The title pretty much says it all, what are is/are the rules on changing wheels at an event? A example is if we had a live axle setup and decided this match we want to play defense for whatever reason and we want to pull off our Colsons and throw on some traction wheels. Can you do that without being reinspected? Could you get around this by keeping both sets on the robot, then you’d just be changing where they were on the robot? If anyone could help me out that would be fantastic.
It is easy to make modifications for each match. It only takes a couple minutes to get reinspected and make sure that the inspectors are aware and ready on what you plan on doing and it will go smoothly.
I may be mistaken, but I believe you wouldn’t need to get reinspected for swapping wheels. An LRI could answer this question better though.
Edit When we do inspection we’ve shown inspectors things like second set of wheel and told them we might switch them, and that has resulted in not having to be reinspected for us.
Not an LRI, but if it changes your robot’s functionality then you need to be reinspected. Imagine switching wheels to all-metal, spiked (no tread) wheels; that wouldn’t be legal, so the inspectors need to see them. The exception being: if your robot with both sets of wheels weighs less than the max weight, you can get inspected in both configurations and then switch as often as you want.
As usual, all rules are subject to change in future games.
If all stays the same, does this mean we could get inspected with both and just switch them out as we wish?
Anything that changes your weight (swapping wheels, adding or subtracting components) should always trigger you to be reinspected. When in doubt, grab an inspector (they are usually pretty eager to do something on Friday and Saturday morning.) and this will make sure you stay legal to play all weekend. If you still have any questions, just ask the LRI at the event.
Not only weight, but height as well. I’ve seen a lot of teams caught by surprise that different diameter or type wheels change the height of the robot (and its mechanisms).
It’s always safe to just ask a robot inspector to look at your robot really quick. Most of the time they don’t even grab the clipboards and just make sure its legal. If you change major parts or enough to change the weight, you should always bring it over to get reweighed.
If you have enough weight available to fit both sets of wheels inside your limit, you could get both configurations inspected at the outset and get approved for either configuration from that point forward. According to previous years’ rules, at least.
To make it easy on you and the inspectors get inspected in both configurations and keep in mind your weight.
Weight of robot + weight of wheels A + weight of wheels B must be equal to or less than max robot weight.
Example 1 Legal
Robot: 110 lbs
Wheels A: 5 lbs
Wheels B: 4 lbs
Example 2 not Legal
Robot: 110 lbs
Wheels A: 6 lbs
Wheels B: 5 lbs
That’s saying both wheel sets are part of your robot though. I would expect this situation would usually be part of the 25lbs hold back.
If you plan to switch back and forth between wheel sets, then according to the rules that have been used for at least the last decade both sets have to count in your robot weight. It would be the same as if you had two different devices that you would trade in and out between matches. All of them together count in the weight limit. If you are just switching wheels because the original wheels weren’t working, and are not going to switch back, then you don’t have to count both in the robot weight. In that case, if the wheels have been assembled or otherwise modified after you got them, they are part of the withholding allowance. All of this is of course contingent on the rules remaining the same.
Yes, at least to a point.
Under the 2017 rules, you could do that provided the entire robot weight (including whichever set of wheels was off the robot) was under the max. You also would be able to do it without reinspection, provided no other changes were made.
If you happen to not fit both sets of wheels under the max weight, you’ll need reinspection every time you switch. Inspectors may or may not be available.
Also, @BrianM, not if you planned ahead and dropped the second set of wheels into the robot bag, or modified them at the event. The part you’re missing is that these wheels are NOT “spares”, they’re “upgrades”. They’re a completely different wheel.
There’s nothing special about wheels, they are just part of a mechanism on the robot. The relevant rules from 2017 are:
I03. Bring it all to Inspection. At the time of Inspection, the ROBOT must be presented with all MECHANISMS (including all COMPONENTS of each MECHANISM), configurations, and decorations that will be used on the ROBOT during the competition event. It is acceptable, however, for a ROBOT to play MATCHES with a subset of the MECHANISMS that were present during Inspection. Only MECHANISMS that were present during the Inspection may be added, removed or reconfigured between MATCHES. If MECHANISMS are changed between MATCHES, the reconfigured ROBOT must still meet all Inspection criteria.
I05. Unless the change is listed below, any change to a ROBOT must get re-inspected. If a ROBOT is modified after it has passed its most recent Inspection, that ROBOT must be reInspected before the ROBOT is eligible to participate in a MATCH. Exceptions are listed in A through F (unless they result in a significant change to the ROBOT’S size, weight, legality, or safety).
A. addition, relocation, or removal of fasteners (e.g. cable ties, tape, and rivets)
B. addition, relocation, or removal of labeling or marking
C. revision of ROBOT code
D. replacement of a COTS COMPONENT with an identical COTS COMPONENT
E. replacement of a MECHANISM with an identical MECHANISM (size, weight, material)
F. additions, removals, or reconfiguration of ROBOT with a subset of MECHANISMS already inspected per I02.
As the post from Al in another thread (quoted below) indicates, if everything fits within the weight limit, you can get inspected in both configurations and then change between them at will. If it doesn’t, then you need to get reinspected every time you change.
So, if you weigh your robot and it’s 120lbs, while your spare wheels are another 5 lbs, you need to get reinspected when you swap them. And then reinspected again when you swap them back. Every time you change wheels, you need to get reinspected. If, on the other hand, your robot is underweight such that you can include the spare wheels and all associated hardware on the scale and still be at 120lbs or less, then you can get inspected in both configurations up front and change without reinspection whenever you want.
I recommend reading the thread Al posted in, it has a great discussion about this.
Example 2 is illegal to run both configurations at the same time without a reinspection, but if you have an inspection every time you switch between those configurations, it is legal. There’s another thread about this, it may not have used to be this way but interpretations / Q&A in 2015 and 2017 worked this way.
We actually do this. We inspect with a spare set of wheels. The exception is if your wheels are COTs, you change changes them without having them having been previously inspected. Colsons are about the only ones that fall into that category. Most wheels are assemblies, and even an assembly of COTs part are not considered to be COTS.
Only if they are identical, in which case it’s one of the exceptions listed under I05 part D or part E (depending on the setup). Per the OP, changing from one type of wheel to a different type does require a reinspection if they aren’t included in your total weight at the time of inspection, as they aren’t identical replacements.
On the other hand, I’ve never seen a team red-carded for not getting a reinspection after replacing a fabricated mechanism with an identical spare. I don’t see why a wheel with tread on it would be any different.
As long as the replacement wheel is the same, it fell under 2017 I05 E.
I05. Unless the change is listed below, any change to a ROBOT must get re-inspected. If a ROBOT is modified after it has passed its most recent Inspection, that ROBOT must be re-Inspected before the ROBOT is eligible to participate in a MATCH. Exceptions are listed in A through F (unless they result in a significant change to the ROBOT’S size, weight, legality, or safety).
- A. addition, relocation, or removal of fasteners (e.g. cable ties, tape, and rivets)
- B. addition, relocation, or removal of labeling or marking
- C. revision of ROBOT code
- D. replacement of a COTS COMPONENT with an identical COTS COMPONENT
- E. **replacement of a MECHANISM with an identical MECHANISM (size, weight, material)
- F. additions, removals, or reconfiguration of ROBOT with a subset of MECHANISMS already inspected per I02.
Exception D covers COTS components. This implies that E covers something else, e.g. MECHANISMS which are FABRICATED ITEMS.
Thank you everyone for the responses, they are all really appreciated