Hi Everyone, new member here. I’m planning on building a standard class sumobot (3 kg and fit inside a 20 cm by 20 cm box). I have experience in PLC programming and a bit of C, but this will be a learning exercise. I was hoping if I post my current shopping list for parts, those with more experience could advise on suitability, compatibility, anything missing and/or any improvements that could be made to my parts list so far? So far I have 1x Arduino Mega board, 2x Pololu 12v 75:1 motors, 2 x 30mm alu wheels, pair of pololu motor brackets,1x pololu dual motor shield for Arduino, 4x ultrasonic sensors (HC-SR04), 4x Pololu QTR1A reflectance sensors, 1x 11.1V lipo battery with star plug.
Any help would be appreciated! Some additional points I’m working out:
Not sure if the battery is suitable, and what charger would be best for it?
May include a Sharp IR sensor as well.
Considering using drop down white flags to confuse to opponent, should this be just gravity powered or motor?
Wheels- 4 or 2 wheels, 4 motors or 2, or 4 wheel drive using 2 motors and some method of transmission such as chain and sprockets.
Since you are still at the first steps, we recommend that you have a look at this blog series, How to Make a Robot. It offers a lot of information about all the basics (electronics, motors, drivers, microcontrollers, sensors, etc.).
At a first glance, your parts seem to make sense. Please note the wheel you chose specifies a 3 mm hole whereas your motor has a 4 mm shaft, therefore these may not be compatible.
The battery seems reasonable. If you draw ~11 A from it (lets say both motors are fully stalled), it should last you about 12 minutes, which should be enough for a few rounds of competition. That being said, since it cannot be charged at more than 2 A, it would take around 1 hour to recharge. We recommend that you get at least two of the batteries, so that you can quickly swap them and have one in use while the other recharges. Also, it is always a good idea to have a backup since batteries can get damage during use (such as sumo bots!) and therefore it is always better to have a solution.
The charger you chose is OK, but will not charge very fast (up to 700 mA per cell). This would take over two hours to complete one full charge. There is also the RB-Ten-28, which is slightly faster at 1 A charge current. To get a full 2 A of charge current (the maximum recommended for your battery pack), you’d need something like the RB-Hui-08 orRB-Hui-04.
You can find our IR range finders here. You may also be interested in some of our LIDAR products, found here.
These would be used to blind opponents’ cliff sensors? Sounds like a great idea (if it is allowed in the competition you participate in). Gravity may do just fine. Worst case, you may want to 3D print some adapter and connect it to a cheap RC servomotor, as found here.
For this one, if you are unsure what you need, we recommend that you check out various examples of other projects online. A fun one is the flipper for a pinball machine, such as this one.
