Al's Annual Inspection Thread 2015

OK, it is that time again so I will start here with Bumpers (Yes, I have had several teams report that they intend to add bumpers this year).

Yes, you can add bumpers this year but they are entirely optional and…

  1. They must be weighed as part of the robot weight, and that total cannot exceed 120 Lbs, R4.
  2. The bumpers when attached must also fit in the TRANSPORT CONFIGURATION R3.
  3. Bumper construction will be inspected for potential safety hazards and attachments like any other robot parts.
  4. As bumpers are entirely optional, they do not need to cover specific areas of the frame perimeter.
  5. Bumpers do not need to be constructed as suggested in the Bumper Design Guide found here. Be aware that the guide is a tried and tested design.

In addition to the rules as published, Team Updates come out on Tuesday and Friday each week. If Team Update changes or modifies a robot rule, that change will be part of the inspection process at subsequent events.

I would like to point out a Team Update was published Friday, 2/6/2015, concerning custom MXP boards. This is not a change in the rule but a clarification to make it easier to understand and flow chart is included. Restated, if you have any active components on your custom made MXP board and you are using any of the PWM outputs on the MXP connector for controlling motors or servos, the board can only be one of the three pre-approved boards listed in R58.

More to come later…

Unless you’re going to install the bumpers (in under 60 seconds) once you reach the playing field.

However, they are still taken into account for Transport Configuration, wherever they are stored on the Robot.

Maybe delete “when attached” from the bullet point.

Is a simplified interpretation: “Except for the pre-approved boards, and boards with no components (board is only line traces), No connection from the MXP board to a Motor Controller.”?

Any thoughts on why Custom Circuits cannot be used for PWM, but are allowed on the CAN Bus, and thus might be controlling the Motor Controllers?

I believe that this is in keeping with R57:

As I interpret it, they are trying to ensure that when they issue the “disable” command, that they are certain that it will have that effect. This is both a safety and a game issue.

Because R59 say all motor controllers on the CAN Bus must be controlled by the RoboRIO and R62 says CUSTOM CIRCUITS or other devices that interfere with those communications are not allowed.

The TRANSPORT CONFIGURATION will be determined during inspection at the same time as weight. Under Tournament rule T6 there is no provision for removing bumpers to determine size limits.

T6 While transferring the ROBOT throughout the event (e.g. between the Team’s Pit, Practice Field, ARENA, Inspection Station, etc.), the ROBOT must not exceed a volume that is 28 in. wide x 42 in. long x 78 in. tall (the TRANSPORT CONFIGURATION).
(Emphasis is mine.)

Safety is our prime concern for everyone involved. As such, nothing may cause robot movement until and during the times the robot is enabled by the Field Management System.

There is also no rule requiring bumpers be attached at their operating position for Transport Configuration. During TC, the bumpers could be sitting inside the robot, and on the field quickly attached with pins.

I’m not getting this Al. Why can’t I remove my bumpers, store them inside the bot, and transport my bot to the practice field, arena, inspection area, etc. Check the weight & TC volume with the bumpers stored inside the bot, and then put them on if needed for additional inspection, just like I’d put any other attachment on after transporting to the inspection station. Since your quoted rules never mention the word BUMPER, how does your bumper restriction not also apply to any other attachment that must be relocated for transporting?

John and Rich,
It is my understanding, that bumpers, if used, are part of the robot, just like an arm, a pickup device or the control system. That means that the bumpers are not considered separate of the ROBOT and all rules apply. As such, the bumpers need to be mounted on the robot for weight and size. I suppose you can (for this year only) have bumpers on moveable parts that retract the bumpers into the robot for determining the TRANSPORT CONFIGURATION. Just as in the past, if you have multiple devices that can be used on your robot, all mechanisms must be weighed together, and the overall size will need to be determined for each configuration under R4. The change in the bumper rules applies to this season. There is no telling what next season will bring.


R3 allows for minor disassembly to be made to get the robot into its transportation configuration. This would allow them to take the bumpers off and place them somewhere on the robot inside the size constraints. Then when they get on the field they would be allowed to reattach them prior to the match.

Al - Is the only option retraction for bumpers? The blue box under R3 states the TRANSPORT CONFIGURATION size constraints can be met with “minor disassembly”., And references G10, which gives a guideline of 60 seconds for on field configuration. I guess the question boils down to the definition of “minor disassembly”. Having a set of bumpers that can be removed and placed inside the robot for transport, then attached quickly with a couple of wing nuts seems to me to meet the intent of the rules.


I can see situations where the only time certain parts, not limited to bumpers, are mounting on the robot is outside of transportation configuration. The rules allow for pieces to be removed from the robot to make it fit in the TC. If all parts of the robot are to be attached at weighing, the robot should not be expected to be within TC. Simply put, being within the TC and having all parts attached might be mutually exclusive for some robots.

‘Bumper’ is not even a glossary item and as such appears to have no special distinction as compared to other attachments or robots components/assemblies/mechanisms. In fact, there is no definition of where the boundary between a bumper and a non-bumper element is. If I want to call my steel bar located in the center of my robot a bumper, there is no rule that says I can’t do so, and doing so has no impact on any aspect of the rules, as near as I can tell. Heck, I can claim my RoboRio is doing double duty as my bumper.

Edit: Having said all that, there is much practical benefit to not having teams remove and attach bumpers for every match. We’ve seen how that works in the past for many teams, but I don’t think the rules speak to the issue.

Hi Al,
I am a bit confused. I thought that bumpers could be attached on the field as long as they go on within 60 seconds (or reasonable time) G10 & G11 and fit within the TRANSPORTATION CONFIGURATION. For example, if I have an upright on the robot (that only rises 6ft) and I use a bungie cord to temporarily secure my bumpers to that upright that is legal within the rules? Does Q&A Q189 say that that bungie cord would not count against the total robot weight?


I have a specific pneumatics question - can air cylinders be plumbed with no control valving (solenoid or otherwise)? I.e. always pressurized in a given configuration so they act as a constant-force spring.

Related to bumpers - I wouldn’t even call them “bumpers” anymore, as that term is associated with a part or parts subjected to specific rules and exempt from volume and weight rules. Bumpers, as in BUMPERS specifically defined by the manual, do not exist in this year’s game.

This is a good question, my 2 cents is that it will be ok as long as it matches the diagram in R67.

I would suggest you wait for your Q&A question to be answered. That will carry more weight than what is posted here.

You can call them “bumpers” but not “BUMPERS”.

James, I’m not aware of any rules that would prohibit that, providing you meet all rules, of course (the cylinder is on the low pressure side, you have all required components for a pneumatic system, everything is properly rated, etc)