Question on Using Motor Components

[DonRotolo]

If you are asking if you can use a magnet (from some source) on your minibot, then yes, in my opinion it is permitted under <R92>. Magnets are allowed on minibots.

My opinion doesn't matter at inspection.

[Res0lu7ion]

Pretty much the idea over here. Lots of opinions and lots of speculation.

I was almost hoping for a team that had a similar situation to share maybe but all thoughts are appreciated.

[Al Skierkiewicz]

If the minibot inspection still required a BOM then you would have to account for the cost of the entire motor. There is no rule that would prevent you from obtaining a "magnet" from any source and using it on the minibot. Providing you don't violate any other robot rule, i.e. allowable glue, hardware or materials.

You are not modifying a motor and still using that motor which would be illegal. Please be careful in how you remove the magnet structure from the motor case.

[Tristan Lall]

This is one for the Q&A.

Make sure to stress that FIRST needs to respond in general terms, so that inspectors can apply the same logic to any subunit of a restricted component. We probably don't want different interpretations for a piece of a motor (<R45> applies), and a piece of a battery (<R55> applies), except to the extent that FIRST absolutely needs to prohibit a particular configuration.

The key question is: under what circumstances is part of something covered by the same rules as the whole?

[Al Skierkiewicz]

Tristan,
R45 & R55 speak to modifying components that you are using on your robot, it does not speak to disassembly and using parts of the component. As to using parts of the battery, I would interject that ...

<R02> ROBOT parts shall not be made from hazardous materials, be unsafe, or cause an unsafe condition.

applies in your example.

Removing parts from any motor for use on the robot does not violate the modification rule for the motors used on the robot unless you are modifying the legal motor with the removed part. Say for instance you wanted to replace a sub standard magent assembly in one KOP motor with a vastly improved magnet assembly from an XYZ motor. That is an illegal modification of the motor. Removing the XYZ magnet to use as a magnet that has nothing to do with motor operation is not illegal.
From Section 4
"In addition, another intent of these rules is to have all energy sources and active actuation systems on the ROBOT (e.g. batteries, compressors, motors, servos, cylinders, and their controllers) drawn from a well-defined set of options. This is to ensure that all teams have access to the same actuation resources, and to ensure that the inspectors are able to accurately assess the legality of a given part."
The modification rules descend from this statement.

[Tristan Lall]

That's the fundamental question: does a part of a restricted component still count as that restricted component? If pressed on the issue at a competition, I'd likely assume no, based on the theory that the intent is to prohibit things used as motors, not parts of motors used as other things—but the rule is sufficiently open to interpretation that the meaning is unclear.

As for the battery example, if I were to take a KOP battery apart, clean all the electrolyte out and strip away the glass mats, keeping mainly the lead, then fill it with epoxy and re-seal the case, I wouldn't see any <R02> issue. (Maybe I just wanted to add weight, and didn't think of the million better ways to do that.) It looks like a battery, but it's not, and I mount it on the robot. Of course I also put a real battery on the robot too, because I like my robot to move. Am I in violation of <R55>? Is that thing a battery for the purposes of the rules?

Now, consider the same sort of thought experiment, but with a motor. I pull the brushes out of an enormous 2 kW DC motor, and hook it up to my robot. I'm using it as a flywheel. Legal? (And what if I did the same thing with my 5^th CIM?)

What I'm getting at is that we're sure FIRST doesn't want us using restricted components for their intended purposes, but there's also a possibility that they don't want us using them in other unforeseen ways.

Using a magnet from the inside of a motor is at the other end of the spectrum to be sure, but it's just a variation on the same question.

[DonRotolo]

IMHO both the above are perfectly legal. The plastic box filled with lead and epoxy should be OK (assuming the lead is encased), and the motor is not being used (and cannot be used) as a motor, so it doesn't fall under the motor rules, it falls under whatever rules govern flywheels.

A piece of a non-permitted item is judged as a piece, not as an item. Does that make sense?

[Tristan Lall]

One more thought experiment, from the other extreme. A team attaches a 5^th CIM to their robot. How much modification do they have to do to it to make it no longer a motor, and therefore legal by the standard discussed above? (And of course, does <R47> apply? Assuming that it isn't a motor because it's modified, is it in violation for being a modified motor?)

Does the standard depend on whether it could be used as a motor, or merely the way in which it is installed and connected?

Originally Posted by DonRotolo

A piece of a non-permitted item is judged as a piece, not as an item. Does that make sense?

Overall, I think that would make sense, and I think it would be a good idea for FIRST to draw the line at the ability to perform the key function of a motor (i.e. to use electrical energy to do mechanical work via a whole bunch of EM field sorcery). (The same goes for batteries, with respect to storing and delivering electrical energy.)

But to offer an supplemental hypothesis (supplemental, because there's no real dispute as to the primary objectives of these rules), what if FIRST wrote the rules this way to give the impression of consistency? Spectators and fellow competitors can see at a glance that every robot is subject to the same power constraints. That's a plausible enough intention that I don't think we can as yet say with certainty where the line is to be drawn. (And this line's position in turn affects the legality of the much more benign magnet from the original post.)

[Kevin Sevcik]

Clearly you guys aren't using Technical Common Sense(tm) if you think disabling a motor and using it as something other than a motor is legal. As of 2009, the GDC was diametrically opposed to this interpretation of the rules. Offhand, I can't think of any significant wording changes that would indicate a modification of this position regarding the HOST BOT. The MINIBOT is a whole other legal field, so I'm unsure what goes there.

From the 2009 Consolidated Q&A:

Motors allowed if not used as a motor
Posted by FRC63 at 01/12/2009 07:35:56 pm
Are we allowed to modify a CIM motor such that it cannot be used as a motor anymore? If we can modify the motors, can we use the modified motors in addition to 4 CIMs on the robot? (4 unmodfied CIMs, and additional modified versions not used as a motor) We would modify the motors by either removing the armature entirely, or modifying the armature so that it would not function as a motor anymore. If we cannot modify/use additional CIM motors, would we be allowed to do the same modifications to another motor that isn't a CIM or in the Kit of Parts?
Thank you
Re: Motors allowed if not used as a motor
Posted by GDC at 01/15/2009 02:59:29 am
Rule <R53> is quite clear - the provided motors cannot be modified in any way, other than within the explicitly described exceptions. If a Kit motor is modified, whether it is used afterwards as a motor or not, it will be considered a violation of Rule <R53>. Any additional motors, whether modified or not, are expressly prohibited by Rule <R52>.

And a long winded follow-up by yours truly:

Clarification on motors not used as motors
Posted by FRC57 at 01/15/2009 10:43:39 am
In a recent Q&A, the GDC stated that it is illegal to modify motors or use additional motors, even if they are no longer used as motors (ie. do not conduct electricity). The ruling seemed to be based on the logic that anything called a motor must be a motor, or possibly that anything potentially usable as a motor is a motor. This seems at odds with the parts usage flowchart and common sense. In short, is a "motor" defined according to the conventional name applied to it in the retail market, by its mere potential to be used as a motor, or by its actual use as an electrical actuator on a robot? Some counter-intuitive examples follow:
1. The parts usage flowchart first asks if a part is designed to conduct electricity, THEN asks if it is a motor. If a motor is no longer designed or intended to conduct electricity, the flow chart would indicate it is legal, but the ruling declare it is not.
2. DC generators can be back-fed and used to generate torque, but are not commonly called motors, actuators, or servos. If the ruling is based solely on the naming of an item, these could be powered from a speed controller <R66B> and used to actuate a device on the robot.
3. DC tachometer generators are useful sensors that could be used as motors, are fundamentally identical to motors, but aren't used as such. If the ruling is based on potential, DC tachs are illegal.
4. Two bearings connected by a common conductive shaft can be used as an inefficient, but spectacular, motor. Again, a ruling based on potential makes supported metal shafts illegal.
In short, the parts usage flow chart and common sense seem to indicate a motor should be defined by its actual use as an electrically conductive actuator on a robot.
Re: Clarification on motors not used as motors
Posted by GDC at 01/15/2009 04:44:25 pm
We never let common sense stand in the way of convoluted logic.
The Parts Use Flowchart is intended as an aide to work through some of the basics of parts/materials selection. It is not intended to replace or override any of the rules defined in Section 8 of The Manual. In every case, if there is a perceived conflict between the written Rule and the Parts Use Flowchart, the written Rule takes precedence.
Rule <R50> and Rule <R51> are very clear. They specifically list the motors that are allowed for use on a ROBOT entered in the 2009 FIRST Robotics Competition. If a motor is not explicitly permitted by those rules then it is not allowed, whether it is powered or used as a motor or not (even if it has lipstick).

I still stand by my reasoning in that Q. The GDC really needs to clarify what on earth their Technical Common Sense(tm) means here. I'm with you fellows in that I know a motor when I see a motor connected to the electrical system such that it spins when a voltage is applied. The 2009 GDC seems to want the most restrictive possible definition that would outlaw anything that is used as a motor or called a motor, and quite possibly something that could even potentially be used as a motor. Perhaps the 2011 has an updated version of Technical Common Sense(tm) with a bugfix for this issue. If anyone wants to bring it up again to refresh our knowledge of the GDC's thinking, I'll back ya up on it.

[Bob Steele]

I know when we asked this question to QA in 2009 in regards to using a small non-kit motor hooked up to generate current that we wanted to use to sense the power (dynomometer) that something was generating we were told that we could not...

By some of this logic... a bunch of wire and a few magnets could be construed to have the potential to be a motor...

i find it hard to believe (but still possible) that any regulation would be written that would preclude the use of a motor..or any part thereof... in a non-motor role to be contrary to
the "motor" rules...

the "motor" rules were written in order to make the game and the robots have a similar base of power.

Actually it is pretty funny to read these threads...

A motor by any other name would still smell and squeak..... GDC Shakespeare...