So I am just working on a little project with my Arduino, nothing big just getting a bigger understanding of how everything works. For a Engineering class we have to use the Arduino to automate a part of a "design project" and I want to make sure I am not thinking bigger and better than my little Arduino can handle.
I current have the Arduino Uno starter kit with the basic components. I can upgrade small things if needed but I dont have the coin to upgrade anything major.
First I have the basic little toy DC motor that came with the kit, how much can one really expect out of this little motor? I am wanting to use it to hold back an object on an inclined plane. Then I want it to start spooling out dental floss and slowly letting the object down the incline. I then want the motor to stop and if at all possible reverse its direction and start pulling line back in and I need it to pull back up the weight of say a large tube sock.
Is this motor capable of say holding back 2 pounds and slowly letting it down the incline then reversing direction and pulling the weight of a tube sock back up? I am well aware that it will need to be geared down somehow to get a bit more torque. But I am curious if I should just upgrade to a bit better of a motor.
Secondly, Is it possible to write a code where when I power up the arduino it pauses say X seconds. It then begins unspooling line for say XX seconds. It then pauses for XXX seconds before reversing direction and pulling in line for XXXX seconds? Can I safely hook all of this up directly to my arduino uno or do I need more parts/boards?
Sorry its so vague and hopefully it makes sense what I am asking. I am brainstorming my design for the project before I run my ideas past my team. I need to automate this so that after I plug in my battery I dont have to touch anything untill I am finished and unplug the battery. I am currently working on sketches and I can upload them of my rough design if it would help you understand better.
Can the little motor slowly let a MAX of 2 lbs down an inclined ramp?
Can the motor then drag the weight of a tube sock back up the incline?
Can the motor be reversed?
Is it possible to write the code I want? and run the motor straight off the arduino without ruining the arduino
I have a little motor that "fits your description". It runs rather fast. To do what you want, you need a speed reduction gear box. This with increase the force the motor can apply to the weight. Motors apply torque, not force directly. By wrapping string around the output shaft of the gear box, you can apply a large force and slowly wrap or unwrap.
You need a motor driver to reverse the motor direction. Cheaper ones are less than $10USD.
So there is my crude sketches. Pretty much the PVC pipe has a sock on the end that has a string on the end of that tied to the motor. The PVC is on a slider angled downwards. After the egg is dropped into the PVC the motor slowly begins spooling out line letting the PVC slide to the edge of the "cliff". The PVC will hit a stop and quit moving out but the motor will continue to spool out line which will slowly lower the sock into the hole. In theory the egg should slowly ride down the hole in the sock. Eventually the egg will drop out and be in the hands of the next team.
So that the next team is able to raise the egg back up I need to get the sock out of the way. My two thoughts were.
A) Have the motor reverse its direction and start winding line back up.
B) Have the string short enough so that it completely unwinds and then starts rewinding the oposite way which would also raise the sock.
Team one gives us the egg and we must take it to team three. Dimensions are close but not exact. Close enough to get my point across. Scribbled in areas are the terrain, we are just building the frame with the PVC. I can go into more detail but we are only brainstorming we have not settled on a design I am just wanting to make sure what I am thinking is even possible with a small arduino uno and a $50 budget. That $50 budget must also buy the materials needed to build the frame and such as well as any motors or shields we may need.
I don't understand why the PVC tube has to slide on a track? Why doesn't it just overhang the edge?
I'm not sure that the way you are thinking of having the string and the sock will also control the tube along the track. Can you experiment with that before you commit too much time to it?
I think you should also experiment to find where is the best place to locate the exit point for the string. Note that there is no need to have the motor and gearbox at the top of the structure.
As someone else has suggested a suitable reduction gear system should enable a small motor to manage your loads. Maybe you could use Lego?
So in the first picture I drew two Vertical dotted lines. Our "machine" must "start" inside of those lines, so we then need to extend it out that last 3 inches to be able to lower the egg down to the next team. If we could start with the machine right up to the edge this would not be as complicated. The track could be something simple like drawer slides your kitchen drawers have. Imagine the pipe as being a drawer and is capable of sliding in and out, it technically wouldnt need any control other than not sliding out untill we are ready.
The sock and string ideally would stop the PVC tube from sliding down untill we want it to. Then when we are ready the motor starts letting out string which would let the PVC slide down to the edge of the cliff and as more string was let out the sock would be able to go down as well. Then we need the motor to pull the sock back up and out of the way.
Imagine you have a rope, its anchored to a tree on one side and you have the other side, up in another tree. Your buddy is hanging in the middle and you want to lower him to the ground so you will slowly let rope out so that he lowers to the ground. same basic concept with the egg, it will be cradled in the sock as it is lowered intill it hits the right spot where it will fall out. The motor wouldnt have to be on top but if its anywhere else one would need to use pulleys so that the string comes from above, other wise the egg in the sock cradle wouldnt work.
I have the same concern as R. Your device may do the lowering egg but won't return to its ready position due to friction or just the angle you apply your force with the string. On the other hand, if you run your string along side the tube but above it, then the string could pull the tube back after release so it's ready for another egg. Like R suggested, get it working manually before adding any motors.
The motors ARE NOT meant to return the whole device to its beginning position (it just needs to move one egg, if it fails we can manually reset it). All I need the motor to do is rewind enough to get the sock out of the way. The actual PVC could stay where its at, I just need to make sure that the sock gets out of the way so that when the next team brings it back up they can hand off the egg without the sock getting in the way.
