How was your electrical board set up/mounted this past year?
Upright, in the middle of the bot
Upright, on a side of the bot
Upright, connected to the robot’s diagonal (or other) supports
Laying down, in the middle of the robot
Laying down, hidden underneath
I was thinking about how we designed our electrical board last year, and i saw some other ways, so i am curious to see how other teams did it, and why.
We chose the first option, upright in the middle of the bot. This worked well for us, but we had to reach through the elevator to get to the backside. I saw a significant number of robots whose boards were hidden underneath, and was wondering the advantage to that? Wouldnt that make it harder to get to?
If you chose Other,
How was your board mounted?
Why did you mount it that way?
Did it work well?
For anyone else,
Why did you mount it that way?
Did it work well?
Im trying to understand the different ways and reasons teams mount their electronics to try to improve ours for next year. Any information would be helpful :)
Since 2017 we’ve been mounting the electronics upside down underneath the robot. Main reason for this is so we have unfettered access to them regardless of the mechanisms we mount above on the robot. We aren’t the best at pre-planning these kinds of things. The bandwidth to get all that CAD done before we need to start manufacturing has not been there in previous years. So our work around is to just mount electronics in a place we know is not going to get obstructed. Has been working pretty well for us so far.
Access is certainly a consideration. But so is available space. And the relative length of wire runs to different mechanisms.
Generally speaking, you want the wire run to your drivetrain (battery -> PDP -> speed controller -> motor) to be as short as possible. That’s going to be the biggest power draw on the entire robot, and by keeping those wires short, you reduce the amount of power lost through heat.
After that, you want to keep the battery -> PDP path as short as possible. All of your power goes through there, and shorter means less power lost to heat.
A robot’s design may include a through-bumper intake that essentially eats up half the space in the bottom of the robot, with the drivetrain gearboxes and motors eating up the rest. An arm design may require significant space for travel, removing the ability for vertical designs on the front/back. A game challenge (like the low bar for Stronghold) may limit the total height of your robot.
The trick is to figure out where it best integrates into your overall robot design, and once you have a location to then figure out how best to access it! Boards on the bottom of a robot may be hinged, so tipping the robot over and removing a couple of screws gives you full, easy access. A hinge may also be used for vertical boards, letting you put the components towards the inside, providing a little protection. Boards may be placed facing outwards, and protected by a piece of lexan that needs to be unbolted to get access. They may even be split into multiple parts to fit in different spots on the robot.
There are a lot of ways to do it, you can never know what the best way is until you have a design to work with
It worked very well because it was right there in the middle of the robot so all the runs could be very short which helped significantly with cable management. We also mounted it this way because it is very easy to access so if we need to replace a fuse or plug a speed controller in or something it made it very easy. In 2018 we used a vertical board and we had accessibility problems all year long so if we needed to unplug or plug something in we almost had to remove the entire PDP from the robot.
So in summary for my team and our robot designs a laying mount was much better then a upright board.
As @Jon_Stratis says, it’s almost always a tradeoff. If your robot design has space available on the back or sides, and you can stand the lift in center of gravity, it’s much easier to access for inspection, diagnostics, and repairs. The robot I worked on in 2015 had a single board on the back (upright diagonal), and the one in 2017 had the RIO and radio and such upright on one side and most of the other control components upright on the opposite side. Much easier to access, but providing a polycarb cover for outward facing boards is essential.
Most of the others I’ve worked on had the controls down inside or just above the chassis because the robot was intentionally low or the manipulators used up most of the accessible area.
Doing the mount at the bottom of the robot, facing down, sounds like a neat idea because you just lay the robot down to access the controls, but a cover is then even more essential especially if the game has terrain or game pieces you can run over. Most of the people I’ve spoken with who have done this did it once and never again.
We had rio, radio and vrm on one side, and pdp and breaker on other side, each covered by a polycarb shield with 2 bolts and holes for easy usb a and Ethernet access on rio. Talons were mounted under ramp.
Yup. We never know where or how our electronics will fit, until we design the rest of the robot. We try to leave a nice space for the electronics, but it doesn’t always work out that way. I prefer having it mounted vertically, facing outward, in it’s own box, but sometimes how the robot works doesn’t let us do that.
On the other hand, make sure that the robot architects understand how much space and access you will need for the control system. 3946’s second-year robot controls suffered from being jammed into too little volume, which was constantly being rearranged. The bad connections and poor access to the control systems were the primary causes of that robot’s TRS (Twitchy Robot Syndrome).
Please explain to me why you want to limit airflow to your electronics, especially your breakers and motor controllers.
Last year we had an upright electrical board and it was great, I highly recommend it… this year our design dictated that we had to mount everything laying down in the base of the robot which was… less than ideal…
There is no single right answer. It depends on the overall design of your robot and you will probably have to change from year to year.
The best way to ensure this is to have the control system components put into the CAD AND have someone from the electrical team review it for all the considerations that @Jon_Stratis listed. If your team is not really proficient in CAD, You can also estimate the area needed by measuring all the control system components and adding about 1 inch to the lengths and widths and calculating the total area in square inches and then add 15-20%. You then review it for the same considerations as above. As a last resort, split it into two areas with all the motor controllers, PCM’s and solenoids in one area and the Roborio, PDP and VRM in another area.
They don’t really need much airflow, but they want to be protected well from other robots, and also from ourselves working on other stuff. Putting all the electronics in a vertical box, with an easily removable cover that faces out, has worked very well for us, when we’ve been able to do it.
we mounted our main electrical pannel on the back of our elevator because there was un used space there that we thought we could utilize and we put our penumatics board laying down underneath the electrical board
This past year, i was in charge of electronics. Due to our experiences in years past, we made it a priority to design and build the electronics first, and plan how things would work around it. It worked, but it was definitely difficult. We wanted to make sure things were nice and neat and accessible, and not need to rush to put everything in at the end because that results in messy wires and thats never fun.
Do you usually find it easier/more efficient to put your electronics in last, and just put them wherever they fit, or to design the electrical board at the same time or before the robot, to make sure there’s room.
This past year, electronics was the last thing to be incorporated into the robot (don’t recommend.) The CAD lead was also expecting 14-15 motors, so we put everything on a very crowded belly pan. This made it quite difficult to get to the motor controllers and wires to be changed or fixed. We were out half a drive train for a match or 2 because we couldn’t get to the CAN wires. Definitely make sure there’s an electronics plan early into the season.
For the past few years, we’ve been mounting the electronics on the upper surface of the robot’s plastic belly pan. This has proven to be an ideal solution, letting us keep our electronics safely protected and keeping room above for mechanisms. We tend to layer other things on boards with removable mounts (like pneumatics) over the electronics, with careful placement so that critical components (like the RoboRIO) can be accessed easily. We’ve actually gotten a lot of compliments from the inspectors for how we’ve done this, so we’re likely to keep doing it unless the robot’s design forces some other solution.