Im a senior at a boarding high school in Wisconsin, taking Advance 3D Concepts. About a month into the new year we were given the task of completing a fully operational ROV. We were in charge of creating everything that had to do with the ROV. Which consist of a remote that controls all movements (for the ROV) in the water, designing the propeller and the ROV on AutoDesk, a program that allows us to construct nearly anything we can imagine. Finally we were in charge of putting it all together so that by the end of the year we had a fully operational ROV. Although In the beginning I was not excited at all about this project, due to me being out my comfort zone. But as I did more and got better I really began to like it, and appreciated the process. I truly had a great time, involving great break throughs and a lot more mistakes. But in the end, I completed ROV that was fully operational. This is what I will be sharing today, including all the do's and do not's that I have learned, and will hopefully, help you create a full operational ROV, while avoiding the same mistakes I made during this long journey.
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Step 1: Gather Your Tools and Materials
- Hot Glue Gun
- 3DC Batteries
- Copper wire
- 3 motors
- 1 20ft Ethernet Chord
- 1 control box like in the picture
- 1 computer with Autodesk and Makerbot
- 1 3D printer with PLA filament
- 3 propellers (That you make)
- 1 battery box that holds 3DC batteries
- 3 switches
- 3 one inch pvc pipes
- Soldering gun
- Rotary tool
Step 2: Preparing the Remote for the ROV
This is when things can get tricky. It does not matter how amazing your ROV design is, without this it won't work. This will give power to your ROV and control it. This step is vital and if your wires (Positive and negative) touch, your motors will fry.
First thing we need to do is to cut three holes into the control box. The holes have to be the same dimensions as your switches. The switches should be able to rest in the control box comfortably and snug. The easiest way to do this is to trace the switches on to the motor box with either a pencil or marker. Then using a knife or a rotary tool (easiest) cut and trace the lines.
Where you decide to put the motors is completely up to you. I chose to look at it as a game console remote, and put my switches in a row, side by side on the cover of the box. You can look at the image above for a better idea.
Step 3: Wiring Your Remote
After you have completed cutting the 3 holes into the control box and insert the switches. Next we need to get started on wiring the remote. The diagram above is a great example on how to do complete it.
The first step is to grab and cut two one inch different colors wires. Then choose what color wire is going to be positive and negative (Thank me later). The most important thing is to create a jump for the wires so that we can control the ROV to go forward and backwards. Without this the remote will not work. To do this solder the wires, positive and negative on all three motors, making a cross between the two wires. You can look at the diagram above for a reference.
Step 4: Wires Part 2
This is where the ethernet cable is needed. Grab one side and strip one end, which is basically taking the plastic cover off, and making sure that all the wires are still attached. I found that grabbing a pair of scissors to lightly twist the covering off the wires worked the best. We then need to pick any three out of the four colors, and attach the positive and negative wires for each corresponding color to each switch. Twist the wires onto the motor before soldering them, so that if any mistakes occur nothing is permanent. You can look at the diagram above and the diagram in the previous step if needed.
Try not to use to much solder, as I learned this can actually prevent the wire from actually touching the metal, which will obviously cause the remote to not work. If you don't have any experience in soldering you should practice before soldering the wires permanently, because if you mess up it is very hard to get the solder off to start over.
Step 5: Wires Part 3
One more step... Just hang in there. Now we need to strip the other side of the ethernet chord (like we did in the last step). Picking the same three colors, grabbing the positive and negative wires, and twist it onto the positive and negative part of the motor. Don't mix up the positive and negative because then your switches will be backwards. By that I mean when you try to go forward, the motor will spin backwards or vice versa. We will end up soldering it but before making it permanent like I did, you should test it. I got lucky that mine worked but some other classmates of mine had to start over because they didn't test it. You can do this while the positive and negative are touching the positive and negative part of the motor. Twisting it or a friend can insure that they are touching. Using the switches make sure that each motor can spin forward, and backwards.
if it does not work the first time, don't be discouraged this can simply just be a broken motor, or one of your positive or negative wires aren't touching the metal of the switch because of to much solder.
After you finished testing the remote and everything works, you should now solder the positive and negative wire to the positive and negative part of the motor. Don't use to much solder and don't get frustrated when it does not stay in place. I completely understand...
Step 6: Powering the Control Box
Now that we have all the wires in the appropriate place, the next step is to actually being able to give the remote power. We do this with the batter box. But first we need to grab and connect all the positive wires to the middle like the image above. This is why we established what color wire was going to be positive and negative before this part because without knowing, this part can get tricky. Now that the positive wires are complete, the same must be done for the negative wires. You can look at the image above for a little more clarity. This was one of the most challenging parts to me (well all the wiring). Finally we take the battery pack and attach the positive and negative wires to their respective pairs (positive and negative) and twist a wire cap (like the image above)or solder them to lock them together. I personally suggest that using the the cap is much easier, nicer and safer. Because if the Positive and negative ever touch the motors will be fried and everything will be ruined.
Step 7: Getting Creative!
Congratulations the hardest part of the ROV is now finished. This is where you have to become creative. Yes again this can be tricky if you don't have experience on AutoDesk, or any program. I personally joined the class late and missed the introduction of AutoDesk and how it worked. So when I got to this part it was quite tricky but when I got the basics of the program I was able to create something simple. You can look at the image above to see my design.
If you are experienced, feel free to create something really cool looking but keep in mind that it has to work. Not all designs will float and work. Where you choose to insert the motors has a lot to do with it as well. So with that being said, go ahead and be simple or really complex. As long as you use the right dimensions so the motor could fit into the ROV.
Step 8: Printing
After finishing your design the next you need to do is print it. This can be done many ways, so pick whatever is easiest for you. I saved my design as an STL file so that the 3D printer software can read it. In this software we we are able to make sure that everything is printed the way we want it. Depending on the design some may need support beams and this is where you can do that. You can shrink or increase your dimensions if needed. Again this can be done in many ways it just depends on the printer and software you use.
Step 9: Waterproofing the Motors
Now that we got the remote and the actual ROV design done, we need to focus on the small but important things. Hang in there, were almost done. First we need to cut three one inch PVC pipes like the image above. I used a saw but whatever will work is fine too. Secondly we need to hollow out each PVC pipe so that we can insert the motors inside. This can be done many ways but I used a rotary tool with a sander like attachment to hallow out a half moon. This is important and a mistake that I made during my long process of trial and error (mostly error) that cost me more time than necessary. You do not need to hallow out the entire PVC pipe, just enough so that the wires that we already soldered to the motor would not be damaged. Its almost like a pocket for the wires. Once the motor is inserted, use goop to make sure that water cannot get inside to the motors or wires. Do not use to much goop all at once (like me) which was a big mistake. This resulted in the base of the rotating rod in the middle of the motor being gooped, stopping the motor from doing its job. If this happens don't worry, carefully pick and cut the goop out with a little blade. Carefully try to get as much as you can so that you can re-goop.
Hopefully you don't make the same mistakes as me! To prevent mistakes like this, one thing that helped me goop successfully the next time is applying the goop on a pencil (that you don't care about). When the goop is on the pencil quickly rub the goop onto the top and bottom of the motor. I say quickly because it dries very quickly! More than likely you are going to need to do this a few times to insure that it there is no leaks or cracks that will allow water to get into the bottom or the top of the motor. Using this technique can prevent you from being careless and sloppy, ultimately leading to mistakes. Although this step may seem small, remember the importance of this step, because if not done properly this can potentially destroy the motor. This is how I got the best results and can vary from person to person.
I also put hot glue on the circumference of the motor, and where I thought the goop didn't fall because of the thickness. This is just another precaution to insure that the motor is waterproof. Again just don't put it where it can prevent the motor from doing its job of spinning the rod in the middle.
Step 10: Inserting the Motors Into the ROV
Now that you have waterproofed the motors you must now insert them into the ROV that you designed. The first thing I did was to made sure that it fit into the slots that I made into the ROV. Now for the best results (in my opinion) is to use a hot glue gun. You must do this quickly! I never really had any experience with an hot glue gun so I didn't realize how fast it actually dried. I ended up having to push the motor into the slot with a hammer... DO NOT make the same mistake I did..
BEFORE applying the hot glue make sure that you know how far down you're going to insert the motor. Where the rod is, is important so it can do its job correctly. Because of my mistake above, one of my motors needs to be pushed down a little more, preventing my ROV from moving (like it should) and having a weak side compared to the other motors.
To make sure that doesn't happen to you, shoot the hot glue on the outside of the PVC pipe (which is the motor) and a little on the inside of the hole where the motor is being inserted. Quickly Insert the motor in the ROV and hold it in its place for about 15 seconds, and you should be golden. Repeat the same steps for the other two motors.
Step 11: Designing Propellers
Congratulations you are almost there! You have a full operational ROV that is ready to go into the water to be played with or whatever your purpose on creating one is. Although it's working and capable of going into the water it wouldn't be much fun. The motors work but the rod isn't capable of pushing the water to move the ROV. So the ROV (hopefully depending on your design) will just float. So propellers are a small but crucial factor to the ROV. This can be frustrating if you don't have AutoDesk or 3D designing skills because of how complex this design can be for a beginner. Personally I still think this is way better than wiring the remote, as we have total freedom and can be as creative as you want. Simple or complex designs can work but the most important thing is that you make the dimensionsfit the motor. Which can be quite hard to get to fit sometimes, because fitting on the motor isn't the only thing we have to worry about. We also need to worry about the height and how wide the propeller is. One of my propellers fit the motor perfectly but would hit the side of the ROV, which obviously isn't going to work. If it doesn't fit do not freak out! If its the height and width of the propeller then you only have one choice and thats to reprint it. If its just to thick or to thin(and hot glue doesn't work) it may be easier to just print a sleeve instead of reprinting another design. Our advance 3D concept's teacher had a bunch of a sleeves that he let us use which saved us a lot of time! We would put the sleeve in to the propeller, making the rod either thicker or thinner, depending on what was needed. You can also see a picture of what that looks like above!
For my ROV I was trying to be the fastest, and I know that the propeller had a lot to do with it, thus influenced my design. In the beginning I had a cone like propeller that was below average in width but pretty tall. But right before It was going to be printed, my teacher who was just doing all the final checks to make sure it would print correctly, came up with the idea to shrink the dimensions of the propeller. making the cone shaped propeller short and wider but still relatively thin. He said that he liked my design but wanted to see how it would affect the propeller. We really didn't know how this would work, but I think we both just wanted to see how it would look. Although logically it made sense and actually helped me with a faster ROV. This is how I got my propeller design, and I suggest to think on your goal for the ROV to help decide.
Something I wish I did is find out exactly how tall or wide a propeller can be without hitting the ROV before designing. This would of saved time and would of made the process a lot smoother. Do Not Make My Mistakes!
This can be extremely difficult and a lot to think about, with an endless amount of possibilities. Which is why I will have the ROV file I printed and my propeller file (before being shrunk) in the end of this instructable for you to download, use or just for inspiration.
Step 12: Printing the Propellers
Refer to Step 8.
Step 13: Adding Your Propellers
YOU'RE ALMOST THERE! All you have to now is to add your propellers to the motors. The best way if it doesn't fit exactly is to use a hot glue gun. Neatly shoot just a little hot glue into the hole of the propeller and quickly insert it into the rod of the motor. Do not put a lot of glue where the propeller will not be able to spin. This is just to make the propeller a little thicker in the inside. Again like in step 13 If the hot glue does not work, it may be easier to just print a sleeve instead of reprinting another design propeller. Our advance 3D concept's teacher had a bunch of sleeves that he let us use. Which saved us a lot of time! We would put the sleeve in to the propeller, making the propeller either thicker or thinner, depending on what was needed. Allowing you to just slide the propeller on. You can also see a picture of what that looks like above!
Step 14: HAVE FUN
These are the files I used from AutoDesk... Please enjoy them and use them for inspiration!!
Participated in the
Robotics Contest 2017