can just Google some images for different types of frame structure, but if your robot will be used for more sophisticated projects such as personal marine research or national competitions, you should consider looking at NOAA's website. I have given a few examples of designs above. You will want a stable design that's center of balance is in the middle of the frame (I have found this works best with our motors when driving the ROV and supporting its weight). You also don't want a frame that is to large of bulky, small and compact work best. Also be conscious of how your motors are placed within the frame; if you don't adjust the motors correctly, then your ROV won't drive in the correct direction (instead of driving forward the vehicle drives up).
Step 2: Planning Your Layout
Once you have your desired frame design, now it is time to figure out your dimensions. Depending on if you're in a competition or not, you may want to figure out the maximum width/length/height allowed by the judges. If you do not have size requirements, just build a frame with sizes compatible to your motor. If your frame is to big/heavy for the motor, it could cause malfunctions or your ROV just won't maneuver with ease. Above is the layout of my ROV. I suggest using trial and error to figure which design will work best. (I went through a series of making small adjustments, which made a big difference in the building process.
Step 3: Pick Your Materials & Start Cutting
For the basic ROV's we have created, we used PVC pipe and joints. You can use different materials, but depending on you're budget and the desired quality of your ROV, PVC pipe is sturdy and is very cheap. For the PVC joints, you will have to figure out which type of joints and the quantity of them. Once you have figured out quantities, measurements, etc., you can start cutting your pipe. you can use pipe cutters, but I have found it easy to use the device above (image one) and a saw. With this device, you get a cleaner cut than with pipe cutters.
Step 4: Drill Holes
The next step your going to do is to drill holes in the pipe and joints. You need to drill holes into the pipe and joints because it will help your ROV sink below the surface and not floating to the top of the surface. But adding foam pipe or tubing later on will help your ROV be buoyant under water and maneuver with ease. I approximately drilled two holes in each pipe, and one hole in each joint.
Step 5: Put It All Together (Final Step)
So after you have all the cut pieces and joints, now you just have to put it together, and make adjustments (if needed/desired). You can easily put it together with your hands, and your finished with your frame. Above are some frames that students from our school district put together. If your having troubles with the PVC slipping out of the joints, then just use pliers to secure the pipes. Once again I will say if you don't like your design than make small adjustments (trial and error) to get your perfect (or near perfect) model.