A render of the control system that team 4069 will be using for the 2019 season. Contains roboRIO, VRM, radio, PDP, and 16 Talon SRX motor controllers in one package that can be easily installed into most chassis.
Keep in mind R50,
If this box is buried in the middle of your robot the circuit breakers will not be easily visible.
More than just following the rules, it’s in your team’s best interest for diagnostic lights to be visible from outside the robot so field staff can help you diagnose when you have a problem. You will also want any components that may need tinkering/replacing to be easily accessible, and it seems like the PDP/VRM may be hard to get to right now.
Additionally, putting the radio in the middle of the robot surrounded by metal, high currents, motors, and EM producing electronics is asking for bad signal strength. You’d definitely benefit from moving the radio out of the middle of the robot, as high and isolated as possible.
EDIT: One more thing. If you design the electronics box before kickoff like you have, you’re setting a rather large requirement that your robot must have space set aside for it. For some games that may be fine, but for others that puts you at a significant disadvantage. While there are certainly some advantages to designing your electronics box pre-kickoff (e.g. you don’t have to design it while you’re trying to design a whole robot), I’d argue that they don’t outweigh the disadvantages. Once you know how the robot will look to best fit your strategy, you can then design a removable electronics box that fits in your robot without setting unnecessary design constraints.
Very cool. Reminds me of these3D printed versions:
In 2018, we used a design similar to this but that contained the radio and roboRIO inside the box, and it was completely closed. While that still passed inspection it was an absolute nightmare when things went wrong, so we’ve definitely learned our lesson on that front. We’ve taken that into account and designed this one to be a lot more open so that the critical components are still easily accessible. Also in working on this, I can say that the PDP and the VRM nestled in there remain easily visible and accessible if anything needs to be done on that front.
Are those (gasp!) XT-60 connectors I see?!? The demon-spawn of FRC robotics?!? We musn’t ever show them lest we be derided and belittled… /sarcasm
But yeah, those are awesome. Never going back to andersons, and I like both layouts. Very good ideas if they work for the design of the year.
re: the tower of power –
Ari is entirely correct, when we designed the tower of power we had space reserved on the robot.
Once we ended up assembling the robot the space that was reserved never materialized, so we had to iterate quick which meant eventually breaking the TOP apart.
We did still use the side plates of the TOP to mount our talons, but the rest of it never made it onto the robot.
(you can see how we rotated the TOP side plates 180* and mounted them in this video, sorry I don’t have a better picture to really show it off.)
Note that “visible for inspection” doesn’t require that the control board be inside the robot at the time of inspection. 116 has been building removable control boxes for more than a decade now. They simply remove the electronics box from the robot for inspection.
It appears that the OP’s design would have most of the diagnostic lights visible from outside the robot.
How do you insert the tool for opening the Wago connectors on the PDP? Is there sufficient space for operating the Weidmuller connectors on the PDP?
What do you fasten the motor controller input and output wires to for strain relief? Without this strain relief, you can break the strands in the wires right where they come out of the motor controller bodies leading to intermittent open circuits.
You may want to use the alternative form of CAD (Cardboard Aided Design) to mock up your designs to verify that you can actually perform the manufacturing and maintenance work necessary.
We have the design manufactured already. Yes the weidmullers are operable, we have little extenders from all of the wagos so that changing power output is plug and play. To that end, the input wires on the talon don’t have to stretch all the way to the PDP, so the strain there is minimal. The output wires are attached to the top of the box.
Are you able to open the Wago connectors if you need to change the extenders? The motor controller input and output wires should be tied down to resist vibration as the robot moves around. How do you remove the upper layer for servicing if the motor controller wires are attached to it?
Don’t forget to publish your CAD, or you can’t use those models post-kickoff!
If you’ve already physically made this design and intend to use it in 2019, I strongly suggest you read over R14:
R14. Physical ROBOT elements created before Kickoff are not permitted. Exceptions are:
A. OPERATOR CONSOLE,
B. BUMPERS (a protective assembly designed to attach to the exterior of the ROBOT and constructed as specified in Section 8.5 Bumper Rules),
C. battery assemblies per R05-B,
D. FABRICATED ITEMS consisting of one COTS electrical device (e.g. a motor or motor controller) and attached components associated with any of the following
Wires modified to facilitate connection to a ROBOT (including removal of existing connectors)
Connectors and any materials to secure and insulate those connectors added
Motor shafts modified and/or gears, pulleys, or sprockets added
Please note that this means that FABRICATED ITEMS from ROBOTS
entered in previous FIRST competitions may not be used on ROBOTS in
the 2018 FIRST® Robotics Competition (other than those allowed per
R14-B through R14-D). Before the formal start of the Build Season,
Teams are encouraged to think as much as they please about their
ROBOTS. They may develop prototypes, create proof-of-concept
models, and conduct design exercises. Teams may gather all the raw
stock materials and COTS COMPONENTS they want.
Example 1: A Team designs and builds a two-speed shifting
transmission during the fall as a training exercise. After Kickoff, they
utilize all the design principles they learned in the fall to design their
ROBOT. To optimize the transmission design for their ROBOT, they
improve the transmission gear ratios and reduce the size, and build two
new transmissions, and place them on the ROBOT. All parts of this
process are permitted activities.
Example 2: A Team re-uses a 2018-legal motor from a previous ROBOT
which has had connectors added to the wires. This is permitted, per
exception D, because the motor is a COTS electrical COMPONENT.
Should I add STEP files to this? We haven’t really done preseason prep in this way before
We’re going to manufacture it again during build season. At the moment it is serving as the control system for our preseason prototypes.
Completely ruling out a connector that is widely used in FRC is a very interesting decision. My experiences with Andersons have been incredibly good. They’re was to work with and the lack of a solder requirement makes everything a lot less stressful when you have to replace a motor controller or a motor at a competition when you have 3 to get it done.
I’m not saying XT-60s are bad but I am saying that Andersons are worlds better.
I also hated Andersons. Then we bought the actual crimper (TRI-crimp) and now I love Andersons. They’re a little pricey but the fact that there’s only one type of crimp is so nice. No need to bother with male/female pairs like with XT60 or similar connectors.
STEP is okay.
I prefer IGS as a generic interchange format.
Though if you use something mainstream, like SolidWorks or Inventor, those native files can be opened by most other programs.
Does F360 have a ‘share model with link’ sort of option? That’s a great way to publish models.